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PART I

MINISTRY OF ELECTRICITY & WATER TECHNICAL SPECIFICATION NO. MEW/SS/1

1. GENERAL REQUIREMENTS AND SPECIFICATIONS 1.1. Scope : This tender covers a turnkey –job for new substation (s) in full working condition and of pleasant modern appearance. Any item of work (civil works and /or apparatus and/ or accessories) not specifically mentioned in the specifications or schedules of prices but which are usual and/or necessary for the satisfactory operation of the plant shall be deemed to be provided by the Contractor and included in his Tender’s price.. All work shall be complete in all details whether such details are mentioned in the specifications or not. Thus the Tender covers the following:- a) Manufacture, testing at factory, packing, delivery C.I.F. Kuwait, clearing charges,

customs and import duties, transport to stores and from stores to site (s), complete erection, testing, commissioning, and handing over of equipment as detailed in the specifications, schedules, Details of Equipment and Tender Drawings as well as the maintenance and guarantee period.

b) Substation buildings and all civil works relating to the substations including substation boundary walls, internal concrete roads and paths, paving, and car shed, all as detailed in the specifications and schedules.

c) Air-conditioning as well as internal and external lighting for the buildings are included in the scope of this Tender.

1.2. Substation Layout : The substation building shall be of reinforced concrete skeleton type construction with flat reinforced concrete roof and shall be as detailed under civil part of this specification and based on the following :- a) Separate rooms shall be provided for each grouping of the 132 KV switchgear, 33 kV

switchgear, 11KV switchgear, control and/or relay boards, batteries, chargers and low voltage distribution board, communication equipment, neutral earthing resistor, water fire fighting equipment, lead acid battery.

b) Other rooms of at least 4 meters x 4 meters for office store and one spare room. c) Basement under the whole building shall be of clear height of 2 meters at least.

Basement shall have two proper accesses and at least two emergency exits with steel ladders.

d) Mezzanine for double storey building shall be of over the entire ground floor ( except the transformers ) unless otherwise approved by the Purchaser. e) Minimum clearance of the switchgear from the substation walls to be as follows:- Front: 1.50 meters with the circuit breaker fully withdrawn (33 & 11 KV switchgear ) 2.5 meters clear for 300 & 132 KV switchgear Back: 1.25 meters for 33 & 11 KV switchgear 1.50 meters for 300 & 132 KV switchgear

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Sides:- a) 33 KV, 11 KV and 132 KV single busbar switchgear rooms. 1.25 meters from one side and 2.25 meters from the other side. Where future

panels are shown on the tender schematic drawing the above clearance to be reckoned from the end of the future panels.

b) 300 KV and 132 KV double busbar switchgear rooms. Sides: 2 meters from one side and 2.5 meters from the other side. Where future

panels are shown on the tender schematic drawing, the above clearances to be reckoned from the end of the future panels.

Ceiling: 0.90 meters (from highest parts of 33 KV and 11 KV switchgear.) For 300 KV and 132 KV switchgear rooms a clear head room of 50 cms. above crane grab. Clearances (front, back and both sides ) for 20 KV and 6.6 KV resistors, link cabinets and

L.T. boards shall be subject to MEW approval. f) For the control room, the minimum clearance behind the board shall be 1.00 meter.

The minimum clearance from the end boards (beyond space for future panels ) to the side walls shall be 80 cms.

The minimum clear distance in front of control panels shall be five(5) meters and preferably 5.5 meters.

The contractor shall submit two or three different layout arrangements complete with elevations for each substation which should be of most modern and pleasant architectural design for the Purchaser’s approval before commencement of detailed design. This may need changes in the arrangement of the substation layout to suit the Purchaser’s practice and to satisfy the requirements for easy and safe operation and maintenance of the equipment. Such changes shall not entitle the contractor to any extra charges or extension of complete dates (also see Clause 1.15 and 1.17 ) Where sun shade in the transformer enclosure is required, minimum clearance of 60 cm. shall be provided between highest part of transformer and bottom side of sun shade.

1.3 Purchaser’s System : The equipment shall be suitable in all respects for operation on the Purchaser’s

system which is as follows:- a) 132 KV System 3-Phase 50 Hz: The highest system voltage is 145 KV. The 132 KV system is solidly earthed. The

design fault level for the switchgear included in this specification shall be 10000 MVA at 145 KV unless specified otherwise in th details of equipment. The switchgear shall be capable of withstanding 132000 volts phase to earth indefinitely under emergency conditions. System impulse withstand level 550 KV.

Minimum creep age distance 4.8 meters (for outdoor bushings). b) 33 KV System 3-Phase 50 Hz. The design fault level for the switchgear shall be 1500 MVA or 1000 MVA at

33000 volt as may be stated in the Details of Equipment. The switchgear shall be capable of withstanding 33000 volts “phase to earth” indefinitely under emergency conditions.

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The neutral is normally earthed through a resistance as follows:- Transformers up to and including 45 MVA- 39 ohms

Transformers above 45 MVA - 24 ohms System highest voltage 36KV System impulse withstand level 170 KV

c) 11 KV System 3-Phase 50 Hz : The design fault level for the switchgear shall be 500MVA at 11KV. The

switchgear shall be capable of withstanding 11000 volts "phase to earth" indefinitely under emergency conditions:

The neutral is normally earthed as follows: For transformers up to and including 20MVA 10.5 ohms For transformers above 20MVA 8 ohms System highest voltage 12KV System impulse withstand level 95KV d) 415 volts System 3-phase 4-wire 50Hz: The design fault level for the switchgear shall be 5MVA at 415 volts except

where specified otherwise in details of equipment. The neutral is solidly earthed. System nominal voltage 415/(240) volts System highest voltage 450/(260) volts e) Fault Duration: i. For 132, 33 & 11kV switchgears the short time current duration shall be not less

than (3) three seconds. ii. For cable design, the maximum fault duration shall be taken as follows: 132kV and 33kV cables (feeder tails) 1.5 secs Ditto but transformer tails 1.2 secs 11kV cables 1.25secs 1000 volts cables 0.50secs 1.4 Site Conditions: The following atmospheric conditions prevail at substation site: Ambient temperature in shade: Maximum 52ºC Minimum -6ºC Maximum sun radiation temperature as measured With a black bulb thermometer 85ºC Average maximum temperature in shade (in summer) 45ºC

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Periods of high humidity are common and humidity of 100% (hundred percent) has

been recorded at 30ºC. Violent sand and dust storms occur and even on comparatively still days, fine dust is carried in suspension in the air. The switchgear and other equipment asked for in this specification must give continuous and trouble free service under the arduous conditions mentioned above. The equipment must be completely vermin proof and as dust and damp proof as practically possible. Tenderers shall indicate the method adopted for the prevention of the ingress of dust and moisture.

NB: Maximum ambient temperature in share for all telemetry equipment, power transformers and

Shunt reactors rooms shall be 55ºC. 1.5 Erection and Erection Tools: The design of the switchgear must be such as to facilitate easy alignment and erection

on the site. The tender price shall include the supply of all foundation shoes, packing shims and foundation bolts etc. and any necessary supporting channel work, special erection tools, lifting tackle and jigs shall be supplied and their prices itemized separately in the Schedules. For the indoor equipment, the Contractor shall provide the necessary pockets for foundation bolts…etc. and/or necessary grooves in the concrete for the supporting channels as indicated in the Contractor’s drawings. All equipment and supporting steel structure not specifically mentioned but which are necessary to complete the switchgear rooms, shall be included in the tender price. All steel work shall be hot-dip galvanized except where otherwise approved. The contractor shall supply and install all necessary bolts and /or channel work, align and level them, and carry out the necessary grouting for the same.

Tenderers are warned that the equipment is liable to very rough handling enroute from the factory to site in Kuwait and it is essential that equipment is braced and packed securely to reduce the possibility of damage and distortion. The Tenderer shall quote the estimated time required for complete erection of the equipment giving details of the number and grades of personnel of the manufacturer who has had a thorough experience in work of similar nature, and who shall supervise all work on site under this contract. Full details shall be given in schedule ’H’ of the number and charges per month for personnel. The costs shall include accommodation, messing, salaries, allowances, local transport,----- etc. Return traveling expenses to and from Kuwait for personnel recruited abroad shall be shown separately.

1.6 Tools and Spares: Tenderers are requested to include in schedule ‘B’ such tools and spare parts other

than those specified with unit prices for each item, as they recommend to be purchased for the maintenance of the equipment supplied under this contract for a period of two years.

The purchaser reserves the right to order any of the spare parts and/or tools as he may finally decide at the rates given in the tender. Two sets of any special tools and one set of any special testing equipment that are required for the assembly, adjustment and checking of the equipment from time to time shall also be included in the schedule. These tools and spare parts shall also be included in the schedule. These tools and spare parts as ordered, shall be handed-over to the Engineer at the Purchaser’s stores in Kuwait.

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All tools and spares should be well treated against corrosion and packed in containers suitable for long storage and marked for identification. These are liable to be checked by the Engineer at the time of taking over and handling charges for checking and repacking shall be included in the rates quoted in the schedule.

The above tools and spares as selected by the Purchaser shall be shipped with the first consignment of switchgear and shall not be used on the contract works.

1.7 Design, Materials, Workmanship and Finish: The equipment shall be designed to ensure satisfactory operation under all conditions

of service and to facilitate easy inspection, cleaning and repairs. All equipment shall be suitable for operation under arduous atmospheric conditions of Kuwait and under such variation of load and voltage as may be met with under working conditions of the system, including those due to short circuit within the ratings of the equipment.

The design shall incorporate every reasonable protection and provision for the safety of all those concerned in the operation and maintenance of the equipment and of the associated equipment supplied under contract.

All apparatus shall operate without undue vibration and with the least practicable amount of noise. Cast iron shall not be used for chambers of oil-filled apparatus or any part of the equipment which may be subject to mechanical stresses. On outdoor equipment, all bolts and nuts in contact with non-ferrous parts shall, unless otherwise approved, be of phosphor bronze. The undersides of all tanks shall be well ventilated to prevent corrosion. No welding, filling or plugging of defective parts will be permitted on site without the sanction , in writing, of the Engineer.

All connections and contacts shall be of ample section and surfaces for carrying continuously the specified current without undue heating and shall be secured by bolts or set of screws of ample size and fitted with lock-nuts or lock washers of approved design.

Mechanism shall be designed to avoid sticking due to rust, corrosion or fine dust. All equipment shall be designed to minimize risk of fire or any damage which may be

caused in the event of fire. All similar components and removable parts shall be interchangeable with each other. The workmanship shall be of the highest grade and the entire construction shall be in

accordance with the best modern practice. Where painting is adopted, all iron work shall be thoroughly cleaned to remove scale,

oil and grease before painting and shall be well protected against corrosion and oxidation. For outdoor equipment at least two coats of paint shall be applied in the manufacturer’s work, and a final coat of paint shall be applied at the site after erection. The color of the final coat shall be approved by the Purchaser. For indoor equipment at least three coats of paint shall be applied at the manufacturer’s works to obtain high class finish. The final coat shall be to BSS 381C. The final coat shall be subject to the approval of the Purchaser. Parts that may be exposed to direct sunshine shall have special treatment to withstand the temperature conditions in Kuwait.

An adequate quantity of paint to be used for the finishing coat shall be dispatched with the switchgear for touching up as necessary on site.

Where galvanized parts are used, the galvanization shall comply with the tests prescribed in BSS. The galvanizing shall be by the hot dip process.

Normally, plated parts shall be in hard chromium finish unless otherwise approved.

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1.8 Station Insulation: For 132kV switchgear 550kV peak shall be the minimum level for either the impulse

withstands voltage or the initial discharge voltage, whichever is taken as basis of design and arrangement of switchgear.

For the 33kV and 11kV switchgear, the impulse withstands voltage levels shall not be less than 170kV and 95kV respectively.

1.9 Earthing System: 1.9.1 Substation Equipment: Each switchgear shall be provided with a copper “Earth Bar” of section area of 30

x 5 or 25 x 3mm as detailed below and its associated control and relay boards with an “Earth Bar” of not less than 25 x 3mm. All metal parts of these boards other than the live parts shall be connected to the earth bar by conductors of not less than 2.5sq.mm cross section area. Where secondary wiring in the switchgear is to be earthed, it shall be done at an accessible place in each panel connected to the earth bar.

The earth bars of the switchgear, control and relay boards shall be connected to the station inner earthing ring at two places in an approved manner. Similarly all the transformers and kiosks shall be connected to the station earthing system, and all indoor equipment in an approved manner.

1.9.2 Station Earthing System: The station earthing system shall comprise two rings, one indoor and one outdoor

for single storey building sub-station. For double storey building two indoor rings and one outdoor ring shall be provided and the two indoor rings shall be connected to each other at two points by copper bars not less than 25x 3mm or stranded copper conductor of cross-section area 95mm2

A) Indoor Rings: The indoor earth rings shall each consist of a bare copper bar 30x5mm or stranded

copper conductor of 150sq.mm. section. All indoor equipment shall be connected to the rings as follows:

i. 300kV, 132kV, 33kV and 11kV switchgear bays shall be bonded together by a continuous earthing bar not less than 30x5mm. Each bonding earthing bar shall be connected at both ends to one of these rings by copper not less than 25x3mm or stranded copper conductor of 95sq.mm. section.

ii. Control and relay panels and all other similar equipment shall be bonded together with a copper bar 25x3mm connected at both ends to these rings by similar copper bar or stranded conductor of 95sq.mm.

iii. L.T. distribution board, resistors enclosures, pilot cable marshalling cabinets and all similar equipment shall be connected at one point to one of the indoor rings by a copper bar not less than

iv. All connections to the earthing bars shall be tinned and bolted in an approved manner. Alternatively, approved suitable grease can be used in lieu of tinning. Where stranded copper conductor is used instead of bars, this shall be neatly arranged and cleaned at intervals of about 75cm.

v. Since the substation buildings (300 and 132kV) are of rectangular in shape the indoor earthing ring shall have cross-connections between parallel sides with a maximum spacing of 10m using the same indoor bar cross-section.

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vi. The indoor earthing ring shall be connected to the substation steel reinforcement

of the basement floor at one point only and connection between outdoor and indoor rings shall be at an appropriate place of the four corners of the substation building, each connection consisting of 2 x 300sq.mm and 2 x 240sq.mm. bars/conductors for 300kV and 132kV substations respectively.

vii. Fixing of earthing copper bar inside the substation building shall be by means of

clips to avoid drilling. Jointing of earth conductors i.e. each of indoor and outdoor rings with all branches, crossings, etc shall be brazed using zinc free brazing material with a melting point of at least 600oC.

viii. Earth connection of each 300kV and 132kV switchgear with indoor earthing ring

shall be with at least two earthing bars/conductors having minimum cross section area of 300sq.mm and 240sq.mm respectively.

B) Outdoor Ring: The substation shall have an efficient earth system consisting of sets each of two

3m x 19mm diameter copper bonded ground rods located at each of the four corners of the station and driven to a depth of 6m at each point and connected to each other by copper bar not less than (40 x10)sq.mm for 300kV substation and (30 x 10)sq.mm for 132kV substation to form an outer ring bus. The outer ring bus and all connections to this bus should be buried to a depth of at least one metre. The tender price shall include all necessary excavation and backfilling of the trenches for the earthing system. Additional sets of ground rods, as specified above, together with disconnecting links and earth pits, shall be provided free of cost, if found necessary to bring the earthing resistance of earthing system to one ohm. If additional parallel outdoor ring is necessary to achieve this value, the cost of such is deemed to be included in the tender price. All connections and joints on the earthing system shall be tinned and taped where necessary in an approved manner. Alternately special grease suitable to replace tinning may be used provided it is approved by the Purchaser. Disconnecting link shall provided at each earth pit, so as to facilitate individual measurement of each earth electrode. Connections to this ring shall be as follows:- 1. Each power and station transformer & shunt reactor shall be connected to this

by means of copper bars not less than 25 x 3mm or stranded copper of 95sq.mm. Each group of transformers & shunt reactors of the same rating shall be bonded together by similar bars.

2. Each transformer & shunt reactor marshalling kiosk shall be connected to this ring by copper bars not less than 25 x 3mm or stranded copper of 95sq.mm.

3. The indoor earth ring shall be connected to this ring by copper bars not less than 30 x 5mm or stranded copper of 150 sq.mm at four points at equal intervals. For two storey building, the ground floor ring only to be connected to the outer ring as above.

4. The direct to earth connections of the transformers neutrals from the earthing link cabinets to earth shall be directly connected to this ring at the earthing test link or earthing pit by means of 400 sq.mm. copper bar or stranded

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copper conductor suitably insulated complete with suitable lugs for the purpose.

5. The earthing connection from the neutral earthing resistor to the above ring shall be of 3 KV insulated copper bar or stranded conductor not less than 400 sq.mm. for the 8 ohms resistors and 24 ohms resistors.

6. The earthing testing links associated with earthing pits can be located inside the basement in an approved manner provided that market to show the outdoor earthing rods location should bear the same number as that given to the corresponding testing link in the basement.

7. The neutral busbar of the L.T. distribution board shall be connected direct to this ring by a fully insulated bar or cable not less than150sq.mm

( insulated for 1000 volts ) which shall be included in the contract price. 8. The buried bare outdoor earthing ring shall be surrounded by not less than 30

cms. around non-corrosive soil of fine texture, the soil being packed as tightly as possible by ramming.

C) Earthing System: 1. Duration of short circuit current is 3 seconds. 2. The general arrangement of the proposed earthing systems is as shown on

drawings attached to these specifications. 3. For earthing of 132 KV cable sealing end boxes connected to SF6 switchgear

( i.e. oil/SF6), the cable sheath will be earthed through the proper earthing terminal provided for this purpose, while the enclosure of the SF6 compartment shall also be earthed separately in addition to the provision of a copper earthing strap to be connected between these two earthings across the insulating gasket to avoid any partial discharge causing pitting of the flanges. This is also applicable where connection between power transformers and 132 KV switchgear is made by SF6 tubing.

4. For transformers & shunt reactors, power cable tail connection to respective switchgears, earthing of the cable sheath shall be made at one side which shall be the switchgear side. This is applicable to all voltage levels.

5. The successful Tenderer shall submit earthing system layout drawings together with detailed calculation for approval of the Purchaser.

6. The earthing system as described above is only for guidance. However based on the approved layout arrangement of each substation and earthing resistivity as measured at the particular substation site, the Contractor shall submit detailed design calculations of earthing system based on maximum ground fault current when transformer neutrals are earthed directly to ground and also when the neutrals are connected through neutral earthing resistor with check on the step and contact voltage which should not exceed the safe limits. Any additional earthing rods, or modification of the earthing system to render the system safe for operation and as approved by MEW will not entitle the Contractor to any extra costs.

1.10 Small Wiring: All small wiring shall have a cross-sectional area of not less than 2.5sq.mm (unless

where otherwise approved) and shall be 600volts, tropical grade PVC insulated, single core cable. Regarding the internal wiring of relay panels, wires of cross-section 1.5sq.mm and 0.8sq.mm.can be used for the signal circuits and connections between modules of electronic protection relays (if applicable) respectively.

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All small wiring shall be suitably terminated and fitted with identification ferrules and marked with circuit numbers in accordance with “British Central Electricity Authority Engineering Recommendation S12 Standard” numbers for small wiring of similar approved standard. Ferrules shall be of the Ring (closed) type. The numbering on the wiring shall read from LEFT to RIGHT when viewed from the front. The trip circuits shall have an additional ferrule colored “Red” and marked “Trip”.

All terminal blocks shall be of an approved design and all exposed terminals shall be enclosed by detachable covers. The “Trip” circuit cables shall be colored black and the instrument transformer cables (C.T.s and V.T.s) colored with their respective phase colors. Alternatively, all small wiring can be uniform color (e.g. gray), but instrument transformer cables shall have additional colored ferrules at both ends of each conductor run, in accordance with their phase colors.

Terminal blocks, small wiring, terminations, ferrules and wire numbering and coloring shall be subject to the approval of the Purchaser.

The interconnections between the transformers, shunt reactors & their respective marshalling kiosks shall be by means of multi-core heat resistant, flame retardant cables of adequate mechanical strength. Multi-core control cables shall be used between the marshalling kiosks and the remote control and relay panels in the substations. All interconnections between the transformers shall be made in the remote control and relay panels inside the substation building.

For the secondary wiring of C.T.s and V.T.s (including open delta), each two wires for each phase shall be brought out to an easily accessible terminal block, where the star, delta or broken delta formation, connection to earth by means of suitable links must be provided. The wiring terminals shall bear clear marking showing the reference of C.T.s ends with respect to busbar side and line side. The above mentioned terminal blocks shall be in the local cubicles for 300kV and 132kV switchgears and low tension compartments on the 33kV and 11kV switchgear panels.

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1.11 Labels and Miniature Circuit Breakers: Each panel of each switchboard shall have a circuit label of adequate dimensions,

mounted on the front of the panel in a prominent position. These labels shall be made of suitable and approved engraving material approximately 2 mm. thick. The labels shall be mounted in rigid frames and arranged for easy insertion and withdrawal. Similar labels of similar material shall be fixed on the rear of each panel. The engravings of all circuit names shall be carried out by the Contractors, except of 11kV outgoing feeder circuits.

Alternative design of labels can be proposed by the Contractor subject to Purchaser’s approval and where necessary, the circuit names (both in Arabic and English) will be given to the contractor for inscribing on labels.

All other labels shall be of similar material and engraved in English. Full details and locations of all labels shall be indicated on the drawings and shall be subject to the approval of the Purchaser.

The labels to be mounted on the switchgear panels shall have the following colors and preferably to be of the same colors that will be mounted on the control and relay panels.

300 MVA transformer circuits Green surface and white letters engraving (300 kV and 132kV sides) 75 MVA transformer circuits Blue surface and white letters engraving (132kV and 33kV sides) 30 MVA transformer circuits Red surface and white letters engraving (132kV and 11kV sides) 20MVA, 15MVA, 5MVA transformer Orange surface and black letters engraving circuits (33kV and 11kv sides) 250/750KVA transformer circuits Black surface and white letters engraving (33kV and 0.433kV sides) Bus section and bus coupler Yellow surface and black letters engraving All feeders of all voltages White surface and direct to earth & resistance Black letter to each engraving. 300kV shunt reactor Silver or light grey letters engraving 132kV shunt reactor Dark green surface and white letters engraving 33kv shunt reactor Brown surface and white letters engraving All necessary miniature circuit breakers shall be supplied and they shall be fitted

with clearly legible labels indicating the circuit and shall be grouped according to their functions to facilitate identification. Labels shall indicate the current rating and code symbols shall correspond with the diagrams.

Miniature circuit breakers shall have auxiliary contacts for local and remote alarm indications whenever these m.c.b.’s tripped or opened. All miniature circuit breakers shall be of an approved make and subject to the Purchaser’s approval.

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1.12 Oil and Compounds: The tenderer shall include in his offer for the full supply, including sufficient

quantity to allow for wastage and for topping-up on site after erection, of all oils and compounds required for the first filling of the transformers, switchgear chambers, tanks and all cable termination boxes. Full details of the oils and compounds to be used shall be submitted for the approval of the purchaser.

1.13 Packing: All switchgear and control boards and alike shall be securely packed in robust

wooden cases. The cases to be lined with water proof material to safeguard the equipment during the sea voyage. Each case shall be marked with Purchaser’s order number and given case serial number addressed to the Ministry of Electricity & Water, Kuwait, Arabia (See previous remarks on rough handling under “Erection and Erection Tools”).

All packing material and wooden cases of the equipments shall be collected from site by the Contractor, loaded on lorries provided by him and disposed off by the Contractor.

1.14 Progress, Inspection and Tests: The contractor shall submit a programme chart within 2 months from signing the

contract and monthly progress reports during both manufacture and erection of all works covered by this contract. In case of deviations from the set programme, the Contractor shall explain the reason for delays.

The Contractor shall provide facilities for an Inspector, appointed by the Ministry of Electricity and Water, to inspect the equipment during manufacture and after completion. The inspector may carryout or witness any tests, in addition to these specified that may be deemed necessary. Further, the inspector shall witness all type tests that may be agreed upon before or after the award of the contract. The equipment shall be despatched only after it has been approved by the Inspector. The certificates of approval shall be submitted to the Purchaser before shipment can be made.

Neither inspection nor passing by the Purchaser and/or his Inspector of work, or plant or material whether carried out or supplied by the Contractor or a subcontractor shall relieve the Contractor of his liability to complete the contract work in accordance with the contract or exonerate him from any of this guarantees.

The contractor shall provide free of cost, all materials for tests and any testing equipment necessary for carrying out the tests.

The charges of the Inspector only shall be borne by the Purchaser. However, the cost of all tests shall be to the Contractor’s cost.

If any material fails during the test a per the test report of our appointed inspector, then such material shall be retested. Repeating the test for the same material for any reason whatsoever (i.e. due to failure during test, material damaged for any reason will be on the contractor's account and to be deducted from your tender price to be paid for our appointed inspector.

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1.15 Drawings: Full dimensioned drawings shall accompany each tender and these drawings shall

describe in details the equipment offered. Additional information in the form of photographs, diagrams and descriptive literature shall be submitted to permit the Purchaser to assess the merits of the equipment offered.

The tenderer shall submit with his offer dimensioned drawings of his proposals showing the provisional layout of the substations. These drawings shall show the proposed arrangements of the different equipment to be supplied under this contract with overall dimensions.

The successful Tenderer shall collect from DEN Department of the Ministry of Electricity and Water immediately after signing the contract, five blank copies of the tender specification who will fill identically to his offer and attach five complete sets of all drawings, catalogues, documents, questionnaire, replies, interchanged correspondence, etc. and this must be submitted not later than one month therefrom.

The successful Tenderer shall submit all drawings including wiring diagrams and schematic circuits for the approval of the Purchaser before beginning the manufacture of the bulk of the work. A period of one month from the date of receipt of the documents in MEW Offices shall be allowed for checking, modifications and approval, and this must in no way delay the initial deliveries or completion dates as specified in the tender. Also the Contractor shall submit three sets, other than these mentioned later, of catalogues, pamphlets, leaflets and literature relating to the equipment being offered before beginning manufacture of the bulk of the work and in time to facilitate checking and approval of the above drawings.

Drawings for approval shall be submitted in five prints and detailed drawings shall be to a scale of not less than 1/50 and shall be fully dimensioned. Each drawing must bear a clear title, contract number, substation name and this must be in “English”. Drawings which are submitted for approval must be supported with sufficient technical details, explanatory notes, description of circuitry especially for electronic (transistorized) protective relays, giving values and types of each component (resistances, inductances, condensers, diode, …etc.) together with trouble shooting tables for checking and approval.

Electrical and mechanical construction drawings should be submitted not later than two months from the date of signing the contract. While schematic drawings and wiring diagrams should be submitted to suit the manufacturing respectively, erection and testing approved programme.

a. Within one month from the date of signing the contract, the Contractor shall submit one set of preliminary drawings for the substation layout and building arrangement for single, double or multi-storey type as required in the civil part of this specification. If the number of stories are not defined in the specifications then two sets to be submitted, one set for single storey building substation and the other set for a double storey building station and for the following:-Substation layout where the substation site is defined based on the proposed substation site.

General arrangement of the building rooms for the various equipment, stairs, etc.

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Section drawings. The Contractor shall delegate at least one Electrical Engineer and an

Architect to discuss the above drawings, modify and re-submit. One month must be allowed for checking, modification and preliminary approval of the above.

All above drawings shall be to a reasonable scale, fully and clearly dimensioned to enable checking of arrangement, clearances…etc. All drawings should be submitted in triplicate.

b. The Contractor shall submit within three months from the date of signing the

contract proposal for the elevations (façade) of the proposed substation buildings. The façade shall be of decorative type of up-to-date design and shall have all the four elevations of the building as well as the boundary wall and the specified material to be used such as marble, travertine, ceramic tiles, Jordanian stones,..etc and as specified in Vol.(II), Schedule ‘J-2’

(Introduction) shall be clearly indicated in the proposal for the Engineers approval. Before proposing the alternative elevations, the Contractor shall first visit the site so as his proposal will blend with the surrounding area. The Purchaser has the right to ask for amendment of drawings and to select the type of façade he thinks most suitable, all at no change to the contract price of completion and handing over periods. One month must be allowed for checking and finalizing these elevations.

c. The contractor shall within one month of handing over to him by the

Purchaser the substation site or site location drawings for each substation, re-submit all the above drawings, modified as necessary, for the Purchaser’s final approval. One month must be allowed for checking, modifications and final approval.

d. Eight (8) complete sets of drawings, one for each substation, necessary for

obtaining the building licence (permit) from the Municipality, and complete with fire fighting requirements shall be submitted as follows:-

Within four months of signing the contract for the substations whose sites are finalized at or before the date of signing the contract.

Within two months from the date of handing to the Contractor the substation site or site location drawing for the substations whose sites are not finalised at the time of signing the contract. This also applies to reserve substations where specified.

One set of drawings as finally agreed upon will be duly stamped and approved by the Purchaser and handed over the Contractor’s representative to start with the detailed civil design.

e. Regarding reserve substations (if specified) submission of layout drawings

shall be as mentioned under (a) above, however the Contractor shall within one month from the date of site release or site location drawings delivery to him, shall submit modified layout arrangement drawings and architectural drawings. One month is allowed for MEW checking, discussion with Contractor’s Engineer and approval.

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One approved set of drawings will be handed over to the Contractor to start civil design.

f. The details civil design including lighting installations and air conditioning

documents shall be submitted together with fully detailed construction drawings, calculations, material list and bill of quantities, all in triplicate within two months from the date of approval of general arrangement drawings and site layout drawings.

A period of one month shall be allowed for checking, modifications and approval of the detailed civil design work. During the approval period, the Contractor’s civil design Engineer must be available in Kuwait for discussions, clarifications and modifications of the offered design as may be necessary.

Four complete sets of all detailed civil design drawings, material lists..etc and as finally approved shall be handed over to the Purchaser before the commencement of any civil works.

g. For each type of equipment six complete sets of all drawings and diagrams

relating to electrical equipment and including constructional drawings true to scale, and as finally approved, together with six sets of “Instruction Manuals” in the English Language, shall be provided before shipment of the first consignment of the switchgear and shall be handed over to the Purchaser before the starting of the erection of the equipment.

The Contractor has to supply to the Ministry , three sets of 35 mm. Silver halide microfilm aperture cards made from ( as fitted or built ) original drawings. The front face of these

aperture cards should be left blank and on the reverse face, the following

details should be shown by the Contractor : Name of SUPPLIER SUPPLIER CONTRACT NO. TITLE OF PROJECT TITLE OF DRAWING REDUCTION RATIO: DATE The Contractor has to specify the year of the contract against the contract

No. and the date when the Microfilms were made also to be shows against the work date on the Aperture Card.

No labels or stickers, showing the above details, should be stuck on to the aperture cards. Details should be printed or typed directly on the cards.

Two samples of a processed Microfilm Aperture card should be submitted to the Ministry for approval.

A transparent polyester copy of internal cable layout in the basement should be submitted to MEW.

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1.16 Delivery and Completion: Each substation and item of work (complete with cabling and civil works) shall be

completed, tested, and commissioned and handed-over within the periods or at the time stated in the Schedule of Programme of Works).

Further, the contractor shall cooperate with other contractors to ensure proper execution of the works so that the above dates are met.

Tenderers shall note that the successful Tenderer will be required to co-operate with the main power cable contractor for cable feeder circuits to enable commissioning of the substation at the specified date and it will be necessary for the cable contractor to lay and joint the cables during the erection of the equipment. Alternatively, if the contractor prefers to complete his work first, then the entire work of the substation shall be completed and handed-over within the specified completion dates minus two months and the necessary staff shall remain until the cable contractor’s work is completed and the switchgear is energized. In this case the contractor shall not be entitled to any claim for waiting time. Tenderers shall state clearly at the bottom of schedule of delivery and completion in their offer on which of the above bases their completion dates are based.

1.17 Site Handing-over and Completion Periods: The contractor shall soon after signing the contract, ask the Purchaser (in writing )

to hand over to him the various substation sites or dimensional drawings of these sites.

a. Within one month from the above request, the Purchaser will hand over to

the contractor the substation site or site drawings for the available sites, together with the soil test results (see Vol.(II), J-2, introduction for available substation site).

b. Within four months from the above request, the Purchaser will hand over to

the contractor the substation site or site drawings for the substations whose specified completion period is 20 months or 21 months, together with the soil test results.

Two months must be allowed to complete the formalities of obtaining the “Building Licence” from the time of receiving the eight (8) complete sets referred to in clause 1.15

(d) above, provided these drawings were complete with all details necessary for the purpose.

All the above shall not affect the completion periods specified for these substations.

c. Within six months from the above request, the Purchaser will handover to the

contractor the substation site or site drawings for the substations whose specified completion period is 22 months or more, together with the soil test results.

N.B. In any of the above cases (a,b & c) when site drawings are handed-over to

the contractor, the site will be handed over to the Contractor with in two months after handing over the above site drawings.

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1.18 Delays caused by the Purchaser: In case of delays caused by the Purchaser, the contractor will be notified to extend

his schedule with corresponding extension of completion dates. Extension of time under the provisions of this paragraph will be granted only for delays not attributable to the contractor. Attention is called to clause 1.15 relative to the submittal of drawings. Accordingly, the contractor shall obtain the Purchaser’s written approval before he ships any part of major equipment. Reference shall also be made to clause 2.44 “Delayed Erection” of the General Conditions of Contract.

If, for reasons for which the Contractor is not responsible it was not possible to energize the substation after completion and successful testing of the contract works, then the guarantee period of one year shall begin from the date of the substation energizing and for a maximum period of fifteen (15) calendar months from the date of completion and testing. For the period between testing and energizing the purchaser will pay only for the commissioning and service Engineer’s waiting time or his return air-fare (as may be decided by the purchaser) at the rates given in Schedule “H”. In this case the Contractor will not be entitled to any other additional costs.

1.19 Standard Specification: Attention of all Tenderers is hereby drawn to the following :- A) All materials and equipment shall comp[y as to minimum: a. With the latest relevant recommendations of the International Electro

technical Commission (IEC) (if available). b. If (a) is not available with the latest relevant British Standard Specification

(B.S.S) This applies to quality of material and testing, etc. If standards as mentioned

above contradict with this tender specifications, then the requirements of this specification shall apply.

B) Tenderers who wish to base their offers on standards other than those mentioned under (A) can do so provided that they confirm in their offers that such standards meet the requirements under (a) as a minimum, and in due time the successful Tenderer will be asked to prove this and if needed be verified by the Inspectors appointed by the Purchaser.

What is mentioned under (A) and (B) above applies wherever BSS is mentioned in the different clauses of these tender specifications.

1.20 Service of an Engineer: A. During the commissioning of the equipment and for a period of four months

commencing immediately after the successful commissioning and energizing of the contract works, the Contractor shall station in Kuwait a competent Engineer acceptable to the Purchaser for the following services:-

1. Attend pre-commissioning tests to familiarize himself with the equipment as installed and with local conditions.

2. To maintain and repair (where necessary) the equipment and keep it in a good working condition bearing in mind the importance of continuity of supply.

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3. To prepare maintenance schedules and advise MEW Staff on maintenance

procedure. When required by MEW Engineer, he will be asked to demonstrate to MEW Staff maintenance by explanations and dismantling and re-assembly of important parts of the equipment.

4. To advise MEW Staff on operation and explain to them the function of the various components of the equipment and procedure to be adopted for repair work.

5. To attend to any outstanding items to complete the contract works. 6. To carry out any other work pertaining to the contract works. The Engineer shall report, at the beginning of each working day, to MEW

Engineer. The working time during this period will be limited to MEW normal working hours, except in emergency cases (if they arise) when the Engineer shall make himself immediately available at a short notice to attend to or advise and supervise the repair work.

The charges of this Engineer for the above period and all costs arising therefrom (e.g. air fares to and from Kuwait, accommodation , messing, transport to and from MEW Offices and to and from site,..etc shall be included in the Tender Price.

The above four months period can be extended for a further period of upto six months if required by the Purchaser. For this extended, period, the Contractor will be paid for the services of the said Engineer at the rates as given in the respective schedules.

B. Protection Engineer: At least one month before energizing the first substation/s, a protection Engineer

should be deputed whose qualifications, i.e. date graduated, name of University, past experience, age ….etc must be submitted to MEW well in advance for checking and approval before arrival to Kuwait. The services of the Engineer who will stay two months after energizing shall cover mainly the testing of relays (by primary and/or secondary injection), analyse the test results and give explanations for the faulty ones, submit detailed test sheet with recommended relay settings based on a detailed calculations and to attend to any trip that may occur after energizing and submit the necessary detailed technical report.

The Engineer shall report, at the beginning of each working day, to MEW Engineer. The working time during the period will be limited to MEW normal working hours, except in emergency case, (if they arise) when the engineer shall make himself immediately available at a short notice to attend or to advise and supervise the repair work.

The charges of this Engineer for the above period and all costs arising therefrom (e.g. air fares to and from Kuwait, accommodation , messing, transport to and from MEW Offices and to and from site,..etc shall be included in the Tender Price.

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The above two months period can be extended for a further period of upto two

months if required by the Purchaser. For this extended, period, the Contractor will be paid for the services of the said Engineers at the rates as given in the respective schedules. The Ministry reserves the right to collect and keep the passports of all the foreign contractors, testing Engineers and protection Engineers in its custody and one of these is permitted to leave without the consent of MEW.

1.21 Guarantees: The Contractor shall guarantee among other things the following:- Quality and strength of material used. Safe electrical and mechanical stresses on all parts of equipment. Performance figures specified by the Tenderer in the schedule of guaranteed

particulars. Satisfactory operation during the maintenance guarantee period stated in the

general conditions of contract. 1.22 Locks & Padlocks: Locks and padlocks of high class material, suitable for weather in Kuwait,

especially the sand storms, shall be supplied for each circuit breaker operating cubicles, marshalling

boxes, and all other outdoor equipment which needs locking facilities. Locking arrangement shall be in accordance with the best modern practice, and the

contractor's drawings submitted for approval of the purchaser, should indicate the various points on the equipment at which locking arrangement will be provided.

All operating cubicles of all types of switchgears, local panels, marshalling cubicles, control and relay boards, and any other cabinets, shall be provided with integral cylindrical type locks. Cylindrical locks for outdoor cabinets shall have weather proof caps. Samples and pamphlets of the proposed types of locks and padlocks shall be submitted for approval.

Two individual keys for each lock or padlock shall be provided. Master keys shall be supplied in addition to above. Twelve master keys of each type shall be supplied. The types of master keys should not exceed two.

Cylindrical locks, padlocks or any other locking arrangement, as specified hereunder, for various substation equipment, shall be suitable for Kuwait weather conditions, especially those used outdoor; where lock/padlocks must be provided with weatherproof caps. The locking arrangement shall be as follows:

1. The circuit breaker cubicle door for 33kV and 11kV as well as for 20kV and 6.6kV Neutral Earthing Switchgear, shall be opened by turning the door handle, and should be provided with facility for padlocking when needed for safety precautions.

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The main isolating contacts shutters inside circuit breaker chambers, for

busbar contacts and cable contacts, shall be provided with facility for padlocking when needed. The bus-bar contacts shutters or cable contacts shutters shall be opened or closed and padlocked independently.

2. The busbar and cable chambers shutters, except pressure relief flaps, for 33kV and 11kV as well as for 20kV and 6.6kV Neutral earthing Switchgear shall be fixed with Allen screws. This arrangement shall apply also for shutters on Bus-section and Bus coupler panels where live parts can be accessible. One Allen key for every three units or less should be provided.

3. All doors for in-door equipment, such as control and relay panels, local control cubicles, low tension boards, pilot marshalling cabinets…etc shall be opened by turning the door handles.

The doors for Telemetry, T.T.B., Telecommunication, Battery Chargers and any other cabinets under the control of The National Control Centres shall be provided with integral cylindrical locks, with two individual keys for each lock and five master keys for each substation.

4. For outdoor equipment, weatherproof padlocks shall be provided on all transformers, oil sampling valves, tap changer and control cabinets. Two keys should be provided with each padlock and five master keys for each substation.

1.23 Sub-Contractors: The contractor shall fill in the schedule giving names of subcontractors and these

shall be subject to the approval of the Purchaser. All subcontractors are responsible to the main contractor and hence subject to the conditions of these specifications.

No subcontractor shall be changed without prior written approval of the Purchaser. 1.24 Sundry Additional Equipment: 1.24.1 The following sundry equipment shall be supplied for each substation and

included in the tender price: a. Operator’s desk and chair. The desk shall be suitably fixed permanently in

the office room subject to MEW approval. b. Substation cleaning equipment. c. Cabinets and racks for spare parts. Tenderers are required to submit drawings and catalogues to show the main

dimensions and features of the equipment offered and these are subject to the approval of the Purchaser.

The operator’s desk shall be of sheet steel construction unless otherwise approved and shall have drawers for keeping log books and other records complete with locking keys. This desk should be supplied wired and complete with terminal blocks, and shall accommodate the telephone sets provided by the Purchaser.

A comfortable chair of steel construction and with a washable upholstery shall be supplied with the desk. The chair shall be of rotating type and shall have suitable means for varying height of its seat to suit the operator.

Suitable vacuum cleaning equipment with accessories capable of reaching the narrow and restricted locations of the substation and its equipment shall

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be included for supply. This equipment should be suitable for operation on 240 volts, 50Hz A.C. supply.

Each substation shall be equipped with suitable cabinets and racks for storing the spare parts. Where racks are provided these shall be clearly shown on the layout drawings of the substation.

1.24.2 Cabinets and Cupboards: a) Tools Cabinet and Tools: Each switchgear shall be provided with a complete set of tools housed in a

floor and wall mounting sheet metal tool cabinet with double leaf doors fitted with handle having integral cylindrical type lock and supplied with two keys. The tools cabinet shall also house all switchgear loose handles, spare mcbs and bulbs..etc. Tools to be provided must be included in the contract price and should be itemised in Schedule ‘G’.

b) Key Cupboards: Each switchboard shall be provided with a sheet metal wall mounting key

cupboard fitted with a single leaf door fitted with handle having integral cylindrical type lock and supplied with two keys. The interior of the cupboard shall be arranged to store substations keys on brass hooks and clearly labelled. The labels will be engraved by the purchaser. The key cupboard shall house a log book for the record of key issues.

1.25 Site Testing: 1.25.1 Site Tests: The contractor shall be responsible for submitting all contract works for site

inspection by the Engineer, before site tests are commenced. Before commissioning, the Contractor shall depute an experienced and qualified testing Engineer from the Manufacturer’s works to carry out the following tests on the equipment and such other tests that may be considered necessary by the Purchaser.

a. Routine high voltage tests. b. Insulation resistance tests. c. Continuity tests. d. Checking of operation, interlocks indication and alarms. e. Primary and secondary current injection tests on all protective circuits. f. Testing of substation earth resistance. g. Lead test, where necessary, shall be carried out in collaboration with the

Purchaser’s Engineers. h. Power cable tests as detailed below. After complete installation of the various circuits and before commissioning,

each circuit shall be subject to the following tests: i) Resistance Measurements: The copper resistance of each core of the completed circuits shall be

measured and the ambient temperature recorded, and the measured value corrected to 20oC.

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ii) High Voltage Tests: For 132 cable circuits (see clause 3.22.2). For 33kV O/F cables, a D.C voltage 75kV for 15 minutes shall be applied

between each phase and the cable screen with the other two phases earthed provided that the oil pressure is brought upto the design level.

For 11kV cables a D.C. voltage of 25kV for 15minutes shall be applied. The Purchaser will, if available, provide electricity free of charge for carrying

out all tests on the equipment included in this contract. But if such a supply is not available the contractor shall provide a suitable Diesel Generator set at his own expense. The contractor is expected to bring all testing equipment to site and carry out pre-commissioning test, which will be witnessed by the engineer. The contractor shall arrange to supply all tests data, in quadruplicate to the Purchaser, in standard form before commissioning of the equipment. The forms shall be approved by the purchaser.

Full details of the testing engineer, i.e. qualifications, college name, past experience, etc shall be submitted well in advance for approval by the Purchaser.

The contractor should submit a complete testing programme before commencing the actual testing.

The contractor’s test engineer shall complete all precommissioning tests, commission all plant and equipment supplied by him, and hand over the entire contract works to the Purchaser in good shape. All the charges connected with the pre-commissioning tests of the equipment shall be included in the tender price.

After completion of all commissioning tests, a request for taking over should made in writing enclosing four copies of all tests as completed and which shall be subject to MEW’s approval.

1.25.2 Testing Equipment: The following testing equipment shall be made available by the contractor

for site testing:- i. A suitable cable D.C. testing set. ii. High voltage testing equipment for all switchgear for test voltage upto 280kV

A.C. iii. Primary current injection testing set, single phase for injection currents upto

1000Amps to check C.T. ratio and connections for polarity of relays and instrument operations …etc. Also testing van for checking directional O/C & E/L relays as well as direction elements in other relays.

iv. Secondary injection testing set, for relay check testing, and complete with suitable timing device.

v. Earth resistance Megger tester. vi. Any other necessary testing equipment and instruments. The contractors’s test engineer shall carry out all commissioning tests in

cooperation with and to the satisfaction of the purchaser’s engineer who will take part in all these tests.

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1.26 Licenses:

Equipment or parts thereof manufactured under license shall NOT be included in the equipment covered by the specifications.

1.27 Manpower Requirements:

Manpower requirements for import of foreign man-power necessary for the execution of the contract works is attached with this specification. Also Form ‘A’ is attached for the same purpose. Both these shall be filled and submitted with the offer.

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PART III TECHNICAL SPECIFICATION NO.MEW/SS/3

132kV SWITCHGEAR 3.1 Switchgear: 3.1.1 General Construction: The 132 kV switchgear shall be of the indoor type SF6 gas insulated suitable for

installation in brick built or pre-cast building. The design shall be such that to ensure optimum continuity and reliability of supply as well as safety of the operators. The switchgear shall have short circuit MVA capacity not less than 10,000MVA at 145kV. The minimum short circuit current rating shall be 40KA at 145kV and the duration of short time current rating must be 3 seconds. The 132kV switchgear for any arrangement should be such that it can be easily extended in the future by the addition of extra feeders. B/S or transformer circuits without the necessity to dismantle any major part of the equipment (C.B.’s V.T.s ..etc) and without the interruption of supply to any circuits more than few hours.

The tenderer must show on the tender drawings how the extension of the switchgear can be carried out.

For testing of the 132kV O/F underground cables, provision shall be made on the switchgear for easy fixing of the 280kV test bushing without dismantling any equipment of the switchgear such as voltage transformers, cable boxes ..etc… The arrangement of H.V. testing must be shown on tender drawings.

132 switchgear of the three phase encapsulated type and single phase encapsulated type are acceptable.

The SF6 gas system of the switchgear shall comprise of several gas compartments sealed from each other by gas tight bushings or barrier of cast resin material or otherwise approved so that any leakage can be quickly localized, the risk of gas loss is minimized and the reliability of the substation is increased to the maximum possible extent.

For the main bus-bars of the 132kV switchgear, each section of the bus-bar shall be completely separated from bus-section circuit breakers compartments and bus-bar selector switches of feeder and transformer control circuits. Alternatively, the bus-bars of each circuit (Feeder control, transformer control, bus-coupler and bus-section circuit breakers) can be completely separated from each other. In either case, the separation shall be by gas tight compartments as described above.

Each switchgear gas compartment shall have a separate valve for pumping in and out of gas. Means of periodical checking of gas pressure for maintenance purposes shall be provided.

Tenderers are requested to confirm in the write-up attached with their offers and to show on one set of 132kV switchgear construction drawings (covering feeder, transformer, bus-section and bus-bars), the provision of pressure relief devices, one in each SF6 gas compartment on each phase and for each bay and each bus-bar section.

The details of the offered devices and recommended pressure settings shall be attached with the offers and the cost of such shall be included in the tender prices. The rated bursting pressure of bursting discs shall allow the operation of the main protection relays.

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The 132kV busbar arrangement shall be as specified for each substation under "Details of Equipment" However, the following are the various kinds of busbar arrangements usually applied in our 132kV Networks:-

a. Double busbar system, one busbar serves as main busbar and the other as a

reserve busbar with bus-coupler bay for on-load transfer and splitting of system is needed. Either both busbars or the main busbar only are provided with bus-section insulators. Each section of the busbar is equipped with busbar quick make earthing switch.

b. Single busbar system with bus-section circuit breakers, each busbar section is

equipped with busbar earthing quick make switch. The feeder and transformer circuits are controlled by circuit breakers or load break switches.

3.1.2 SF6 Gas Monitoring: The detection and monitoring of SF6 gas pressures and alarm/trip and inter-trip

indications and arrangements, all shall be provided as follows:- i. Each three SF6 gas compartments (i.e. for three phase in each bay shall be

connected by auxiliary piping by suitable stop valves and commonly connected to gas density relays for continuous monitoring of the gas pressure. These relays shall be equipped with the necessary contacts set at recommended pressure for local as well as remote (Control Board and National Control Center) alarm indications.

It is to be noted that the gas density relay (pressure, temperature compensated switches) shall be supplied for the circuit breaker gas compartment. However, for all other compartments where no interruption takes place pressure switches can be provided if this will not affect the insulation level in case of gas leak or causes false alarm/trip signals. Otherwise gas density relays shall be provided similar to circuit breaker compartment

without extra price.

ii. Together with each of the above density relay, one pressure indicating meter shall be provided and both installed adjacent to the switchgear i.e. in the local operating cubicles. In addition, isolating valves should be provided for periodical checking of the various

compartments.

iii. For periodical checking of the SF6 gas pressure in any compartment, one portable pressure gauge shall be provided for connection to the auxiliary SF6 piping above and the cost if such should be included in the tender price and be confirmed by mentioning the same in

the list of special equipments of each substation.

iv. For gas pressure alarm and lock out, trip/inter-trip, the gas density relays shall be of the two stage type and shall be arranged as follows:

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a) Stage I:

If gas pressure drops in any compartment in any bay below a pre-set value, this will give an alarm locally on the local control cubicle, remote control board and to the National

Control Centre.

b) Stage II: If the gas pressure continues to drop, however, not allowed to reach the

locking out pressure of the circuit breaker, the following tripping and inter-trip arrangement has to be provided:

1. If the gas leak is in the circuit breaker compartment, this breaker shall trip and inter-trip signal to be issued to all circuit breakers connected to the same switchgear zone. However, in case this circuit breaker is controlling a feeder circuit, then inter-tripping shall also be provided for the far end circuit breaker at the remote substation. The tripping of the circuit breakers shall be followed by locking out of switching.

2. If the gas leak is in any compartment of the switchgear bay, on the bus-bar side, this bay breaker shall trip and inter-trip all circuit breakers connected to the same.

3. If the gas leak is in any line side compartment i.e., line isolator, V.T.’s …etc, this bay breaker shall trop and inter-trip the far end circuit breaker. If the feeder is connected to the substation equipped with load break switching, the inter-trip arrangement shall trip the corresponding 132kV bus-section circuit breaker and 11kV transformer control circuit breaker of the later station. The necessary inter-tripping relays together with pilot wire supervision of the tripping cores and availability monitored for healthy conditions and failure shall be indicated locally and remotely similar to all above alarms at the National Control Centre. For this purpose, clean contacts (potential-free) and of the fleeting type with holding time not less than 25m.sec. shall be provided.

Necessary means shall be provided to detect the gas compartment in which internal are might take place. SF6 gas checker equipment (chemical method) may be accepted for locating the faulty gas compartment. Complete set of SF6 gas checker equipment together with two dozen of detecting elements as spare should be supplied for each substation. In case any gas compartment is completely electrically isolated and in such a case if there is a leak in that compartment then it should not cause tripping/inter-tripping of any circuit breaker.

3.2 Station Insulation Levels: For 132kV switchgear 550kV peak shall be minimum level for either impulse

withstand voltage or the initial discharge voltage whichever is taken as basis of design and arrangement of the switchgear.

For outdoor bushings, the impulse withstand level shall be 650kV, (Test voltage 750kV) and the minimum creep age distance 4.8metres.

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3.3 Bus-bars, Insulators, Etc.: Bus-bars of copper or aluminum tubes shall be provided. Copper busbars if used,

shall be made of high conductivity electrolytic copper in accordance with BSS 159 or at least equivalent.

Each and every connection made either to a transformer, circuit breaker, or any other bushing shall be so designed to allow for expansion or contraction in an unrestricted manner at the bushing end, so that there is no possibility of any stressing being imposed on the bushing insulators in any place and none of the insulators in any place and none of the insulators are subjected to any of the conductor’s stresses caused by variation of temperature.

Suitable arrangement shall also be made to allow for thermal expansion and contraction of the main bus-bars and this shall be subjected to the approval of the Purchaser.

The bus-bars shall be so arranged that they may be extended in length without difficulty. The design of connectors for the bus-bars and connection to other parts of the equipment shall be such as to permit easy dismantling for maintenance or repair purposes.

Bus-bars tubes shall be of adequate diameter to avoid initial discharge and suitable measures shall be taken to prevent corona discharge especially at sharp edges and corners.

Each bus-bar section should be securely jointed to other sections by means of high quality busing insulators through gas tight flanges.

3.4 Clearances: The minimum clearances in the 132kV switchgear shall withstand the impulse test

voltage level of 115% of the system impulse insulation level, i.e. 630kV. For outdoor equipments, the clearances between live parts and earthed metal parts

shall conform to BSS 162 and also shall conform to station insulation level specified under clause 3.2. Further, these clearances must be ample to give satisfactory operation under the worst climatic conditions encountered in Kuwait.

3.5 Temperature Rise: Each current carrying component of the equipment supplied shall be capable of

continuous operation at the specified ratings without exceeding the maximum temperature stated in the appropriate BSS taking into account Kuwait’s temperature conditions. Tenderers shall state BSS rating alongside to Kuwait Rating in each case.

3.6 Circuit Breakers: 132kV circuit breakers shall be of the SF6 gas insulated type where SF6 gas will

serve also as arc quenching medium. The circuit breaker must be in the separate gas compartment.

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The C.B. arching chamber shall be of puffer type. Special consideration shall be

given to the breaking and closing time during tender analysis. On the other hand, the tenderers shall guarantee in their technical write up attached with their offer that the offered C.B’s are restrict free over switching of at least up to 160amps capacitive current. Design of gas system with double pressure will not be accepted.

In case of severe drop of circuit breaker gas presure or whenever the hydraulic or compressed air system has some trouble, the C.B. shall be locked-out for electrical and manual operation and alarm shall be shown locally and also signalled to National Control Centre. The lockout against manual operation shall be through an inter locking magnet, normally energized under heating condition of SF6 gas and mechanism.

132kV circuit breakers shall have a guaranteed breaking current of 40kA at 145kV, 50Hz under Kuwait conditions. The Kuwait ratings of the circuit breakers shall be stated in the schedule. The circuit breakers offered shall conform to either British Standard Specification No.5311 or IEC recommendation No.56. Short circuit type test certificates for the circuit breakers from an internationally recognized testing authority acceptable to the purchaser, shall accompany each and every tender to show that the circuit breaker has been tested to BSS 5311 or I.E.C.No.56. Alternatively, if such type of test certificates is not available, tenderer must submit a short circuit type test certificate from an internationally recognized testing authority acceptable to the purchaser with each and every tender, to show that the circuit breaker has been tested for the symmetrical (100%) 3-phase short circuit MVA capacity in accordance with BSS or IEC or VDE.

In the later case, the successful Tenderer will be required to carry out (or produce) complete short circuit tests for the five duties in accordance with BSS 5311 or IEC 56 at an internationally recognized testing authority before despatch of the first consignment of the circuit breakers. Such tests will be witnessed by the Purchaser’s representatives and the Contractor shall afford all facilities and bear all costs arising therefrom.

Further, tenderer should submit a type test certificate for the inductive and capacitive currents which the circuit breakers can interrupt. The circuit breaker shall be capable of making and breaking capacitive currents not less than 160Amps at zero power factor.

Details of any device incorporated in the circuit breaker to limit or control the rate of rise of recovery voltage across the contracts shall be stated.

Means shall be provided to allow easy access to the contacts for periodical inspection and repair.

All insulating parts of the circuit breakers shall be constructed throughout non-hygroscopic and non-flammable materials.

If oil hydraulic operating mechanism is provided then every precaution should be taken against oil leaking or contamination.

Also oil pressure for smooth and definite operation should continuously be checked through manometers mounted on the operating cubicles. A locking device shall be provided so that in case of oil pressure drop it will lock-out and give local and remote alarm signals.

Descriptive literature with full details of main features and showing general arrangement of the breakers should accompany the offer.

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3.6.1 Circuit Breaker Operating Mechanism: Operating mechanism shall be trip free. A mechanically operated indicator shall

be provided for each circuit breaker operating mechanism to show whether the breaker is open or closed. Also remote indication for open/closed positions shall be provided on the control board. Additional clean set of contacts (potential-free) and of fleeting type with holding time not less than 25m.sec. shall be provided for remote supervisory and control system to indicate the circuit breaker “Open” or “Closed” position.

Means shall be provided for manual operation of the circuit breakers for maintenance purposes. All manual operations shall be so designed to close or open the breaker by one movement. The drive mechanism can be either charged spring, hydraulic or pneumatic type.

Auxiliary power supply for tripping and closure shall be 220 volts D.C. from the storage batteries. Electrical closing devices shall operate satisfactorily between 80 % and 120 % normal voltage at maximum ambient temperature of 52oC.

If compressed air drive is offered, this shall be as described under details in clause 8.3 and the price of compressed air system shall be included in the quoted price for 132 KV switchgear of schedule (J-1)

In case of spring operated mechanism, these shall be motor charged. Provision for manual charging of spring shall be provided with mechanical indication of spring charged condition. Provision for remote indication of spring charged/uncharged state shall be so provided. The closing springs must be suitable for charging while the circuit while the circuit breaker is closed and the closing mechanism when charged shall not operate by vibration caused by the circuit breaker opening on fault. The motor shall automatically charge the closing spring after the closing operation.

Circuit breaker operating mechanism, auxiliary switches and associated equipment, control switches, control and power cable terminations shall be accommodated in sheet steel, vermin proof and weather proof cubicles specially designed to suit the weather conditions in Kuwait. These cubicles shall preferably be free standing with front access. These cubicles shall be well ventilated and heaters for prevention of condensation of moisture inside the cubicles shall be provided.

Arrangement shall be made for removal of circuit breaker for maintenance with minimum interference with other components in the circuit, i.e. insulators, V.T.s C.T.s etc ........

Further, such removals shall not be possible unless it is in the open position. 3.7 Isolators: 132kV isolators shall be of the sliding co-axial type. Isolating switches shall be

so installed as to permit maintenance of any section of the equipment and the switchgear plant when the remainder is alive. When the 132 KV circuit breakers operating mechanism is of the hydraulic or pneumatic type, the isolators operating mechanism can be of similar type.

The gap between terminals of the same pole with the isolator in open position shall be long enough to withstand a minimum impulse wave of 115 % of the specified impulse rating to earth, or other initial discharge is above the ( BIL ) breakdown insulation level.

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Isolating switches shall be rated as specified in the schedules, and shall be designed for live and off-load operations. Main contacts shall be of the high pressure line type and shall be suitably screened.

Also isolators mechanism shall be so designed, that the isolators cannot be opened by force due to faulty currents and shall be self locking in both open and closed positions. All three phases shall be operated by the mechanism simultaneously.

The contacts of the isolators shall carry their rated current without over-heating or welding, and shall be of such a design that would not call for more frequent maintenance than once in two years.

The isolators shall be electrically interlocked with their respective breakers, such that the isolators cannot be opened or closed unless the associated breaker is opened and the breaker cannot be closed unless the associated isolators are in definite position, i.e. fully closed or fully opened.

Operating mechanism of the isolators shall be of robust construction and shall be capable of free operation un-affected by the climatic condition at site. The mechanism shall be complete with auxiliary switches, terminal box and cable glands and the same shall be housed in a weather-proof enclosure.

The isolators shall be motor operated. The 132kV bus-bar coupler and section isolators, bus-bar selection isolators shall be electrically interlocked with their associated circuit breakers and bus-bar earthing switches and circuit breaker maintenance earthing switches. However, for 132kV feeder or transformer isolators, these shall be electrically interlocked with associated circuit breakers and maintenance earthing switches and mechanically/electrically interlocked with feeder or transformer earthing switch as applicable. Provision shall be made for operation electrically on the local control panel as well as remotely on the control board. Similarly, semaphore indication for position ON/OFF indication shall be provided at both local and remote. For position indication at the National Control Centre and manual operation with mechanical indication reference is made to the description given in the above clause. For 132kV voltage transformer’s isolators, this shall be manually operated only provided with mechanical indication.

3.8 Load Break Switches: Where 132kV SF6 load break switches are specified in the details of equipment,

these shall be of 550kV impulse withstand level and capable of closing on a short circuit through fault current not less than 100K amps peak.

These switches shall be suitably rated to connect and interrupt full load current of the respective circuit at 0.7 power factor. Also they shall be capable of making and breaking capacitive and inductive currents. The capacitive currents shall be not less than 160Amps.

The L.B. switches shall be motor operated and shall be electrically controlled from the local cubicles as well as remotely from the control board of the control room. Also provision shall be made for local hand operation for emergency cases.

All tenderers shall confirm the above duties and shall submit evidence of tests carried on these switches for this purpose. Provision shall be made for remote indication and control from the 132kV control board and from the National Control Centre.

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3.9 Earthing Switches: a. Earthing switches shall be provided for each outgoing and incoming circuit.

Positive means of mechanical interlocking between the earthing switches and line, transformer isolators shall be provided. In case of three phase encapsulated switchgear three position switch incorporating busbar isolator and earthing switch is acceptable.

b. Bus-bar earthing switches shall also be provided. These shall be fully interlocked so that any bus-bar earthing switch cannot be closed unless all the corresponding bus-bar selection isolators are in the open position.

c. Earthing switches shall also be provided for earthing the 132kV cables of transformers. These switches shall be interlocked with both the 132kV and 33kV and/or 11kV isolators of the corresponding transformers.

d. Each 132kV circuit breaker shall be provided with two earthing switches, one on each side of the circuit breaker and these should not be included in the circuit breaker gas compartment to permit maintenance of the circuit breakers with the bus-bar alive. These earthing switches shall be fully interlocked with the corresponding line isolators, bus-bar selection isolators and circuit breakers.

The bus-bar earthing switches, feeders and transformers earthing switches shall be suitable for closing on full short circuit making current of 100Kamps peak without endangering operator. All tenderers shall confirm this in their offers and shall submit evidence of tests carried out on the earthing switches for this purposes.

Spring charges motor/hand operated mechanism with mechanical indication of “ON/OFF’ positions and remote indication on the control board shall be provided for the earthing switches.

The earthing switches shall be motor operated and shall be electrically controlled from the local control panel only. But the earthing switches for feeders (underground and O/H line circuits) shall be interlocked with the secondary voltage from voltage transformers while the m.cb. is in closed position so that these earthing switches cannot be closed unless the corresponding feeder is de-energized. However, position indication shall be provided locally on the local panel and remotely on the 132kV control board. Local manual operation with mechanical indication shall also be provided.

The feeder earthing switches shall also be interlocked with 132kV High voltage side isolator of voltage transformer i.e. the earthing switches cannot be closed if this isolator is in open position.

3.10 Auxiliary Switches and Contractors: Circuit breakers and isolating device shall include all necessary auxiliary

switches, contactors and mechanisms for remote indication, protection control, interlocking and such other services as specified. Not less than four spare auxiliary contacts (two normally closed and two normally open positions), shall be provided with each circuit breaker. All auxiliary switches should be wired upto a suitable terminal block in the operating mechanism cubicles.

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The contacts for all auxiliary switches shall be strong and shall have a positive

wiping action while closing and shall be suitable for service under climatic conditions specified. All auxiliary switches for use with the purchaser’s remote supervisory and control system shall be clean contacts (potential-free) and of the fleeting type with holding time not less than 25m.sec.

3.11 Current transformers: Protective and instrument C.T.s shall be in conformity with BSS 3938 and of

suitable rating for the protective scheme specified. Instrument current transformers shall be of class “I” accuracy.

This contract includes all protective and instrument C.T.s shown on drawings and enumerated in the details of equipment.

The current transformers primary conductor shall be capable of withstanding short circuit ratings of the associated circuit breaker. Secondary windings of the current transformers shall be rated 1A or 5A, except where 1Amps secondary is specified. For metering current transformer, secondary can be rated either 1 or 5Amps to suit the measuring transducers for remote metering at Supervisory Centre. C.T.s shall be capable of carrying 25% in excess of the rated current continuously without injurious heating and the C.T.s for protective purposes shall have over-current saturation factors not less than those obtained at the design short circuit level of the system, unless otherwise approved.

The capacity of instrument current and voltage transformers shall be adequate for connecting the transducers associated with the remote supervisory and control system.

Since the C.T. forms a part of the composite single phase unit, means shall be provided for easy changing in the case of damage.

The 132kV Sf6 insulated current transformers associated with bus-bar protection of the bus-section and bus-coupler circuit breakers shall be one on each side, i.e. one before and the second after the circuit breaker, i.e. over-lap. However, for feeders and transformer circuits, the C.T. cores for the same protection shall be the outer most core on the line and transformer side respectively, i.e. covering the circuit breakers and the other C.T. cores. Regarding transformer and U/G feeder differential and O/H line distance protection, these shall be located on bus-bar side.

3.12 Voltage transformers: The 132kV voltage transformers shall be in sets of three single phase units, cast

resin insulated or foil insulated and encapsulated in SF6 gas filled enclosure which shall be provided with its own gas monitoring and filling system, SF6 gas compartment for 132kV voltage transformer can also be common with the line isolators compartment. In case of 3-phase encapsulated switchgear 3-phase voltage transformer is acceptable.

For high voltage testing of cables from the remote end of cable, an isolator shall be provided on the primary side of the voltage transformer or any other suitable arrangement so that this test

can be carried out without the necessity of removing any component of the switchgear such as V.T.s cable boxes, ...etc. Where such an isolator is provided, it shall be of manual operation and with necessary interlocks. Semaphore ON/OFF position indication shall be provided on local control cubicle.

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The voltage transformers shall have miniature circuit breakers in their secondary, with auxiliary contacts, to indicate V.T.s, “OFF” on the control board. Further, auxiliary clean (potential-free) contacts shall be provided for remote supervisory system. Voltage transformers supplied under this contract shall be of robust constructions and shall comply with BSS 3941 or at least equivalent to it. The miniature circuit breakers shall be labelled to indicate their function.

3.13 SF6 Gas Tightness: Special attention should be given to SF6 gas tightness in the various

compartments of the switchgear. Tenderers shall state clearly in their offers and guarantee the maximum SF6 gas losses (percent per year).

3.14 132kV Cables End Sealing Boxes: The cable end sealing boxes shall be provided complete with cast resin cones,

flanges, clamps, packing materials for gas, fixing bolts and other fittings necessary including proper sized glands to suit cable sizes, oil monitoring, piping connections and any other accessories shall be supplied under this contract and its cost shall be included in the contract price.

All the 32kV cable end sealing boxes shall be located totally in the basement and the SF6 tubing connections between the switchgear and cable end sealing boxes shall extend to the basement. The extension of the SF6 tubing shall be made down to an approved distance from the basement ceiling so that the oil carrying component shall be below the switchgear's room floor. If the supply and jointing of the 132kV cables is provided under separate contract, then these cables boxes shall meet the requirements of the cable manufacturer at no extra cost. In this case, only jointing materials such as oil, tapes ..etc., will be supplied by the cable contractor who will carry out the cable jointing. The contractor should fully cooperate with the cable contractor.

Any material and/or accessories necessary for complete jointing of all the 132kV cables to the 132kV switchgear shall meet the requirements of the cable manufacturer and the same together with any accessories or material that are deemed necessary to be obtained from the cable manufacturers, shall be supplied and included in the tender price.

3.15 132kV SF6 Insulated Tubing: Where specified SF6 tubing shall be supplied for connection between 132kV

switchgear and 132/33kV or 132/11kV transformers and/or for 132kV feeder circuits. The tubing shall be 132kV SF6 gas insulated, complete with bus-bars, flanges, insulating core, piping for gas monitoring valves, supporting structures, bellows (for expansion and contraction of bus-bars) and any other fittings necessary to render the connection complete in every respect. Each section of the tubing shall be provided with measure for periodical checking of SF6 gas pressure.

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The tenderers should submit with their offers, complete technical details (dimensions, materials, sealing arrangement, ...etc) showing the construction of these tubing arrangement especially for the termination at both ends. Again this SF6 tubing shall be fitted with the necessary pressure relief devices like other compartments of the switchgear.

Regarding the connection points of the primary active parts, whether at the switchgear, transformer or intermediate, these connections shall have clear indication marks to ensure full engagement if it is of the slip-on type.

3.16 Local Control Cubicles: For local control of 132 KV switchgear, control cubicles shall be provided in the

132 KV switchgear room having the following the essential controls, indications and alarms:

Mimic diagram with position indication of circuit breakers and all other isolators and earthing switches.

One voltmeter for each 132 KV feeder circuit. Various alarms for SF6 gas, hydraulic system if applicable, and voltage

transformer miniature circuit breaker tripped, and any other alarm indications, the contractor deems necessary to be shown locally. Compressed air system or charge spring motor drive mechanism troubles shall also (if applicable) be added.

A key operated switch for local/ remote control. All controls shall be by means of key switches for each. However, an additional

key switch for by-passing the interlocking for emergency/ maintenance shall be provided. The interlock by-pass switch shall be of the self return type and its locking key can only be taken while the switch is in the off position. Alternatively, one key switch can be provided for all controls together with push buttons for each control in addition to the by-pass key switch.

Pressure gauges and gas density relays for monitoring the SF6 gas condition of various compartments can be installed on the respective SF6 gas enclosures. However, it is preferred to have these meters and relays installed in the above local cubicles.

It is to be noted that the local-remote switch will be wired so that when set on ‘local’ position switching is only possible locally and when set on ‘remote’, operation is only possible remotely either from the control board or from the control centre.

3.17 Pilot Cable Marshalling Cabinets: It is the general practice in Kuwait to lay 34-core pilot cable with each 132 KV

underground cable circuit. The telephone and indication cores are 0.9 mm diameter and other cores are 2.5

sq.mm conductors. The pilot conductors are polythene insulated, polythene sheathed, steel wire armoured and PVC overall sheathed cable.

One sheet steel cabinet shall be provided in the 132 KV switchgear room to receive the 34-core pilot cables associated with the 132 cables.

The cabinet shall be suitable for floor mounting with double leaf lift-off doors and reasonably dust, damp protected and vermin proof, 34-way terminal blocks, one per feeder circuit (including future circuits ), shall be provided inside the cabinet and arranged to receive the multi insulated bridging plugs. The plug shall be either color coded or numbered to facilitate easy identification.

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Two additional 34-way terminal blocks shall be provided for substation services and arranged to permit routing of circuits selectively through pilot cables.

Provisions shall be made for bottom entry of pilot cables and suitable brass glands of the compression type shall be provided. Similarly, entries shall be provided for control cable terminations from the switchgear, control board and other apparatus within the substation. Each terminal block shall be clearly labelled.

The pilot cable marshalling cabinets shall be provided with copper earthing bar (25 x 3mm) with adequate number of holes with proper screws, washers and nuts for earthing the pilot cable armours and pilot cores screens. For internal wiring of the marshalling cabinets, this shall run in adequate plastic open ducts with removable covers properly fixed to the cabinet wall. The internal looping between terminal blocks in the same cabinet shall be made to Site Engineer’s satisfaction.

The small wiring connection between the marshalling cabinets and the remote control board/relay board shall be as follows and subject to site engineer’s approval:

i. Two cables, each 8 cores, 2.5 sq.mm PVC insulated, PVC sheathed and armoured required for each feeder circuit. The cores of the first cable shall be 4-core for inter-trip, 2-core for Solkor protection and 2-cores as spare. The second cable to be used for 4-core for oil pressure alarm/trip and 4-core spare. These cables shall have each pair separately screened. These cables shall be of the fire retardant.

ii. In case voltage induction protective equipment (isolating or neutralizing transformers) are located in the marshalling cabinet, or in a panel next to it, the associated cables used for connection to control and relay panels shall be of the 2kV insulation level.

iii. The insulation level of the terminal blocks, wiring, control cabling to the control and relay boards shall be 15kV for 132kV cabinets. Tenderers are requested to submit with their offers drawings of the marshalling cabinets showing the arrangement of the terminal blocks, and surge arrestors. This should be complete with technical data and details which shall be subject to the Purchaser’s approval.

Attached drawings MB/7/421-B shows typical arrangement of the required wiring for the 132kV pilot cable marshalling cabinet.

All control cables and connections between the marshalling cabinet and substation equipment including oil tank pits are included in this contract. For the out-going circuits, two cores control cable for each circuit shall be provided for oil tank pit, each cable about 35m long.

Tenderers are requested to allow in their offers for the supply and erection of the following accessories:

i. Hot dip galvanized steel supporting channels complete with cable cleats, clamps screws, nuts, etc. There shall be at least two horizontal channels properly fixed to the basement wall with reasonable spacing. All the control cables and future pilot cables (supplied by others) shall be mounted on these channels.

ii. Necessary pilot cables holding rings, clips, lugs and earthing wires, clamps for earthing the armour wires and screen of these pilot cables shall be earthed. The arrangement of this earthing shall be subject to the Purchaser’s approval. However, it shall be carried out to the satisfaction of the site engineer.

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3.18 Substation O/H Line Take-Off Gantries: (where specified) Take-off gantry for each double circuit overhead lines (one ACSR conductor per

phase) shall be made of galvanized lattice steel structures and to have three pinnacles to receive one standard galvanized steel wire (overhead lines, earth shield conductor) form the terminal tower and arranged to give 30o angle for protection. The phase conductor spacings shall not be less than 2.6m and for a maximum take-off angle of deviation (horizontal 0 to 30 o and vertical 1:4). The gantry shall be complete with take-off tension insulators of the “Long Rod” anti-fog type complete with adjustable arcing horns and shall be attached to the horizontal gantry beam. Civil foundation work for the gantry, conductor clamps, earthing of structures, clamps and conductors and all sundry items to complete shall be included in the tender price. All copper droppers tee or straight copper or bimetallic clamps for connection to outdoor equipment shall be included in the price.

Each gantry shall be complete with step bolts on diagonally opposite legs and have anti-climbing devices fitted. These will require MEW approval.

Bolts will not be less than 15mm. Dia. And shall be fitted with an anti-vibration locking device. The threaded portion of bolts shall not project into any bearing plane. Each bolt shall have a minimum of two threads projecting beyond the outer face of the nut. No angle section less than 45x45x5 shall be used and main member shall have a minimum thickness of 8mm.

Each gantry and its foundation overturning or uprooting shall be capable of supporting the maximum working loads derived from the conductor and earthwire tensions, wind pressure on conductors, structures, ...etc with a factor of safety 2.5.

The wind is to be considered as a force of 80Kg/sq.m acting on conductors and fittings and 125Kg/sq.m on 1.5 times the projected area of one face of the structure.

The maximum tension of phase and earth wire conductors is 1700Kgs and

400Kgs respectively. The wave trap (350Kgs) shall be suspended from the bottom of the gantry and this must be considered in the design. The height of the boom of gantry shall be 10m from the ground.

3.19 132kV Outdoor, 3-single phase Surge Arrestors: (where specified) The surge arrestors shall be heavy duty with rated discharge current pf 20kA and

rated voltage of 120kV. The lighting arrestors shall comply with the relevant BSS and the Purchaser’s system (Clause 1.3) and shall have a minimum creep age distance of 4800mm. The surge arrestors shall be complete with surge detectors and counters.

The earthing of the above equipment shall generally be in accordance of Clause 1.9. final arrangement and details of the earthing arrangement shall be subject to MEW approval.

3.20 Measures to reduce Propagation of Transient Over voltages in measuring

Control & Pilot cables: Transient over voltages of higher frequency may be generated by means of

switching actions of H.V circuit breakers and isolators or caused by other atmospheric surges likewise be transmitted through coupling inductances and

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capacitances of measuring transformers, secondary cables or other direct means to measuring, monitoring, protection and control equipment.

The level of the transient over voltage shall be effectively reduced by adequate measures such as careful grounding of measuring transformers neutrals, proper and adequate earthing, provision of metal screens for cables passing in parallel for long distance with high current carrying equipment.

3.21 Special Equipment: The following equipment shall be provided as part of the special equipment and

their price shall be included in the tender price and shall be handed over to the Purchaser in good condition after completing commissioning tests:

a) Three high voltage testing bushings, 280kV D.C for direct current H.V testing of power cables connected to the switchgear applicable.

b) Three high voltage testing bushings, 280kV, A.C. for switchgear testing as applicable. These shall be supplied only if different from (a) above. This must be confirmed in the offer.

c) Any necessary adaptors, flanges, accessories, bolts and nuts ...etc necessary for connecting the above bushings to the switchgear and to the test cable.

d) Testing cable, 30m long, insulated for 280kV, for connecting the above test bushings to the H.V. testing transformer outside the building, supplied on a modern drum and complete with connectors.

e) Pneumatic or rubber wheeled truck which should be adequately dimensioned and designed to carry any equipment likely to be moved in and out of the 132kV switchgear room either for removal or for maintenance purposes.

f) Suitable ladder with rubber wheels or similar arrangement for the purpose of maintaining the 132kV switchgear equipment.

g) Special device for detecting and locating any SF6 gas leak. h) SF6 gas handling units for extracting and pumping in SF6 complete with

compressors, storage tanks, gauges, piping, vacuum pumps etc. i) One set of compressed SF6 bottles, each sufficient for one cable feeder

circuit and one transformer circuit. j) Portable pressure gauge for periodical checking of SF6 gas pressure in

various compartments. k) Primary current injection cable for testing protective circuits, ..etc... Testing

cables 630sq.mm. copper conductor, 600volts, 30m long complete with connectors, wound on a wooden drum.

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3.22 Switchgear Testing: 3.22.1 Factory Tests: The contractor shall carry out all routine sample and type tests on all equipment

and accessories included in the contract, in accordance with relevant British Standard specifications or I.E.C unless otherwise approved. The contractor shall carry out any additional tests at no extra charges to the contract price that are necessary to determine that the work complies with the requirements of this specification.

All samples used for testing shall be at the Contractor’s expenses. All the instruments used for testing purposes shall, if required, by the

Inspector/Engineer will be calibrated by an approved authority. a) Routine Tests: i) Operational tests for circuit breakers and isolators (as per BSS.5311 and

162) ii) Millivolt drop test across circuit breaker contacts and between terminals. iii) Power frequency high voltage test in accordance with BSS.5311 and 162 as

applicable. b) Type Tests: i. Mechanical endurance tests for 132kV circuit breakers. Each type of circuit

breaker shall be operated 500 times at least 10% of which shall be make-break operations. The operating mechanism shall be in service during this test. The mechanical endurance tests for 132kV isolators shall be in accordance with BSS.5311.

ii. Temperature rise test in accordance with BSS.5311 as applicable. This test shall be carried out on each type of switchgear and for each circuit equipment (i.e. isolators, C.T.’s connections, bus bars......etc)

iii. Short circuit test, short time current test, capacitive and inductive making and breaking test, power frequency test, power frequency test, ...etc., as described earlier under 132kV circuit breakers.

iv. For measuring and protection transformers the determination of accuracy class and displacement angle shall be carried out on each type.

v. The impulse test will be carried out on a complete assembly plants or parts thereof.

vi. One single phase of the surge arrestors will be tested as follows: Wet power frequency spark-over test. Front of wave impulse spark-over test. Switching surge spark-over test. Residual voltage test. High current impulse test Long duration impulse test. Operating duty test. Pressure relief test at least 77% rated voltage. N.B: 1) A type test certificate for the temperature rise tests and impulse test can be

accepted in lieu of this test. For endurance tests, this can be waived, provided that such tests were performed on similar equipment supplied to MEW previously. For short circuit type tests, reference should be made to clause 3.6.

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2) Type test certificates of similar arrestors with rated seal-off voltage 90 to 110% of the test specimen will also be accepted.

3) A type test certificate for the capacitive and inductive making and breaking tests on 132kV circuit breaker can be accepted in lieu of this test.

3.22.2 Site Tests: Provision for testing at site the 132kV switchgear and the 132kV power cables

connected to it shall be provided and details of these shall be clearly shown on the drawing.

The site high voltage testing on the 132kV switchgear shall comprise of the following:-

a. Each phase to earth at 210kV A.C. for one minute. b. Between two phases at 210kV A.C. for one minute. c. All 132kV cables connected to the switchgear to be tested at 270kV D.C.

phase to earth for 15minutes.

For 132kV cables, testing from remote and direct current test voltage of 150kV will be used. It should be possible to carry out this test without dismantling any of the 132kV equipment (see clause 3.12). All Tenderers are requested to confirm this in their offers.

N.B.: Tenderers are requested to attach with their offers the following: 1. The time required in hours of replacement of each kind of switchgear

components i.e., C.B. pole, isolator pole, earthing switch pole, etc... the given period must cover the entire working hours including gas pumping out, dismantling, removal, installation of new piece, adjustment, evacuation of compartment, pumping in gas, testing and energizing and putting the respective circuits in operation.

2. Referring to clause 3.1 above regarding the use of over-pressure relief devices in the offered switchgear. Tenderers are requested to submit with their offers, internal arcing test report of the critical compartments such as circuit breaker or voltage transformer or cable sealing end box, etc...with and without the use of pressure relief devices.

3. The required test report must be supported by photos, oscillograms, pressure rise curves and calculations of mechanical strength of the enclosure and fixing bolts, strength of spacers, all in relation to the rated short circuit current, minimum volume of gas compartments, maximum expected arc voltage. The maximum operating time of the pressure relief disc must allow with a good margin of the tripping of the circuit breaker due to the operation of the main protective relays. However, tenderers are requested also to confirm in the write-up attached with their offers that NO injury or danger will result to personnel in the nearby of the switchgear in case of the occurrence of such an internal fault. Offers not accompanied with the above may not be considered.

Attention of all tenderers is drawn to the following: If 132kV circuit breaker offered is of the same type supplied previously and

working in our network, it is a must that the tenderer should mention clearly if any slight changes have been made on the offered one and in this case the respective detailed workshop drawings and tests carried out on the modified type switchgear must be submitted with the offer.

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PART IV

TECHNICAL SPECIFICATION NO.MEW/SS/4 33KV, 20KV, 11KV & 6.6KV

SWITCHGEARS

4. Switchgear:

The switchgear offered shall be of the totally enclosed, metal clad type with either horizontal or vertical draw out / fixed C.B. with disconnections of the SF6 gas insulated type. The design shall be such that to ensure optimum continuity and reliability of supply as well as safety of the operators.

Offers will be only considered for switchgear suitable for installation indoors in brick built or precast building.

The minimum impulses voltage withstand level for the various types of switchgears shall be as follows:

33KV Switchgear 170KV 20KV Switchgear 125KV 11KV Switchgear 95KV 6.6KV Switchgear 60KV

The switchboard shall be of robust construction and shall be unaffected on whole or part by the forces imposed by short circuit or other fault currents, operation, installation, vibration and charges of temperature. The Switchgear shall be generally in accordance with British Standard Specification No.162 unless specified otherwise herein. The busbars on the switchboard shall be arranged to permit future extension at either side Phase rotation and color markings shall be in accordance with British Standard Specification No.158. The circuit breakers shall conform to the British Standard Specification No.5311 or IEC Recommendation No.56. All instruments, transformers, other components, all materials and compounds used in the switchgear shall comply with the appropriate and latest BSS unless where otherwise specified. The impulse withstand voltage for the switchgear and circuit breakers shall not be less than specified above.

4.1 The Metal Clad Switchgear (air insulated type): 4.1.1 General Construction:

The switchgear shall be designed to facilitate inspection, cleaning , maintenance and repairs. All units of the same rating shall be fully interchangeable. The carriage of the circuit breakers shall be correctly aligned and it shall be possible to rack the carriage in and out easily and without the application of excessive force. A device with a mechanical advantage shall be provided for this purpose where necessary. Partitioning shall be provided between adjacent panels of the switchgear and for compartments (i.e. cable box compartment, circuit breaker compartments, etc.). Means of over-pressure release (due to internal flash-over) such as hinged flap-covers, spring assisted which keeps the flap cover in normally closed position.

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The application of plastic rivets or screws on three sides of the flap covers will be

accepted provided two flaps of each size per substation are supplied free of charges as spares. However, measures for ventilation must be provided where it is necessary to avoid moisture condensation.

Switchgears of the (DUPLEX) back to back design where transfer of circuit breakers from front to back for busbar selection will not be accepted.

The 33KV and 11KV double busbars switchgears shall be provided with on load transfer arrangement, (i.e. a suitable interlock between busbar disconnections (isolators) and bus-coupler and bus-section circuit breakers and disconnections (isolators) to transfer the loads from one busbar to the second one without opening the outgoing and incoming circuit breakers. The disconnections (isolators) shall comply with IEC 129:1975 and IEC 273:1979 as applicable.

Disconnections (isolators) can be either mechanically driven or manually operated. Motor operated disconnections (isolators) are preferred. Local switch operations of B/B disconnections (isolators) shall be affected from front side unless otherwise approved. The switchgear must be dust protected and vermin-proof with degree of protection IP51 in accordance with IEC recommendation 144/1. Accordingly, when the circuit breaker is in the test position, the cubicle front door can be completely closed to fulfill the above protection degree. However, if the circuit breaker truck shall have its front sheet stands for a door, thus in test position, the truck will be projecting outside the cubicles. In this case all the live parts should be completely protected against dust and vermin and measures provided to prevent access of vermin to the circuit breaker parts.

4.1.2 Busbars and Cable Box Compartments:

The busbars shall be of the hard drawn, high conductivity electrolytic copper / aluminum and shall be air insulated. The busbar compartment shall be so designed that maintenance of one set of busbars can be carried out while the other set of busbars is alive and in this case, no live parts shall be accessible to the operator. The shutters of the busbars compartment must ensure not to stick in open or closed position. The main busbars of the 33KV switchgear shall be partitioned between adjacent panels. The 11KV busbars shall be partitioned between adjacent sections.

The shutters of the busbar compartment and cable box compartment shall open and close simultaneously when C.B. is racked in or out respectively. However, for maintenance purposes either set of shutters for cable or busbar side can be closed/opened independently and shall have the independent padlocking. The use of screen for shutters or use of removable shutters is not acceptable.

The partitioning referred to in clause 4.1 and 4.1.1 shall be by means of common steel sheets or reinforced fiber glass of adequate thickness to oppose the dynamic force in case of internal flash over. Calculations of strength of offered partitioning material shall be submitted for approval. The partitioning shall have no openings which will readily permit passage of flame, vapour or gases.

The 33KV and 11KV power cable box compartment shall be totally isolated from other compartments such as circuit breakers, busbars and low tension compartments and provided with its own explosion vent.

The bottom of the cable compartment shall be provided with sheets from non-ferrous metal plate divided into two halves and fixed on the perimeter with

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screws. These sheets shall have the appropriate holes with correct diameter, factory made to suit the cable box arrangement.

However, the gap around the cables/cable boxes must be within the permissible limit as recommended in the respective IEC standards. The above sheet shall be one hour fire resistant. Fire resistant filling material shall be used to fill these gaps which shall be subject to MEW approval.

4.1.3 Isolation and Interlocks:

The switchboard must be provided with an approved means of isolation of the circuit breakers and circuits and be complete with automatic shutters to screen off all live parts. Particular attention shall be given to the design of the spouts to safeguard against flash overs or tracking under the high humidity and dusty conditions. The switchgears shall be fully interlocked to prevent unauthorized or mail- operation, safety of personnel and continuity of supply are the prime considerations. Master keyed locks each with two individual numbered keys and twelve master pass keys shall be included in the tender price for :

a) Locking out the breaker in the isolated position. b) Locking movable screening “ LIVE” parts. c) Locking circuit breaker control switches where applicable. d) Locking voltage transformer spout shutters when provided. The maximum number of master key types suitable for above should not exceed

two. To facilitate phasing out of any incoming circuit against either busbars,

arrangement shall be provided to enable easy manual opening of the above moving shutters independently with the circuit breaker withdrawn, and provision of locking any of these shutters independently in the “OPEN” or “CLOSED” position shall be provided.

4.1.4 Tank Carriage:

Particular attention shall be paid in the design with fully interlocked controls to prevent danger to personnel and apparatus, where wheeled carriage for the removal of circuit breaker from the switchboard is not an integral part of the switchgear, such carriage for each substation shall be supplied. Should the separate carriage be a combined tank lowering device and carriage, this must be clearly stated.

4.1.5 Current Transformers:

The contract includes the supply of all the necessary protection and instrument current transformers as detailed in the schedule of equipment and any other current transformers required for the proper functioning of the equipment and indicating devices.

Protective and metering C.T.’s shall be in accordance with BSS:3938 or IEC 185. The primary winding conductors shall have short circuit rating not less than the

associated switchgear. The C.T.’s shall be capable of carrying an overload of 25% continuously without

injurious heating. The current transformers shall have secondary rated 1amp or 5amps except where

specified and shall preferably be of the bar primary type.

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The capacity of the C.T.’s provided shall be adequate for operating the associated protective devices and instruments and transducers for remote metering at the National Control Centre. For 33KV switchgear busbar protection, the bus section and bus-coupler panels, each shall have two sets of current transformers, one on each side of the circuit breaker. While for 33KV feeder and transformer circuits one set of C.T.’s shall be installed on the line side of the C.B. and shall be the outer most C.T for 33KV feeder and transformer panels. The C.T.s for differential and over-current protection shall be on the busbar side.

Each C.T. shall carry an identifying label showing serial number, turns ratio, actual ratio, VA capacity and class. Where double ratio secondary windings are specified, a label shall be provided indicating clearly the connections required for either ratio. These connections and the ratio in use shall be shown on the appropriate schematic and connection diagrams.

4.1.6 Voltage Transformers:

The voltage transformers shall be of class (1) for metering and 3 P for protection to BSS 3941 or IEC 186. The VA capacity of the voltage transformers shall be determined by the manufacturer and shall be capable of an overload of 50% indefinitely under the worst temperature conditions encountered in Kuwait.

The voltage transformers shall preferably be of the withdrawable type. The main contact must be of the plug-in type and not of the sliding type. The voltage transformer secondaries shall have protective miniature circuit breakers shall have contacts wired to locally as well as remotely to the control board m.c.b. tripped and this indication shall also be wired for indication at the National Control Centre. The voltage transformer shall be connected in the zone protected by the current transformers for the corresponding circuit i.e. not in the busbar zone.

4.1.7 Pressure Switches:

The double busbar 33KV and 11KV switchgear shall be provided with a system of detectors and auxiliary relays to protect the switchgear from fire breakout. This system comprises of pressure switch located in each compartment of all panels to sense the over-pressure due to flash-over that may occur due to insulation breakdown. These switches shall be arranged to cut-off the electrical supply to the faulty zone (through auxiliary relay giving total operating Time not more than 100m.s.) and as follows:

i. If the pressure switch in busbar compartment operates, then all 33KV (or 11KV) incoming circuit breakers shall be tripped.

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ii. If the pressure switch in one of the incoming 33KV (or 11KV) circuit breakers

compartment operates then all the 33KV (or 11KV) incoming circuit breakers shall be tripped. Also the associated high voltage circuit breaker with that particular transformer shall be inter-tripped.

iii. If the pressure switch in one of the cable compartment of 33KV (or 11KV) outgoing feeder operates, then the associated 33KV (or 11KV) out going circuit breaker only shall be tripped.

iv. If the pressure switch in one of the outgoing 33KV (or 11KV) circuit breaker compartment operates then that particular circuit breaker and all the 33KV (or 11KV) incoming circuit breakers shall be tripped.

v. If the pressure switch in one of the 33KV (or 11KV) incoming cable compartment operates then the associated 33KV (or 11KV) circuit breaker shall be tripped. Also the associated high voltage circuit breaker with that particular transformer shall be inter-tripped.

The tenderer shall submit with his offer enough details of the detectors proposed indicating the operating pressure and response time. The final details and arrangements shall be subject to the approval of the Purchaser.

Where single busbars system for 33KV and 11KV switchgears are specified in the Details of Equipment, these shall be provided with busbar zone protection as described under MEW technical specification No.MEW/SS/6 – Protection Schemes.

Auxiliary alarm indication relays shall be provided and fixed on each panel of the control board, however, auxiliary clean contacts of these relays shall be paralleled as one group alarm for remote indication at the National Control Centre.

4.2 The SF6 gas Insulated Switchgear: 4.2.1 General Construction:

The switchgear shall be of the indoor type SF6 gas insulated suitable for installation in brick built or pre-cast building. The design shall be such that to ensure optimum continuity and reliability of supply as well as safety of the operators. The switchgear for any arrangement should be such that it can be easily extended in the future by the addition of extra feeders, B/S pr transformer circuits without the necessity to dismantle any major part of the equipment (C.B.’s V.T.’s....etc) and without the interruption of supply to any circuits more than few hours.

The tenderer must show on the tender drawings how the extension of the switchgear can be carried out.

For testing of the underground cables, provision shall be made on the switchgear for easy fixing of the test bushing without dismantling any equipment of the switchgear such as voltage transformers, cable boxes, ..etc. The arrangement of H.V. testing must be shown on tender drawings.

The SF6 gas system of the switchgear shall comprise of several gas compartments sealed from each other by gas tight bushings or barrier or cast resin material or otherwise approved so that any leakage can be quickly localized, the risk of gas loss is minimized and the reliability of the substation is increased to the maximum possible extent.

For the main bus-bars of the switchgear, each section of the busbar shall be completely separated from bus-section circuit breakers compartments and busbar selector switches of feeder and transformer control circuits. Alternatively, the

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busbars of each circuit (feeder control, transformer control, bus-coupler and bus-section circuit breakers) can be completely separated from each other. In either case, the separation shall be by gas tight compartments as described above.

The 33KV and 11KV double busbars switchgears shall be provided with on-load transfer arrangement (i.e. a suitable interlock between busbar disconnections (isolators) and bus-coupler and bus-section circuit breakers and disconnections (isolators) to transfer the loads from one busbar to the second one without opening the outgoing and incoming circuit breakers. The disconnections (isolators) shall comply with IEC 129:1975 and IEC : 273 :1979 as applicable.

Disconnections (isolators) can be either mechanically driven or manually operated. Motor operated disconnections(isolators) are preferred. Local switch operations of B/B disconnections (isolators) shall be affected from front side unless otherwise approved. The switchgear must be dust protected and vermin-proof with degree of protection IP51 in accordance with IEC recommendation 144/1.

Each switchgear gas compartment shall have a separate valve for pumping in and out of gas. Means of periodical checking of gas pressure for maintenance purposes shall be provided.

Each panel of the SF6 gas insulated switchgear has to be provided with a mimic diagram to show the position of the switching devices under all service conditions.

All interlocks that prevent potentially dangerous mal-operations must be constructed such that they cannot be defeated easily.

Tenderers are requested to confirm in the write-up attached with their offers and to show on one set of switchgear construction drawings (covering feeder, transformer, bus-section and bus-bars), the provision of pressure relief devices, one in each SF6 gas compartment on each phase and for each bay and each busbar section.

The details of the offered devices and recommended pressure settings shall be attached with the cost of such shall be included in the tender prices. The rated bursting pressure of bursting dics shall allow the operation of the main protection relays.

The 33 KV & 11 KV busbar arrangement shall be as specified for each substation under “Details of Equipment”.

4.2.2 SF6 Gas Monitoring :

The detection and monitoring of SF6 gas pressures and alarm/trip and inter-trip indications, all shall be provided complete with gas monitoring devices, pressure switches for local and remote indications against loss of gas pressure. The alarm indication shall be provided on each 33 KV and 11 KV panel separate, however, one group alarm signal shall be sent to National Control Centre.

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Necessary means shall be provided to detect the gas compartment in which

internal arc might take place. SF6 gas checker equipment ( chemical method ) may be accepted for locating the faulty gas compartment. Complete set of SF6 gas checker equipment together with two dozen of detecting elements as spare should be supplied for each substation. In case any gas compartment is completely electrically isolated and in such a case if there is a leak in that compartment then it should not cause tripping/intertripping of any circuit breaker.

4.2.3 Bus –Bars, Insulators,.....etc. :

The Bus-bars shall be made of high conductivity electrolytic copper in accordance with BSS.159 or at least equivalent.

Each and every connection made either to a transformer, circuit breaker, or any other bushing shall be so designed to allow for expansion or contraction in an unrestricted manner at the bushing end, so that there is no possibility of any stressing being imposed on the bushing insulators in any place and none of the insulators are subjected to any part the conductor’s stress caused by variation of temperature.

Suitable arrangement shall also be made to allow for thermal expansion and contraction of the main busbars and this shall be subjected to the approval of the purchaser.

The busbars shall be so arranged that they may be extended in length without difficulty. The design of connectors for the busbars and connection to other parts of the equipment shall be such as to permit easy dismantling for maintenance or repair purposes.

Busbars shall be of adequate diameter to avoid initial discharge and suitable measures shall be taken to prevent corona discharge especially at sharp edges and corners.

Each busbar section should be securely jointed to other sections by means of high quality bushing insulators through gas tight flanges.

4.2.4 Current Transformers :

The contract includes the supply of all the necessary protection and instrument current transformers as detailed in the schedule of equipment and any other current transformers required for the proper functioning of the equipment and indicating devices.

Protective and metering C.t.’s shall be in accordance with BSS : 3938 or IEC 185. The primary winding conductors shall have short circuit rating not less than the

associated switchgear. The C.T.’s shall be capable of carrying an overload of 25% continuously without

injurious heating. The current transformers shall have secondary rated 1 amp or 5 amps except

where specified and shall preferably be of the bar primary type. The capacity of the C.T.’s provided shall be adequate for operating the associated

protective devices and instruments and transducers for remote metering at the National Control Centre. For 33 KV switchgear busbar protection, the bus section and bus-coupler panels, each shall have two sets of current transformers, one on each side of the circuit breaker. While for 33 KV feeder and transformer circuits one set of C.T.’s shall be installed on the line side of the C.B. and shall be the

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outermost C.T. for 33 KV feeder and transformer panels. The C.T.s for differential and over-current protection shall be on the busbar side.

Each C.T. shall carry an identifying label showing serial number, turns ratio, actual ratio, VA capacity and class. Where double ratio secondary windings are specified, a label shall be provided indicating clearly the connections required for either ratio. These connections and the ratio in use shall be shown on the appropriate schematic and connection diagrams.

4.2.5 Voltage Transformers:

The voltage transformers shall be of class (1) for metering and 3 P for protection to BSS 3941 or IEC 186. The VA capacity of the voltage transformers shall be determined by the manufacturer and shall be capable of an overload of 50% indefinitely under the worst temperature conditions encountered in Kuwait.

For high voltage testing of cables from the remote end of cable, an isolator shall be provided on the primary side of the voltage transformer or any other suitable arrangement so that this test can be carried out without the necessity of removing any component of the switchgear such as V.T.s cable boxes, ....etc. Where such an isolator is provided, it shall be of manual operation and with necessary interlocks. Semaphore ON/OFF position indication shall be provided on local control cubicle.

The voltage transformer secondary shall have protective miniature circuit breakers shall have contacts wired to locally as well as remotely to the control board m.c.b. tripped and this indication shall also be wired for indication at the National Control Centre. The voltage transformer shall be connected in the zone protected by the current transformers for the corresponding circuit i.e. not in the busbar zone.

4.2.6 SF6 Gas Tightness:

Special attention should be given to SF6 gas tightness in the various compartments of the switchgear. Tenderers shall state clearly in their offers and guarantee the maximum SF6 gas losses (percent per year).

4.3 Earthing Switchgear:

Each switchboard shall be provided with a copper “earth bar” of sectional area of not less than 30 x 5mm and its associated control board with an “earth bar” of not less than 25 x 3mm. The earthing bar shall pass through along the whole length of the board and connected to each panel.

All metal parts of the switchboard other than “LIVE” parts shall be connected to the “earth bar” in an approved manner. All metal instrument cases shall be connecte to the “earth bar” by conductors of not less than 2,5sq.mm cross section.

Where necessary wiring in the switchgear is to be earthed it shall be done in accessible place in each panel through a copper link connected to the earth bar. All voltage transformers shall be individually earthed in an approved manner.

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4.4 Duty of Plant: a) Rating & Breaking Capacity:

All current carrying parts of the switchgear including current transformers, isolating contacts, busbars, connections and joints shall be capable of carrying theirspecified rated currents continuously under the worst temperature conditions encountered in Kuwait and in all parts the temperature rise shall be as specified in the British Standard Specification Nos. 5311 and 159 or any other relevant British Standard Specification, taking into consideration Kuwait’s temperature conditions. Tenderers shall state the equivalent BSS rating along side the Kuwait

ratings in each case.

b) Circuit Breakers:

The circuit breakers shall be of the SF6 insulated or vacuum type an evidence to show that the offered circuit breaker which they are offering is in service for at least three years, must be submitted with the offer.

The SF6 gas shall be for arc interruption in the circuit breaker and which will be of the segregated type. Each circuit breaker must be provided with gas monitoring devices, pressure switches for local and remote alarm indications against loss of gas pressure.

Tenderers who are offering SF6 or vacuum circuit breaker for 33KV and 11KV switchgear must fill the appropriate details in the schedule of “General Particulars and Guarantees” with complete and clear technical data.

Also they have to attach with their offers technical literature, description and instructions for operation and maintenance. The short circuit current rating for 33KV switchgear shall be 16KA (1000MVA) and 24KA (1500MVA) at 36KV and for 11KV switchgear 25KA (500MVA) at 12KV.

The circuit breakers shall have a guaranteed capacity as specified in the “Details of Equipment” of their respective rated voltage and must conform to British Standard Specification No.5311 or IEC recommendation No.56. Short circuit type test certificates for the 33kV and 11kV switchgear from the internationally recognized testing authority acceptable to the purchaser shall accompany each and every tender to show that the circuit breaker has been fully type tested to BSS 5311 or IEC 56. The above type test certificate for each circuit breaker rating shall be submitted with each tender.

Alternatively, if such certificates are not available, tenderers must submit a short circuit type test certificate from an internationally recognized testing authority acceptable to the purchaser, with each and every tender to show that the circuit breakers had been tested for fully symmetrical short circuit MVA capacity in accordance with BSS, IEC or VDE. In this case the successful tenderer will be required to carry out (or produce) complete short circuit tests for each 33KV and 11KV circuit breakers rating and for the above five duties in accordance with BSS 5311 or IEC 56, at an internationally recognized testing authority before the dispatch of the first consignment of switchgear. Such tests will be witnessed by the Purchaser’s representative and the contractor shall afford all facilities and bear all costs arising there from.

Where the SF6 circuit breaker is metal enclosed, tenderers are requested to show by detailed calculations in their offers how the over pressure resulting from internal flash over due to insulation failure or restricting of the arc released with

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reference to the operating time of the protective back up relay which can be taken as two seconds.

Tenderers are requested to submit with their offers, details of pressure relief arrangement adopted on the circuit breaker poles. At approval stage detailed calculations of the strength of the C.B. components and the mode of pressure relief against explosion shall be subject to MEW approval.

Regarding SF6 gas pressure, auxiliary SF6 piping, valves, gas density relay with auxiliary alarm sets of contacts (one for alarm and second for lockout against electrical and manual operation) and pressure gauge with inlet stop valves for each circuit breaker shall be provided for continuous monitoring and periodical checking. The alarm indication shall be provided on each 33KV and 11KV panel separate, however, one group alarm signal shall be sent to the National Control Centre.

c) Normal Current Rating:

The normal current ratings as specified in the attached details of equipment shall be the normal continuous ratings under the worst temperature conditions encountered in Kuwait.

d) Operation:

Operating mechanism shall be tripped free unless otherwise approved. A mechanically operated indication shall be provided on each circuit breaker operating mechanism to show whether the breaker is opened or closed. Also, remote indication for open/close position of breaker shall be provided on the control board. Means shall be provided for the manual operation of the circuit breakers for maintenance purposes.

All manually operating gear shall be so designed to close or open the breaker by one movement. Emergency “manual” trip shall also be provided on the switchgear cubicle. Power supply for tripping and closing coils shall be from the d.c. station and tripping batteries respectively.

Electrical closing devices shall operate satisfactorily between 80% and 120% of normal voltage with coils at 52C.

In case of spring-operated mechanism, these shall be motor charged. Provision for manual charging of spring shall be provided for emergency closing. A local release shall be provided for with mechanically indication of spring charged condition. A 433volts, 3 phase or 250 volts single phase, 50 cycles supply shall be used for the motors. The closing springs must be suitable for charging while circuit breaker is closed and the closing mechanism when charged, shall not operate by vibration caused by the circuit breaker on a fault.

Automatic spring re-charging shall be provided on each circuit breaker. For the purpose of load shedding, the 33 KV circuit breakers closing operating must be possible without the need for manual or motor charging. Therefore, the closing operation, after tripping, can be effected remotely from the National Control Centre immediately.

4.5 Auxiliary Switches and Contactors:

Circuit breakers shall be provided with suitably rated auxiliary switches (and contactors) necessary for the various purposes and services as required by this specification.

Auxiliary contactors shall be provided only where the circuit requirements cannot be met by the auxiliary switchgear arrangement. Contactor coils shall be capable

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of operation within the same voltage limits as specified for the associated circuit breaker spring release and trip coils.

Four spare auxiliary switches ( two normally opened and two normally closed ) shall be provided on each circuit breaker. However, these contacts shall be wired to the associated low tension compartments.

The connection of all auxiliary switches (and contactors as well as the associated coil connections and interconnections between auxiliary switches, shall be wired to a terminal board located in the operating cubicles or other approved positions.

4.6 Pilot Cable Marshalling Cabinets:

It is the general practice in Kuwait, to lay 16-core pilot cables with each 11 kV feeder and 34-core pilot cable with each 33 KV feeder. These pilot cables are used for solkor pilot wire protection intertripping between substations, telecontrol, telesignalling and telemetering to National Control Centre as well as telephone communication.

The telephone and indication cores are 0.9 mm diameter and protection cores are 2.5 sq. mm conductors. The pilot conductors are impregnated paper or polyethene insulated, polythene sheathed steel wire armoured and PVC overall sheathed cables.

One sheet steel cabinet shall be provided in the 11KV switchgear room to receive the 16-core pilot cables associated with 11kV feeders. One similar cabinet shall be provided in the 33 KV switchgear room to receive the 34-core cable associated with 33 KV cables.

The cabinet shall be suitable for floor mounting with double leaf lift off doors and reasonable dust, damp and vermin proof.

34-way terminal blocks, one per feeder circuit (including future circuit) shall be provided inside the cabinet and arranged to receive multi-core cables. The terminal blocks shall be of the type having insulated bridging plugs. (M/s Standard Telephone and Cables Ltd., produces a suitable type). The plug shall be either color coded or numbered to facilitate easy identifications. A 66-way terminal block shall be installed and wired in the marshalling cabinet associated with the 11 KV circuits (see drawing No. MD/76C).

Two additional 34-way terminal blocks shall be provided for each cabinet for substation services and arranged to permit routing of circuits selectively through pilot cables. For the pilot cable marshalling cabinets associated with the 11 KV cables, 20-way terminal blocks shall be provided but number of blocks shall be as above. The terminal blocks shall be suitable to receive wires terminated with lugs. However, all connections other than the pilot cable side shall be included in the tender price.

Provisions shall be made for bottom entry of pilot cable and suitable brass glands of the compression type shall be provided. Similarly, suitable entries shall be provided for control cable terminations from the switchgear control board and other apparatus within the substation. Each terminal block shall be clearly labelled.

The pilot cable marshalling cabinets shall be provided with copper earthing bar (25 x 3mm) with adequate number of holes with proper screws, washers and nuts for earthing the pilot cable armour and pilot core screens. For internal wiring of the marshalling cabinets, this shall run in adequate plastic open ducts with removable covers properly fixed to the cabinet wall.

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The internal looping between terminal blocks in the same cabinet shall be made to site Engineer’s satisfaction.

The control cables for connection between the marshalling cabinets and the remote control board/relay board shall be fire-proof and allocated as follows and subject to site Engineer’s approval.

i. Two cables each 6-core, 2.5 sq.mm. PVC sheathed and armoured for each feeder

circuit. The six cores of the first cable shall be 2-cores for inter-trip, 3-core for solkor and 2-cores as spare. The solkor and inter-trip protection pairs shall each be separately screened. The second cable to be used for alarms e.g. 33KV cable oil pressure alarm, etc.

ii. The insulation level of the terminal blocks, wiring, control cabling to the control

and relay board shall be 5 KV for 33 kV and 11 kV cabinets. Tenderers are requested to submit with their offers, drawings of the marshalling cabinets showing the arrangement for the terminal blocks, surge arrestors.

This has to be complete with technical data and details which shall be subject to the Purchaser’s approval.

Attached drawings MD/7/421-B, MD/75-B & MD/76-C showing the typical arrangement of the required wiring for the 132 KV, 33 KV and 11 KV pilot cable marshalling cabinets.

All control cables and connections between the marshalling cabinets and substation equipment and to oil tank pits for 33 KV oil filled cables are included in this contract. For the outgoing circuits, two core control cables for each circuit should be provided for oil tank pits, each cable about 35 meters long.

Tenderers are requested to allow in their offers for the supply and erection of the following accessories:

iii. Hot dip galvanized steel supporting channels complete with cable cleats, clamps, screws, nuts, etc. There shall be at least two horizontal channels properly fixed to the basement wall with reasonable spacing. All the control cables and future pilot cables (supplied by others) shall be mounted on these channels.

iv. Necessary pilot cable holding rings, clips, lugs and earthing wires. Clamps for earthing the armour wires and screen of these pilot cables. The arrangement of this earthing shall be subject to the Purchaser’s approval. However, it shall be carried out to the satisfaction of the site Engineer.

4.7 Cable Terminal Boxes:

a) 11KV Cables : (Feeder Circuits)

Each feeder cable end and dividing box shall be suitable to receive 300 sq.mm. 3-core 11 KV copper conductors XLPE insulated SWA screened cable and shall be complete with compression type cable lugs, compression type brass glands, wire armour clamps and earth bonding clamps, connection copper bonding strips and one set of compression tools for termination /jointing type HT 130 C of M/S Cambre or Type Y-35 of M/S BICC make. Tools and accessories for jointing work have to be supplied with each substation(complete sets of copper lugs ) have to be provided for each 11 kV feeder and the cost of such as well as for the sets of tools have to be included in the tender price.

Termination of the 11 kV feeders shall be of the heat shrinkable type and the

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design shall facilitate jointing and provide sufficient space for crossing of cores and earthing of screens without damage to the insulation when phasing out.

It is to be noted that the length from the crutch of the cable to the cable terminal lug shall be about 630 sq.mm and accordingly all components of the heat shrinkable termination ssuch as non-tracking, stress control tubing, insulating sleeve, boots, etc. shall be suitable for this length.

The glands shall be of the compression type and made of brass with internal diameter of minimum 72 mm together with copper bonding facility for earthing. Regarding cable lugs, this shall be of the compression type made of copper with single hole of 17 mm diameter on the flat palm of the lug for connection.

All the above components for termination and connection shall be supplied for all feeders and the cost of such shall be included in the offer price.

The cable box compartment shall be completely vermin-proof and compression glands shall be provided for 11 KV cable entry. Further, pressure relief arrangement should be provided.

b) 132/33 KV, 132/11.5 KV and 33/11.5 KV Transformer Circuits: i) 11 KV Cable Termination Boxes:

The cable end box of the 132/11.5 KV transformers on the 11 KV switchgear panels shall be suitable to receive nine single core 630 sq.mm. PILC&S 11KV cables of copper conductors (3 cables per phase). For 33/11.5 KV transformer, the cable end sealing box shall be suitable to receive six single core 630 sq.mm. PILC&S 11 KV copper cables (2 cables per phase).

Termination of the 11KV cables shall be of the heat shrinkable type complete with compression copper lugs and brass wiping glands.

ii) 33 KV Cable Terminal Boxes:

The cable sealing end box of the 132/33 KV transformers on the 33 KV switchgear panels shall be suitable to receive six single core 1000 sq.mm. PILC&S or XLPE 33 KV cables with copper conductors (two cables per phase).

For 33/11.5 KV transformers, the cable boxes of 33 KV side shall be similar to the above but suitable to receive three single core 240sq.mm. 33 KV PILC&S cables or XLPE cable.

The above cable boxes under “b” (i & ii) shall be complete with flexible links, cable lugs, brass wiping glands, earth bonding clamps and connection to the earthing bar.

The boxes shall be designed for compound filling with markings to indicate the recommended compound level for various ambient temperatures. The design shall facilitate jointing without excessive bonding or stress on the bushings. All jointing material and compound shall be included in the tender price.

c) 33KV Cables : (Feeder Circuits)

Each 33 KV cable feeder panels shall be provided with a cable end sealing box suitable to receive three single core 400 sq.mm. 33 KV PILC&S cables. The boxes shall be complete with flexible terminations, cable lugs, brass wiping glands, earth bonding clamps and connections to earth bar.

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The boxes shall be designed for compound filling. All jointing material and compound will be included.

NB: Cable boxes shall be separated from all other compartments such as C.B.’s, busbar and low tension compartments, etc. Arrangement of cable boxes shall be approved by the Purchaser.

d) 11/0.433 KV Station Transformer Circuits, 11KV Cable Termination

Boxes:

The cable end boxes of the 11/0.433 KV transformer’s 11 KV switchgear panel shall be suitable to receive 185 sq.mm 3-core stranded copper conductor, XLPE insulated and PVC sheathed, wire armoured and overall PVC sheathed 11KV cables.

The 11 KV switchgear cable terminal boxes for the station transformer shall be of the h eat shrinkable type and the design shall facilitate jointing and provide sufficient space for crossing of cores and earthing of screens without damage to the insulation when phasing out. The boxes shall be complete with compression type cable lugs and compression type brass glands, wire armouring and earth bonding clamps.

4.8 Switchgear Earthing Devices:

Provision shall be made for earthing of power cables, transformers and the busbars of 33 kV and 11kV switchboards. The earthing shall be through a fault making earth switch fully interlocked.

Earthing devices shall be fully interlocked with the circuit breaker and /or isolators (as applicable) and shall be capable of closing on a three phase short circuit current of 26.3 KA, 17.5 KA for 1500 MVA and 1000MVA 33kV switchgear respectively and 26.3 KA for 11kv without sustaining any damage or endangering the operator. Evidence of testing the earthing devices for this duty should be submitted with the offer. Busbar earthing switches cannot be closed unless all corresponding busbar selection isolator/circuit breakers (as applicable ) are in open position. Also when the earthing switch is in the closed position, it should not be possible to close the corresponding busbar isolators/breakers as applicable. Earthing busbars shall be made at either the bus-coupler or bus-selection panel and electrical interlocking to the respective C.Bs or disconnections shall be provided and approved by MEW. Key-switch interlocking will not be accepted.

4.9 Testing Plugs :

Each switchboard shall be provided with two sets of 3-phase test plugs fully insulated for test voltage usually applied to switchboard and cables. Terminals for the test plugs shall be arranged to receive flexible conductors up to 185 sq. mm. Single core cable normally used for current injection tests.

4.10 Grounding of Power Transformer Neutrals :

The neutral point of each of the power transformers shall be separately and individually earthed through a metallic earthing resistor. The earthing resistor shall be one of the following sizes:

For 132/33 KV Transformers:

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24 ohms for 75 MVA 39 ohms for 45 MVA For 132/ 11.5 kV Transforms: 8 ohms 30 MVA For 33/11.5 kV Transformers: 10.5 ohms for 20/15 MVA The earthing arrangements shall comprise the above resistor connected to the

transformer neutral from one end by means of solid PILC under ground cables through suitable bolted copper links together with the necessary separate cores of current transformers for restricted earth fault and standby E/F protections housed in steel cabinets ( one independent cabinet for each transformer )which shall be fitted with the relevant cable and boxes for connection of the incoming and outgoing neutral cables. The resistors as well as the cabinets shall be located in a separate room and the arrangements shall be subject to the Purchaser’s approval.

4.10.1 Neutral Cabinets, Earthing Links and Current Transformers:

For each transformer, one sheet cabinet shall be provided. The cabinet shall be floor mounted with suitable front door and key switch. The cabinet shall be reasonably dust protected and vermin-proof. Inside the cabinet, there will be a protective wire mesh with danger sign against touch of the equipment inside the cabinet. This mesh will be fixed by screws around the perimeter to prevent accidental touch of the main circuit components.

For neutral cable connections, each cabinet shall be provided with the necessary cable end boxes for single core solid cables; one for incoming from transformer low tension cable-box suitable for PILC & S or XLPE cables and the second for outgoing XLPE insulated PVC sheathed cable to the earthing resistor.

The current transformers for REF protection shall be mounted on the incoming cable, while that for standby protection shall be mounted before the earthing link for resistor. In case the earthing resistor is out of service for repair or maintenance a provision shall be made for fixing the copper earthing link to achieve a direct connection to ground through a copper busbar 40 x 10 sq. mm. or 400 sq.mm. stranded conductor suitably insulated and which shall be subject to MEW approval.

The copper earthing links shall be fixed by bolts and nuts, however, insulated from the mounting steel frames provided in the cabinet for this purpose.

The physical dimensions, clearances and details of the earthing link shall be subject to the Purchaser’s approval. The cabinet and all supporting frames shall be connected to the indoor substation earthing ring by means of 25 x 3 sq.mm. bar or 75 sq.mm. stranded copper conductor.

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The earthing links as well as the current transformers shall be insulated for the

line voltage of the low voltage side of the associated power transformers and shall be capable of carrying the maximum possible ground fault current for each circuit connection, i.e., through earthing resistor and direct to ground for the specified durations.

Since the earthing resistor circuit will be normally in operation, only one copper earthing link shall be provided and which shall be transferred to the direct connection to ground in abnormal or routine maintenance cases. This request is applicable only if the two links provided are identical, otherwise two links have to be provided for each transformer cabinet.

4.11 Neutral Earthing Resistors: i) 33 KV System Neutral Earthing Resistors :

24 ohms neutral earthing metallic resistor shall be supplied for earthing the neutral of the 132/33 KV, 75 MVA and, 30 ohms for earthing the neutral of the 132/33 KV 45 MVA transformers.

The resistor shall be capable of carrying the earth fault current of 800 Amps. for 24 ohms resistors and 500 Amps. for 39 ohms resistors for a period of 30 seconds at an ambient temperature of 52 C without mechanical damage, internal flashover or movement and with a total temperature rise not exceeding that stated in the schedule of guarantees. The resistance shall limit the initial fault current on the application of full phase voltage of 10 KV to 800 Amps. for 24 ohms resistor and 500 Amps for 39 ohms resistor at an ambient temperature of 52 C.

The resistor shall be unbreakable and rustless. The bank forming the resistance shall be assembled in frames mounted on common base channels and suitably screened with expanded metal so that no live metal is exposed. The top shall be drip proof and suitable for indoor installation. Suitable studs shall be provided for earthing the protective metallic housing (screen ).

A 33 KV cable sealing end box shall be provided for high voltage connection suitable to receive 1000 sq. mm. 33 KV single core XLPE insulated and PVC sheathed cables for the 75 MVA transformers or to receive 500 sq. mm. 33 KV single core XLPE insulated and PVC sheathed cables for the 45 MVA transformers.

A bar type insulated terminal shall be provided for the outgoing earthing connections, not less than 400 sq. mm. Cross-section area, suitably insulated.

ii) 11 KV System Neutral Earthing Resistors :

8 and 10.5 ohms metallic type earthing resistors shall be supplied for earthing the neutral of the 132/11.5KV and 33/11.5KV transformers.

The rating of the neutral earthing resistor shall be 800 Amps. for the 8 ohms resistor and 600 Amps. for the 10.5 ohms resistor respectively.

The resistor shall be as follows : One unbreakable, rustles earthing resistor for use in the neutral of 11 KV 3-phase 50 Hz , system to limit the initial fault current on the application of full phase to neutral voltage of 6350 volts, to 800/600 Amps at an ambient temperature of 52C. The resistance consist of grids of standard sheradized metal material built into banks fitted with mica and micanite primary insulation and porcelain secondary insulation.

The resistor shall be capable of carrying the fault current of 800/600 Amps. for a period of 30 seconds at an ambient temperature of 52 C without mechanical

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damage, internal flashover or movement. The banks forming the resistance to be assembled in frames mounted on common

base channels and suitably screened by expanded metal. The roof to be drip-proof and suitable for indoor installation.

A cable sealing box shall be provided for the incoming single core 630 sq.mm. 11 KV, XLPE insulated and PVC sheathed cable. A bar type insulated terminal shall be provided for the outgoing each connection not less than 400 sq.mm. cross section area suitably insulated. Suitable studs shall be provided for earthing the protective metallic housing (screen).

4.12 Special Equipment: (for 33/11 KV substations only)

Tenderers are required to include in their offers for the provision of the following equipment where SF6 33 KV and /or 11 KV SF6 insulated circuit breakers or switchgear are offered. The cost of these equipments shall be included in the tender price:

1. SF6 handling unit complete with vacuum pumps, compressor valves, pressure

gauges, etc. 2. SF6 gas leakage detector 3. SF6 gas bottles complete with gas sufficient for filling 3 phase of two 33KV and

two 11KV bays. 4. Any other portable pressure meters necessary for periodical maintenance of the

SF6 circuit breakers or switchgear. The respective technical pamphlets of the above equipment to be attached to the offer.

4.13 Switchgear Factory Testing:

The contractor shall carry out all routine and type tests in accordance with relevant British Standard or I.E.C. specifications unless otherwise approved. The contractor shall carryout any additional test that are in the opinion of the Purchaser or his representative necessary to

determine that the work complies with this specification.

a) Routine Tests for Circuit Breakers: (as per BSS 5311 and 9230) i) Voltage tests on control and auxiliary circuits. ii) Millivolt drop test across circuit breaker contacts and between terminals iii) Power Frequency high voltage test in accordance with BSS 5311 and 5162 as

applicable. iv) Mechanical operating tests.

b) Type Tests: i) Mechanical endurance tests for 33 KV and 11 KV circuit breakers. Each type

of circuit breaker shall be operated 5000 times at least 10 percent of which shall be make-break operations, where the operating mechanism shall be in service during this test.

ii) Temperature rise test in accordance with BSS: 5311 and 1622 as applicable. This test shall be carried out on each type of switchgear and for each circuit breaker rating.

iii) Impulse voltage withstands tests.

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Note: 1- A type test certificate for the temperature rise tests can be accepted in lieu of

this test. For endurance tests, this can be waived provided that such test were

performed on similar equipment supplied to MEW previously. 2- The impulse withstand voltage test must be carried out as the switchgear is

assembled in service, i.e. with the additional fire protection equipment installed such as smoke detectors and fire fighting gas nozzles and associated piping.

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PART V

TECHNICAL SPECIFICATION MEW/SS/5 POWER TRANSFORMERS

5. Power Transformer. 5.1 Type :

The transformer shall be of the double wound core type, three phase, oil immersed, natural oil circulation type suitable for outdoor installation and operation under the climatic conditions referred to in the specification Clause No.1.4.

All transformers shall be provided with the required accessories as specified in the “Details of Equipment”.

The transformers shall strictly comply with the British Standard Spec. No.171, unless otherwise stated in this specification.

5.2 Continuous Maximum rating :

The transformers shall be capable of carrying their specified load continuously under the worst temperature conditions encountered in Kuwait, and at any tapping, without the temperature rise of oil in the hottest region exceeding 40oC as measured by thermometer and that of the winding 50oC as measured by winding resistance. For cast resin insulated station transformers, temperature rise shall not exceed 80oC as measured by resistance.

If any transformer exceeds the above temperature rise limits on the test it may be rejected. All Tenderers shall state in the schedule of Guarantees the equivalent BSS continuous maximum rating for the transformers offered.

5.3 Method of Cooling:

The cooling of the transformers shall be by natural oil circulation in external banks of cooling radiators. The external cooling medium shall be natural air or air blast as detailed in the “Details of Equipment”, except where otherwise specified.

5.4 Voltage Ratio:

The voltage ratio of the transformers on nominal tappings and a on-load shall be as specified in the “Details of Equipment”.

The high voltage windings shall have tapings, arranged to give variations of

transformation ratio in steps as specified in the “Details of Equipment”. 5.5 Impedance Voltage & Regulation :

The impedance at normal ratio and M.C.R. ( Maximum Continuous Rating) shall be as specified in the “Details of Equipment”.

The voltage regulations from on-load to continuous maximum rated output at 1.0 power factor and 0.8 lagging power factor shall be as stated in schedules.

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5.6 Electrical Connections :

The transformers shall be in accordance with BSS.171 as follows:- a) 300/132 KV transformers : H.V. winding - Star L.V. winding - Star Vector Group - YNyno (with tertiary compensation winding ) b) 132/33 KV & 33/11.5 KV Transformers: H.V. winding - Delta L.V. winding - Star Vector Group - Dy11

c) 132/11.5 KV Transformers: H.V. winding - Delta L.V. winding - Zig-Zag Vector Group - DZ10

d) 11/0.433 KV Station Transformers: H.V. winding - Delta L.V. winding - Star Vector Group - Dy11 5.7 Duty Under Fault Conditions :

All the transformers shall be capable of withstanding without damage or distress any external fault between phases for THREE seconds, with the voltage on other side of the transformer maintained at its full normal value.

5.8 Parallel Operation :

The transformers of each type shall be designed for operating in parallel. In addition, the transformers shall be designed to operate in parallel with additional similar transformers that may be installed in the future.

5.9 Insulation Level:

All transformers insulation level shall be standard 1 to BSS 171 for the system highest voltages corresponding to the operating voltage ratings 275 KV, 132 KV, 33 KV and 11 KV.

5.10 Harmonic Voltage:

The design of the transformers shall be such as to suppress voltage harmonics (particularly third and fifth ) to a minimum, to eliminate wave distortion and high frequency disturbances.

5.11 Vibration & Noise:

Every care shall be taken to reduce noise and vibration to the level obtained in good modern practice. Since these substations will be installed in residential areas, therefore the noise level outside the transformer housing shall not exceed the specified limits in VDE standard for such areas. However, a noise level of 50

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db at a distance of 30 meters is acceptable. The Tenderer shall submit the details of the tests and method adopted to measure

the noise level in the factory. This test is to be carried out in presence of the Inspector/Engineer appointed by MEW. Cladding of transformer room walls with special material to obtain the required limit of noise level may be adopted. However, The cost of such be included in the tender price. It shall be noted that above mentioned limit of noise level shall be when the transformer is fully loaded and all the blowers are running.

5.12 Windings :

The designed maximum current density in the windings of the transformers shall not exceed 2.6 amperes per sq.mm. at continuous maximum rating of the transformer with normal voltage and frequency. In the case of air blast cooled transformers, this current density may be increased to a maximum of 3.4 Amps/sq.mm.

The conductors shall be make from high conductivity electrolytic copper of best quality. All windings shall be fully insulated as defined in BSS. All neutral points shall be insulated for full line voltage, expect for the 300/132 kV transformer stated elsewhere in the specification. Tenderers shall submit drawings with their offers showing types of windings, methods of bracing and clamping, details of oil cooling ducts with dimensions and state what precautions are taken to prevent shrinkage of insulating material in service, particular attention must be given to the bracing of the winding and terminals to withstand shocks which may occur during handling and transport having regard to the rough handling to be expected during unloading in Kuwait. Foil spiral type winding is not acceptable.

5.13 Core :

The core shall be constructed of the best quality low loss, cold rolled, grain oriented electrical steel laminations.

The flux density in any part of the core shall not exceed 17500 lines per net square centimeter at normal voltage and frequency.

The core shall be provided with an ample number of cooling channels in order to ensure its proper circulation of oil and efficient cooling.

All core plates shall be insulated from one another to reduce the core loss to a minimum and the core shall be held together by bolts and clamping plates to keep the magnetic noise at a minimum level. All bolts and clamps shall be adequately insulated. The completed core shall be provided with lifting eyes to facilitate its removal from transformers. All steel sections used for supporting the core are to be thoroughly sand blasted after cutting, drilling and welding. Design of supporting frame shall take into consideration complete emptying of tank through a drain-valve, the avoidance of movement of the core relative to the tank during transport, installation and operation.

Details of earthing of the inactive part and screening of the core if applied to be submitted with the offer.

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5.14 Insulation :

All insulations of the transformers shall be class ‘A’ in accordance with BSS 2757, ( except where another class is specified ). The winding shall be insulated with best quality paper and treated to prevent the formation of acid in the insulating oil. The transformers will be connected to a system which is earthed as follows :-

300 KV System - Solidly earthed 132 KV System - Solidly earthed 33 KV System - Earthed through resistors of 39 ohms and 24 ohms for 45 and 75 MVA transformers respectively. 11 KV System - Earthed through resistors of 8 ohms and 10.5 ohms for 132/11 KV and 33/11 KV transformers respectively. Over voltage can occur due to exposure of the system to lightning and switching

surges. The neutral shall be insulated for system line toline voltage, except for 300/132 KV transformers where the neutral shall be insulated for phase-to-earth voltage.

5.15 On - Load Voltage Control :

Where on-load tap change is specified, the transformers shall be provided with ON-LOAD TAP CHANGE equipment to vary the effective transformation ratio without producing phase displacement. The tap change shall be effected on the high voltage winding. The transformer tap change equipment control shall be of the Dummy Master and Follower Type i.e. each group of transformers change simultaneously. Provision shall be made for a Dummy Master to control three or four transformers in each group.

The oil in the chamber housing the tap changer selector switch may be in communication with the oil in the main transformer tank, but the tap change circuit making and breaking switch shall be accommodated in separate oil filled chamber separated from the main transformer tank. The duty rating of the switches shall have a continuous maximum rating of the transformer and shall give trouble free operation under Kuwait Conditions. Limited devices shall be provided to limit the operation of switches to the range of tapping specified.

The tap-changer shall be of the fast resistor type and shall be continuously rated for operation under Kuwait Conditions and at the extreme positions of the tap-change winding. The equipment shall be designed to ensure that when a tap change has commenced it shall be completed independently of the operation of the control relays or switches. In the event of failure of auxiliary electrical supply during a tap change or any other contingency, which would result in the tap change not being completed, approved means shall be provided to safe-guard the transformers and auxiliary apparatus.

The equipment shall be arranged for operation as desired giving the following selections:-

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a) On-load automatic group operation from the master control. b) On-load manual remote group operation c) Individual automatic operation of each transformer d) Individual manual remote operation of each transformer e) Individual manual hand gear operation of each transformer f) Individual local electrical operation of each transformer g) Any one transformer as individual and the other two/three in parallel The equipment to be supplied by the Tenderer shall be arranged to comply with

the following:- 1. The hand gear operation of mechanism shall be interlocked to prevent the

electrical motor drive operation while the hand gear is in use. 2. It shall not be possible for any two electrical points to be in operation

simultaneously. 3. Operation from any control switch shall cause one tap movement only unless

the control switch is returned to the Off position between successive operations.

4. All electrical control switching and hand operating gear shall be clearly labelled to indicate the direction of tap change.

5. The local control switches and other apparatus shall be mounted inside the marshalling kiosks.

6. A mechanical tap position indicator shall be fitted on the transformer and shall be visible from ground level. A device for registering the total number of tap change operations and a hand reset register device for counting tap change operation between periods of maintenance shall be fitted.

7. A remote indicating device shall be provided for installation in the control room. The device shall indicate the tap positions and shall be scaled 1-21.

8. The tap-change drive mechanism shall be provided with a separate contact row with 21 positions for remote supervisory indications. The contacts shall be potential free and wired to the telemetry cabinet without the insertion of tap-position transducer or resistance box, since the tap positions are required to be signaled to the National Control Centre as indications and not as measurements.

9. The automatic voltage regulation shall be initiated by means of voltage regulator relay. This relay shall close the “Raise” or “Lower” contacts when the voltage falls or rises by an amount equal to a preset voltage deviation valve. A time delay element shall be provided to give a variable setting range of 20 to 120 seconds.

The response time should be inversely proportional to the voltage deviation. In case of severe voltage drop under fault conditions of the high voltage system the regulator should lockout through no-volt contacts by means of voltage-setting adjustable in the range between 70% and 90% of the desired voltage.

The sensitivity of the relay shall be adjustable between ± 0.5% and ±3% either variable or in steps.

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10. In the event of the transformers forming a group and operating in parallel

getting out of step due to faulty tap change operation, a device shall be connected in the control system to make inoperative the automatic "Tap Change". This device shall set off an alarm to indicate the condition electrically at a remote point. The device shall be of the hand reset type.

The device should also be provided with additional clean set of auxiliary contacts (potential free) and wired to suitable terminal blocks in the control panel or tap change control desk for use as an alarm to the "Remote Supervisory and Control Center" of the Purchaser’s system.

11. Out –of-step relays of tap changes should have an adjustable time-lag of 0.20 seconds.

12. Step-by-step description of operating sequence should be given for all automatic tap – change control with the aid of a comprehensive schematic drawing.

13. A warning lamp should be connected to the control system to indicate that tap-changing is in progress.

14. Tap-changing will be transmitted to the “Remote Supervisory and Control Center” of the Purchaser for “Data Logging Purchases”. This applies when transformer is set on manual and either set on individual or master in case of parallel with other transformers. Details shall be subject to the purchaser’s approval. All necessary wiring for the above should be brought to a suitable terminal block in the control panel.

15. The tap-changing driving mechanism shall be fully rated for the worst temperature conditions in Kuwait. The summer sun temperature causes heating of surfaces exposed to the direct sunshine as follows:-

Assume a cube with surfaces on the Top, North, South, East and West sides

:-

Top side maximum average temperature : 70 oC West side maximum average temperature : 63 oC South side maximum average temperature : 60 oC East side maximum average temperature : 55 oC North side maximum average temperature : 52 oC

All motors, contactors, contactors, clutches and brakes shall be designed to give trouble free operation and shall be robust construction to prevent distortion due to variations in temperatures that can occur in Kuwait during the year. The contactors shall have silver plated contacts and where necessary, shall be of the self-wiping type. The current carrying capacity shall be derated to 80% selection switch chamber and the conservator tank with the latest relevant B.S.S. Tenderers shall state the BSS and Kuwait Ratings in their offers.

Similarly, cables shall be derated to 70% of the BSS rating. 5.16 Off-Load Tap Change :

Where off-load (off-circuit) tap change is specified, the transformers shall be provided with “Off load Tap Change” equipment to vary the effective transformation ratio without producing phase displacement.

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The tap change shall be effected on the high voltage windings of the transformers. The range of the tap change and the number of steps and the size of each step shall be as specified in the “Details of Equipment”.

5.17 Main Tank:

The main tank shall be designed to house the transformer core and windings and arranged to prevent any movement of the core structure inside the tank. Provision shall be made to enable the core to be lifted out with case for maintenance inspection.

The tank shall be of mild steel plate construction of adequate dimensions braced and reinforced where necessary to prevent any distortion due to transportation, lifting, internal pressure, and temperature variations.

The top of tank shall have provision to give access to terminations of windings, earthing points…etc, without completely draining the tank of oil.

Each transformer tank shall be fitted with suitable skids for mounting on pre-prepared concrete foundations provided. Where transformers with wheels are provided, necessary rails and fixing clamps shall be provided at no extra cost.

The whole of the tank and fittings shall be sand blasted inside and outside to remove all scale and rust before painting. The inside of the tank shall be painted with an approved oil resisting varnish. The tank shall be provided with hauling lugs of adequate strength for withdrawal of the transformer in an out of the transformer bay.

One set of the necessary steel ropes, slings, tackles, jacks required for erection shall be provided.

5.18 Jacking Lugs:

Each transformer shall be provided with at least four jacking lugs located near the four corners of the transformer tank. The lugs shall be approximately 50cms above the ground level.

5.19 Conservator:

A conservator tank shall be located conveniently on the top of the tank. Suitable oil gauges shall be provided at each end which can be easily read from the ground level. The temperature range to be expected under Kuwait’s conditions in the open is –6 o C to 84 o C.

The conservator tank shall be of two sections (one for main tank and the second for the tap-changer). Each is provided with filling cap, drain and oil sampling valve device.

The pipe connections from the conservator to the main tank and tap change selector switch chamber shall be designed to have smooth run without sharp bends.

All pipes connected to the conservator tank shall protrude at least five cms above the bottom of the tank.

The oil level gauges shall be of the magnetic type with contacts for local and remote supervisory low oil level alarm indications.

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5.20 Cooling Radiators:

The banks of cooling radiators of the transformers shall be designed and arranged so that they are detachable from the main tank for purposes of transport. Valves shall be provided to shut off the oil leaving the main tank in to the cooling tanks. Air vent holes and drain plugs shall be provided on the banks to facilitate filling and draining of the banks on site. The tube bank shall be connected to the main tank by bolted flange joints.

5.21 Valves:

Drain valves shall be provided to completely drain the main tank, the conservator tank, the tap change apparatus chambers, cooling tube banks and disconnecting link chambers.

Set valves with clearly marked position indicators and padlocking facilities shall be provided between:

a) The main tank and conservator. b) The conservator and tap selection switch chamber. c) The conservator and each cable disconnecting link chambers. d) Between main tank and cooling tube banks. Oil sampling valve device shall be provided at suitable points on the main tank,

the tube banks and tap change selection switch chamber, and the conservator tank. 5.22 Explosion Vent:

An explosion vent shall be provided on the main tank and arrangements shall be provided to prevent ingress of rain water and sand when the relief diaphragm is ruptured. When metallic diaphragms are used, then every protective measure must be taken to have them not in contact with polluted atmospheric conditions. Alternatively, pressure relief device can be used with auxiliary contacts wired for local and remote alarm indication.

5.23 Breather:

Each portion of the conservator vessel shall be fitted with Silica Gel Breather with replaceable elements. The breather shall be arranged at such a height that it may be readily accessible from ground level and suitable observation window to be provided in the breather.

5.24 Earthing Terminals:

Suitable earthing terminals for earthing the tank structure shall be fitted close to each of the four corners of the tank so that connections to the earth terminals can be make to suit local conditions.

5.25 Gaskets & Joints:

All gaskets used for making oil tight joint shall conform to B.S. AU 120/1966 and B.S. 3063/1965 as applicable, taking into account Kuwait’s temperature conditions. A sample of gaskets material together with technical data shall be submitted for approval. All power transformers rated 15 MVA and above should be provided with ladder for easy climbing for maintenance purpose. This ladder

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should be detachable type but should be attached to each transformer. 5.26 Rating and Diagram Plates:

Each transformer shall be provided with substantial brass or stainless steel diagram and rating plates and shall give all information relating to the transformer and cooling medium.

The following information shall be included:- Rating in MVA or KVA Temperature rise by oil oC Temperature rise by resistance oC Volts at no load and normal tapping : H.V. Side ---------- L.V. Side ---------- Current at rated capacity and normal tapping : H.V. Side ---------- L.V. Side ---------- Impedance voltage at normal ratio % Short circuit current : H.V. Side ---------Amps. L.V. Side ---------Amps. Duration of short circuit current : Seconds Number of phases Diagram of connections Manufacturer’s Serial No. Frequency Vector group reference and diagram Weight of oil Total weight of transformer Quantity of oil in liters Year of manufacture Purchaser’s name and address The plates shall not be less than 2.5 mm thick and the marking shall be engraved

thereon and the background being filled in black. 5.27 Disconnecting Link Chamber:

The winding terminals of the transformers other than station transformers shall be arranged to be brought out to the cable termination boxes through a separate oil filled disconnecting link chamber. Each camber shall be connected to the oil conservator by means of pipes not less than 12.5mm I.D. and fitted with a control valve.

Each chamber shall be provided with a draining plug, a filling plug and an air vent plug. A suitable earth terminal shall be provided to enable either the transformer winding or cable terminations to be earthed during high voltage tests.

The disconnecting chambers for high and low voltage sides shall be completely separated from each other. The link chambers of the 275 kVA and 132kV windings shall be separate for each phase and pipe connections to the conservator shall have suitable valves and gas relays. Detailed drawings shall be submitted for approval.

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5.28 Cable Boxes:

Except where otherwise specified in the “Details of Equipment” cable end boxes of the oil filled type shall be provided on the transformer for high voltage side. For low voltage side the cable end boxes shall be either liquid compound type or unfilled type (air type) depending upon the type of cables used. The design and arrangement of the boxes shall meet the requirements of the cable manufacturer. The boxes shall have suitable filling caps, air vents, expansion domes, brass wiping glands and cable bedding clamps. Compound draining plugs of ample dimensions shall be provided. Fully detailed drawings shall be submitted for approval of the Purchaser.

The design shall be such as to facilitate any jointing with particular attention to the minimum bending of cores and fitting of cable clamps or lugs. The transformer external terminals shall be fitted with flexible links and solid cast brass lugs or clamps to receive the specified sizes or copper conductors. Cable supports and clamps shall be fitted below the boxes. The cable shall be arranged for vertical entry of cables from bottom. The brass wiping glands shall be fully insulated when single core cables are used Plastic oil compound level gauges are not acceptable since it suffers from discolouring and cracking due to high temperature.

5.29 132 kV Outdoor Bushing:

Where specified, outdoor conductor type bushings shall be provided on the transformer. The bushings shall be oil filled and arrangements shall be made to prevent the oil in the bushing communicating with the transformer oil. Each bushing shall be provided with an approved type of oil level indicator and fitted with arcing rings or horns of an approved type.

Outdoor insulators and fittings shall not be affected by atmospheric conditions, proximity to the cast, dust and sand acid and alkaline fumes.

The bushings shall be oil tight and shall comply with the arrangements of B.S. 223. The bushings shall be complete with all the necessary line or busbar connectors. The leakage distance shall not be less than 4.8 metres and the impulse withstand level shall not be less than 650kV.

5.30 SF6 Tubing:(Where Specified)

Where specified, SF6 tubing shall be supplied for connection between the 300kV and 132kV switchgears and the disconnecting link chambers of the 275/132kV and 132/33kV transformers.

The tubing shall be SF6 gas insulated complete with tubular bus-bar conductors, connections between sections of bus-bars separating cast resin cones between adjacent compartments respectively, the oil in the disconnecting link chamber with safety measure for proper sealing between oil and gas. Suitable gaskets preferably of the two ‘O’ ring type to be provided. The tubing shall be complete with various types of enclosures to suit any passage between the equipments and to be complete with flanges, bellows, piping, connections and valves and pressure switches for gas filling, gas pressure monitoring.

The necessary supporting structures and any other fittings to render the work complete in every respect.

Full details of such arrangement must be submitted for approval by the Purchaser.

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5.31 Buchholz Protection:

Double float buchholz protection device shall be provided for the main tank and a gas relay for the tap change switch compartment. The buchholz and gas relays shall be electrically connected to trip and alarm relays located on the switchgear remote control panel. In case of segregated tap change switching chambers for the three phases, three gas relays will be provided.

The buchholz device shall be inserted in the pile work and provided with suitable valves on both sides of the devices to facilitate easy service.

Unless otherwise approved, by-pass with control valves shall be provided to enable oil to by-pass the buchholz device during oil filtration.

The buchholz device incorporate a test cock for testing purpose. Each substation shall be provided with a suitable foot operated air pump together

with terminal adaptors for testing of the Buchholz as well as other gas relays used on the transformers. The cost of such shall be included in the tender price.

5.32 Forced Air Cooling Fans:

These shall be operated by electric motors. The motors shall be continuously rated for Kuwait worst temperature conditions and shall be vermin, water and dust proof.

The transformers shall be capable of operating continuously at full load under worst temperature conditions encountered in Kuwait and without the temperature rise exceeding those stated in clause 5.2 with only ¾ of the number of blowers in operation, to allow for the maintenance of the blowers without reduction of load.

415/240 volts, 50Hz supply shall be used for the above. The above blowers shall be automatically switched on when the transformers

temperature exceeds a pre-determined value and switch off automatically when the temperature falls below a pre-determined value. Clean contacts (potential free) shall be provided and wired to give “Blower running” indication at the Supervisory and Control Centre. Further, blowers supply voltage failure and fan trouble alarm should be provided for local and remote supervisory indication.

All motors shall be of the totally enclosed, squirrel cage, fan cooled, direct starting type. The motors, control gear and auxiliary apparatus shall be or robust construction insulated with class ‘B’ materials and in accordance with BSS.2613 including dimensional standard where stated, unless otherwise specified herein. Arrangement of the control gear for auto and manual starting, selection of fans for operation will be entirely to the satisfaction of the purchaser.

5.33 Marshalling Kiosk:

Each transformer shall be provided with a marshalling kiosk located adjacent to the transformers. The kiosk shall be of the outdoor type of sheet steel construction fitted with two access doors and one after the other. Alternatively, the kiosk may be mounted on the transformer. The kiosk must be dust, damp, rain and vermin proof and shall be designed for the temperature conditions in Kuwait. The front access doors shall be fitted with wire reinforced glass inspection panels. Locks and handles linked with bolts shall be fitted to doors. If the tenderer prefers to provide the marshalling kiosk with one door, the sealing of such door should provide a degree of protection of IP65 in accordance with IEC:144.

The kiosk shall accommodate all the following:

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1. Transformer oil temperature indicator. 2. Transformer winding temperature indicator 3. Terminal blocks and test links for (1) and (2) above 4. Local tap change selector and control switches 5. Marshalling terminal blocks for connections between transformer auxiliaries,

remote control panel, C.T.s and V.T.s and marshalling kiosk. 6. Control switches, fuses, protective device associated with tap change motor

circuits which normally cannot be accommodated in “Tap Change” motor drive compartment.

7. Equipment associated with blower controls. 8. The kiosk shall be provided with heater elements suitably controlled by a

switch, temperature and humidity relay to prevent condensation during high humidity periods.

9. The control cabinets for O.L.T.C. drive, fan control, oil level, winding temperature etc must be brought down to man-height level or a platform permanently installed has to be provided for easy checking, measuring…etc.

5.34 Instruments:

a) Winding temperature indicator calibrated to show the temperature of the hottest region of the windings shall be provided. The device may be of the type comprising a current transformer, heating coil, hot oil pocket, temperature measuring and arranged to produce the desired relationship between winding temperature and hot oil temperature through mercury/liquid filled Bourdon and capillary tube, calibary tube of oil & winding temperature power transformers should be provided with suitable cover to protect against mechanical damage and direct sun.

The indicator shall be fitted with two sets of fixed and moving contacts, one for “trip” and one for “alarm” adjustable to close between the range of 60oC to 120o C. These contacts shall be of the heavy duty type mercury switch re-open when the temperature has fallen not more than 10 o C. Two separate contact circuits, one for “alarm” and one for “trip” shall be provided for connection between devices and control board. Facility for manual operation of its mechanism movement for testing purposes should be provided in any convenient form eg. an outside projecting knob hand access with a pointer at the remote end.

The maximum temperature pointer shall be incorporated with the indicator to show the highest temperature reached and arranged for hand re-setting.

It is to be noted that the indicator only is allowed to be installed in the marshalling kiosk, all other components shall be installed on the top of the transformer tank.

b) Oil Temperature Indicator:

A dial type instrument together with mercury/liquid filled capillary and Bourdon tubes to indicate the temperature of oil in the hottest region of the main tank shall be provided.

The indicator shall be fitted with two separate sets of fixed and moving contacts one for “Alarm” and one “Trip” adjustable to close between the

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range of 60 o C to 120 o C. The contacts shall re-open when the temperature has fallen down not more than 10 o C.

These contacts must be of the heavy duty type mercury switches and should be equipped (as in the case of the winding temperature indicator) with facility for manual operation of its mechanism movement for testing purposes.

Two separate circuits shall be provided between the devices and the control board. A maximum temperature pointer shall be provided to show the highest temperature reached and shall be arranged for hand re-setting.

5.35 Tender Analysis:

The cost of the transformers and their annual losses will be taken into account for the determination of the successful offer.

The capitalization will be based on the following assumptions: Interest on capital 10% Capitalization period 20 years Price of energy loss KD0/029 per Kwh Demand Factor 0.65 Loss load factor 0.3 a) Transformer’s energy 8760 x Iron loss per year

b) Transformer’s energy 8760 x Loss load factor (demand factor) 2 x copper loss (F.L) copper loss per year

c) Total energy losses (a) + (b)

d) Present value of losses 8.51 (a+b) x price of energy per KWH

If the acceptance tests of the transformers show that the actual losses exceed the values stated in the schedule of particulars and Guarantees, the excess total losses (c)" will be capitalized according to the above assumptions and the sum thus obtained deducted from the money due to the contractor as a penalty. For this purpose no tolerance will be allowed on the figures stated in the schedule of particulars and Guarantees. At any rate, the actual losses should not exceed the figures stated in the schedule of particulars and Guarantees by more than the tolerances given in BSS.171.

NOTE: The losses to be stated in the schedule of particulars and Guarantees shall be given without tolerance.

5.36 Transformer Fire Protection:

The power transformer shall be provided with a water fire fighting system. This water system shall be of the high pressure type, consisting mainly of water reservoir of steel with suitable lining and adequate capacity sufficient for putting out fire on at least one of the biggest size of transformers. However, in case the blast walls are not specified between transformers and will not be provided, the capacity of the reservoir shall be sufficient for putting out the fire of at least two transformers. The reservoir shall be fitted with the necessary water level and pressure gauges and wired to alarm relays located in the control room, for local and remote alarm indication at the Supervisory Centre.

For water supply to this reservoir two water pumps, one stand-by to the other shall be provided, both pumps shall be suitable for automatic starting in case the one in service is out of order. For maintaining air pressure over the water in the reservoir, two air compressors (one standby to the other) shall be provided and shall be

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suitable for automatic starting. The fire fighting system shall also cover the supply, erection, test and commissioning of the necessary piping (which will be of the ring system), valves of all kinds as needs, nozzles, fire detectors and any other fittings necessary for putting out fire on or within the transformer enclosure. Means of periodical checking and maintenance have to be provided. Piping connection with valves to be made suitable for either water city network or by water tanker for supply of water to the water reservoir, these connections have to be located on the boundary wall at the main gate. Full details of the proposed arrangement shall be subject to the approval of the Purchaser.

The material selection for the fire fighting equipment, i.e. pumps, pipes, tanks, valves, ..etc should be compatible with the water quality available which is highly corrosive in nature. A typical water analysis is as shown in the following table:

CHEMICAL ANALYSIS OF POTABLE WATER

Parameters Concentration mg/L

Conductivity μ ohms cm –1 466 PH 7.6 T.D.S 246 CO3 0 HCO3 12 T.Alkalinity (CaCo3) 10 SO4 79 Cl 63 Ca 24 Mg 9 Na 39 K 1.2

The internal surfaces of steel tanks must be prepared by blasting prior to coating in

accordance with the “Steel structure painting council (USA)”. Standard S.S.P.C. Grade SP10 (Swedish Standards Sa 2½) Internal surfaces of

tanks shall then receive three coats of coal tar epoxy (Hempel 1513 or equivalent or better), amounting to a total dry thickness of 375 microns. The minimum total dry thickness should not be less than 300 microns.

All pipes used for fire fighting system including connections from water tanker and KFB (Kuwait Fire Brigade) shall be of the ductile iron type with restrain joints of the Kubolock – T type of M/s. Kubota of Japan or similar.

However, the following shall be noted: 1) The capacity of main water reservoir (tank) shall be based on a discharge rate

of not less than 15 litr/min/sq.m. of projected area of a rectangular prism envelope for the transformer including radiators and conservator and water spray shall be sufficient for putting out the fire and cooling the transformers so that no re-ignition will occur. In addition to the main tank a reserve outdoor water tank for fire fighting shall also be provided. This tank shall be of the same water capacity of the main tank and shall be suitable for connection to city water main water tanker and Kuwait Fire Brigade inlet pipe. The details shall be subject to MEW approval. One common water supply connection for fire brigade inlet for direct spraying over transformer

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on fire to be provided. 2) The minimum pressure at the nozzle shall be 5kg/sq.mm. 3) If the proposed system requires priming for the fire pumps then priming

pump and auxiliary tank shall be provided for this purpose and the price of such shall be included in the tender.

4) During operation of the fire fighting system (for putting out the fire and cooling the transformer) the air compressor shall operate automatically to keep the required air pressure in the water reservoir during this period.

5) Manual operation of each pump and compressor shall be provided for transformer fire fighting system testing purposes. Shrouded push button will be provided for each transformer bay. Discharge of water will stop after 0.25 minute through and adjustable timer.

6) A group of any one set of detectors in each transformers housing shall be arranged when actuated, to instantaneously operate the water system which in turn will trip both H.V. and L.V. circuit breakers of the transformer on fire.

7) Strainers shall be provided to prevent foreign particles and dust from reaching the nozzles.

8) Automatic drain valve to drain the left over water in the pipe after fire fighting has been completed shall be provided.

9) The capacity of air compressor shall be sufficient for charging the water tank within three hours.

N.B: 1. Testing fire fighting system of any transformer will trip both H.V.

and L.V. side circuit breaker automatically through pressure switch on discharge water pressure line.

2. Trip of transformer circuit breakers whether on fire or under testing will be affected from pressure switch mentioned above. Other transformers will remain in service.

3. Necessary provision shall be made to transmit low water level alarm and fire fighting system operated alarm to National Control Centre. Necessary annunciator shall be provided for these alarms in the fire fighting room and also in the control room. The location of these annunciators shall be subject to the approval of the Purchaser.

4. Emergency push-button to be provided for transformer fire fighting outside each transformer bay shall be provided with weather-proof metal housing to protect the glass cover from accidental breaking. The housing shall be completed with swinging type water-proof metal cover. The details shall be submitted for MEW approval.

5.37 Station Transformers :

Each substation shall be provided with two indoor type station transformers 11/0.433 KV of the cast resin type and constructed with copper or aluminium windings. If transformers with aluminium windings are offered, these should be provided with copper or brass terminal on both the high voltage and low voltage sides for connecting the 11 KV and 1000V copper cables. The copper terminals shall be connected to the aluminium windings in an approved manner. The casting process shall be carried out under vacuum to prevent partial discharge on the H.V. windings. The insulation class of H.V. and L.V. windings shall be class ‘F’ to be

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resistant against extreme temperature fluctuations. The transformers shall be safe against impulse voltage due to lightning or

switching surges and shall have adequate short circuit strength in accordance with B.S.171.

The transformers shall be protected against thermal overload by the use of two sensors embedded in the windings; one for alarm and the other for tripping. The connections for these sensors must be brought out to terminal strip.

For technical data requirements, tenderers are referred to the ‘Details of Equipment’ in this tender, however, the transformers shall be housed in a suitable sheet steel enclosure with all tap change terminals properly insulated. The thickness of the housing shall not be less than 3mm.

The enclosure shall be provided with skids and its has to be dust protected and vermin proof with degree of protection IP3 in accordance with IEC recommendation 144-1. However, measures for ventilation have to be provided. Regarding the L.T. cable box, this shall be tar epoxy resin filled otherwise as approved by the Purchaser. However, bare connections are not accepted.

5.38 Transformer Tests:

a) Routine Test1s:

The following routine tests shall be applied to all transformers in accordance with

BSS 171:

1. Measurements of winding resistance 2. Ratio, polarity and phase relationships 3. Impedance voltage 4. Load losses 5. No load losses and No load current 6. Insulation resistance 7. Induced over-voltage withstand b) Mechanical Tests:

The following tests shall be applied as routine tests on all transforms: 1) Bushings:

Each transformer bushing insulator shall be hydraulically tested using transformer oil to BSS 148 as the testing medium. The temperature of the oil shall not be less than 90oC initially and the pressure maintained at 0.7Kg/sq.cm for continuous period of 24 hours

with no trace of oil leakage.

2) Cable Boxes:

All cable boxes and disconnecting chambers shall also be tested as (1) above.

3) Transformer Tank …etc.

All tanks and oil filled compartments shall be tested for oil tightness by being completely filled with oil viscosity for greater than that of BSS 148 insulating oil at a temperature of 15oC and subjected for at least 12 hours to a pressure of 0.35Kg/Sq.cm. above normal pressure. No leakage of oil shall occur during the application of excess pressure.

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c) Type Tests: The contractor shall carry out the following type tests on one transformer of each

size:

i) Impulse Voltage Withstand Test:

This shall be applied, in turn on one leg of the H.V winding and one leg of L.V. winding and shall be applied in accordance with BSS 171 & 923. The test voltage shall be in

accordance with Table 8 of BSS 171: 1970.

ii) Power Frequency Withstand Voltage Tests:

This shall be carried out in accordance with BSS 1761 on one transformer of

each size.

iii) Temperature Rise Test:

This shall be applied in accordance with BSS 171 on one transformer of each type. The transformer shall be tested with its voltage control and cooling system where applicable. The test shall be carried out with 100% blowers running, with 75% blowers running and with no blowers running. The temperature rise shall not exceed the specified limits after taking into consideration Kuwait’s maximum ambient temperatures. This has to be carried out for both standard and Kuwait conditions.

d) Hydraulic Pressure Tests: (For 132/33kV, 132/11.5kV and 33/11.5kV Transformers only) The following test shall be carried out on one transformer of each size complete

with its conservator tank radiators and other fittings. The transformer shall be subject to a pressure of 0.35Kg/sq.cm above normal. The

permanent deflection of flat plates after the release of pressure shall not exceed the values specified in the following table:-

Length of Flat plate in cms Permanent deflection in cms Up to 100 0.50 105 to 130 0.64 135 to 175 0.80 180 to 200 0.95 205 to 230 1.11 235 to 250 1.25 255 to 305 1.58 310 to Above 1.90

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PART VI TECHNICAL SPECIFICATIONS NO.MEW/SS/6

CONTROL AND RELAY BOARDS

6. Switchgear Remote Control and Relay Boards:

All 132,33, and 11kV switchgear shall be supplied with its own remote control and relay boards which shall be equipped with the required control equipment, instruments, relays and all other accessories as detailed in this specification and outlined in the schedules. Each control and relay board shall have an earthing copper bar 30 x 5mm passing through along the whole length of the board and connected at the end/s to the inner earthing ring.

6.1 General:

The control and relay boards shall be of sheet steel construction with hinged and lift off doors at the rear complete and easy access to all equipment and terminals shall be from the rear. The boards shall be of rigid construction and free from vibration and distortion and shall be unaffected by changes in temperature. Access doors shall be fitted with integral handles linked to locking bolts and incorporating master keyed locks.

Interior of panels shall be painted white and have built in lighting controlled by switches actuated by the access doors and suitable for 240volts single phase A.C.50Hz supply.

Circuit labels shall be provided on the front and rear of each panel and the access doors. The front of the control board shall be arranged to form circuit panels to receive control switches, indicating instruments, relays, indicating lamps, semaphore, mimic diagrams and secondary wiring terminal testing blocks. Relay boards may be separated if specified in the “Details of Equipment”.

6.2 Main Features of Equipment:

The different equipment to be mounted on the control boards shall have the main features outlined below:-

i. Control switches for opening and closing the circuit breakers shall be of the pistol-

grip spring return barrel type, with provision for locking in neutral position, alternatively of the illuminated miniature discrepancy type. This also applies to the 132 kV isolators.

ii. Instruments shall be of the flush mounting type with black bezels. Ammeter and voltmeters can be either of the moving iron type or moving coil type and shall be of the square or rectangular pattern with dials to suit front size not less than 96mm kilowatt, kilovar and power factor meters shall be square or rectangular of similar size.

iii. Indicating lamps shall be provided with colored glass (not plastic) lenses to indicate failure of V.T. circuits, healthy trip, auto-trip alarm....etc. Lenses of material other than glass is subject of MEW approval.

iv. Semaphore position indicators used in conjunction with the mimic diagrams shall be of the normally de-energized type. The mimic diagram shall show the 132kV,33kV and 11kV bus-bars selector switches, circuit breakers, neutral earthing arrangements, power and station transformers.

v. Secondary wiring, testing switches (test/service switch) shall be provided on the front of each panel to facilitate testing of circuits of protective relays, Alternatively, testing sockets and the respective type of plugs can be provided. The test switches or sockets shall be mounted in an accessible position and suitably insulated and fitted with detachable dust and damp proof covers.

In case withdrawable type relays are offered where testing by a secondary injection

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can be carried out by the use of test plugs, the Tenderer shall include in his offer in lieu of the specified test switches the cost of supply of two plugs complete with leads and terminals suitable for each kind of relay in each substation. The test switches for Solkor (R) relays should not interfere with pilot cable.

vi. The boards shall accommodate all necessary transformer remote relay, indications and alarms visual alarms, with alarm cancellation and test push buttons shall be provided.

vii. The boards shall house all the transducers, remote control relays....etc. Thus it may be a better arrangement to supply a separate board to accommodate all the protective relays. Each section of the front of the control Board shall not accommodate the equipment of more than two circuits and the width of this section shall be not less than 700mm wide.

However, drawings of internal back of the front and side views showing each panel of the control and relay board, tap-desk ...etc with the equipment as will be finally installed shall be submitted for approval. Adequate spacing and clearances between auxiliary relays, contactors, various kinds of switches, annunciators, metering instruments, control cable runs...etc. should be available for easy accessibility to any piece of equipment and for safety of personnel. Manufacturing of these panels should not start prior to engineer’s approval.

Arrangement and calibration of various instruments shall be as given below:- 1. All ammeters should have proper size and calibration to read upto the twentieth of

the full scale from zero to maximum. 2. All 11kV voltmeters should be calibrated to read also 0.1kV difference from 9kV to

12kV. 3. All 33kV voltmeters should be calibrated to read 0.2kV difference from 30kV to

35kV. 4. All 132kv voltmeters should be calibrated to read 1.0kV difference from 120kV to

140kV. 5. All MW and MVAR meters should be calibrated to read a difference of 5MW or

MVAR for the whole range. 6. It is also essential to install all instruments and relays belonging to one circuit in one

panel vertically below the circuit name label, with clear identification between adjacent panel.

7. With the specified 11kV 30/1Amp current transformer for 250KVA transformer panel; a single phase isolating transformer with suitable ratio is required for connection in the secondary wiring of the 11kV C.T to feed the ammeter in the yellow phase so that the maximum current value passing through the ammeter under designed fault level will not exceed the thermal capability of the ammeter for three seconds.

6.3 Transformer Tap Change Control Desks:

The sub-station shall be provided with one/two/three panel transformer tap-change control desks which shall be located in front of the remote control board. Alternatively, these could be part of the control board, whichever is more suitable for the control room equipment layout.

In this case, each transformer control shall be housed in a separate panel or section of the boards. These desks shall be sheet metal construction with hinged and lift off doors fitted at rear. Each panel shall be arranged to house the following services:-

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a. Voltmeter b. Tap-change “raise” and “lower” control switch c. Tap-change position indicator d. Tap-change control selector switch or switches i.e. “hand” or “automatic” –

“individual” or parallel operation - “leader” or “follower” – regulation control ....etc. e. Tap- change motor trouble, emergency trip push-button f. Tap-change in operation indication lamp g. Out-of step relay and alarm h. Voltage regulation relay with time delay. i. All contactors, terminal blocks, small wiring and apparatus associated with the

remote control of tap-change equipment. j. Relay for the “raise-tap”, “lower tap” The voltmeter and tap-change position indicators shall be vertically mounted at the top of

the desks. Operation control and selectors shall be positioned on the inclined cover of the desks. The voltage regulator relay and out-of-step relay shall be positioned in the lower vertical face of the panel.

Alternative offers for miniature type control board or desk with miniature illuminated control discrepancy switches can be submitted. This should accommodate all instruments, indication, control switches..etc referred to under control panels in the “Details of Equipment” and those mentioned above. In this case, a separate relay board shall be supplied to accommodate the protection relays.

6.4 Synchronizing Panels: (If specified in the Details of Equipment Vol. II of this

Specification)

132kV control boards shall be provided with synchronizing panel mounted at one end. The panel to accommodate the necessary synchrony scope, voltmeters, frequency meters and selector switches. The panel shall also accommodate the synchronizing relay and the synchronizing by-pass. The synchronizing shall be drawn out and rotating type.

The synchronizing relay and the schemes proposed shall be subject to the approval of the purchaser.

6.5 Annunciator Block:

Window type annunciator board shall be provided at a suitable place on the control board with necessary alarm windows where alarms of Common Nature Equipment’s (such as battery charges, air compressors etc.) whether specified or found necessary for the whole substation shall be connected. In addition to the above, four windows as spare shall be provided in this block. These alarms should have auxiliary alarm contacts, which will be connected to substation general alarm for remote supervisory indication.

6.6 Frequency Shedding Relay:

For each 132/33/11kV substation, under frequency shedding relays together with the necessary master trip time delayed relays are to be provided along with 33kV control board and arranged to trip the 33kV feeders in case of supply failure. The technical specifications of these relays are also described under clause 6.7.11.

6.7 Protection:

Protection equipment shall be designed to provide discrimination between faulty and healthy circuits. All equipment shall remain stable during transient phenomena, which may arise during switching or other disturbances to the system.

Protection scheme specified shall include all necessary interposing C.T.’s and inter-tripping relays where necessary and whether these relays have to be installed locally and/or remotely of the far end of substations.

Full details of protection, synchronizing, inter-tripping scheme shall be submitted and

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shall be subject to the approval of the Purchaser. Each relay shall have a set of clean contacts (potential free) with holding time not less than

25m.s. which shall be connected to suitable terminals block in the control panel, to be used for telesignalling to the “Remote Supervisory and Control Center”. These terminal blocks shall be wired to the transfer terminal blocks cabinets.

6.7.1 Circuits and Protection: The circuit breakers will control the circuits detailed below:- 1) 132kV, 3/C, 300sq.mm or 630sq.mm O/F underground cable circuits. 2) 132kV overhead line circuits 3) 132/11kV, 132/33kV and 33/11.5kV power transformer circuits. 4) 11/0.433kV, 250KVA station transformer circuits 5) 33kV and 11kV underground cable feeder and overhead lines feeder circuits. 6) 132kV (single and double busbar) and 33kV (single busbar only) bus-bar zone

protection. 7) 132, 33 and 11kV bus-coupler and bus-section circuits. 6.7.2 132kV Underground Feeder Protection:

Main protection equipment shall protect each feeder by means of unit feeder protection using pilot cores between feeder terminals and shall match with the existing protection equipment at the other end of the feeders which is high speed solkor ‘RF’ feeder protection relays and associated apparatus manufactured by M/s. A. Reyrolle & Co., of England. The solkor ‘RF” relay shall be surge proof insulated for 15kV.

The distance between the two ends of circuit provided with the pilot wire feeder protection may be assumed to vary between 12kms to 15kms. Means shall be provided for the adjustment and this shall be stated in the tender.

i. The summation transformers and tuned relays shall be immune from operation by currents of frequencies other than system power frequency, i.e. 50Hz.

The protection shall be stable for through fault currents up to full 3-phase short circuit current and shall meet the requirements of M/s. A.Reyrolle & Co., of England and as given in their pamphlet No.1328.

The magnetizing curves of the current transformers for this protection shall be submitted for approval to check their characteristics and to match them with the C.T.s at the other end of the feeders. The purchaser shall approve in wiring the characteristics of these C.T.s before manufacture proceeds.

ii. Directional over current and earth leakage I.D.M.T.L. relays with characteristics of BSS 142 as back-up protection shall be supplied. These relays shall have a setting range of 50% - 200% in steps of 25% for the over current element, and a range of 20% to 80% in steps of 20% for the earth leakage element. The time multiplier shall be adjustable between 0 – 3 seconds at ten times the plug setting. The time multiplier settings shall be 0.1 to spotlessly adjustable or 0 – 0.5 divided into 20 equal parts. The over current relays shall be suitable for 90o connection.

The directional earth fault relay should have an inherent angle in the range of 40 o to 60 o. All protective relays shall have coils rated for 220v D.C. without the use of resistors for voltage dropping.

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6.7.3 132kV O/H Line Protection: a) Main Protection: 132kV feeder protective relays for use without pilot wires shall be of the directional

high speed distance type with carrier accelerated intertripping for first zone. The required relays shall have three directional impedance zones as a minimum. The protection shall operate selectively for phase and ground faults in the protected direction and adjusted time selected for each step. The reach of each zone shall be adjustable and the minimum and maximum length of feeder that can be protected shall be given in the data sheets. The necessary P.L.C. equipment for inter-tripping should be included in the contract. For each fault compensation factors should be indicated how such a factor be calculated and used to get accurate measurement of fault distance and accordingly false operation of healthy phases can be provided. Also for any kind of fault the mutual impedance and arc resistance effects should be allowed or it should be clearly shown how these will be compensated or considered when adjusting the various zones. The protective relay shall be provided with means to avoid operation due to hunting occurring on the system during abnormal conditions.

Full detailed calculations of the various zones and programme of testing must be submitted prior to commissioning tests. The protection shall provide for automatic high speed time delayed single shot enclosure for any type of fault. Selector switch to be provided suitable for 3 phase reclosure or non-reclosure.

Carrier current acceleration will be provided for inter-tripping the rear end C.B. having the fault occurring in its second zone. Provision shall be made to have no reclosure when circuit breaker opens through the control switch or it tripped-by the back-up protection.

Starting of impedance relays should be through under impedance relays together with either under voltage or over current relays which is subject to the approval of the Purchaser.

The protection relay proposed should be supported by technical literature, method of calculation of settings, testing procedure and instruction manual for operation and maintenance. A time chart should be provided to show minimum operational time of various relays and contactors upto issue of trip signal.

The relays should be fitted with auxiliary relays for carrier signal receiving transmitting and blocking as the case may be, cabling between the protection and the carrier equipment is included in the contract price. Each relays shall be provided with “Fault Locator” unit i.e. Distance Measurement to the fault. For each distance relay one independent fault locator will be provided. However, the necessary relays to compensate for the mutual inductance effect of overhead line circuits running in parallel with the concerned circuit shall also be provided.

b) Directional over current and earth leakage I.D.MT.L relays with characteristics to BSS 142 as back-up protection shall be supplied. These relays shall have a setting range of 50% -200% in steps of 25% for the over current element and a range of 20% to 80% in steps of 20% for the earth leakage element . The time multiplier shall be adjustable between 0-3seconds at ten times the plug setting. The time multiplier shall be divided as per clause 6.7.2 (b) above.

The directional earth fault relay should have an inherent angle in the range of 40o to 60 o. All protective relays shall have coils rated for 220V.D.C. Without the use of resistors for voltage dropping.

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6.7.4 Power Transformer Protection: a) Main Protection:

The main protection for these transformers shall be the biased differential type for phase and earth faults similar to “Duo-Bias Transformer Protection” of M/s. Reyrolle & Co., of England. The current transformers on the L.V. side shall operate satisfactorily with the current transformers or the H.V. side. In this respect C.T.s characteristics must be checked and certified by the relay manufacturers and this shall be subject to the approval of the Purchaser.

The secondary winding of transformer shall also be protected by means of restricted earth leakage protection. The four current transformers for this protection (3 for phases and one for neutral) shall be separate from these of the main protection. The relays shall be of the current differential type (Voltage operated relays not acceptable) and shall be highly sensitive to faults inside the protected zone and at the same time stable for faults outside the protected zone.

Tenderers may offer an alternative similar scheme for transformers protection and this will be subject to the approval of the Purchaser.

b) The combined neutral resistance earthing of the power transformers shall be protected by means of stand-by earth fault relay of the inverse time lag type.

The standard characteristics shall be based on that of an earthing resistor with a maximum short time setting of 30 seconds at the specified maximum earth fault current. The relays shall have current settings of 10% to 40% and time setting variable from 0-30 seconds at 100% rated current.

The relays should be arranged to trip all three transformers low voltage side circuit breakers simultaneously together with the neutral resistance earthing circuit breaker when this trip as a result of a persistent earth fault. Standby E/F relay tripping circuits to be connected through test links to facilitate the tests carried out at maintenance time.

c) In addition , the usual Buchholz, tap changer, winding and oil temperature protection for these transformers shall be provided.

d) Back-up Protection: Back-up protection on the high voltage side of the transformer shall use non-

directional overcurrent and earth leakage relays. These relays comprise two overcurrent units and one earth leakage unit.

The relays shall have the inverse definite minimum time lag characteristics ( I.D.M.T.L. ). The overcurrent units to have a current range from 50% to 200% in steps of 25% and time setting adjustable from zero to 3 seconds at the current setting. For earth leakage unit the current range to be from 10% to 40% in steps of 10% and time setting similar to that of overcurrent units having characteristics to BSS No. 142. The time multiplier setting shall be adjustable as per clause 6.7.3(b).

e) Interlocking and inter-tripping of the high voltage side circuit breaker/local break switch with the corresponding low voltage side circuit breaker of the transformer circuit shall be arranged such that :-

i. The H.V side circuit breaker cannot be closed unless the LV side circuit breaker and associate earthing switch are in the fully open position.

ii. The 11 KV bus-bar selection isolators cannot be closed unless the associated circuit breaker and 11 KV bus-bar earthing switch are both open.

iii. The low voltage side circuit breaker shall trip when the high voltage side C.B. or the load break switch is opened.

iv. The 132 KV transformer earthing switch can be closed only if the associated 132 KV isolator is open and the corresponding 11kV isolators are both open.

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v. The 11kV earthing switch cannot be closed unless the corresponding 132kV earthing switch is closed and the 11kV busbars isolators are both open and the 11kV circuit breaker is opened and withdrawn.

vi. When any of the transformer protective devices (i.e. transformer differential relays, over current and earth leakage relays, stand-by earth fault relay, buchholz and temperature device...etc) operate, these should be wired to trip the associated high and low voltage side circuit breakers.

6.7.5 Local 11/0.433kV 250KVA Transformer Protection:

Non-directional over current and earth leakage of the inverse current definite minimum time. The relays shall have a current range of 50% - 200% in steps of 25% for the over current elements and a range of 10% - 40% in steps of 10% for the earth leakage element. The time multiplier shall be variable from 0 – 3 seconds of the time the plug setting and shall have characteristics in accordance with BSS 142. The time multiplier shall be adjustable in accordance with clause 6.7.3 (b).

6.7.6 33kV Underground Cable Feeder and Overhead Line Feeder Circuits: a) Main Protection: This shall be of the unit feeder protection using pilot cable cores and shall be of the high

speed Solkor ‘RF’ as described under 6.7.2 (a) above except that the Solkor ‘RF’ relays shall be insulated for 5kV.

b) Back-up Protection: i. With 132/33/11kV substations, this will comprise non-directional overcurrent and

earth leakage relays. The characteristics shall be of I.D.M.T.L. type with range of settings, time multiplier to that specified under 6.7.3(b) above.

ii. With 33/11kV substations, the protection shall be of the directional O/C and E/L relays similar to that described under 6.7.2.(b) above.

Note: No instantaneous O/C or E/L tripping relay to be provided for 132 KV and 33 KV feeders, bus-coupler, bus-section and transformer circuits.

6.7.7 11 KV Underground Cable Feeder Protection : a. Each feeder circuit shall be protected by “Unit feeder protection” and shall match

the existing protection on the other end which comprises plain “Solkor RF” feeder protection system using relays and associated apparatus manufactured by M/s. A. Reyrolle & Co. The Solkor ‘RF” relays shall be insulated for 5 KV.

The ratio of current transformers shall be 400/IA, 15 VA capacity class X accuracy and they shall have characteristics matching transformers already connected to the system. Attention is drawn to the requirements for the satisfactory operation of Solkor RF protection, published by M/s. A.Reyrolle & Co., in their pamphlet No.1328 “Solkor Protective” under the paragraph “Current Transformers”.

The Contractor shall submit the “Magnetization Characteristics Curve” and a “Ratio Error Curve” under the burden conditions applying to the Solkor ‘RF’ protection cover the range of through fault current. The Purchaser shall approve in writing the characteristics curves for the current transformers before manufacture can proceed.

b. Back-up protection is required for all feeder panels of the switchboard. This protection shall comprise of non-directional over current and earth leakage relays of the inverse current definite minimum time type. The relays shall have a range of 50% to200% in steps of 25% for the over current elements and a range of 20% to 80% in steps of 20% for the earth leakage elements. The time multiplier shall be variable from 0-3 seconds at ten times the plug setting. The time multiplier shall be divided as per clause 6.7.2 (b) above.

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The current transformers for the “back-up” protection shall have a ratio of 400/1 or 5amps, 15VA capacity class 10P accuracy. A suitable switchboard pattern ammeter shall be connected in the yellow phase and scaled 0-460amps.

6.7.8 132kV and 33kV Busbar Zone Protection:

This type of protection is required only for the 33kV single busbar system 132kV both single and double busbar systems. The system of protective relays shall sense all types of faults that occur in the busbar zone only. Accordingly, the concerned busbar protection relays shall issue trip signals to all the circuit breakers feeding into the bus faulty zone.

The 132kV busbar zone protection relays shall be of the fully transistorized type complete with built in automatic testing device for periodical testing. However, the necessary terminal block arrangement for secondary injection testing has also to be provided. The protection shall be provided with an automatic testing facility in addition to monitoring of the relay output so that an alarm is signalled locally and remotely in case of mal-functioning by the relay without causing false tripping.

The busbar zone protection scheme shall be of the low or moderate impedance type using current balance.

Relays for supervising of secondary wiring shall be provided to avoid false tripping and to give alarm for rectifying the trouble. For this protection separate core on the current transformer shall be provided.

The proposed scheme shall be submitted for approval by the Purchaser. Busbar protection and circuit breaker fail protection scheme should be provided both with

test trip links and test switches for individual bay and complete zone testing. For 132kV System only: Means shall be provided to indicate without dismantling which section of the busbars has

a short circuit faults such a fault occurs to enable its quick isolation and restoration of supply.

If for any reason the bus-bar protection fails to isolate faulty zone or any breaker feeding such zone or any breaker feeding such zone fails to trip an inter-trip arrangement shall be provided to trip the far end circuit breakers of the connected feeders at the remote end substations and the low voltage side circuit breaker of transformers if connected to the faulty zone. All necessary inter-tripping relays for receiving and sending trip signal shall be provided. Regarding remote end of cable underground circuit, similar equipment shall be provided at the far end when specified in the details of equipment.

For the above purpose the necessary inter-tripping high frequency relays shall be included in the offer. However, for 132kV feeder circuits where pilot cable inter-tripping cores are to be used, supervision relay shall be provided to monitor the healthy condition of these cores and to give alarm in case of damage, in addition an alarm also to be signaled locally and remotely if the auxiliary supply for supervision fails.

132kV Circuit Breaker Failure Back-up Protection: The protection which is required for all 132kV circuits should inter-trip all feeding local

and remote circuit breaker in case this protection is actuated. However, if a circuit breaker is isolated from both sides then testing of this protection should not cause inter-tripping of other circuit breakers.

6.7.9 132kV, 33kV and 11kV Bus-Coupler & Bus Section Circuit Breakers: The protection shall be non-directional over current and earth leakage protection similar to

6.7.6 (b-1) above, except for the current transformer ratio and details.

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N.B.i) All over current and earth leakage relays shall have characteristics in accordance with BSS

142. ii) Wiring diagram for differential and restricted earth fault protection of transformers has to

be submitted showing all main current and matching transformers with marking of bus and line side and vector group of each and numbering of relay terminals connected.

6.7.10 Proposed System of Selective Operation of Circuit Breakers for various locations of Faults shall be as follows:- This is only applicable for substations equipped with load break switches. a) Faults of the 132kV Cable Feeders: These are mainly sensed by feeder protection which should trip the busbar section

C.B.'s and the 11kV C.B.s controlling the 132/11.5kV transformer connected to this section of 132kV busbar.

b) Fault on Bus-Bar: i. Fault on One Bus-Bar Section Associated with Feeder of End Section: Busbar protection shall trip the busbar section C.B. and issue trip signals

through surge proof intertripping relays to the 132kV C.B. at far end as well as the 11kV C.B. of the connected transformers.

ii. Faults on Middle Section of the 132kV Bus-bar: Busbar protection shall be arranged similar to (i) above except that it should

trip both bus section circuit breakers. c) 132/11.5kV Transformer Faults: i) The operation of any of the protective relays for the transformers associated

with end sections feeders shall trip the bus-section C.B. as well as the associated 11kV C.B. This also shall trip through surge proof inter-tripping relays the corresponding 132kV circuit breaker at the far end.

ii) The operation of any protection relays of the 132/11.5kV power transformer connected to the middle busbar section shall trip the corresponding 11kV circuit breakers and the two bus section circuit breakers as well as to send tripping signal (through surge proof intertripping relay) to trip the 132kV circuit breaker at remote end of the middle section feeder.

NB All 132kV circuit breakers shall be provided with “Fail-to-trip” protective relays.

6.7.11 33kV Feeder Circuits:

Along with the 33kV switchgear in 132/33/11kV & 300/132/33kV substations, two under frequency relays together with the necessary time delayed the frequency relays shall be provided. The frequency relays are required for load shedding in case of loss of supply and shall be erected on the 33kV remote control board with one on each end. The auxiliary contacts of these relays shall be in series connection and actuating the associated time delay relay erected on the bus-coupler control panel which will be wired to trip the 33kV feeder circuits through its auxiliary contacts which will be 10 pairs at least.

The frequency relay shall preferably be similar to type FTG of M/s GEC make and shall be of draw-out, flush mounting type with the following main characteristics:-

Setting : 47 to 50.5Hz in 0.1Hz step Contacts : 3 pairs of normally open self reset contacts. Voltage setting : 240 volts AC 50Hz D.C. supply : 240volts Operation indication : Hand reset flag indication Regarding the master-trip relay, this shall have the following data:- Time-lag setting range : 0 - 20 seconds Re-setting time : 0.1 seconds

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Direction of the time lag : Delayed pick-up Kind of operating current : 240 volts D.C. 6.7.12 Protection Relays:

Unless otherwise stated in the specifications, all protection relays shall be manufactured by one of the companies as mentioned in schedule A-1 of Approved Suppliers/Manufacturers.

However, it is upto the tenderer to select the relay out of the approved manufacturers for reliable delivery since no substation will be taken over without being complete with all relays and the contractor will be responsible for any delays arising therefrom.

6.7.13 Synchronizing: (132kV switchgear of major substations of voltage 132/33/11kV & 132/33kV) Synchronizing facilities shall be provided across the circuit breakers and the following

requirements should meet with: 1. The synchronizing circuit must be established before the incoming circuit breaker

can be closed. 2. Voltage transformer secondary shall not be paralleled. 3. The number of plugs shall be a minimum and preferably one only 4. One synchronizing operation allowed at one time in the whole substation, thus one

synchronizing key to be provided. A synchronizing relay shall be provided and so connected to prevent closing the open

circuit breaker if the phase separation of the running voltage and incoming voltage vectors are beyond pre-determined limit. A switch shall be provided to enable by-passing the check synchronizing relay when the synchronizing feature is not required.

The synchronizing scheme should allow for the running voltage bus wires to be always energized through auxiliary contacts of voltage selection relays from one voltage transformer at a time. Provision shall be made to telemeter the busbar voltage from the running bus by means of voltmeter transducer. Also from this auxiliary bus, the busbar live signal shall be arranged to be telesignalled to the supervisory centre for each busbar section. All the necessary relays contactors, wiring, etc. have to be provided.

6.7.14 General Notes: 1. Below every relay, contactor and miniature breaker, etc., there should be a label

fixed showing its functional name and the C.T. ratio in use for C.T.s with double ratio.

2. The polarity of current and voltage transformers and the corresponding terminal numbers on the connected relays must be carefully marked on the drawings so as to operate in the correct direction in case of fault occurrence.

3. For all electronic relays, a step-by-step description of the sequence of operation of the electronic circuitry with the aid of a signal flow diagram, giving the terminal number where such signals can be detected at various stages starting from input and ending at output. Also trouble shooting tables, blocks diagram splitting the relay circuitry in logic and binary blocks must be submitted for checking and approval by the Purchaser.

4. For automatic on-load tap changes, a step-by-step description of the sequence of operation and a time chart and relative schematic comprehensive drawings to be submitted.

5. The connection of the voltage coil of directional overcurrent and earth leakage relay shall be 90o. This means that R phase to be connected to B-Y voltage and B phase to R-Y voltage.

6. The tripping circuit of the stand-by E/F relay should also be connected through test links to facilitate testing.

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7. Proper control wiring identification ferrules ( sleeve type ) shall be provided at both ends of the control wiring. The wiring terminal shall be numbered with ring ferrules in such a manner that if a wire is connected between terminal block x2.6 and relay e5.3, then the wire terminal at x2 should read e5.3 and the wire terminal at e5 should read x2.6. This system shall be strictly adopted in preparation of drawings as well as various panels for easy tracing of the wiring. It is clarified that equipment and transformer tap change are not required to be ferruling of back to back system. However external wiring should follow back to back ferruling system.

8. All tripping relays located inside local control panels and relay panels which can cause tripping if touched accidently during maintenance shall be provided with additional safety covers, which, when necessary can be removed in case any testing or maintenance is to be carried out on these relays. In addition to this, a prominent and suitably worded caution label should be provided.

The maximum operating time allowed for tripping relays is 10ms. An evidence of suitability of the proposed relay/contactor to safe operation (i.e. no false tripping due to mechanical shock and vibration) has to be submitted. These tripping relays/contactors must be manufactured and tested in accordance with the IEC 255 (4 & 5) and BSS 142, 5992 as applicable.

6.7.15 Pilot Cable Supervision: (For 132kV & 33kV Systems) For pilot cable supervision, high frequency guard tone used with inter-tripping equipment

shall be utilized. The loss of this tone shall be transmitted to the control centre and shall mean either inter-tripping equipment faulty or pilot cable faulty.

To avoid occurrence of flash-over across the terminals in the marshalling cabinet, tenderers are requested to provide the necessary protective measures for terminal equipment as well as the operation staff against induced voltage due to phase-to-ground faults on the associated power cables.

For all pilot cable cores other than Solkor (RF) cores suitably rated surge arrestors approved by the purchaser shall be installed for protection of terminal equipment and operating personnel.

These surge arrestors are preferably installed in a separate panel located adjacent to the marshalling cabinet.

On the other hand the terminal blocks in the M/C, control cabling to control room and inter-tripping relays for the far end substation (where applicable) shall be insulated for at least 5kV & 15kV, for 33kV and 132kV systems respectively.

The cost of supply and erection of the above shall be included in the tender price, however, the arrangement shall be subject to the Purchaser’s approval.

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PART VII SPECIFICATION NO. MEW/SS/7

TECHNICAL SPECIFICATIONS FOR INDICATIONS, ALARMS, REMOTE CONTROL AND METERING IN SUBSTATIONS

PERTAINING TO THE SUPERVISORY CONTROL CENTRES

A. GENERAL: The Ministry of Electricity & Water has Supervisory and Remote Control Centers for its

network. The equipment covered by this specification shall include all the necessary provisions for the above purpose which shall be included in the tender price.

The Supervisory Control System comprises of the following: a. Status monitoring of circuit breakers, load break switches, isolators etc. b. Data gathering of volts, amps, MW, MVAR, F,T,H etc. c. Monitoring of trouble alarms. d. Supervisory remote control of circuit breaker, load break switches, isolators,

transformer tap changers, etc. e. Communications. f. Fast inter-trip PLC protection for OHL circuits. This tender includes the telemetry equipment itself associated with the above as a

separate part. However, this part shall include all the necessary equipment that have to be installed and wired at the substation to realize the monitoring of status, alarms, telemetry and telecontrol as detailed below hereafter:

B. Requirements for the Remote Control, Telesignalling and Telemetering in the Substations: The following remote controls, telesignalling and telemeterings are required for the

different types of equipment in each substation: 275KV, 132KV, 33KV, 11KV circuits and 275/132KV, 132/33KV, 132/11.5KV and 33/11.5KV transformers. I. Circuit Breakers: A. 275kV circuit breaker: This covers all 275KV circuit breakers for feeders, bus coupler, bus sections and

275/132KV transformers. i. Remote control : open/close ii. Status: - open/close - Supervisory/local - State of auto re-closure (in service or out of service for overhead line circuits only) iii. Alarms: For all: - Poles discrepancy alarm - Driving mechanism trouble alarm - Arching chamber pressure low alarm - Isolation pressure low alarm - Circuit breaker failure to trip protection alarm - Inter trip alarm - Bay SF6 gas pressure low trip - Over current relay trip - Earth fault relay trip For OHL circuits: - Distance protection “A” alarm - Distance protection “B” alarm

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- Underground cable low oil pressure alarm - Underground cable low oil pressure trip - Pilot cable fault alarm - Pilot cable supervision supply fail alarm - Distance protection “A” trip (main protection A) (with separate signal for each step)

- Distance protection “B” trip (main protection B) (with separate signal for each step)

- Auto reclosure operated. - Directional compensated earth fault relay trip. For Underground Cable Circuits: - Underground cable low oil pressure alarm - Underground cable low oil pressure trip - Pilot cable fault alarm - Pilot cable supervision supply fail alarm - Impedance protection “B” Trip (main protection ’B’) (with separate signal for each stage) - Solkor trip (main protection ’A’) - Impedance protection “B” Alarm iv. Metering: Feeders : MW and MVAR (with polarity) Bus-coupler ) Bus-sections) : Amps. Transformers 275/132KV : None B. 132KV Circuit Breakers: This covers all 132KV circuit breakers and load break switches for 132KV feeders &

reactors, bus couplers, bus sections, and 275/132KV, 132/33KV & 132/11.5KV transformers.

Note: Low voltage side of 300 MVA 275/132KV transformers will be housed either in a separate cubicle or in the 275 KV TTB in addition to the terminals in 132KV cabinet. CBO & CBC indications and MW & MVAR measurements will be connected separately to both terminal sets in proper order for double monitoring in future.

i) Remote control : open/close ii) Status : open/close Supervisory/local State of auto reclosure (in service or out of service for overhead line circuits) iii) Alarms : Poles discrepancy (for breakers and load break switches) alarm Driving mechanism trouble alarm Arching chamber pressure low alarm (for SF6 breakers) for

other types of breakers this signal is replaced either by low oil level alarm or vacuum disruption alarm or low air pressure alarm.

Isolation pressure low alarm Distance protection Alarm (for overhead line circuits)

Main protection trip operated by solkor for underground

cable circuits, by Duo Bias for transformers and by distance protection for overhead line circuits (with separate signal for each step)

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Inter trip (except for directly connected reactor) Over current relay trip Earth fault relay trip Underground cable low oil pressure alarm Underground cable low oil pressure trip Pilot cable fault alarm (for feeders) Pilot cable supervision supply fail alarm (for feeders) Auto reclosure operated (for overhead line circuits) Circuit breaker failure to trip protection alarm (for low

voltage side of 275/132KV transformers) iv) Metering: Feeders: MW and MVAR (with polarity) Bus coupler, ) Bus section ): amps. Transformers 275/) MW & MVAR (with polarity) double 132kV ): set (one for 300KV system and the other for 132KV

system) Transformer 132/33KV ) None Transformers 132/11.5KV ) None

C. 33kV Circuit Breakers: This covers all 33KV circuit breakers for feeders & reactors, bus couplers, bus section and

132/33KV & 33/11.5KV transformers. i) Remote control : open/close ii) Status : open/close isolated (withdrawn) supervisory/local iii) Alarms : Low air and high air pressure alarm (if compressed air

drive and/or air blast circuit breakers are used. This alarm for each bay has to be looped to the 33KV station compressed air supply fail alarm).

Auto-trip (all trappings due to operation of any of the protections have to be looped to this trip except for 132/33KV transformers)

Driving mechanism trouble, poles discrepancy, arcing chamber pressure and inter trip (for 132/33 & 132/11KV Transformer breakers only)

Underground cable low oil pressure alarm (for underground cable feeders & transformers)

Underground Cable low oil pressure trip (for 132/33KV transformers only)

Pilot cable fault alarm (for feeders only)Pilot cable supervision supply fail Alarm (for feeders only)

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iv) Metering: Feeders : Amps, volts Bus coupler & : Amps. Bus-sections Transformers 132/33KV : MW, MVAR (with polarity) Transformers 132/11.5KV : None D. 11kV Circuit Breakers: a) This covers the 11KV circuit breakers controlling 132/11.5 and 33/11.5KV

transformers: i) Remote control : same as for (C-i, ii & iii above) ii) Status : Except for cable low oil pressure alarm for: iii) Alarms : 33/11.5KV transformers iv) Metering : MW & MVAR (with polarity) Amps, volts. b) This covers all 11KV circuit breakers for feeders, bus sections, bus couplers and

11/0.415KV Station Transformers: i) Remote control : None ii) Status : open/close iii) Alarms : Auto-trip iv) Metering : Amps II. Isolators: A) 275KV Isolators: This covers all the line isolators, bus bar selector isolators and bus bar section isolators: i) Remote control : None ii) Status : open/close iii) Alarms : None iv) Metering : None B) 132kV Isolators: a) This covers all bus bar section isolators, Bus bar selector isolators and reactor

isolators connected in parallel to a feeder breaker: i) Remote control : None ii) Status : Open/Close iii) Alarms : None iv) Metering : None b) This covers the line isolators for 132KV mesh type bus bars and Bus Bars having

one & half breaker system (the two breakers controlling the circuits are treated in such systems as bus section breakers):

i) Remote control : Open/Close ii) Status : Open/Close iii) Alarms : Same as I-B (iii) except poles discrepancy Alarm and

Arcing chamber pressure low Alarms iv) Metering : Same as I-B (iv) above NB:- The remote control open and close is to be wired through the normal interlock

with the breakers, earth switches and the local/remote switches of the breakers controlling the respective bay for (b) above.

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c) 33KV and 11KV isolators: This covers the bus bar section isolators and reactor isolators connected in parallel

to a feeder breaker. i) Remote control : None ii) Status : Open/Close iii) Alarms : None iv) Metering : None III. Bus Bars: A. 275kV Bus Bars: i) Remote control : None ii) Status : Bus Bar live (one indication for each bus bar section) iii) Alarms : Bus Bar protection trip for each section of a busbar Bus Bar protection Failure Alarm Bus Bar gas pressure low Alarm Bus Bar gas pressure low Trip iv) Metering : KV – one measurement for each bus bar section Frequency B. 132kV Bus Bars: i) Remote control : None ii) Status : Bus Bar live (one indication for single bus bar

substations and two indications for double bus bar substation for 132KV voltage level irrespective of number of bus-section).

iii) Alarms : Bus Bar protection trip for each section of a busbar Bus Bar protection Failure Alarm Bus Bar gas pressure low Alarm Bus Bar gas pressure low Trip iv) Metering : KV – one measurement for single bus bar substations

and two measurements for double bus bar substations. C. 33kV Bus Bar: i) Remote control : None ii) Status : None iii) Alarms : Bus Bar protection trip for each section of a bus bar Bus Bar protection Failure Alarm. iv) Metering : None IV. Transformers: (Transfer Terminal Blocks for this part are to be provided in the TTB cubicle housing the

low voltage side of the transformer. Note: In addition to individual open/close Remote Control, it is required to provide one

Group command open/close software-wise for the LV side breakers of 275/132, 132/33, 132/11, 33/11KV transformers group. A group of transformers consists up to 4 transformers normally but a maximum of 8 Nos. should be considered. The command is to be executed irrespective of number of transformers in operation at any moment.).

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A. 275/132KV Transformers: i) Remote control : Raise/Lower (tap) ii) Status : Transformer under supervisory control Transformer parallel Tap changer in progress (in case of manual and non-

follower only) Transformer Blowers/Fans running Transformer oil pumps running Tap changer position (21 positions) iii) Alarms : Out-of-step group alarm for all transformers (to be

connected to terminal 145 of transformer No:2) Transformer Buchholz Alarm Transformer Buchholz Trip Transformer Tap changer Buchholz Alarm Transformer Tap changer Buchholz Trip Transformer Winding temperature Alarm Transformer Winding temperature Trip Transformer oil temperature Alarm Transformer oil temperature Trip Transformer Low oil level Alarm Transformer underground Cable low oil pressure alarm

Transformer tubing gas pressure low Alarm Restricted earth fault H (High voltage side) Restricted earth fault L (Low voltage side) Duo Bias “A” Trip Duo Bias “B” Trip Under frequency relay Trip Group alarm for all

Transformers (To be connected to Terminal No.144 of transformer No.1)

Tap Changer drive motor trouble Transformer oil pumps trouble B. 132/33KV, 132/11.5KV and 33/11.5KV transformers: i) Remote control : Raise/Lower (tap) ii) Status : Transformer Tap changer under supervisory control Transformer Tap changer under only for 33/11.5 local manual control Transformer tap changer under transformer local automatic control Transformer parallel Tap change in progress (in case of manual and non-

follower only)- Transformer Blowers/Fans running Tap changer position (21 positions) iii) Alarms : i) 132/33KV and 132/11.5 KV Transformer - under frequency relay trip (To be connected to

Terminal No.144 of Transformer No.1) - Out of step alarm per group of Transformers (To

be connected to Terminal No.145 of Transformer

No.2)

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- Restricted Earth Fault trip - Stand-by Earth Fault trip per group of transformer s

(To be connected to Terminal No.143 of Transformer No.1)

- Buchholz Transformer Alarm - Buchholz Transformer Trip - Buchholz Tap changer Alarm - Buchholz Tap changer Trip - Oil temperature alarm - Oil temperature trip - Winding temperature alarm - Winding temperature trip - Low oil level transformer alarm ii) 33/11.5KV Transformers - Out of step alarm (per group of transformers to be connected to Terminal No.145 of transformer

No.2) - High oil and high winding temperature alarm

(combined) Buchholz surge tank and low oil level alarm

(combined) - Transformer trip (all the trippings of transformer

due to any of its protection have to be looped to the

transformer trip alarm) - Under ground cable low oil pressure alarm. V. Shunt Reactors: At present, in some substations, reactors are connected together with a feeder to a breaker

panel through an isolator for different voltage levels. They may be finally connected to individual breakers.

i) Remote : Open/Close ii) Status : Open/Close Supervisory/Local Line isolator open/close (for 300KV UGC feeder with

300KV reactor) Isolated Breaker (in case of reactors connected with

300/33KV transformer tertiary) Reactor isolator (expect for 33KV) Feeder/Reactor combined isolator (only for 300KV UGC feeder with 300KV reactor) Reactors Fans Running Poles discrepancy alarm (except 33KV) Driving mechanism trouble alarm Arching chamber pressure (except 33KV) UGC low oil pressure alarm Isolation pressure low alarm (except 33KV) Pilot cable fault alarm (only for 300KV UGC feeder with 300KV reactor)

Pilot cable supervisory fail alarm (only for 300KV UGC feeder with 300KV reactor).

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Distance protection main B alarm (only for 300KV UGC feeder with 300KV reactor) Reactors fans trouble alarm (except for 132KV) Reactor Buchholz Alarm Reactor Buchholz Trip Reactor oil temperature Alarm Reactor oil temperature Trip Reactor Winding temperature Alarm Reactor Winding temperature Trip Reactor Low oil Level Alarm Reactor alarm (except for 132 & 33KV) Main protection A trip (only for 300KV UGC feeder with 300KV reactor) Main protection B trip (only for 300KV UGC feeder with 300KV reactor) Stages for main protection B (only for 300KV UGC feeder with 300KV reactor) Over current relay trip Earth fault relay trip UGC low oil pressure trip (except for 33KV) Inter trip Alarm (except for 33KV) SF6 pressure low trip (except for 132KV & 33KV) CB failure to trip (except for 132KV & 33KV) Restricted earth fault relay HV side trip (except for 132KV & 33KV) Reactor CB arcing fault trip (only for 33KV) iv) Metering : MW and MVAR in case of 275KV reactors whether they are

connected alone or with another feeder. Amps. in case of all reactors whether connected alone or with

another feeder. VI. General: (Station alarms & measurements are to be provided in the TTB cabinet for highest voltage

level. For substations having 300KV voltage level then these are to be provided separately for 300KV voltage level then these are to be provided separately for 300kV and the next highest voltage level available and common alarms are to be brought separately to the respective terminals from source i.e. control/switchgear relay/transformers panels. If 33KV voltage level is not the highest voltage then separate set of terminal sections are to be provided in the 33KV TTB cabinet and only the Bus Bar Trip are to be wired to it).

A. Station Alarms: - A.C. supply failure - D.C. supply failure (for 300KV substations DC supply failure I + DC supply failure II are to be looped together) - Compressed air master tank (if used) - Communication failure - Telemetry supply failure - PLC supply failure - General alarm 300KV (concerning switchgear, relay & Control panels) for 300KV substations only - General alarm 132KV (concerning switchgear, relay & Control panels) for 132KV,132/33/11.5KV, 132/11.5KV substations only - General alarm 33KV (concerning switchgear, relay & Control panels) for 132KV, 132/33/11.5KV, 132/11.5KV substations only - General alarm 11KV (concerning switchgear, relay & Control panels) for 132KV,132/33/11.5KV, 132/11.5KV substations only

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N.B.: Any other grouped alarms which are not acquired as single alarm or with some other alarm must be connected to general alarms according to voltage levels in their respective control panels and only one wire to be connected to the TTB, looping at TTB is not allowed.

- Section services Alarm (Air Conditioning, Control Room temperature Alarm.....etc.) - 11KV Ring Main Alarm for 132/33/11.5KV, 132/11.5KV and 33/11.5KV

substations only. - Fire fighting system operated alarm For All - Fire fighting system failure Substations B. Station Metering: - Bus bar voltage as out line in III-A(iv) & B (iv) - Temperature For 300KV - Humidity substations - Dust content of atmosphere only - Wind speed - Wind direction - Frequency NB: If an alarm not individually monitored, the same to be looped to the nearest

meaning individually monitored alarm at control panel. In case a fleeting type alarm (s) has to be looped to a persistent type of

alarms the same to be indicated separately for MEW approval. This is emphasized that in no case additional alarms are to be wired to the

TTBs other than what is indicated in the approved TTB arrangement already available with the tenderer (more explanation can be given to the successful bidder on enquiry) and no looping of alarms on the TTBs is allowed. If required such loopings are to be made in switchgear/control/relay/transformer panels.

For requirements of wiring of 275kV, 132kV,33kV and 11kV panels insulation and de coupling indicated in Appendix 7.1.

The specification for transducers indicated in appendix 7.2 The designations, abbreviations and type of above mentioned tele-

information are shown in TTB arrangement and 300/132/33/11KV pud sheets as indicated in Appendix 7.3.

The connection for MW, MVAR transducers and the voltage selection circuit for busbar live and busbar voltage for single/double busbar s/stns is shown in Appendix 7.4.

VII. General Alarm Terminals: A terminal assembly of 9 terminals is to be provided just below station terminals for future

use for connection of General Alarm. VIII. TTB Cabinet: 240 V AC supply and 48 V DC supply is to be brought to each TTB cabinet on suitable

terminations.

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7. Appendices: 7.1 For requirements of wiring of 275 kV, 132 kV, 33 kV and 11kV panels insulation and

decoupling: It is particularly regarded that, in view of the strong interference prevailing in substation and in the Control Centre, two separate sources will be supplied, one for all the high voltage devices, the other for all the remote control equipment.

In addition, the feeder cables for all the latter equipment will never be installed close to the high voltage equipment. In particular, the potential of the remote control will not be connected directly to the contacts on the HV equipment.

This means that the use of decoupling devices are to be foreseen. For the same reason it is recommended that the potential used on high voltage equipment

does not penetrate into the remote control equipment. The input/output circuits of such equipment must have the following levels of insulation:

- dielectric resistance at 50 Hz : 500 Volts - surge wave : in common mode : 500 volts in differential mode : 300 Volts Telesignalling: In figure 1, the decoupling device D must be able to cope with the following insulation in

addition to the connecting cables and input/output terminals of RTU. Dielectric performance : 2 KV at 50 HZ during 1 min. Surge wave: in common mode : 2 KV in differential mode : 1 KV Although shown in figure 1 with electromechanical relays, other means of decoupling may

be used, for instance opto-couplers. Remote Control: It is necessary here to use the principle of galvanic decoupling as shown in figure 2. The contractor shall arrange for intermediate auxiliary relays suitable rated for the transfer

of closing control orders received from the above relays to energize the respective closing circuits. However, in general if a breaker has tripped due to operation of any protection while it is in supervisory rode the remote closing or opening command should be executed without the need to manually reset any alarm.

Facilities provided: The contractor will include in his offer the supply and installation of all the necessary

transducers, control interposing relays, auxiliary contacts on the circuit breakers and control and selector switches and all the necessary auxiliary relays and contacts along with cubicles/cabinets, if needed, to accommodate the transducers and relays for the purpose as described below. All such equipments etc. will be subject to the approval of MEW.

i) Status and Telesignalling: As regards the status and telesignals potential free contacts will have to be provided

for use with the R.T.U and these will be wired to the suitable terminal blocks in the control panels.

The status of devices such as circuit breakers, isolators etc., will take the form of two contacts forming two normally complementary loops, the complementary function being ensured by the interlocks of the 275 KV, 132 KV, 33 KV and 11 KV equipment.

The transmitting devices will transmit a non-complementary state which occurs during an abnormal situation.

Telesignalling are initiated by a single contact making or breaking a loop. For local signalling in the substation, the alarms must be held in by mechanical or

electrical means but for the transmission to the Control Centre they are not to be taken from latching circuits.

When the alarm signals are derived from the annunciator boards with mechanical latching, e.g.:

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Mauell type : MR 11/10-2a Reyrolle type : RPGI/B62 or similar or with electrical self holding circuits, the alarms will be taken from the automatic

reset contacts and not from the manual reset contacts. The potential free contacts used on the protective relays for remote supervision

alarms must be of the fleeting type provided that the make time (period during which the contacts are in closed position) of these contacts is not less than 25 ms. Otherwise, intermediate auxiliary relays must be provided to satisfy this condition.

ii) Command Outputs: For the Remote Supervisory Control ( open/close of circuit breaker and raise/lower

of tap changer ) the contactor will provide the interposing relays rated at 48 +/-20% volts d.c. He will also provide intermediate auxiliary relays suitably rated for the transfer of control orders received from the above relays to energise the respective operating circuits.

iii) Measured Values: The current and voltage transformers will be connected to the transducers through

suitable terminal blocks in the control panels. For the measurement of the power (active and reactive) the use will be made of the

“Aaron principle” for the connection of the power transducers to the metering transformers, in order to detect unbalanced load conditions in the network. (See the figure of the Appendix 7.2 : watt metric and varmetric transducer wiring).

iv) Transfer Terminal Block Assembly (TTB): To guarantee a clear demarcation between the HV switchgear equipment and the

remote control equipment and to facilitate the testing without the removing of wires, the use of terminal block assemblies comprising terminals with link plugs will be provided.

Any information concerning a feeder circuit is normally made available at the terminals inside the feeder control boards or the protection boards.

Therefore, one separate feeder oriented transfer terminal block assembly (TTB) for each of the existing voltage levels (275KV, 132KV, 33KV and 11KV) will be provided, each accommodated in a separate cabinet clearly labelled with the exception of the 132KV low voltage side of 300MVA transformers which is to be housed in addition in a different cubicle so as to be connected to the W substation RTU and the terminals in the 132KV TTB could be connected to the A or B substation RTU and used for double monitoring. The 33KV shunt reactors are to be housed in the same cubicle as that of low voltage side of 300MVA transformer.

This arrangement offers the following characteristics: - The digital signals (indications and alarms, commands) will be grouped and led

to the TTB (figure 3). - The digital and analogue (measured values) signals will be separated from each

other by using separate cables and terminal block groups (figure 3). - The order of terminal block sections will be arranged according to the physical

order in the installation of the feeder control boards (figure 3). - New T.T.B cabinets must be fully equipped for the capacity according to the

busbar arrangements and provision of extension as indicated earlier. - TTB cabinets should be provided with internal lighting and identical panel key

for all cabinets. Three panel keys with each cabinet is to be supplied. - Separate terminal block sections and order will be provided for transformer

information (figure 3). - The function-oriented terminal designation scheme will be provided with a high

degree of systematization (figure 5 and figure 5a of TTB arrangements. This device must meet the following requirements:- - Organisation of the terminal block assembly in several main groups (figure 3 & 4

of TTB arrangements) i.e.

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- Telemetering group (all measured values) - Indication/control group for feeders (all voltage levels) - Indication/control group for transformers (all voltage levels) which are installed on the low voltage side. - Indication group for the substation. In this way, a subdivision of the terminal block assembly is obtained so as to separate terminal groups for analogue signals (measured values) and for digital signals (indications, alarms and commands). (figures 5 and 5a of TTB arrangement).

- Within the terminal block groups, optimum distribution of the terminals among the various feeders and transformers to obtain terminal sections according to a fixed order.

- Within a terminal section, distribution of individual terminals among the different function in a fixed order.

- Each terminal section must be labelled with the designations of the feeder, transformer etc. and follow the same order as exists for the HV equipment

A definite function is always allotted to a definitive terminal. The terminal block section for each feeder circuit includes only those terminals

required for the actual number and type of functions associated with the feeder. In addition, a definite number of spare terminals are included in each section.

For a better understanding, the terminal designations include additional information for the user.

This is illustrated by the numbering scheme which is as follows: Status indications : 1-40, 101-140, 201-240, 501-530 Alarms : 41-68, 141-168, 241-268, 341-368 Common return for indications : 69, 169, 269, 369, 569 and alarms Commands : 91-98, 191-198 Common return for commands : 99,199 It is to be noted that each section has its own common return wire which results in

galvanic isolation between the different terminal block sections (feeder – transformer).

In addition to the indications and alarms, commands are wired to the corresponding terminal block sections of the TTB for feeder and transformer circuits.

Isolating terminals must be used fitted with link plugs to facilitate testing without removing the connected wires and best suited to fulfill the specification as mentioned here above.

The main features are: - clear segregation - test sockets integrated in the clamping screw for 50V DC and 240V AC easy

mounting minimum space requirement designed to accept cross sections From 0.5mm.sq. (multi-core cable to remote control apparatus) up to 2.5mm.sq.

(control cable to control boards) The front face of TTB cubicle will accommodate the feeder, bus section, bus

coupler and high voltage/low voltage transformers terminals for indications, alarms and remote controls where as the left side will accommodate all the measurements and the right side will accommodate the transformer part, station indications and alarms, GA terminals, 240 V AC and 48V DC terminals. All the wiring coming from the substation side will be connected on left hand side of terminals while the right hand side of terminals will be connected to the telemetry equipment. All cablings inside the TTB cubicles will run in common cable trays of approved type. Each TTB cubicle will be provided with an earth busbar at the bottom to which all earth connections are to be made. When more details for the above are required, these will be given to the successful tenderer. Properly engraved cable identification ties will be provided for easy identification of cables. Numbered

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ferrules of permanent type matching with the numbering on the transfer terminal blocks are to be provided on the wires connected on the switchgear side and vice versa. Bay identification with type of signals/measurements will also to be provided for each set of terminals. All cubicles should be easily identifiable with clearly engraved labels.

(v) Cables and Wiring: - The capacity of each cable will take into consideration several spare cores. - A definite number of spare terminals in the TTB have been requested, these

terminals will be connected to RTU as well as the switchgear/transformer/control or protection panels with some of the spare cores, the remaining spare cores will be kept to replace any core which would become faulty in the future.

- All alarms, indications, measurements and Remote control are to be picked up from/connected to the source i.e. from/to switchgear, transformer, control or protection panels and are connected to the transfer terminal blocks. This applies even for the unavailable alarms the difference being only that at the switchgear, transformer, control/protection panel such alarms will be terminated on the terminals and will not go any further.

- In case if any free terminals are not available in the switchgear, transformer, control / protection panel the same is to be supplied according to MEW practice and matching with the existing terminals.

- The cables will be fixed firmly by appropriate means on both ends and labelled by engraved ties as well.

- Remote closing/opening of circuit breakers should be possible in case of protection alarms namely main protection trip, over current relay trip, earth fault relay trip, under frequency relay trip, restricted E/F relay trip etc.

- The screen of the cables will be connected to the earthing located at the bottom of the equipment.

- The wires will be clearly segregated according to their function, they will be ferruled by means of unloosing system.

- No more than two wires will be accepted in the same terminal. - The termination point at RTU should be arranged in a similar way as in TTB cabinet

i.e. the terminal strip at the input side should be segregated for each switchgear bay and labelled. Standard numbering plan is to be followed on all individual feeder oriented strips in RTU.

- In case if the T.T.B. cabinets are located in different buildings, the contractor has to wire the information from the TTB cabinets to the RTU by means of suitable cables taking into consideration the distance, the interference expected due to running of cables along with power cables etc.

- Common return for indication, alarms and commands are to be connected to the telemetry positive potential which is grounded on the power supply.

(vi) Specifications for the Requirement of Cables: a) General: The specification will cover all the cables to be supplied for the connection between

the different equipments in substations and DCC which are to be laid in suitable trenches or trays subject to MEW approval. Further all cables will be provided with engraved cable identification ties of approved type. Wherever feasible numbered permanent type of ferrules will be provided for cable core identification. The Tenderer will precise each type of cable:

1. its construction 2. its electrical properties All the cables proposed to be used has to be flame retardent type as per IEC 332 and

subject to MEW approval.

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b) Type of Cables: 1. Indoor Telephone Cables: These cables will be of multi-core type, each conductor having a diameter not

less than 0.8mm (0.5mm.sq. cross section) between all equipment excluding item 2 and 3 detailed below:

The number of pairs will be precised as well as the colour code. The telephone cables will be screened. 2. Telephone cables PVC insulated 15kV Grade: These cables will be used for connection between marshalling cabinet,

protection box and annunciator board and also between marshalling cabinet and isolating transformers. They will be multi-core cables, each conductor having a diameter not less than 0.8mm. The number of pairs will be precised as well as the colour code. The telephone cables will be screened.

3. Power Cables: The power cables will be multi conductor, each conductor having a cross

section not less than 2.5mm.sq. and they will be screened and PVC overall jacketed. The core identification code will be defined. These cables will be used for all modification works between substation equipment and TTB except from transducers to TTB which will not be less than 1.5sq.M.

c) Cable Connection: Separate cables are to be laid between each switchgear, transformer,

control/protection panel to TTB cabinet and to the terminal block on the RTU for indication/control, except for measurements as indicated in figure 3.

The measurements will have to be connected from the control panels to TTB by separate cables but from TTB to RTU they could be combined for more than one bay. For station alarms and measurements similar arrangement is to be foreseen.

H. VOLTAGE RELAYS REMOTE CONTROL EQUIPMENTS EQUIPMENT

ELECTRONIC H.V. EQUIPMENT TELEMETRY COMMON POTENTIAL RETURN (POSITIVE POTENTIAL)

FIG. 1

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REMOTE RELAYS HV EQUIPMENT CONTROL EQUIPMENT TELEMETRY COMMON RETURN HV (POSITIVE POTENTIAL) POTENTIAL

FIG. 2 Appendix 7.2 Specifications of the Transducers: 1. General: The transducers used must be exclusively of the static type, namely 100% electronic

without auxiliary power supply, and they must be of the current output type. 2. Input: 2.1 Current Transducers 1 ampere or 5 amperes taken from the red phase current transformer. 2.2 Voltage Transducers: 110V AC taken from phase to phase (red and yellow) of the secondary of the voltage

transformer. 2.3 Wattmetric and Varmetric transducers: Current input : 1A or 5A Voltage input : 110V AC The connection of the transducer must be a “three phase” connection. The scheme of

wiring is shown in the figure 2. 3. Output: 3.1 Current Transducers: The output must be proportional to the input (straight line characteristic) and range from 0

to 10mA, the 10mA corresponding to nominal input +30% overload, i.e. for 1A or 5 A input, output =10mA = 7.7mA.

3.2 Voltage Transducers: The output must be proportional to the input, but with a linearly expanded range and must

range from 0 to 10mA, the 10mA corresponding to nominal input +20% i.e. Low range scale: Input : 0 to 80% of 110V Output : 0 to 2mA High range expanded scale: Input : 80% to 120% of 110V Output : 2mA to 10mA

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3.3 Wattmeteric and Varmetric Transducers: The output must be proportional to the input (straight line characteristic) and bi-directional

with the range –10mA to 0 to +10mA, the 10mA corresponds to nominal input +30% overload.

i.e. input = 1A or 5A output = 10/1.3mA = 7.7mA 110V AC 4. Miscellaneous for all the Transducers: For all the types of transducers (current, voltage, watt metric, varmetric) it must be

possible to vary +/- 50% of the output to suit any required output current. 4.1 Power Consumption: less than 2 VA per current circuit less than 2 VA per voltage circuit. 4.2 Secondary load Impedance: The secondary load impedance for a current of 10 mA can vary between 0 and 1500 ohms.

The output circuit must be capable of remaining permanently open without destruction, and without irreversible modification of characteristics of the transducers. A 0.1 micro Farad filter capacitor can be connected by the use, if necessary in parallel with the secondary load (equivalent capacity of the wiring).

4.3 Dielectric Insulation: 4.3.1 Testing at 50Hz: The dielectric characteristic of the transducer must be such that they can withstand a 50Hz

AC voltage for a period of 1min, having the following values with respect to ground: - 2kV applied to the current and voltage circuits - 500V, applied to the output circuits. 4.3.2 Shock Wave Testing: The peak voltage value is 3kV in common mode, and 2kV in differential mode, for the

measurement circuits. For the other circuits, the peak value is 1KV in both differential and common modes.

4.4 Reference Conditions: The reference conditions are as follows: f = 50Hz, t = 20oC, Cos 0 = 1 or Sin 0 = 1 The errors are expressed in K%, of K being the accuracy index (0.5) except for frequency

transducer which is to be of 0.2 and temperature & humidity transducers which are to be of 1.

4.5 Accuracy Under Reference Conditions: All the transducers must be class 0.5 except the frequency transducer which is to be of

class 0.2 and temperature and unidity transducers which are to be of class 1. The curves for proportional DC current under the reference conditions and with respect to

a variable current must be linear over full scale range. In particular, the output current must be nil for an LV reference power level of O, or K% at most.

Over the complete read scale range, the output current absolute error must not exceed: - For Class 0.5% units : 0.5 x 10mA = 0.05 mA 100 - For Class 0.2% units : 0.2 x 10mA = 0.02 mA 100 - For Class 1% units : 1 x 10mA = 0.01 mA

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4.6 External Influences: 4.6.1 Variation in accuracy with the temperature and the humidity: The temperature can vary between –5oC and +55oC and the humidity can vary between 0

to 100%. Over this range, proportional DC current error, measured under reference conditions must be less than +/- K%.

4.6.2 Variations in Accuracy according to the power Factor: The proportional DC current error with variations in the power factor, measured under

reference conditions, with Cos 0 = 0.5 lagging and 0.7 leading for active power transducers, and Sin 0 = 0.5 ( Cos 0 = 0.886 and –0.866 ) for reactive power transducers, must be less than =/- K%.

4.6.3 Variations in Accuracy with the input Voltage: The input voltage may vary between two limits : 0.8Vn and 1.20 V n (Where V n is normal input voltage, 110 volts). The proportional DC current error at limit values, measured under reference conditions,

must be less than +/-K%. 4.6.4 Variations in Accuracy with the Frequency: The frequency variation range is from 46 Hz to 51 Hz. The proportional DC current error

at these variation limits, measured under reference conditions, must be less than +/- K%. 4.6.5 Resistance to Over currents: The transducer must be capable of withstanding two times the rated current permanently,

and a current equal to 10 times its nominal current for 0.5 seconds (this current can have a form which is practically sine wave, or pulse form in the events of current transformer saturation).

4.6.6 Stability in Temperature: With the unit permanently powered, under reference conditions, it must show no accuracy

drift with respect to initial measurement (tested after 15minutes warm-up period). 4.6.7 Residual Ripple: This must be less than 50 micro amps for 5mA, and 100 micro amps for 10mA. 4.6.8 Response Time: The response time must be better than 500ms for a total scale deviation from 0 to 99%. 4.6.9 Storage Temperature: Storage temperature can be up to +70oC. 4.6.10 Various with the Harmonic Distortion: With a harmonic distortion of 2%, the error must not exceed +/- K%. 4.7 Components: 4.7.1 Metals: Iron and steel are in general to be painted or galvanized or alternatively have chromium or

copper-nickel plated or other approved protective finish. The steel screws and nuts to be used are to be zinc, cadmium or chromium. 4.7.2 Fabrics Cork, Paper, etc.... The fabrics, cork, paper and similar materials, which are not subsequently to be protected

by impregnation are to be adequately treated with an approved fungicide. Sleeving and fabrics treated with linseed oil or varnishes must not be used.

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4.7.3 Adhesives: The adhesives are to be specially selected to ensure the types which are impervious to

moisture resistant to mould growth and not subject to the ravages of insects. Casein cement is not to be used.

4.7.4 Printed Circuit Boards and Circuitry: The circuitry will be completely solid state. The printed circuit boards will be epoxy glass

material. The components having a shelf life of less than 5 years should not be used. Electrolytic

capacitors having a shorter life may be used, provided they will reform themselves after one hour in service.

4.8 Spares: The following spares to be supplied and its cost to be included in the contract price: 4.8.1 Two numbers transducer of each type (amps, volts, watt metric, varmetric) and of each

current transformer ratio. 4.8.2 Ten percent of total number of relays required for circuit breakers and transducers tap

changers controls. Appendix 7.3: The designations, abbreviations and type of above mentioned tele-information are shown in TTB arrangement and 300/132/33/11kV PUD sheets. Appendix 7.4: The connection for MW, MVAR transducers and the voltage selection circuit for busbar live and busbar voltage for single/double busbar substations.

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PART VIII

TECHNICAL SPECIFICATION NO.MEW/SS/8 SUBSTATION AUXILIARIES

8.1 Low Voltage Distribution Boards: 8.1.1 General: The low voltage distribution board shall be supplied from the local transformers and the

board will be used to provide the necessary A.C. supplies to the substation. The switchboard shall be arranged to permit future extension at each end.

8.1.2 Arrangement: The distribution board shall comprise of :- a) Two isolators for the local transformers incoming circuits. b) One bus-section isolator. c) Six 30 amps and four 60 amps, 3-phase molded case circuit breakers to control various

circuits in the substation. d) Six 100 amps, 3-phase molded case C.B.s to control various circuits in the substation. e) One 500Amps, 3-phase molded case C.B. located in the bus section panel. The C.B. shall

be used for connection of supply from MEW mobile emergency diesel generating unit. The switch shall be completed with necessary clamps, earthing connection and shall be suitable for the specified cable below.

f) All necessary molded case and miniature circuit breakers to control the various substation equipment such as battery chargers, tap-changer, switchgear, charging motors, air compressors and pumps (where applicable), indicators and alarms, etc.

g) One panel to accommodate all the necessary charging equipment for each of the two 220volts and 110 volts batteries and all controls, indicating instruments and any indications associated with these battery chargers.

h) All necessary current transformers, relays, instruments and indications as detailed in the “Details of Equipment”.

i) All necessary sundry items to complete. N.B: The necessary distribution boards for items (c) and (d) above will be supplied and the

price of such shall be included in the tender price. The basic arrangement of L.T. Board and auxiliary distribution board shall be submitted with the offer. However, the details shall be subject to the approval of the Purchaser.

8.1.3 Switchboards: The switchboards offered shall be of the totally enclosed type. Circuit breaker units to the

same rating shall be completely inter-changeable. The busbars shall be of high conductivity, hard drawn electrolytic copper. The common

neutral earth busbar shall be located at the lower section of the switchboard such that the combined neutral and earth wire conductors of outgoing cables may be directly connected to this bar. This bar shall be directly earthed with connection to the outdoor earthing ring (as in clause 1.9.2) at the nearest earthing pit.

The switchboard shall conform to BSS.5486 or IEC 439. The phase rotation and colour markings shall be in accordance with BSS.158.

Each transformer control isolator panel shall be provided with a bolted copper link for connections of the neutral cable to the combined neutral/earth busbar. Electrical and/or mechanical interlocking against parallel operation of the transformers shall be provided. Also electrical interlocking between 11kV C.B. and L.T isolators both controlling local transformers shall be provided and shall be subject to MEW approval

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8.1.4 Transformer Control and Bus-Section Isolators: The isolators shall be 3-single pole, air break pole operated, off-load, continuously rated

1600/500Amps (as may be stated in the Details of Equipment) at Kuwait’s worst temperature conditions and complying with BSS.3078. However, the isolator shall have a standard rating not less than 2000/600Amps. The selected ratings shall be required in “Details of Equipment” of the specification.

The isolator shall be provided with 3 Nos. copper connecting bars terminated in a way suitable to receive necessary copper cable lugs for cables as specified.

The lugs shall be complete with bolts, nuts and lock washers. Interlocking shall be provided to prevent parallelling of the transformers and the 11kV circuit breaker cannot be closed if the L.T. Isolator is open and the isolator can only be closed if the 11kV C.B. is open.

8.1.5 Moulded Case Circuit Breakers: The moulded case circuit breakers shall be quick-make and quick-break on manual or

automatic operation and the handle mechanism shall be trip-free. Automatic tripping of the circuit breaker shall be obtained by means of thermal device which has to be provided with time delay tripping on overload and a magnetic device for instantaneous tripping on short circuit and the setting shall be adjustable from the front side of the breaker.

The circuit breakers shall be of the heavy duty type having a breaking capacity as detailed in specifications.

These breakers shall be complete with mechanical “ON/OFF” indicators and auxiliary contacts for remote alarm indication in case the breaker tripped due to a fault on the protected circuit or opened by hand.

8.1.6 Combination Fuses Switches: Combination fuses switches shall be of 3-pole and neutral type totally enclosed with

interlocked handle and fitted with “ON” and “OFF” mechanical indicator. The switches shall be capable of making and breaking their assigned current load and shall be fitted with high rupturing capacity fuses of the cartridge type. The combination fuse switches shall comply with BSS.861 and relevant British Standard Specification and shall be complete with sput shrouds insulated phase barriers and fully rated contacts...etc.

8.1.7 Continuous Maximum Rating: The following ratings shall be “Maximum Continuous Rating” under Kuwait’s worst

temperature conditions:- i) Transformer Isolator : 500 Amps or 1600 Amps ii) Bus-bar (Phase) : 600 Amps or 1600 Amps iii) Bus-bar (Neutral) : 300 Amps or 800 Amps iv) Moulded Case Circuit : 30 Amps, 60 Amps, 100 Amps breaker for S/Stn Service and 500Amps. v) Bus-section isolator : 500 Amps or 1600 Amps vi) Combination Fuse switch for mobile diesel generator : 500 Amps Tenderers shall state the derating factors in each case and these shall not be less than 20%. The selected ratings as required under “Details of Equipments”. 8.1.8 Protection : a) Moulded Case Circuit Breakers: These shall have a Kuwait Current Rating of 500 Amps and as detailed under 8.15 above. b) Alarms : i) Total A.C. main supply voltage failure alarm and earth fault relays equipped with

auxiliary contacts for local and remote supervisory alarm indications. ii) All circuit breakers above must be equipped with auxiliary contacts for remote

indications at the Supervisory Centre in case these are tripped due to a fault in the sub-circuit or opened initially by hand. These contacts are grouped to give a local alarm on the 11kV Control Board in addition to the required remote indication.

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8.1.9 Cables: i) Transformer Control: Each transformer control isolator shall be provided with suitable clamps for clamping 630

or 500sq.mm stranded copper conductors, cross-linked, polythelene insulated and extruded PVC served, single core, 1000Volts cables. The clamp shall be of non-magnetic metal.

ii) Moulded Case Circuit Breakers: Each moulded case circuit breaker of 100Amps rating shall be supplied with a suitable

cable clamp for 1000volts, 35 to 50sq.mm. stranded copper conductors, 4 core XLPE or PVC insulated, PVC sheathed, steel wire armoured and PVC overall sheathed. Provision for clamping and earthing of the wire armour shall be provided.

iii) The following miniature circuit breakers shall be provided for the control A.C. supply to telemetry equipment:

2 MCB’s 15A/415 V/AC capacity 3 phase for chargers. 1 MCB of 15A/240 V/AC capacity 1 phase for panel lights. 1 MCB of 15A/240 V/AC capacity 1 phase as spare. 8.1.10 Emergency Diesel Generating Unit : Supply and install the necessary cable length in accordance with the approved substation

arrangement between the 500 Amps, circuit breaker required under 8.1.2.(e) above in the main L.T. Board for the above purpose and a separate wall mounted 500 Amps. Switch fuse complete with fuses located in the entrance of the substation. The cables shall be 4 single core, 1.0 kV 300 sq,mm, standard copper conductors, XLPE insulated, PVC sheathed. The switch fuse shall be complete with the necessary lugs, bolts, nuts, --etc. for connection to the generating diesel unit.

The cost of the above cable and switch fuse shall be included in the offer price. Interlocking against parallel running of the two supplies i.e.- from the station transformers and the diesel unit has to be provided, key switch interlocking is accepted.

8.2 Substation D.C. Batteries and Charging Equipment : 8.2.1 General The Station batteries shall be of the nickel cadmium alkaline type, tropically rated for a

maximum and minimum ambient temperature of 52ºC and –6ºC and shall be in general to the relevant BSS or its equivalent and shall be subject to approval of the Purchaser.

The batteries shall preferably be installed in tiers and shall be in a separate room. Suitable stands for the batteries shall be supplied. The stands shall be mounted on porcelain insulators.

The coil containers shall be either of plastic of the best kind with adequate thickness, durable, unbreakable and suitable for 52oC ambient temperature, or alternatively to be of sheet steel, with suitable measures taken to prevent corrosion. The cells shall be complete with plates, opening for topping up, gas release measurement of density and temperatures and provided with stoppers to prevent any foreign matter dropping in. Cells shall be numbered and polarity of thermal cell indicated.

Batteries supplied shall be complete with all connectors for battery charging equipment, connections between tier of battery and between cells.

The tender price shall include all cables, connections, earthing of batteries and charging equipment and initial charging and putting the battery into service.

The following accessories and spare parts shall be supplied for each substation, the cost of which shall be included in the contract price :-

1) 36 Nos. spare loose cells each for control and tripping batteries and 18 cells for emergency

lighting battery, all complete with loose solid electrolyte. 2) Loose solid electrolyte—25 kgs. 3) Main Diodes- 2 Nos. and Main Thyristors - 2 Nos. of each type used. 4) Contractors and relays - one No. of each type and rating used.

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5) Two hydrometers. 6) Two thermometers. 7) One cell testing voltmeter. 8) One set of special tools. 9) One cell bridging connector. 10) Two instruction books in English language. 11) Two spare m.c.b’s of each type and rating used. The above accessed (items 5 to 11 ) shall be supplied in a box which shall be

mounted on the wall or in a suitable compartment in the charging or control cubicles.

NB: The offered batteries must be of the independent cell type., i.e. each cell of 1.2 V rating must have separate positive and negative terminal and separate enclosure, so that in case of defect or damage, then that one will be replaced. Tenderers are requested to confirm that in their offers.

Another six sets of instruction books and drawings for each battery and associated charging and control equipment shall be supplied to the purchaser.

Along with each control and tripping battery, an auxiliary D.C .distribution board of the total enclosed type fully equipped with the necessary m.c.b. with suitable ratings to supply various loads shall be provided. These auxiliary boards shall be both ground mounted and located in the charger room, the details of which shall be subject to MEW approval. However, for supply to Telemetry equipment, one m.c.b. of 10 A- 220 volts D.C. capacity for fault lamp indication shall be provided.

8.2.2 Control and Charging Equipment: The charging equipment shall be housed in well ventilated cubicles unless otherwise

approved. The control and charging equipment shall be complete with necessary rectifiers, control fuses (input) switches and any other associated protective equipment.

The charger shall maintain the battery normally floating so that no discharge occur under normal loading within +/-6 % supply voltage variations and the battery remains fully charged. Further, the chargers of the 220 V batteries shall be arranged to give constant output voltage.

In addition, a high rate charging shall be provided for quick re-charging of the battery after a heavy discharge and this shall not be more than 5 hours starting from flat conditions.

The battery capacities shall be calculated on basis of maintenance co-efficient 0.8 and co-efficient depending on discharge, time shall be taken from curve drawn for ambient temperature of –6oC and at final voltage of 1.1 volt / cell provided that this will not be less than 80 % of the floating voltage of the battery.

The control equipment of the 110 volts D.C. emergency lighting battery shall be supplied with double pole changeover contactors to automatically cut in the 110 volts D.C. supply for substation emergency light when A.C. main supply fails and to automatically cut when the substation A.C. main supply is restored.

A “ charge fail ” alarm relays with auxiliary clean sets of contacts (potential–free) shall be provided for the 220 volts batteries for transmission to the purchaser’s “Remote Supervisory and Control Centre”. Another set of auxiliary contacts for local and remote centre alarm indication of "D.C. Fail".

8.2.3 Substation Control and Tripping Batteries : The substation D.C. battery supplied shall be 220 V and shall be used for closing of the

circuit breakers, indication lamp, circuits and other D.C. circuits related to the equipment at the substation.

The ampere-hour-capacity of each battery shall be determined and stated by the Tenderers in the schedule. The control battery shall be of adequate capacity to meet the following requirements with the charger out of service :-

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1- All indication lighting in the control and relay boards for a period of five hours. 2- At the end of five hours period, the battery shall have adequate capacity for two

closing operations of circuit breakers requiring maximum closing current, and at the end of these operations, the battery shall have a voltage not below 80% of the floating voltage.

The ampere hour-capacity of the tripping battery shall be sufficient for tripping maximum number of circuits breakers that may happen simultaneously then left without charging for about five hours and at the end of this period, the battery shall have a voltage not less than 80% of the floating voltage.

Detailed calculations of the capacity of each battery to fulfill the above requirements must be submitted for the approval of the purchaser.

8.2.4 110 Volts D.C. Emergency Lighting Battery : A separate 110 Volts D.C. battery tropically rated, 45 ampere hour for emergency load of

1600 watts for 3 hours shall be provided. The charging gear for this battery shall provide an automatically controlled “High Rate” output of 4.5 amperes and an alternative “Trickle” rate of 40/60 milli-amperes. Manual control of charge rate shall also be provided.

8.2.5 Battery Supervision ( for the 220 Volts Batteries ): Earth fault relays for each of these batteries shall be provided to supervise the dc currents

and give local and remote alarm indications in case of a solid or partial earth faults occur on one of the positive or negative sides of the d.c. circuits (single fault). Further, means for rapid checking of insulation level to earth on the positive or negative side shall be provided. An insulation level instrument for continuous measurement shall also be provided. Rapid checking of insulation level is not required.

8.2.6 48V Batteries and 48V DC chargers for Substation Telemetry Equipment: General Characteristics: Each battery will consist of 24 accumulator cells for lead-Acid "semi-fixed" or "compact

stationary" type. The autonomy of each battery will be of 8 hours. Each battery will mandatorily be operated in the floating battery mode to eliminate

entirely, even in a transient period, any over voltage which might damage the supplied transistorized equipment. A single charger will be installed, which will supply a maximum voltage of 58V, and in no event any higher voltage even during an extremely short time interval is allowed.

8.2.7 Conditions of Operation: The charging device must perform the following functions: 8.2.7.1 Normal operation as floating battery: It must supply a constant voltage to the following: - Battery topping-up current - Current absorbed by user The current peak peaks exceeding the charger peak load will be furnished by both

charger and battery. 8.2.7.2 Failure of A.C. supply: The power absorbed by the user will be supplied by the battery only.

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8.2.7.3 Return of A.C. supply: There are two possibilities: Duration of failure les than 5 minutes: The rectifier will resume its previous operating mode i.e. floating battery mode or boost

charge mode. Duration of failure over 5 minutes: The rectifier will operate automatically at the boost charge rate during 12 hours

(adjustable between 0 and 24 hours); then will automatically return to its floating battery operating mode. No manual switch will be required to pass over to boost charge in such a case.

8.2.7.4 Operating in boost charge: This mode allows of prolonged charging in order to completely regenerate the battery. It may occur for instance after prolonged breakdown (i.e. over 10 minutes) of the AC

main supply, during which time the battery alone will furnish the load of the user. The passing over from the floating battery operation, to the boost charging operation,

and vice versa, will take place automatically and manually by means of changeover switches.

At the least the period of time in boost charge operation must b adjustable (from 0 up to 24 hours).

8.2.7.5 Manual Adjustment: A manually controlled adjusting device will be required to perform the following

operations: - In the even of failure of the voltage regulating device, there will be the possibility of

using the charger by manually regulating the voltage to between 46 and 54 V at an amperage of between 0 and 1 nominal, at an AC supply voltage of between +/-10% of its rated value.

The switch to change over to manual will be located inside he rectifier to prevent its being accessible to unauthorized persons.

8.2.8 Electrical Characteristics: 8.2.8.1 AC supply voltage: The nominal AC supply voltage must have the following characteristics: - 415 volts, 3 phase, 50Hz - Fluctuation limits of nominal voltage :+/- 10% - Fluctuation limits of frequency: 46-51Hz 8.2.8.2 Rated floating voltage: The rated floating battery voltage will be specified by the tenderer, compatible with the

proposed battery. 8.2.8.3 Rated boost voltage: The tenderer will also specify the rated boost voltage. 8.2.8.4 Rated power: The rated power will be equal to the product of the rated boost voltage by the rated

rectified amperage. THIS VALUE WHICH DETERMINES THE DIMENSIONING OF THE CHARGER

MUST BE SPECIFIED BY THE TENDERERS COMPATIBLE WITH THE CONSUMPTION OF THE VARIOUS ITEMS OF EQUIPMENT FED, KPLUS THE CONSUMPTION OF ANY EXISTING EQUIPMENT INSTALLED AS INTERMEDIATE STATION PLUS AN EXTRA RESERVE OF 30%.

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In general, the rated amperage of each charge will be equal to the maximum using amperage.

THE RATED RECTIFIED AMPERAGE DIRECTLY CONDITIONS THE

CAPACITY OF EACH BATTERY. THIS CAPACITY MUST BE SUCH THAT THERE WILL BE 8

HOURS SELF-SUFFICIENCY FOR A MAXIMUM VALUE OF THE USING AMPERAGE.

8.2.8.5 Filtering: Each charger must have one filtering device. With the charger supplying a purely

resistive charge, the rms AC values measured at the resistor terminals must be les than 300 mV at 50Hz and less than 10 mV at between 300 and 3000 Hz. The charge will however be always connected to the battery, that is it will never feed the load directly.

8.2.8.6 Dynamic Characteristics of the Chargers: With an output current varying between 0 and the rated rectified amperage, the voltage

at the terminals of the battery must be kept to within the following limits: - In the floating battery operation: +/-1% of the rated - In the boost charging operation: +/- of the boosting voltage For an instantaneous variation of the output of one half the rated amperage, the rectified

voltage at the battery terminal must return to the specified limits within a period of less than 0.5 second after the end of the disturbance. During such disturbance the rectified voltage may vary within +7% of the rated voltage, depending on the operating mode of the charger.

Each charger must be provided with an output current limiting device. 8.2.8.7 Risk of over voltage: To prevent any over voltage, it will in all the case be made impossible for the charger

to operate directly on the user load. 8.2.8.8 Supervision of the voltage of the Battery: A relay connected down line of the user output protection will be incorporated in the

charger to give the necessary alarms in case of over voltage and under voltage and trips for over voltage.

8.2.8.9 Earthing of positive pole of user system: Control and monitoring instruments: The unit will contain the following minimum items: - Externally, front face: 1 manual ON/OFF selector switch or keys to energize the charger assembly. 1 voltmeter to measure the voltage of the battery 1 set of indication lights - Inside the unit:

1 selector switch to select the charger operating modes (floating battery, boost charge, adjustable output, automatic operation).

Sundry-adjusting devices required for proper operation: regulation of the voltage, voltages operating period in equalization mode, etc).

Connecting terminals located at the bottom or top of the charger fronts (mains supply circuit, DC circuit, alarms and common protective circuits). All the cabling

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will be properly ferruled and numbered for identifications. In the distribution cabinet of the user outputs 1 bolted strip to earth the positive pole

at a single point.

8.2.8.10 Signals and Alarms: All the defects and failures must cause the lighting of lamps and the closing of one

single loop on the alarm circuit. A drop of the AC voltage during system disturbances must not be deemed as a charger defect and will not cause an alarm. However, loss of AC supply to the charger is to be signaled as an alarm.

8.2.8.11 Protection and operation instrument: Whatever its capacity the chargers will mandatorily be provided with a contactor on the

AC side to enable it to be automatically de-energized in addition to an MCB or contactor on the AC distribution board of the substation.

On the DC side the charger will be supplied with two magnetic switches or 1 two pole circuit breakers to ensure selectivity of the switching and with an adequate cutting capacity.

All the auxiliary circuits inside of charger will have miniature circuit breakers. 8.2.8.12 DC Distribution: All the necessary DC distribution boards and cabling connecting different supervisory

control equipment have to be provided by the contractor under the supervision of telemetry subcontractor.

The DC distribution boards will be equipped with the necessary MCB's of adequate capacities including reasonable amount of spares. The incoming cables from charger/battery are to be connected t the DC bus through a M.C.B.

8.2.9 Technology: 8.2.9.1 Presentation: Each equipment will be designed in the form of cabinet. All the connecting terminals, control and switchgears and test points will be readily

accessible and clearly identifiable. Screwed name plates will be installed on every cabinet. 8.2.9.2 Maintenance: Each equipment will incorporate test points allowing for the complete checking of the

proper operation. Such test points will be clearly visible on the typical schematic. The adjusting and

maintenance instructions will specify the signal values and waveforms which must normally be found and maintenance manual must be accompanying each set of equipment.

Normal tools and measuring devices will be supplied with each power unit of substations.

8.2.9.3 Batteries: All the batteries in control centre and in each substation must be lead-acid type, housed

in clear translucent containers, with marking of maximum and minimum fluid level and marks of polarity. The battery plug will be spark proof.

All the batteries are to be placed on wooden stands in substations. All batteries are to be provided with name plates indicating the type, capacity, etc. and

their maintenance and operational procedures.

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8.2.10 Civil Works: For the substations communications battery room and battery charger room, if required,

the contractor is responsible to carry out necessary civil, electrical and air conditioning works such as making partition wall, laying of ceramic tiles, provision of 350 cfm capacity extract fans in battery rooms, necessary air intake arrangement with filters, etc. The substation communication battery room and battery charger rooms shall conform to latest MEW specifications for substations and shall also conform to Kuwait Fire Brigade requirements.

Moreover, the tenderer will be responsible for making necessary holes for all the equipment to provide the cables up to AC supply points and to provide circuit breakers on designated substation L.T. boards in the substations.

Tenderers may carry out necessary surveys for this work in existing substations and MEW will arrange for such surveys.

8.3 Compressed Air System: In case compressed air is used for the driving mechanism of circuit breaker, isolators,

earthing switches, ...etc., air blast circuit breakers are provided, the tenderer has to include in his offer a complete up-to-date automatic (start and stop of compressors) with all alarm indications for local and remote indications in the control room in addition to potential-free contacts for signalling the troubles to the supervisory control centre.

The compressed air system shall comprise of 433 volts, 3-phase, 50Hz, motor compressor units for air-blast circuit breakers, and pneumatic drive of 132kV equipment, these should be provided with local receivers with adequate capacity for two or more closing operations before the local air pressure reaches the low pressure lockout limit, without being replenished by the control air storage receivers.

The compressed air system shall be of the duplicate centrally operated air generating equipment of adequate capacity to supply the 132kV switchgear or air-blast circuit breakers and any other associated equipment shall be provided. Tenderers should guarantee that the compressed air shall be free from dust and moisture under the specified climatic conditions.

Heaters or any other dehydrants for conditioning the compressed air at the airblast circuit breakers or local equipment with the switchgear is not allowed. Full details of air consumption for each type of use (i.e. airblast C.B’s, C.B. under drive, isolator drive, ...etc) shall be stated in the tender referred to storage pressure in the control receivers.

Compressed air pipe system shall be of the duplicate (Ring) system with the necessary valves for maintaining air supply to any one equipment in case of leakage at one point of the piping. Pipes shall be of copper adequate size and strength to withstand the working pressure/s and detailed calculations to prove this must be submitted for approval. Means shall be provided for expansion and contraction compensation of these pipes due to temperature variations.

Detailed calculations for the capacity of main receivers related to the consumption of compressed air shall be submitted for approval.

The contract price shall include separate local panel equipped with pressure meters, ON/OFF push buttons for operation, ON/OFF indication, motor/compressor trouble alarm indications, protective gear, auxiliary relays/contactors or miniature circuit breakers with auxiliary contacts for local and remote supervisory alarm indication.

The compressed air system shall also comprise of safety valves, lock-out devices for high pressure and alarm of loss of air pressure. All insulating parts in contact with compressed air shall be of non-hygroscopic and non-inflammable materials.

Descriptive literature with full details of the main features and layout arrangement must accompany the tender.

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However, the compressed air system shall mainly comprise of the following:- i) Two air compressor units complete with air dryers and filters. ii) Two high air pressure storage receivers. iii) One control protection panel iv) One set of copper piping, interconnecting all the high pressure air storage receivers,

reducing valves, contact manometers, high and low pressure gauges and switches, automatic drain valves, signalling and indication devices for high and low pressures, A.C. failure and all other material to complete.

v) One set of duplicate copper piping with branches for each equipment (C.B. isolator, ...etc) including isolating valves, joints, .....etc. to complete the system.

8.4 Fire Protection: 8.4.1 General: The substation design shall be such as to comply with the following requirements and be

subject to the approval of the Ministry and Kuwait Fire Department respectively. The contractor shall be responsible for obtaining all information necessary to prepare the designs accordingly. The following outline specifications shall be the basic requirements of MEW.

Any additional or modified requirements to assure the efficient operation of the system but within the scope of supply and subject to approval of the Fire Authority shall not entitle the contractor for any claims of additional costs. No claim for delay will be entertained.

8.4.2 Structural Fire Protection: The fire resistance of the structural elements shall be as follows: a) Basements (including basement roof) 2hrs b) All other structural elements 1 hr For the purposes of calculating fire resistance of reinforced concrete elements, the

recommendations of B.S. CO 114 Appendix 'A' may be used. 8.4.3 Means of Escape: Adequate means of escape shall be provided from all parts of the building and in general

shall be as follows: From the basement, a minimum of two stairways shall be provided with direct access

within protected route to the outside. From all parts of the building, a maximum of 30metres travel distance shall be permitted to a protected stairway or external door if required.

All corridors and stairs shall be provided with self-contained emergency lighting rated at 1hour including illuminated exit signs at each exit from each floor (including basement). These are to be automatically switched on in case of the substation A.C. supply failure only.

8.4.4 Fire Enclosures: All rooms normally specified as being required for the substation shall be considered as

fire enclosures and all openings between enclosures or to corridors, etc.., shall be sealed in an approved manner to have fire resistance of 1 hour except doors between switchgear rooms, transformer shelters and basement zones to have fire resistance of 2 hours. Materials used shall be in accordance with B.S.476. Doors and frames, closing with 25mm rebates, shall be 1 hour or two hrs fire resistance to BS.476 certified by approved authority. All openings between floors shall be considered as being between fire enclosures.

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8.4.5 Fire Extinguishing Equipment: Fire extinguishing equipment shall be of approved type and full technical specifications

and drawings shall be submitted for approval by Kuwait Fire Department. The following principles may be applied:- i. Transformers, water deluge system as specified under separate clause of this

specification, the detectors shall work due to temperature rise. ii. All control cables used throughout the substation shall be of the free retardant type

except for internal wiring in the control and relay panel, marshalling cabinets, local control cubicles, ...etc. These fire retardant control cables to be tested according to IEC-332-4970.

iii. All power cables including low tension cables connections to battery chargers, compressors, pumps, etc shall be painted by one hour fire resistance material.

iv. Each phase of the 132kV cable sealing end boxes shall be protected by aluminium shield of semi-circle shape and of suitable length to shield cable oil bursting from the 132kV cable gland (in case of internal flash-over in it) to be directed down. Under each 132kV, 3 single phases cable boxes, a sill of concrete projecting with 10cms above basement finished floor level has to be constructed. This shall form a container to receive the cable oil as a result of the above. In case XLPE cables are used then the fire fighting system is not required for the concerned compartment.

v. For putting out the fire in the basement, a central type dry chemical powder system with the main container located in the fire fighting gas system room shall be provided. The powder container capacity shall be sufficient for the biggest fire zone and system of piping and valves shall be arranged for discharge of powder to the zone on fire only. In any case the capacity of the cylinders of dry chemical powder shall be sufficient for three bays, the one on fire and two adjacent bays (one on each side). In case XLPE cables are used, then the fire fighting system is not required for the concerned compartment.

Alternative arrangement as may be proposed by the tenderer shall be subject to MEW and KFD approval, however this will not change the contracted price.

vi. Smoke detectors shall be used for sensing the fire breakout in the basement. Detectors shall be of the ionization type.

vii. Change of make, size, number, arrangement, ...etc of the fire system to the satisfaction of the Purchaser will not entitle the contractor to any extra charges.

viii. For 33kV and 11kV switchgear, the fire fighting gas system required under items 8.4.5(iv) above shall also be used here for the circuit breaker and cable box compartments only. In case SF6 gas filled or vacuum circuit breakers and XLPE cables with heat shrinkable termination (Raychem type) are used, then the fire fighting gas system is not required for the concerned compartment. The gas system shall be arranged for discharge in the panel on only.

ix. All openings between any two fire enclosures and which are used for cable, pipe, etc passage shall be sealed with fire resistance material having a resisting time of two hours. The arrangement and material shall be subject to the approval of the Purchaser.

x. The various fire enclosures of the building shall be provided with the following fire detecting system:

1.i Charger Room: One smoke ionization detector to be provided on the ceiling in addition to heat

detectors in each charger and auxiliary d.c. voltage panel. 1.ii Control Room: Smoke ionization detectors to be provided on the ceiling. 1.iii Communication Room: One smoke ionization detector to be provided on the ceiling.

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1.iv Mezzanine: Ionization smoke detectors and heat detectors to be provided. 1.v 20KV, 6.6KV Neutral Resistors Room: One smoke ionization detector to be provided on the ceiling. 1.vi LV Board Room: One smoke ionization detector to be provided on the ceiling for each room. 1.vii Cable Basement and Gallery: Ionization smoke detectors and heat detectors to be provided. 1.viii Battery Room Spare & Store Room: Heat detectors of 80oC fixed temperature explosion proof type to be provided. 1.ix Spare & Store Room: 1. Smoke ionization detectors to be provided. 2. 33kV and 11kV switchgear, heat detectors of the fixed temperature 100oC and

120oC for alarm and trip discharge for the fire fighting gas system shall be provided and installed in the concerned compartments.

3. The detectors associated with the battery chargers shall be of the two stage type giving alarm at first followed by trip order to incoming supply circuit breakers.

4. Detectors used on the basement shall actuate the powder system operation and issue a trip order to the incoming supply circuit breakers to that zone on fire only.

5. Where two kinds of detectors are used in any one fire zone, the detection system shall be of the double knock type and these through double line dependancy and installed on two different line cards.

6. The make, type and number of the detector, fire fighting gas cylinders, extinguishers, type of paint, material for sealing of openings, etc, shall be fully to the approval of the purchaser and any modification required shall not entitle the contractor for any extra charges.

8.4.6 ARGON, FM200 & INERGEN FIRE FIGHTING GASES: The above gases systems shall consist basically of the following: i) Two sets of cylinders (one set as standby) housed in a separate room. Each set shall

be sufficient for the largest zone as mentioned above. ii) Necessary piping of the ring system complete with proper size and type of nozzles. iii) Means of continuous checking of the gas content in each cylinder shall be provided

and in case of leak in any, an alarm shall be indicated in the fire alarm panel. iv) Provision of automatic switch-over to the standby set of cylinders, so that in case the

set in operation position does not respond to a received signal from the detecting system, the standby set will immediately put in operation. An alarm indicator of the failure of the set in operation shall be shown on the fire alarm panel. Cylinders to be equipped with liquid gas level indicators and separate control panel for gas system to be provided. Safety valves to be provided for both halon and dry powder cylinders.

8.4.7a) The basement and mezzanine shall be provided with exhaust fans for ventilation under

normal operating conditions. These fans shall be provided with dust filters at the inlet and with automatic dampers which shall close in case of occurance of fire break-out.

The staircase shall be provided with an openable window to outside the building for fresh air-intake. However, these shall be provided with dust filters.

b) Manually operated fire extinguishers of the type BCF 1211 shall be provided at strategic points throughout the building. Generally, one extinguisher shall be provided at each exit to the stairways. In addition, main equipment rooms shall be provided with one fire extinguisher adjacent to each exit door.

c) Fire Alarm Panel: It should be noted that an air-conditioned room is to be provided for fire alarm panels of

fire fighting gas and dry powder fire fighting panels located near the main entrance of the substation building. One fire alarm panel shall be provided and installed in the control

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room. This shall be with an annunciator showing various fire enclosures in the substation. All fire alarms received from the different detectors including that of the water system for transformers shall give local alarm indication and audible sign alarm in all floors with connection for remote signalling to the National Control Centre. The panel shall also be provided with locking-out facility for any of these alarms, one common alarm signal shall be provided to be displayed at Kuwait Fire Dept., where connection of this alarm from the fire alarm panel shall be through telephone cable and shall be carried out by others. One “Fire Fighting Alarm” and one “Fire Fighting Fail Alarm” to be transmitted to NCC.

Manually operated fire alarm shall be provided at each exit for each floor and in each main equipment room. The manually operated alarms shall be also signalled to the National Control Centre.

Additional key switches shall be provided for defeating of the alarm/trip/operation halon system needed when substation is under maintenance.

Fire alarm installation shall be in accordance with BSCP 5839:1980 panel to be to BS 3116:1974.

d) Flame Proof Areas: Battery rooms shall be considered as flame proof areas and all electrical fittings (lights,

permanently operated fan with key operated isolation switch, ...etc) flame proof rated to Hydrogen BSS.4683. All electrical switches to be external to these rooms.

e) Air Conditioning and Ventilation: In case airconditioning system uses ducts fire dampers at compartments walls (triggered

by fusible links) have to be provided. A/C system to be automatically shut down when any fire alarm in the airconditioned rooms breaks out.

f) Adjacent Buildings: Where substation buildings are not surrounded by a solid boundary wall, the contractor

shall pay particular attention to the requirements of Fire Department regarding the size and type of external doors and other openings. The location of adjacent buildings shall be taken into account in determining the fire resistance period of the door and finishing materials which shall have a fire resistance time of not less than three hours.

g) Standards: All fire protection equipment and materials shall conform to recognized British Standard

or MFPA standards. The cost of the above fire fighting equipments has to be filled in Schedule “J-1” of Prices

and Unit rates. All operating instructions and identification of various zones of fire fighting is to be

provided in the substation both in English and Arabic languages. N.B: Sub-clauses 8.4.5, 8.4.6 and 8.4.7 described above, the tenderer shall submit all

the design and installation criteria with full reference to the American NFPA standards and codes of practice. However, the tenderer may base his offer on BSS standards provided that it does not contradict or be inferior to the NFPA standards. Regarding 8.4.2, 8.4.3, 8.4.4 and 8.4.7 (d) and (f) the design and material shall confirm to either BSS or NFPA standards subject to MEW approval.

8.5 Telephone Facilities in the Substation: Telephone facilities to NCC and DCC are required and these are mainly as follows: a) Distribution box of two lines capacity in the tele-communication room. Inner line has outlets in telecommunication room, control room, office, 132KV

switchgear room and marshalling cabinets. The other line has outlets in tele-communication room, control room, office, 33 &

11KV switchgear rooms, 33 & 11KV marshalling cabinets (as applicable).

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b) The locations of the above outlets are as follows: Control Room: The outlets have to be fixed on a riser of 15cms over the floor, underneath the

Control desk. Switchgear Room: The outlets should be wall type one metre over the floor and front of the middle of

the switchgear. Telecommunication Room, Offices: It should be wall type in a suitable place 50 cms over the floor. Marshalling Cabinets: The outlets should be close to the marshalling cabinets and wall type 50cms over the

floor. c) The writing between the D.B and the different outlets by a suitable conduit.

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PART IX TECHNICAL SPECIFICATION NO.MEW/SS/9 PPOWER CABLES AND CONTROL CABLES

9. General: The work covered by this specification includes the supply and installation of 132kV, oil-

filled cable feeder tails and power and station transformer cable tails of all voltage levels. The 132kV O/F cable feeder tails shall be supplied in accordance with the specified total

lengths of all circuits. However, the manufacture of these cables shall not be started without first obtaining the written approval of the Purchaser who will decide the cable drum lengths to suit the approved cable routes. Making of road crossings outside the substation boundaries is not part of this specification, however, laying of cables and pulling through these crossings must be included in the offer price. Surplus cables of length of 30metres and above only shall be delivered to MEW Stores by the Contractor. These cables shall be wound on drums and protected against sun rays by battens or other approved method since they will be stored in the open. For oil filled cables the drums shall be complete with oil pressure tanks and pressure gauges to keep the oil pressure inside the cable. Other prices of cables shall be considered as scrap and disposed off by the Contractor.

Regarding transformer cable tails of all voltage levels, the Tenderer shall include in his offer the cost of supply and installation and jointing complete in every respect all necessary cables and accessories for the purpose. Attention of Tenderers is drawn to the fact that the quoted price should be based on the maximum length that may be needed in accordance with the layout arrangement of the substation as finally approved by MEW. If for any reason the approved layout is modified resulting in an increase of the cable lengths, this will not entitle the Contractor for claim for any extras to the contract price. After complete installation of work, any surplus quantities of cables, accessories...etc shall be removed by the Contractor from site(s) and disposed off by carting away to his stores or dump and the cost of such should be included in the offer price.

9.1 Operating Conditions: The cables shall give trouble free service under the worst site conditions (climatic and

soil) encountered in Kuwait and shall carry their rated current continuously under the worst climatic conditions which prevail in summer (see clause 1.4) and the soil conditions mentioned below and shall withstand the maximum fault currents stated in this specification without damage or deterioration.

a. The cables will be exposed to direct rays of the sun at the terminations at the outdoor sealing ends and at the transformers and shunt reactors. They should be capable of withstanding such exposure continuously in service without any deleterious effect on the insulation, sheathing or covering. They should also be suitable for storage in the open for a period at least two years without battens or shuttering. For protection of cables and cable sealing ends where used on power transformers and reactors, sun shielding shall be provided.

b. The cables will be laid partly in ducts or concrete trenches, but where cables are buried in the ground, this should be at a depth of 1.5meters for 132kV cables and 1.4metres for 33kV cables where soil varies from sandy to rock-like gatch compared to dry hard clay, with a corresponding ground thermal resistivity “g” of 120oC cm/watt and a ground temperature varying from 35oC in summer to 15oC in winter. For 11kV and 1kV cables, depth of laying shall be 90 and 75cms respectively.

The soil in Kuwait is very corrosive. Sulphate reducing bacteria is common to all soils in Kuwait areas and as the soil is generally rich in sulphates, the anaerobic conditions which may arise in contact with buried pipes and cables favour the development these anaerobic organisms which generate hydrogen sulphide and consequently render these areas most corrosive.

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In view of the high temperature encountered in Kuwait, it should be stressed that PVC plasticizers should be of long chain high molecular weight type to reduce the loss of plasticizer in the hot and corrosive conditions. This prevents shrinkage of the PVC with subsequent cracking of the film.

Typical analysis of the soil sample is as follows:- Appearance : Wet coarse sand with some

clay Ph value of water in contact with the sands : 10.00 Calcium sulphate as CaCO4 : 25.00% dry basis Calcium carbonate as CaCO3 : 40.00% dry basis Magnesium sulphate MgSO4 : 6.00% dry basis Sodium Chloride as NaCl : 5.00% dry basis Iron as Fe2O3 : 2.00% dry basis Sulphate reducing : Present Moisture : 15.00% N.B. The sand is not corrosive under dry aerated conditions, but under anaerobic

conditions, the sulphate reducing bacteria in the sand will result in serious corrosion of metals in contact with the sand. The cable coverings over the lead sheath as stated in these specifications are designed to combat this. Where PVC (as sheath covering or overall covering) is used, the PVC should be suitable for the soil conditions. Tenderers should confirm in their offers that the PVC will be suitable of these conditions.

9.2 General Specification Applicable to Power Cables: The cables shall have insulation levels to withstand any voltage surges that may occur due

to switching operations, sudden load variations, faults, etc. The cables shall satisfy the requirements of BSS.6480 for paper insulated cables as a minimum and IEC 141-1 & ESI-09-4 standards for oil filled cables and IEC502 & IEC840 for XLPE cables, as well as the requirements of these specifications.

9.2.1 Conductors: The conductors for the 132kV, 33kV & 11kV and 1000 volts single core and 11kV 3 core

cables shall be made from clean and smooth stranded plain annealed high conductivity electrolytic copper wires laid up and shaped into circular cores complying with IEC 228 and BSS 6480. Conductivity should not be less than 100% international not less tan 100% international standard. Oval or sector shaped conductors will not be accepted. Aluminium conductors for these cables will not be accepted.

9.2.2 Insulation: a) The insulation for 132kV 1/C, 33kV 3/C oil filled cables and 33 & 11kV PILC&S shall be

of the best quality wood pulp kraft paper. All PILC&S cables shall be of the mass impregnated non-draining type.

b) The insulation for the 11kV, 3/C and 1/C and 1000volts single core cables shall be hard grade, heat resisting cross linked polythylene (XLPE) applied by an extrusion process. The insulation shall be free from any contaminations larger than 0.25mm in its largest dimensions or perosities or voids larger than 0.13mm. The maximum number of voids between 0.5mm and 0.13mm allowed shall be 30 voids per cubic of insulation. In plant repairs of the insulation are prohibited unless specifically agreed to by the Purchaser.

The XLPE insulation shall be applied by a combined extrusion and vulcanization process and shall form a compact homogenous body.

c) The insulation shall withstand an impulse test voltage of 650kV, 195kV and 95for 132kV, 33kV and 11kV cables respectively.

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9.2.3 Lead Sheath: The sheath where specified shall be of lead alloy ”E” for solid cables conforming to BSS

801. For oil filled cables the sheath shall be either of lead alloy type 1/2C or tellerium allowed lead (Kb-Pb Te 0.04) conforming to DIN 17640. The quality of extrusion shall be of the highest order so as to exclude the possibility of any weakness in the sheath. The sheath for all types of cables should be applied using continuous lead sheath process by using continuous extrusion machines. Extrusion by discontinuous machines will not be accepted. Aluminimum sheathed cables will not be accepted for any type of size of cables.

For the 1000volts cables, the sheath shall be of PVC. The PVC insulation shall be free from foreign materials and defects liable to reduce the electrical strength of the insulation and shall be type 9 (Table 1) of BS 6746. It shall be applied by any extrusion process and shall form a compact homogenous body.

9.2.4 Armour Wires: All armour wires (where specified) shall be galvanized steel to B.S. 1442. Galvanizing

shall be carried out in accordance with BSS 443. Sizes and the numbers of wires shall be stated in the schedules.

9.2.5 Metal Tape Reinforcement: If metal tape reinforcement of lead sheath is specified, this will consist of 2 layers of non-

magnetic material, stainless steel tape or hard copper tape or tin bronze with suitable bedding under the tape reinforcement.

9.2.6 Compound: The compound used shall not melt or run when exposed to the temperature prevailing

during transit or at site in Kuwait during operation. 9.2.7 Serving: The soil in Kuwait is naturally very corrosive and it is essential therefore that the serving

of the cables be designed to prevent corrosion. Reference should be made to operating conditions described in this specification.

9.2.8 Graphite Coating: A thin layer of graphite coating is to be applied to the outer covering to permit electric

tests. 9.2.9 Lime Wash: The lime wash should be such as to prevent adhesion between turns and layers of cables

and between cable and drum at temperature likely to be met with during transit or storage in the open.

9.2.10 Cable Lugs: The cable lugs shall be of copper of the same quality as the conductor. The length of the

above shall not be less than 65mm for 300sq.mm 11kV cables and 120mm for 1000sq.mm 1000volts cables. The lug bore thickness should not be less than 10mm. Dimensioned drawings of the lugs shall be submitted with the offer.

9.3 Details of Power Cables and Pilot Cables: 9.3.1 Oil-Filled 630sq.mm 1/Core 132kV Cables: i) Conductors: The conductors shall be of stranded plain annealed high conductivity copper shaped into

circular cores and shall have a cross-sectional area of 630sq.mm and formed with central oil duct of 12mm diameter.

ii) Conductor Screening: Two layers of semi conducting carbon paper tapes of a total nominal thickness of 0.2mm

shall be applied over each conductor.

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iii) Insulation: The thickness shall not be less than the value corresponding to a peak impulse voltage

level of 650kV and system highest voltage of 145kV, but the minimum thickness shall not be less than 8.5mm.

iv) Core Screening: Two layers of semi-conducting carbon paper tape having a total nominal thickness of

0.2mm shall be applied over each conductor and a metalized paper or non-ferrous metal tape screen shall be applied over the paper insulation and reinforced by a copper woven fabric tape.

v) Sheathing: The cable shall then be drawn either into lead alloy ½ C conforming to BSS 801 or

tellerium alloyed lead (Kb-Pb Te 0.04) conforming to (DIN 17640) and lightly reinforced by means of helically applied tapes. The minimum average thickness shall not be less than 2.5mm and the minimum thickness at any point shall not be less than 2.3mm. The sheath should be applied on the insulated cable using continuous lead sheath process (See clause 9.2.3 above)

vi) Serving & Bedding: The following layers shall be applied over lead alloy sheath: a. Coating of water proof insulating compound. b. Suitable bedding and metal tape reinforcement which shall consist of two layers of non-

magnetic material (tin, bronze, stainless steel or hard copper tapes) and further served as follows:-

c. Outer covering of extruded Black PVC jacket of minimum average thickness at any point not less than the values given in table 1 below. The PVC shall conform to BSS 6746 and shall fulfill the test requirements for PVC type 9 of table 3 of BSS 6746 as minimum and shall be suitable for site conditions stated under clause 9.1.

The PVC sheath shall be embossed with voltage designation (132kV) and the cross-section area of conductor and the manufacturer’s name and year of manufacture and with same manner described in BSS.6480 and ESI standard 09-4.

Tenderers should submit with their offers a guarantee for the suitability of the PVC to the site condition mentioned in this specification .

d. Graphite coating. e. Overall lime water.

Table Calculated diameter under oversheath

Minimum average Thickness

Minimum thickness at any point

Above mm Upto and including mm

mm Mm

25 30 2 1.6 30 35 2.2 1.77 35 40 2.4 1.94 40 45 2.6 2.11 45 50 2.8 2.28 50 52.5 3.0 2.45 62.5 77.5 3.3 2.71 77.5 -- 3.6 2.96

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9.3.2 Oil Filled 240 sq.mm. Single Core 132 kV Cables: i) Conductors: The conductors shall be of standard plain annealed high conductivity copper wires shaped

into circular cores of a cross sectional area 240 sq.mm. and formed with central oil duct of 12 mm.diameter.

ii) Conductor Screening: Two layers of semi-conducting carbon paper tapes of a total nominal thickness of 0.20

mm. iii) Insulation: The thickness shall not be less than the value corresponding to an impulse voltage level of

650 kV peak and system highest voltage of 145 kV but not less than 9.6 mm. iv) Core Screening: A metalized paper or non-ferrous paper metal type screen shall be applied over the paper

insulation of each core which shall be reinforced by a copper woven fabric tape. v) Sheathing: The cable shall then be drawn either into lead alloy ½ C confirming to BSS 801 or

tellerium alloyed lead ( Kb-Pb-Te—0.04 ) confirming to DIN 17640 and lightly reinforced by means of helically applied metal tapes. The minimum average thickness shall not be less than 2.3 mm and the minimum thickness at any point shall not be less than 2.16mm (see Clause 9.2.3 ).

vi) Serving & Bedding: The following layers shall be applied over the lead alloy sheath: a. Coating of water proof insulating compound. b. Suitable bedding and metal type reinforcement which shall consist of two layers of non-

magnetic material ( tin-bronze, stainless steel or hard copper ) and further served as follows:-

c. Outer covering of extruded Black jacket of minimum average thickness and minimum thickness at any point not less than the value given in 9.3.1 above. The PVC shall conform to BSS 6746 and shall fulfill the test requirements for PVC type 9 of table 3 of BSS 6746 as a minimum and shall be suitable for site conditions stated under clause 9.1.

The PVC sheath shall be embossed with voltage designation (132 kV ) and the manufacturer’s name and with the same manner described in BSS 6480 and ESI standard 09-4. The tenderers should submit with their offers a guarantee for the suitability of the PVC to site conditions mentioned in this specification.

d. Graphite coating. e. Overall lime wash. 9.3.3 Solid 1000sqmm Single Core 33kV PILC&S Cables: i. Conductors: The conductors shall be stranded plain annealed high conductivity copper wire shaped into

circular cores and shall have cross sectional area of 1000sq.mm. ii. Insulation: The insulation thickness should be designed for an impulse voltage of 195kV peak but the

thickness shall not be less than 6.8mm. iii. Screening: Screening over the conductor and over the insulation shall be provided as per clause

9.3.1(H). iv. Sheathing: Lead alloy E or ½ C Tellerium alloyed lead (KbPb-Te-0.04) minimum average thickness

not less than 2.3mm and minimum at any point not less than 2.08mm. v. Serving: Outer covering of extruded black PVC jacket of minimum thickness at any point not less

than the values given in Table 1 under clause 9.3.1 of this specification. The PVC shall conform to BSS 6746 and shall fulfill the test requirements for PVC type 9 of Table 3 BSS 6746 as a minimum and shall be suitable for site conditions stated under clause 9.1.

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The PVC sheath shall be embossed with voltage designation 33kV cross-sectional area of conductor and the manufacturer's name, manufacturing year and with the same manner described in BSS 6460 and ESI standard 09.3.

9.3.4 Solid 500 & 400 & 240sq.mm. Single Core 33kV PILC&S Cables: i) Conductors: The conductors shall be stranded plain annealed high conductivity copper

wires shaped into circular cores and shall have cross-sectional area of 500sq.mm / 400sq.mm. / 240 sq.mm as may be specified in the Details of Equipment.

ii) Insulation: Thickness shall not be less than 6.8mm and as 9.3.3(ii) above. iii) Screening: As 9.3.3(iii) above. iv) Sheathing: Same as 9.3.3(iv) above but with minimum average thickness and minimum at

any point as follows: - for 500sq.mm. & 400sq.mm. 1.9mm & 1.7mm - for 240sq.mm 1.8mm & 1.6mm v) Serving: As 9.3.3(v) above. 9.3.5 Solid, 1000sq.mm. 1/Core 33kV XLPE Insulated Cables: i) Conductors, shall be of stranded copper wires shaped in circular conductor and shall

have a cross-section area of 1000sq.mm. or 500sq.mm. complying to BSS 6360. ii) Insulation, XLPE as specified under clause 9.2.2(b) and in accordance with IEC

502. iii) Screening, shall be of semi-conducting thermoplastic or thermosetting material over

the conductor and similar layer extruded over the insulation as per IEC standard 502, but thickness should not be less than 8mm.

iv) Outer Sheath, shall be extruded PVC hard grade heat resisting type complying with BSS.6746(Table 1-type 9) and IEC 502 (clause 12).

9.3.6 Solid 500sq.mm. 1/core 33kV XLPE Insulated Cable: i) Conductors: same as 9.3.5 above but conductor cross-section area is 500sq.mm. ii) Insulation: same as 9.3.5(ii) above. iii) Screening: same as in 9.3.5(iii) above. iv) Outer Sheath, same as in 9.3.5(iv) above. 9.3.7 Solid 630sq.mm. 1/core 11kV XLPE Insulated Cables: The components of this cable is the same as that described above under 9.3.6. However,

the thickness of insulation, screen sheath, serving and bedding shall suit the rated voltage of 11kV and cross section of conductor and shall be in accordance with IEC standard 502.

9.3.8 Solid 500sq.mm & 630sq.mm. 1/core 11kV PILC&S Cables: i) Conductors: The conductors shall be of stranded copper wires shaped into circular cores and shall have

a cross sectional area of 500 and 630sq.mm. ii) Insulation: Thickness not less than 2.8mm. iii) Sheathing: Leading alloy E or ½ C or tellurium alloy nominal thickness not less than 1.8mm. iv) Serving: As 9.3.3(v) above. 9.3.9 Solid 3/Core 300sq.mm. & 185sq.mm 11kV XLPE Insulated Cables: i) Conductors: The conductors shall be of stranded copper wires shaped into circular cores and cross-

sectional area of core shall be 300sq.m.. and 185sq.mm. respectively. The conductor shall comply with BSS6360.

ii) Insulation: Cross-linked polythelene XLPE between conductors and between conductor and sheath as

specified under clause 9.2.2(b) above.

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iii) Screening: A semi-conducting screen shall be extruded over the conductor. This layer shall consist of

black semi-conducting thermo-plastic or thermosetting material, and shall be easily removable from the conductor. This layer shall have an average thickness of 0.38mm when measured over top of the strands and shall be cylindrical. A similar semi-conducting screen shall be extruded over the insulation without scratching the surface.

iv) Sheathing: PVC hard grade heat resisting type complying with BSS 6746 (Table 1- Type 9). v) Laying up and Bedding: The 3-core shall be laid up together with suitable semi-conducting tape, or an extruded

layer of semi-conducting material. vi) Armour: The cable shall be armoured with galvanized steel wires to give it mechanical strength and

also act as a low resistance earth return conductor. Electrical contacts shall be maintained between the core screens and the earthed armour through the conductive beeding.

vii) Short Circuit Rating: The cable shall carry without damages or undue stress a fault current of 18,000 Amps for

1.25 seconds after a continuous period of full load. Under these conditions, the final temperature of the conductor shall not be such as to damage the insulation.

9.3.10 Solid 1/Core 630, 500 & 300sq.mm 1000 Volts XLPE Cable: a) Construction: i) The conductors shall be of stranded copper wires shaped into circular conductors and shall

have a cross-sectional area of 300, 500 & 630sq.mm. shall comply with BSS.No. 6360. ii) Insulation: XLPE and it shall be applied by a combined extrusion and vulcanization

process and shall form a compact homogenous body. iii) Oversheath:PVC hard grade, heat resisting type complying with BSS.6746:1969 (Table 1-

Type 9). b) Current Rating: The current ratings of cables for the site and installation conditions mentioned above shall

be stated. These should be based on maximum conductor temperature in normal operating conditions not exceeding 90C. Where ratings are specified for only standard conditions, appropriate adjustment factors should be stated for Kuwait conditions.

c) Short Circuit Rating: Offers should be accompanied with short circuit current curves with XLPE insulation. It

is assumed the conductor is at its maximum operating temperature of 90C before the occurance of the short circuit and the maximum conductor temperature after a fault duration of 0.5 seconds will be 250C.

The cables shall carry the above short circuit currents without damage or undue stress. The formula used in evaluating the short circuit current should be stated. 9.3.11 34-Core Pilot and Telephone Cables: (associated with 132 kV Cable Feeder Tails) These cables are required for the conveyance of alarm, control, protection, telephone and

telemetry signals throughout the existing and future networks. These cables shall be of copper conductors, polythene insulated and polythene inner

sheathed armoured with galvanized steel wire armour and overall sheathed with PVC. The cable shall be insulated to withstand induced voltage level upto 15 kV and should generally comply with Electricity Supply Industry (ESI-09-6) standard as a minimum.

a) Make-up of Pilot Cables: i) 2-core (one pair): each core shall consist of copper conductor of cross-sectional area 2.5

sq.mm. \polythene insulated and the pair shall be screened for use with Solkor protection system.

ii) 4-core (two pairs ) : each core shall consist of copper conductor of cross-sectional area 2.5 sq.mm. polythene insulated and each pair twisted and screened for use with intertripping system.

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iii) Twenty eight cores : ( 14 pairs ) each core shall consist of copper conductor of cross sectional area of 0.645 sq.mm. unscreened and polythene insulated. Each pair shall be separated and twisted for use with telephony and telemetry system.

b) Conductor: The conductors shall comply with BS 6360 in so far as applicable for plain annealed

copper wires. c) Insulation: The cores shall be insulated with polythene of type (03) compound in accordance with

B.S.6234. The thickness of insulation shall not be less than 0.8 mm. d) Inner Sheath ( Bedding ) : The inner sheath shall consist of an extruded covering of black polythene which shall be of

type (03C) compound in accordance with B.S. 6234. The thickness of inner sheath shall not be less than 1.8 mm.

An overall screen made of copper around the 17 pairs shall be applied above the inner sheath. A suitable polythene bedding of minimum thickness of 0.5 mm. shall be applied over the overall screen.

e) Armour: The armour shall consist of one layer of galvanized steel wire complying with the

requirements of B.S. 1442 ( metric unit ) and of diameter not less than 1.6 mm. N.B. These cables shall be designed to withstand induced voltage level up to 15 kV.

However, the above insulation thickness and armour wire diameter are minimum and may have to be increased to suit the above induced voltage level and to meet the maximum attenuation requirements specified later.

f) Overall Sheath : The overall sheath shall consist of an extruded PVC jacket. It shall be also black in color

and withstand without deterioration during storage and site conditions outlined above. The PVC shall comply with B.S.No.6746/1969 (type 5 of table 1). The thickness of PVC overall sheath shall not be less than 1.9 mm. The sheath shall be embossed “ 34-core pilot cable ”, the name of the manufacturer and year of manufacturing.

g) Attenuation : The maximum attenuation of the audio pairs at 1KHz and at 10C shall not exceed 0.77

db/1000 M. The nominal attenuation of the audio pairs at the above conditions shall be 0.7 db/1000

meters. The measured attenuation shall be corrected by multiplying the value obtained (1 + .002 ) (T-10), where T is temperature of the cable in oC.

h) Cross-Talk: Cross talk between all pairs shall not be worse than 74 db at 1300 Hz. i) Impedance : Nominal impedance at 1KHz shall be 490 ohms. j) Method of Twining and Laying: The lengths of lay of conductors forming pairs shall differ for adjacent pairs and shall not

exceed 150 mm. The lengths of lay of the pairs shall be chosen so that cross-talk is as small as possible.

The direction of lay of successive layers is at the discretion of the manufacturer. k) Identification of Cores: The cores shall be clearly identified by colors. The following scheme of identification

shall be used :- Blue/White For solkor Yellow/White ) Intertripping and Green/White ) interlocking Brown/White ) Blue/White ) Blue/White/white ) Blue/Yellow/white )

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Blue/Green/White ) Blue/Brown/White) Blue/Slate/White ) Yellow/Slate/White ) Yellow/White/White ) Telemetry and Yellow/Green/White ) Telemetry Yellow/Brown/White ) Yellow/Slate/White ) Green/White/White ) Green/Brown/White ) Green/Slate/White ) Alternatively, the following scheme of identification can be offered: For solkor : Blue/White For inter-tripping : Red/Yellow Green/Brown For telemetry and : Black/Violet Telephony (Red/Yellow (Green/Brown, Alternative concluding Blue/White 9.3.12 Warning Tapes, Cable Protection Grid, Cover Tiles, and Joint Marker: The scope of this tender includes the supply of the necessary quantities of warning tapes

and cable protection grids and the installation of the same above the 630 sq.mm. 132 kV power cables, wherever the power cables are laid in the ground. The specification of these tapes and grids is as follows :-

a) Warning Tapes: The warning tapes shall be of orange colored (33 KV) & yellow colored (132KV). The

warning tapes shall be of high density polythene tape or any other alternative material. However, the materials offered should be suitable for site conditions mentioned under clause 9.1.

A guarantee for this suitability should be submitted with the offer. The tapes should not be less than 15 cms. width and 0.5 mm. thickness. This warning tape

should be labelled in capital letters, “ DANGER HIGH VOLTAGE CABLE” in both English and Arabic languages. The size of the letters should not be less than 4cms in length and the letters should be printed in black colour. A sample of this tape should be submitted with the offer and will be subject to MEW approval.

b) Cable Protection Net: A suitable cable protection net of yellow coloured (132kV) & orange (33kV) high density

polyethylene or any alternative materials suitable for site conditions mentioned in this specification.

A guarantee for this suitability should be submitted with the offer. The protection net shall be of 60 & 40cms and 2 x 60 and 2 x 40cms width for single

circuit and double circuits of 132 and 33kV cables respectively. The thickness of this protection net should not be less than 3mm.

The above tapes and protection grid shall be laid according to MEW specification for cable laying.

c) The 132kV cable feeder tails where laid in ground shall be protected by concrete tiles as per attached drawing No.MDA/1/560. At the free end of these cables, joint markers shall be supplied and installed as per drawing Nos. MC/7/143-E and MD/1//24E.

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9.4 Laying up of Power Cables: Soon after the works tests are completed, both ends of every length of cable shall be sealed

by means of a metal cup over each end and plumbed to the sheath. The ends shall be marked with the letters ‘A’ to ‘Z’ to indicate the running and tail ends respectively. Letter stamping shall be at least at two places for each end.

Tenderers are requested to include in their offer price for the provision of galvanized steel supporting bridges of the cage type with slides made inclined 30o to horizontal level. These bridges are needed for crossing of power cables to each other on the ground in the basement, avoiding touching so that current ratings are not affected. The design, dimensions and number of these bridges shall be sufficient to cover the crossing of all power cables included in this tender and also for future feeder cable circuits, however, this shall be subject to the approval of MEW site Engineer.

Provision of supporting structures and cable crossing bridges in the basement as may be approved by the Purchaser is also to be supplied for 11 kV outgoing feeders where cables will be supplied and laid by others.

9.5 Packing and Cable Lengths: Tenderers are warned that equipment is liable to every rough handling enroute from the

Factory to the site in Kuwait. It is essential that the packing is efficient and strong with extra reinforcement where necessary to ensure the safe delivery to site. All packages shall have the Purchaser’s order number, shipping marks and manufacturer’s identity mark clearly indicated.

The finished cables shall be wound on strong cable drums reinforced by rods of steel and provided with central core through which an axle can pass. The drums shall be provided with wooden battens to protect the cable from damage. The drums shall be adequately labelled to indicate particulars of cable, i.e. voltage, conductor size, number of cores, gross and net weight ...etc. The direction for rolling shall be recorded on the drum together with temperature at which measurement was made.

The drum length of each type of cable shall be proportioned to ensure that no straight through joints are needed. Drum and all packing shall be disposed off by carting to dump by the contractor and the cost of such shall be included in the offer price. All empty barrels are to be totally protected, closed for the re-use and to be collected, stored at a suitable place as per MEW instructions.

9.6 Cable Schedules & Records: The contractor shall take all records of the cables and submit 3 sets of standard 35mm

silver halide microfilm aperture cards photographed from the approved electrical & civil drawings for cables, and cable record drawings. The details of microfilm is given under clause 1.15 above.

The cable record drawings must be submitted, these records shall be carefully taken on site during the installation of the works. The final presentation of the records and schedules shall be approved by the Purchaser. The records shall show the routes, the exact location of each cable, the position of each termination and shall have schedules showing the phasing of joints, the date of jointing, the name of the jointer, the lengths between their terminations, the serial number of the cable drums, the direction of the lay of the cable, i.e. A and Z ends, soil conditions, positions of ducts and sectional inserts of cable trench giving the relative positions of the cable, tiles, depths and spacings. Any other services that cross the route of the cable shall be recorded. Measured values of resistance and capacitance shall be recorded for each length of cable between terminations. The records shall also include the route profile (to be measured by the contractor) with all the informations of the “As Built” hydraulic system ( No. of pressure tanks per phase, pressure tank and gauge levels etc... setting of pressure ... etc. ).

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9.7 Termination of 132 kV Feeder Tails: The arrangement of cables and the method of laying, installation and bonding shall be

subject to approval by the Purchaser. Cables, joints and terminations shall be supplied and installed in such a manner that the maximum voltage rise permitted on sheaths under full load conditions is 65volts. Bonding and earthing arrangements shall be suitably designed to meet this limitation. The minimum size of bonding lead shall be 300sq.mm copper and normally these shall be of the concentric type. All earthing connections shall be capable of disconnection for testing purposes by means of 3 single phase bolted links enclosed in water tight boxes.

9.8 Cable Laying and Installation: The cables will be partly buried directly in the ground and partly pulled through ducts.

Cables shall be laid direct from the drums into the trenches and special rollers shall be employed for this purpose. The cables shall be laid in Trefoil formation.

Where burying directly in the ground, the contractor shall excavate trenches of 1.5M depth from kerbstone, provide a bedding of 10cms of fine sieved sand at the bottom of the trench. After laying of power and pilot cables, the contractor shall provide a covering of soft sand to a depth of 15cms over the cable. Cable cover tiles shall then be laid over the line of the cable, covering both the power cable and its associated pilot cable. Each circuit shall be separately tiled.

Backfill the trench further 30cms of excavated material, laying of cable protection grid, further backfilling 20cms laying of warning tapes, completion of the backfilling to the normal ground level (See attached drawings).

Where cables are laid in concrete trenches or substation basement they shall be neatly arranged and single core cables shall be arranged in trefoil formation. Where cables are laid on trays or supported by cleats, they shall be neatly and symmetrically arranged. Cross-over shall be avoided as much as possible.

9.9 132kV Outdoor Sealing Ends: Where 132kV oil filled cables are to be terminated at one end by outdoor sealing end

boxes and other accessories, the creep age distance of the outdoor sealing end boxes shall not be less than 4818mm.

Tenderers shall attach to their offers drawings showing in detail the proposed method of terminating the cables. The other end of the cables shall be connected directly to outdoor 132kV switchgear through 1/core sealing end boxes.

The termination of the cables in the sealing ends shall also include the supply and installation of the necessary Hot dipped galvanized steel structures for supporting the sealing ends of the cables near the switchgear of the O/H line take off gantry, and shall also include making of the necessary foundations for the structures. These structures must be designed so as to make possible easy jump ring between the sealing ends and the switchgear bushings or the slack span conductor at the take off gantry.

The height of the steel supporting structures above ground level shall be such that the minimum clearance between the live parts and the ground shall not be less than 4600mm and the spacing between phases not less than 2600mm. Exposed cables shall be protected against sun rays by means of approved sun shield.

The installation work of these sealing ends shall also include the supply and installation of jump ring between the 132kV sealing ends and the slack span of the overhead line take off gantry including suitable bimetallic connections between the jump ring and the overhead line conductors. Also the sealing end shall have the suitable top connectors to connect the overhead line slack span to the sealing end.

The maximum distance between the sealing ends, take-off gantries or terminal towers can be taken jump ring arrangement shall be subject to MEW approval.

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9.10 Hydraulic Requirements: 1. An independent oil feed is required for each phase cable i.e. separate sets of tanks for each

phase. 2. "Long" routes shall be divided into separate hydraulic sections by using stop joints. 3. In each oil section under no load minimum temperature condition there should exist a

quantity of oil, known as “surplus oil”, which should be available to maintain pressure with an oil leak present until remedial section can be taken. As an absolute theoretical minimum quantity of surplus oil has been suggested as 10 litres but, in assessing practical designs. The Purchaser will expect to find proposals that load to quantities of surplus oil greater than this figure.

4. Preliminary hydraulic design details based on the foregoing principles and taking into consideration the cooling and heating transients will be settled with the Purchaser after the approved route has been issued. The contractor shall accept all requirements specified by the Purchaser’s Engineer at that time and at no extra cost if these requirements are greater than originally envisaged by the contractor at the tendering stage.

5. Pressure gauges shall normally be ranged from (1.00) to (+6.00) bars and be fitted at both ends of the oil section and also at both ends of the stop joints at least one pressure gauge with alarm contacts to be provided from one side of the oil section.

6. All hydraulic piping works, tanks...etc must be prevented from carrying power system fault current eg., by using insulating coupling connectors and all metallic parts of tanks, pipes...etc should be earthed.

7. Pressure gauges with alarm contacts shall be equipped with 2-stage contacts so as to detect a changed situation and bring out automatically in sequence the following actions:-

a) Firstly, an alarm signal to indicate that a pressure value has been dropped which is just below the minimum operating pressure.

b) Secondly, an initiation signal at emergency minimum pressure to cause the circuit be tripped out. The contractor shall wire up these contacts to marshalling kiosks provided by you in the substations. For en-route pressure gauges, the contractors shall connect these contacts via a suitable T-joint into an associated pilot cable. In case of using more than one set of stop joints in the feeder circuit, separate alarm cables to be used to transfer the alarm signals to the nearest substation from the concerned stop joint the price of which is included in tender price.

8. Gauges contacts shall be suitable for 240V AC/DC and each gauge terminals shall be connected to terminal blocks which shall be housed in water proof casing.

9. Valves: The oil control system shall be designed such that leak location and testing may be carried

out without the disconnection of any permanent pipework. Valves additional to those specified below shall be installed only with the approval of the

Engineer. i. Three valves per tank, one to feed the system, one to fill for boost the tank and one

for the gauge, the latter being of a three-way, two position type to facilitate testing of the gauge.

ii. One per manifold where two or more tanks are installed in an inaccessible position and the tanks are feeding to a single position.

iii. One for each individual oil feed. 10. Provision shall be made for the hydraulic testing of gauges i.e. it should be possible test

LOP alarms alarms by reducing the pressure in the gauge. If it is not possible to employ test blocks then the contractor should ensure any gauge, bleeding pipes shall be sealed off with a blank nut and nipple so that unintentional operation of valves will not result in loss of oil.

11. Oil pipes should be either PVC insulated copper or PVC oversheathed, steel armoured lead depending on circumstances of use-copper for inside substation and in open pits, but armoured lead for all buried applications. Buried pipes should be protected by cover tiles,

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protection net and warning tape. 12. Oil tanks and other hydraulic equipment should be provided with purpose-made earthing

lugs or bosses. Bonding cables for hydraulic equipment shall be of suitable size, copper, PVC insulated, single core.

9.11 Bonding and Earthing Requirements for 132/33kV Cables: For 132 & 33kV Cable Tail Circuits to O/H lines:

A- For 132kV Cable Tail Circuits: 1. Single point bonding of the power cable lead sheaths is required to eliminate sheath

circulating currents. 2. Cables and terminations shall be designed, manufactured and installed so as to result

in a fully insulated sheath and to permit the routine application of PVC over sheath test 10kV DC for 1 minute prior to commissioning and during the first two years of service, the anti-corrosion covering to be tested at six monthly intervals at 5kV DC for one minute.

3. The maximum permitted sheath standing voltage to earth under full load conditions shall be 65 volts.

4. For 132kV cables a stranded 300sq.mm. copper earth continuity conductor insulated with PVC (minimum average thickness 3.3mm) complying with BS 6346 so far as it applies, shall be provided along the whole length of each single point bonded circuit and in close proximity to the power cables with cables laid in flat formation, the earthing cable shall be installed between two of power cables and transposed midway. The earthing cable shall be connected at both ends to the main substation earthing system and at suitable position to the main sheath bonds for 33kV cables the cross section of earth continuity conductor shall be 120sq.mm.

5. Sheath voltage limiter units (SVL's) shall be connected to the unearthed end(s) of the tails. The star point of the SVL's shall be connected to the earthing cable specified in (4) above.

6. All sheath bonding connections shall be made via disconnecting link boxes so as to facilitate routine over sheath integrity testing. All bonding leads shall be PVC insulated, of conductor size 300 sq.mm. copper and be made as short as possible.

7. Link boxes shall be galvanized steel with lockable lis bearing externally the legend "DANGER – ELECTRICITY" and internally the legend "THESE LINKS MUST BE CLOSED WHEN THE CABLE IS IN SERVICE". The insulation shall be such as to withstand an impulse test of 17.5Kvp from link to earth and 37.5KV between links. Link contact resistance shall not exceed 20 micro-ohms. Links and contacts faces shall be tinned copper and shall be held firmly together by bolts. The legends should be written in both Arabic and English words.

8. Inside substations, the bonding cable from the "Earthy" end of the link box shall be connected to the inner earth ring bar. The specified 300 sq.mm. bonding cable shall be used to connect to the substation earthing system. The connection to the substation earth bar shall be made by brazing a flag connector to the bar and bolting the bonding. Inside substations, the bonding cable from the "Earthy" end of the link box shall be connected to the inner earth ring bar. The specified 300 sq.mm. bonding cable shall be used to connect to the substation earthing system. The connection to the substation earth bar shall be made by brazing a flag connector to the bar and bolting the bonding cable lug onto the flag cable lug onto the flag.

9. On termination glands there need to be earthing connection flags or bosses of sufficient size to accommodate the connection to the specified size of bonding cable.

10. On flanged joint sleeves there should be two such flanges, one on each side of the flanges that the bonding cable can be connected to both sides of the sleeve without having to rely on the electrical continuity of the flange bolts.

11. The foregoing paragraphs represent summary of significant requirements but it is expected that in case any queries arise on this topic reference would be made to internationally recognized source documents which would include the following:

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1. Electra paper No.28, May 1973 by Study Committee No.21. The design of

specially bonded cable system (also follow up paper No.47). 2. British Electricity Board document C55/2 insulated sheath power cable

systems. For 33kV Cable Tails to Overhead Lines: The sheath will be solidly bonded from both sides (as switchgear and at outdoor sealing

ends). B- Earthing Requirements for 132 & 33kV Complete Feeder Circuits: 1. Solid bonding of the power cable lead sheaths is required. The overall design shall

be such as to permit the routine application of PVC over sheath tests (10KV) DC for 1 minute prior to commissioning and during the first two years of service, (5KV) DC of 1 minute.

2. At straight joints the lead sheaths of the three single core cables forming one circuit shall be bonded together using insulated bonding cable (see 4, below) but without making any special provision for disconnection during sheath testing. The overall installation shall be sufficiently insulated from earth so as to withstand the sheath test. The connection to the lead sheath s may conveniently be made by connecting the bonding cable to the joint sleeves. If the sleeves are flanged then the bonding cable must be connected to both sides of the continuity of the flange bolts.

3. At terminations and trifurcating joints the lead sheaths of the three single core cables forming one circuit shall be connected to earth using insulated bonding cables (see 3, below) and via 3-phase link boxes (see 5, below).

4. Bonding cables for power cable sheaths shall in all cases, be of single core, 300 sq.mm. stranded copper, PVC insulated construction. The size of cable shall be used regardless as to the anticipated magnitude of fault current at any particular point in the network. The insulation thickness shall be 3.3 mm minimum average. The cable shall be embossed with the wording "ELECTRIC CABLE" – BONDING LEAD" and the outer surface of the PVC shall be graphite coated. The construction of the cable shall be in accordance with B.S. 6346 in so far as it applies. The insulation shall be spark tested at 25kV DC for 1 minute.

5. Link boxes shall be galvanized steel with lockable lids bearing externally the legend "DANGER – ELECTRICITY" and internally the legend "THESE LINKS MUST BE CLOSED WHEN THE CABLE IS IN SERVICE". The insulation shall be such as to withstand an impulse test of 17.5Kvp from link to earth and 37.5Kvp between links. Link contact resistance shall not exceed 20 micro-ohms. Links and contact faces shall be tinned copper and shall be held firmly together by bolts.

9.12 Joint Pits and Oil Pressure Tank Pits: All oil filled cable joints and oil pressure tanks shall be housed in suitable pits which shall

be designed and built in accordance with the following requirements for those either within or outside the boundary walls of substations. These pits (except buried type) shall be of prefabricated structural elements.

All pits, except buried type shall be provided with galvanized steel ladders and shall be such as to prevent the ingress of rain or ground water. The size of all pits shall be such as to allow comfortable working space for jointers. These pits shall be provided with manhole cover of adequate size to allow the removal of any equipment that may be required, this cover to be of circular type with clear opening of minimum diameter of 75 cms ready made cast iron. Padlocks shall be provided to manhole covers.

Tenderers shall submit design drawings and calculations which will be subject to the approval of the Purchaser. Nor more than one set of joints or one set of tanks shall be located in each pit (set per circuit). Also it will not be permitted to pass more than the cables of one circuit inside the pit, and thus if two circuits were specified, the cables of the

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2nd circuit will pass under the pit in concrete encased asbestos ducts to be constructed under the pit. The cost of this duct is included in the pit prices.

A) Pits within Substation Boundaries: Pits for joints and tanks shall be consisting of cast insitu concrete floor slab minimum 15

cms thick and reinforced with suitable steel mesh, 15 cms thick precast reinforced concrete walls with fair face finish internally. Top slabs shall be made of precast reinforced concrete, removable strips with a maximum width of 70 cms and each to be provided with galvanized steel handles for lifting and shall be adequate to sustain a wheel load of 4 tonnes or superimposed load of 500kgs/sq.M and to be designed in a manner to stop rain water. The level of the top cover shall be 20 cms above yard level. Suitable concrete or steel bollards shall be provided around the pits, 75 cms hgh and spaced at one metre centers.

1. In-situ concrete mix to be 1:2:4 with crushing strength of 240 kg/sq.cm. Crushing strength for precast reinforced concrete to be 320 kgs/sq.cm. 2. Stability shall be required for the pit as one unit under several working conditions. NB: For all 33kV cables, the contractor has to construct the above pits having suitable

dimensions. For 132kV cable circuits wherever it is specified that cables will be jointed to the SF6 switchgear, the contractor will have to construct the above pits and this should have internal dimensions of 3.5x2x2 M. However, for all the 132kV circuits where it is specified that cables will be jointed to 132kV cable tails laid by others. The contractor will construct a pit inside the substation for each 132kV cable circuit and having the same dimensions 3.5x2x2M and he will use this pit for accommodation of his oil tanks necessary for the circuit.

B) Pits outside Substation Boundaries: 1. Pits for straight joints shall be semi-buried type and shall consist of pre-fabricated

elements or steel mesh reinforced concrete base slabs minimum 15 cms. thick, concrete block walls and 30 cms. deep top R.C. the beams. The joint shall be protected using fiber glass sleeve and the space between the outer joint sleeve and the fiber glass sleeve shall be filled with bitumen. The completed joints shall be surrounded by sieved sand carefully compacted by hand to depth of 10 cms. above the top of the fiber glass sleeves. Precast paving slabs shall be placed on top of the pit back-filled with selected sand up to ground level. Suitably marker pad shall be placed on top of the pit back filled with selected sand up to ground level. Suitable marker pad shall be positioned 5cms above the surface. The whole arrangement shall be subject to MEW’s approval. Where sheaths bounding link boxes are required, they shall be installed in shallow pit adjacent to the straight joint and accessible from the surfaces where required asbestos or PVC 6" inch pipes to be encased in the concrete blinding to avoid blocking of electrical reserve for other circuits and their cost shall be included in the pit prices.

2. Pits for feeder joints and oil pressure tanks shall be of similar designs to (A) above, except that the covers to be designed to sustain a wheel load of 10 tonnes to the effect of a vehicle mounting adjacent to the pit top slab which shall be at a level of 20 cms above the ground level.

C) Link Boxes for Bonding : Link boxes for bonding purposes shall be installed in the basement near the respective

cable circuit and preferably to be wall mounted in such a manner as to be accessible at all times. In the case of unfilled joint pits, the link boxes may be positioned inside the pit itself. Bonding lead connections between joints and link boxes shall be suitably protected from mechanical damage. Contractors shall include in their submission showing the detailed arrangements proposed for installing these link boxes in each of the various circumstances specified.

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D) Earthing and Bonding of Oil Tanks: Insulated inserts are required in oil feed pipes to joints. Oil tanks shall be bonded and

connected to outdoor earthing ring by means of (30 x 5)sq.mm copper tape. Other hydraulic equipment such as oil pressure gauges shall be connected to indoor earthing ring by means of 2.5sq.mm copper conductor. The incoming armour wires of pilot cables should not be bonded to the alarm gauge metal work.

9.13 Asbestos Pipes: 1. All cables shall pass through approved ducts under roads and elsewhere as directed

by the Engineer. 2. Ducts shall be of 4" and 6" diameter asbestos pipes, purchased from the National

Industries Co. 3. Pipes shall be of standard quality with minimum crushing strengths of

450Kgm/sq.cm laid as one single length piece under the road or each carriageway where possible, both ends of pipe cut perfectly perpendicular to the body.

4. If more than one single length is to be used, both ends of pipes shall be butt-jointed, held firmly together in position wrapped with building paper or other approved material before casting of surrounding concrete.

5. All asbestos ducts shall be laid in mass concrete mix 1:3:6 extending 10cms below the bottom and 15cms above the top duct with 5 cms separation between the ducts.

6. Cement to be used for encasing of concrete shall be ordinary portland sand and coarse aggregate to comply with the specification.

7. Small lengths or cut pieces of pipes with multiple jointing to make one single length under any road crossing shall not be permitted.

8. Pieces of pipes shorter than 3.00metres long shall not be used unless under unavoidable circumstances.

9. All depths at which the ducts are to be laid under road crossing shall be agreed with the Engineer.

10. Both ends of all spare ducts under road-crossings shall be plugged by the appropriate soft wood plugs of tapering type approved by the Engineer before backfilling.

11. After laying of power and control cables through ducts, a sealing material such as Dense Mastic (plast) shall be used. It is necessary at first to clear the ducts of loose material by air jetting. The cables should be maintained centrally in the duct so that the sealant forms an even anulus around the cable.

9.14 Control Cable & Power Service Cables: All control and power service cables A.C and D.C including the multicore cables shall be

PVC tropical grade insulated cables and shall generally conform to the requirements of BS6346 and 6746 wherever applicable.

The multicore cables for control, alarm, indication, protection, current and voltage transformers secondary circuits shall be of 600 volts grade and those required for power service in the substation shall be 1000 volts grade.

Control and power cables supplied should be suitable for initial storage in the open yard and for continuous service after laying without any deleterious effects on the insulation and /or sheathing.

The control and power cables shall be tested in accordance with BSS 6346 and 6746 unless otherwise approved.

Tenderers shall furnish general particulars and guarantees for the cables specified as called for in the schedules.

Except when otherwise specified, the smallest cross section area of control cable conductors to be used shall be 2.5sq.mm.

Regarding internal wiring of relay panels, wired of cross sections 1.5sq.mm and 0.8sq.mm

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can be used for signal circuits and connections between modules of electronic relays (if applicable) and as required under class 1.10 of the specifications.

All control cables between sub-station equipments shall be of the fire-retardant type in accordance with IEC. Publication 332-1970 and BSS 4066 Part 1/1980 as required in clause 8.4.5 (iii) of this specification.

The contract price shall include cleats, trays and other fixing arrangements for the cleats and trays, etc....in the basement or trenches and they shall be subject to the approval of the Purchaser.

The contractor shall not be entitled to any extra charge required to complete the work according to drawings as finally approved by the purchaser, cable terminal glands and other accessories including material that may be required to prevent entry of vermin and dust into the cubicles shall be applied.

Particular attention should be given to cable entries from basement into the switchgear, control and relay boards, L.T. distribution board and battery charger cubicles, etc....where necessary, bottom plates with all the necessary terminal glands and fire resisting material has to be provided to prevent access to vermin from underneath the equipment and to prevent spread of fire from one zone to another.

When designing control cable layouts, the contractor shall provide sufficient trays to accommodate one or two layers of control cables only on any one tray. All iron trays, iron cleats and cleat parts and iron supports shall be hot dip galvanized. Control cables exposed to sun should be protected in an approved manner.

9.15 Factory Testing: The contractor shall carry out all routine and type tests on all equipment and accessories

included in the contract in accordance with the relevant British Standard Specifications unless otherwise approved. The contractor shall carry out any additional tests that are necessary to determine that the work complies with the requirements of this specification.

All samples used for testing shall be at the contractor’s expense and shall not affect the lengths of cables to be supplied under this contract. This also applies to other accessories.

All instruments used for testing purposes shall, if approved by the Engineer, be calibrated by an approved authority.

9.15.1 Control Cable Tests: The cables shall be tested in accordance with BS.3346 and 2746 as applicable or V.D.E

unless otherwise approved. A) Routine Tests: All lengths of completed cables shall be tested before despatch according to the following: 1) Voltage tests: The completed cable shall be subject to a voltage of 3KV r.m.s for five minutes. 2) Insulation Resistance Tests: The insulation resistance between each conductor and the remaining conductors in

the cable which shall be bunched and earthed shall be measured immediately after the voltage test in (1) above and shall not be less than 15meg.ohms.

3) Conductor Resistance: The conductor resistance shall be measured and the same shall not be greater than

the guaranteed figures. B) Type Tests: Measurements of thickness of insulation and sheath. A representative sample of each type and size of manufactured cable shall be examined

and the minimum and average thickness of insulation and sheath determined. These shall not be less than

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the guaranteed long and shall be taken not less than 30cms from the end of drum length. The PVC insulating and sheath of the cable shall be subjected to the tests specified in

Table 1 and 2 of BSS 6746 and shall comply with the requirements stated therein. All samples used in the above tests shall be to the cost of the contractor and shall not affect the length of the cables to be supplied under this contract.

9.15.2 Power Cables (132kV, 33kV & 11kV Cables): A) Routine Tests: All lengths of cable shall be tested before despatch according to the following:- i) Conductor Resistance Tests: The copper resistance of the conductors shall be measured by direct current at room

temperature and corrected for temperature in accordance with I.E.C. Publication 141-1 and BSS 6480. The values thus obtained shall not be greater than the guaranteed values stated in the Schedules or more than 4% greater than the calculated values as per I.E.C. Publication 141-1 and BSS 6480.

ii) Capacitance Tests: The electrostatic capacitance of each drum length of completed cable shall be

measured at power frequency and shall not be greater than the guaranteed values stated in the schedules.

iii) High Voltage Tests: The voltage tests shall be carried out with alternating current in accordance with

BSS 6480 for solid cables and I.E.C. 141-1 for oil filled cables. iv) Dielectric Power Factor/Voltage Tests: Each drum length of completed 132kV and 33kV oil filled cables shall be tested for

power factor at normal frequency and at ambient temperature and at 50, 125 and 200% of normal voltage. The power factor of the charging KVA after correction to a temperature of 20oC shall not exceed the guaranteed values stated in the Schedules or the values stipulated in I.E.C Publication 141-1 whichever is smaller. For 33 and 11kV solid cables, the power factor shall be in accordance with BSS 6480.

v) Voltage Test on Anti-Corrosion Covering: This shall be carried out in accordance with BSS 6480 where extruded PVC

oversheath is specified. Accessories: Tests analysis of plumbing and solder to check in compliance with BSS 219. Tests should

be carried out on samples selected from each batch. B. Type Tests: 1. Power Cables: The following tests shall be made on samples taken from cables manufactured for the

contract. i) Measurements of Thickness of Insulation: Sheathing, Serving and Weights: A sample shall be selected from each 40 meters of each type of completed cables, and

shall be at least 60 cms long. Then the minimum and average thickness of insulation shall be determined and the paper checked for wrinkles or tears. The minimum and average thickness of lead sheath, armouring and the various coverings of the bedding and servicing shall be determined, and these shall agreed with the guaranteed values. Also the weights of copper, lead and steel per meter of cable shall be determined.

ii) Bending Tests: The bending test shall be made on a sample of the completed cable (with all coverings)

having a length of not less than hundred times the diameter of the lead sheath. The bending tests shall be conducted in accordance with IEC publication 141-1 for oil filled cables and BSS 6480 for solid cables.

The samples shall then be power frequency high voltage tested in accordance with BSS 6480 for solid cables and IEC Publication 141-1 for oil filled cables.

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A specimen taken from the sample that has been tested shall then be dismantled and examined. The condition of the paper insulation, lead sheath, protective covering and armour shall comply with the requirements of BSS 6480.

iii) Loading Cycle-Power Factor Tests: For 132kV and 33kV Cables: This test shall be carried out on a sample of cable selected from the contract works. The

sample shall be complete with sealing end boxes and other accessories and shall be not less than 30metres in length with adjacent accessories not less than 4 meters apart and shall be laid out on the floor of the test bay.

The sample shall be heated up to the maximum conductor temperature stated in the guarantee schedule by passing current through conductors. During the twenty days of the test, the cable shall be alive at 1.5 x the service voltage. The heating current shall be mentioned at 50oC above normal maximum temperature or at least three hours and switched off for 18 hours and the cycle repeated twenty times. The power factor of the charging KVA shall be measured at 50% and 150% of the normal voltage as follows:-

a) Before the commencement of the test. b) When the cable has reached maximum temperature during each cycle. c) When the cable has cooled to minimum temperature during each cycle. The power factor shall, in addition, be measured at normal voltage at temperature of above

60oC and 40oC during cooling in each cycle. The power factor at the stipulated voltage shall not vary substantially from cycle to cycle.

iv) Dielectric Thermal Resistance Test: (For Oil-Filled Cables) A sample of the cable selected by the Inspector shall be tested for thermal resistance of the

dielectric at the maximum temperature to operate and under stipulated conditions. v) Mechanical Test on Pressure Retaining Sheath: (For Oil-Filled Cables) A sample of the cable at least 3 meters long is to be maintained for seven(7) days at

internal pressure equal to twice the maximum pressure during which period no leakage shall occur. This applies to oil-filled cables only.

vi) Dielectric Security Test: (33kV & 132kV Cables) A sample of the cables at least 10metres in length (excluding terminations) shall be

subjected at ambient temperature to a power frequency test voltage applied between conductor and screen. The value of the test voltage shall be 47.5kV cables and 190kV for 132kV cables and it shall be applied for 24 hours without the occurance of a breakdown of the insulation or flashover of the sealing ends.

2. Accessories: (Oil-Filled Cables) Pressure test on pressure gauges and alarm gauges shall be carried out in accordance with

Clauses 21 to 26 of I.E.C Publication 141-1. 9.15.3 1000Volts Single Core Cables: The cable will be tested in accordance with BSS6346 or 6480. The measurement of thickness and weight sample tests shall be carried out on one metre

length of cable. The minimum and average thickness of insulation shall be determined and these shall

agree with the guaranteed values. Also the weight of copper per meter of cable shall be determined.

9.15.4 Pilot Cables and Accessories: A) Routine Tests: i) Conductor Resistance Test: The resistance of the conductors shall be measured as specified in B.S.6360/1969 and

shall meet the requirements of this standard.

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ii) Voltage Routine tests: The voltage test shall be made with alternating current of approximately sine form at any

frequency from 40-62 Hz. inclusive. The voltage shall be increased gradually and maintained continuously for one minute at 10 KV (rms) between all unscreened conductors whilst excluding the single screened pair by connecting its cover and screen to the centre tap of one 10 KV. For screened pair, a separate 10 KV DC test shall be conducted with the screen connected to zero potential connection and 15 KV (rms ) between conductors and armour which shall be earthed.

Alternatively, the following D.C. test procedure may be followed :- Core-Core : 20 KV D.C with the screen maintained at the intermediate level of 10

KV D.C. Core-Core : 30 KV. D.C. with the screen connected to the cores. iii) Mutual Capacitance Test: The mutual capacitance of the cable shall be measured between the two conductors of

each pair with the other conductors and the armour earthed. The measurements shall be made using alternating current and a suitable bridge and the mean value obtained shall be recorded.

iv) Capacitance Unbalance Tests: Pair to pair capacitance unbalance measurements shall be made at audio frequency. All

conductors other than those under test being connected to the armour and earth. The measured values shall be divided by :½

( L/500 + V L/500 ) Where L is the length in meters. Lengths less than 100 meters shall be considered as 100

meters. No corrected unbalance measurements shall exceed 500 pf. The corrected unbalance

between carrier pairs shall not exceed 50pf. In order to limit the amount of testing, measurements will normally be made between adjacent pairs, except that all combinations between carrier pairs shall be measured. The measured values of capacitance unbalance shall be recorded for use in the preparation of jointing schedules to obtain the necessary balance to meet the cross-talk requirements.

v) Mutual Inductance: Mutual inductance measurements shall be made at 5KHz on carrier pairs. The measured

values shall be divided by:½ ( L/500 + V L/500 ) Where L is the length in meters of the cable under test, lengths less than 100 meters being

considered as 100 meters. The corrected mutual inductance shall not exceed 0.50mH. vi) Galvanized Routine Tests: Samples selected by the Purchaser’s representative of all galvanized material shall be

subjected to the galvanized tests set out in BSS.443 (testing of zinc coating on galvanized wires).

vii) Insulation Resistance Tests: The insulation resistance shall be measured between each conductor and the other

conductors connected to armour by applying 500 V. D.C. for one minute. The insulation resistance shall not be less than 12500 mega ohm/km at 20oC.

viii) Extruded PVC Over-sheath Test: Extruded P.V.C. over-sheath shall be spark test in the manner described in Clause 16.2 of

B.S. 6346. ix) Voltage Test: Voltage test on anti-corrosion covering in accordance with BSS 6480. B) Type Tests: i. Measurement of Thickness of Insulation, Sheathing, Armouring, Serving and

Bedding: Ten representative samples of the manufactured cables shall be examined and

average thickness of insulation, sheathing, armouring, bedding and serving shall be determined. The samples shall be at least 60cms long and shall be cut not less than

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30cms from the end of the drum length. Also, the weights of copper and steel per metre of cable shall be determined.

ii. Voltage Test: A sample of the manufactured cable together with a joint box shall be tested and

shall not break-down when a voltage of 5kV is applied for 5 minutes between pilot cores and between core and the lead connected to armour. Subsequently, the sample shall be tested and shall not breakdown when a voltage of 2.5kV is applied for five minutes between screened cores and between each screened core and the armour. Screens and armour shall be earthed during this test.

C) Accessories: i) Visual dimensional checks on selected samples at each batch of joint boxes (not less than

one joint box of each 50 boxes). ii) Tests check inner lead sleeve composition. iii) Test analysis of plumbing and solder to check in compliance with B.S. 219. Tests should

be carried out on samples selected from each batch (but less than one sample of each 200 sticks).

9.15.5 Site Tests: 1) Power Cables: After complete installation of the various circuits and before commissioning, each circuit

shall be subject to the following tests: i) Resistance Measurements: The copper resistance of each core of the completed circuits shall be measured and the

ambient value corrected to 20oC. ii) Capacitance Measurements: The capacitance between phase and between each phase and the lead sheath shall be

measured and the ambient temperature recorded. iii) High Voltage Tests: After the circuit has been brought upto its design oil pressure, a D.C. voltage of 270kV

shall be applied to 132kV cables between each core and screen for a duration of 15minutes, the other two phases being earthed. The high voltage test as well as the oil tests will be carried out on each circuit when it is completed by the cable contractor under a separate cable contract. However, the substation contractor has to co-ordinate and co-operate with the cable contractor and should carry out all the necessary works at the substation end for such tests.

Where 132kV cable feeder tails are required in connection with cutting-in of 132kV overhead line cables, the substation contractor shall carry out the H.V. and oil tests on each completed circuit.

iv) Special Bonding Equipment Tests: a) With all earthing links removed, the PVC over-sheath shall successfully with stand a

test voltage of 10kV D.C applied between lead sheath and earth for one minute. During this test, the lead sheaths of the other two phases shall be earthed. The test shall be repeated on the other phases in turn.

b) With bonding links disconnected, a suitable variable voltage D.C. test supply be applied in turn between each of the 3 disc leads and the earth lead. The resulting currents shall be measured and after correction for ambient temperature, shall lie within the declared limits. With the 3 disc leads then connected to the earth lead and all four disconnected from earth, the resistance between them and any metallic casing shall be not less than 10M when measured on a 1000volts ‘Megger’.

c) Contact resistance measurements shall be made across link faces and SVL connections. The resistance of the former shall not exceed 20 and of the latter 50.

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2) Pilot Cables: a) After Laying and Before Jointing: The following tests shall be carried out on each length of cable: i) Continuity: The continuity of all conductors shall be confirmed. ii) Insulation Resistance: The insulation resistance of individual lengths shall be measured between each

conductor and other conductors connected to the armour by applying 500V D.C. for one minute.

b) After Laying and Jointing: The following tests shall be carried out in each laid and jointed cable:

i) Voltage Withstand Tests: Each laid and jointed cable shall be subjected to the following high voltage tests: 1) Each of the unscreened pairs shall be tested with 15kV D.C. applied between the

two conductors of the pair. 2) For screened pairs, the following tests shall be carried out: a) 10kV D.C between the conductors of the screened cores with the screen

floating. b) 5kV D.C between the conductors of the screened cores and the screen which

shall be earthed. 3) 25kV D.C. between all conductors and screen jointed together with the armour the

screen during the test shall not be earthed while the armour shall be earthed. ii) Conductor Resistance: The conductor resistance shall be measured and recorded. iii) Insulation Resistance: The insulation resistance shall be measured between each conductor and the

other conductors connected to the armour by applying 500volts D.C for one minute.

iv) Attenuation, cross-talk and impedance test in accordance with ESI 09-6 standard.

9.16 Test of Power Cables (132 & 33kV) & 11kV & 1kV: 9.16.1 XLPE Cables: The tests shall be carried out generally in accordance with IEC 840 for 132kV cables and

IEC 502 for 33kV ^ 11kV cables unless otherwise specified hereunder. A- Routine Tests: The following tests shall be carried out on each manufactured length of cables, to check

that the whole of each length complies with the requirements. 1. Conductor Resistance Measurement: The complete cable length shall be in the test room, which shall be maintained at a

reasonable constant temperature for at least 12 hours before the test. If it is doubtful whether the conductor temperature is the same as the room temperature the resistance shall be measured after the cable has been in the test room for 24 hours. Alternatively, the resistance shall be measured on a sample of conductor, conditioned for at least 1 hour in a temperature controlled bath.

The DC resistance of the conductor shall be corrected to a temperature of 20ºC and 1KM length in accordance with IEC Publication 228.

The DC resistance of the conductor at 20ºC shall not exceed the appropriate maximum value specified in IEC Publication 228 if applicable.

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2. Measurement of Capacitance: The capacitance shall be measured between conductor and metallic screen. The

measured value shall not exceed the nominal value specified by the manufacturer by more than 896.

3. Partial Discharge Test: The partial discharge test shall be carried out in accordance with IEC Publication

885-2 except that the sensitivity as defined in IEC publication 885-2 shall be 10pC or less.

The test voltage shall be raised to and held at 1.75 Uo for 108 and then slowly reduced to 1.5 Uo.

The magnitude of the discharge at 1.5 Uo shall not exceed 10 pC. 4. Voltage Test: The voltage test shall be made at ambient temperature using an alternating test

voltage at power frequency. The test voltage shall be raised gradually to the specified value which shall then be

held for 30 minutes between the conductor and metallic screen. The test voltage shall be 2.5 Uo. No breakdown of the insulation shall occur. 5. Electrical Test on non-Metallic Sheath: The non-metallic sheath shall be subjected to the routine electrical test specified in

IEC publication 229. B- Sample Tests: General: The following tests shall be made on samples of manufactured cables, the number of

samples chosen shall be limited to not more than 10% of the number of lengths: 1. Conductor examination. 2. Measurement of thickness of insulation and non-metallic sheaths. 3. Measurement of the thickness of metallic sheaths. 4. Hot set test for XLPE insulation. The above tests shall be carried out in accordance with the requirements of IEC 840 for

132kV cables and IEC 502 for 3kV cables and shall fulfill the values given therein. C- Type Tests: General: The appropriate type tests specified hereunder shall be made before the manufacturer

supplies on a general commercial basis, a type of cable covered by this standard, in order to demonstrate satisfactory performance requirements. The type tests shall comprise the electrical tests on the complete cable and the appropriate tests on cable components.

D- Electrical Tests on Complete Cable: The following sequence of tests shall be performed on samples of complete cable at least

10 meters in length excluding the test accessories. 1. Bending test followed by partial discharge test 2. Tan Delta measurement 3. Heating cycle voltage test, followed by partial discharge measurement 4. Impulse withstand test followed by a power frequency voltage test. The above tests

except (2 above) shall be applied successively on the same samples. Details of Tests I. Bending test followed by partial discharge test: a. The sample shall be bent around a test cylinder (e.g. the hub of a drum) at room

temperature for at least one complete turn. It shall then be unwound and the process repeated except that the bending of the sample shall be in the reverse direction.

This cycle of operation shall be carried out three times in total. b. The diameter of the test cylinder shall not be greater than:

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25 (d +D) + 5% for cables with lead and corrugated aluminium sheath or with overlapped longitudinally applied metal foil: 20 (d + D) + 5% for others Where: D = measured external diameter of the cable in millimeters. D = measured diameter of the conductor in millimeters. c. On completion of this test, the cable shall be subjected to the partial discharge test

magnitude of the discharge at 1.5 Uo shall not exceed 5 pC. 2. Tan Delta Measurement: a. The sample shall be heated by a suitable method and the temperature of the

conductor determined either by measuring its resistance or by thermocouples on the surface of the screen, or by thermocouples on the conductor of another sample of the same cable heated by the same means.

The sample shall be heated until the conductor reaches a temperature equal to the maximum rated temperature of the insulation in normal operation within +/-5ºC.

b. Tan delta shall be measured at a power frequency voltage of Uo at the temperature specified above.

c. The measured value shall not exceed the value specified in table II of IEC 840. 3. Heating Cycle Voltage Test: a. The sample shall be in a U bend having diameter specimen. b. The sample shall be heated by a suitable method, until the conductor reaches a

temperature which shall be not less than 10ºC and not greater than 15ºC above the maximum rated temperature of the insulation in normal operation.

c. The heating shall be applied for at least 8 hours and shall be followed by at least 16 hours of natural cooling. The conductor temperature shall be maintained within the stated temperature limits for the last 2 hours of each current loading period.

d. The cycle of heating and cooling shall be carried out 20 times. e. During the whole of the test period a voltage of 2 Uo shall be applied to the sample. f. After the final cycle the sample at ambient temperature shall be subjected to and

comply with the requirements of the partial discharge test in accordance with sub-clause 1-C above.

4. Impulse Voltage Test (followed by A.C. voltage test): a. The impulse test shall be performed on the sample at a conductor temperature which

shall be not less than 5ºC and not greater than 10ºC above the maximum rated temperature of the insulation for normal operation. The impulse voltage shall be applied according to the procedures given in IEC publication 230.

b. The cable shall withstand without failure 10 positive and 10 negative voltage impulse of the appropriate value specified in Table I of IEC 840.

c. After the impulse test, the cable sample shall be subjected to ambient temperature to a power frequency voltage test at 2.5 Uo for 15 minutes No breakdown of the insulation shall occur.

II. Type Tests on Cable Compounds: The non-electrical type tests and type tests to check that the materials used for the

cable components have satisfactory properties shall be carried out as detailed in IEC 840.

The method of tests and test results should satisfy the requirement of IEC 840. D- Electrical Tests after Installation: (Site Tests): 1. Insulation: Tests on new installation are made when the installation of the cable and its

accessories has been completed.

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1.1 DC Testing: A DC voltage equal to 3 Uo shall be applied for 15 minutes. 1.2 AC Testing: As an alternative to the DC test an AC voltage test at power frequency in

accordance with item a) or b) below, can be used: a. Test for 5 minutes with the phase to phase voltage (U) applied between the

conductor and the metallic screen. b. Test for 24 hours with the normal phase to earth voltage of the system (Uo). 2. Non-metallic sheaths: The non-metallic sheath shall be subjected to the site tests specified in IEC

publication 229.

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PART X TECHNICAL SPECIFICATION NO.MEW/SS/10

CIVIL ENGINEERING WORKS, AIR CONDITIONING AND ELECTRICAL INSTALLATIONS

10.1 Special Conditions for Civil, A.C. and E.I Works: 10.1.1 General: These special conditions of contract shall be read in conjunction with the General

Conditions of Tender for civil works and other contract documents and in case of difference between any of these special conditions shall be followed for the execution of Civil Works, together with what is described under “INTRODUCTION”.

10.1.2 Extent of Civil Works: Since the contract is a turnkey project, the work involved in this part of the contract shall

comprise the design, construction and completion in all respects, testing, setting to work, maintenance and final handing over of substation building(s) as explained in the “INTRODUCTION” and finally as shown in the successful tenderer’s approved drawings.

The work involved shall also generally comprise the following: a. Excavation and casting of reinforced concrete foundations and basements. b. Reinforced concrete columns, beams, basement floor, ground floor, (mezzanine

floor and first floor), (both if required), roof slab, transformer bases and shelter to same.

c. Cavity walls, solids walls, tiling, paving and painting. d. Supply and installation of equipment for air-conditioning and ventilation services. e. Electric lighting and power services. f. Execution of miscellaneous ancillary works in connection with the above. 10.1.3 Description of Civil Works: Tenderers are requested to submit with their offers proposed preliminary designs and

general arrangement. The successful tenderer shall be required to submit different proposals for facade elements to comply with what is described in the introduction and to the full satisfaction of the Engineer.

10.1.4 Foundations for power transformers shall be adjacent to building(s) externally and shall

have shelter with approved type of sun shade, tracks or rails for loading, pulling-in or pulling-out, anchors, if required and described in the introduction and the bill of quantities together with blast walls, ducts, etc.

10.1.5 Design of Foundations for Sub-station & Transformers: Design of all foundations shall be based on soil bearing capacity of 1.5kgm/sq.cm and

the same designs shall be maintained and followed for all bearing capacities of above 1.5Kgm/sq.cm but should the capacity prove to be less than 1.5kgm/sq.cm, the contractor shall re-design the foundations as per new bearing capacities even if this requires the introduction of raft foundations or on piles and execute the works accordingly at no extra cost to the Ministry under either of the above possibilities. Tenderer should refer to clause 1.11 section 1 (obtaining information) to familiarize himself with site conditions. Tenderers can also make their own enquiries about any available data with MEW on site conditions. Reference should also be made to Vol. II, Schedule J-2- Introduction regarding available substation sites.

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10.1.6 Handing Over of Site or Sites of Works: Ministry due to delay in acquisition of sites etc., the number of calendar days elapsed

after the expiry of the specified period will be added to the completion dates and the same will accordingly be extended. The purchaser shall within twelve months hand-over to the contractor the site of the Reserve substation. (if specified) or site drawings together with soil test results, and the contractor shall in this case, complete and hand-over the substation within twelve months from the date of the above handing over of site or site drawings. The minimum completion and handing over period is to be taken as eighteen (18) calendar months from the date of signing the contract.

a) Working Area: The contractor shall confine his activities within the site(s) of work as far as this can

physically be possible and should be required additional working area, he shall not encroach upon or intrude into the neighborhood but approach the Engineer for the necessary guidance and he shall be fully responsible to obtain the necessary construction or temporary license from the other authorities in time to avoid and delay in specified completion period.

b) Items manufactured off the site or works such as precast concrete elements, doors, structural steel work or any other items to be incorporated in the works, the Engineer or his representative reserves the right to visit and inspect the place of manufacture at any time during the contract period. The contractor shall the Engineer of the proposed date of manufacture 3 days at least before such manufacture.

10.1.7 Site or Sites of Work: For site or sites of work, refer to "INTRODUCTION". 10.1.8 Manner of Execution: a. The Contractor shall commence works and carry out all such portions of work

which have been given priority in the contract or as may be informed by the Engineer in writing. He shall have separate gangs of workmen for each trade on each site.

b. All formwork either sawn or wrought shall be prepared in advance and all reinforcement shall be bent to sizes and shapes and stored as directed by the Engineer.

10.1.9 Contractor's Staff & Supervision: Contractor's staff for supervision of civil works shall be mainly as follows: 1. One B.Sc. Civil Chief Engineer from the main contractor civil staff should be

appointed for every three substation sites or less and should be five years past experience working as a senior engineer for design and execution of high voltage substations and buildings of similar nature.

2. One Resident Engineer of the subcontractor at every site (for details refer to Schedule (O).

3. One foreman of the subcontractor at every site. The qualifications of the appointed staff shall be submitted for approval. Failing to

provide the said staff, the Engineer reserves the right to stop the works at any time and NO claims for extension of time or extra charges will be allowed.

10.1.10 Contractor’s Attendance: The contractor shall allow access to the site(s) and afford all reasonable facilities

whenever required during the contract period and wherever required with in the site(s) of work for other contractors so that they too shall be able to complete their works concurrently with the civil works. The contractor shall, on written instructions from the Engineer, attend upon and execute all or any necessary work in connection during the

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continuance of contract period and the cost of such attendance shall be included in the rates laid down in the contract and be not treated as variation order, and no extension of time in the contract period will be given under such cases unless prior approval is obtained from the Engineer.

10.1.11 Site Facilities to Engineer’s Representatives: Immediately upon receiving of the site(s) and prior to commencement of permanent

works, the contractor shall arrange either of the following for the exclusive use of Engineer’s representative:

a) Supply & install on sites within one month, one number new and self contained mobile office(s) weathertight in all respects having one office room, one kitchenette, one toilet with drainage, all fully equipped and furnished with doors, windows fly screens, pin-up boards, electric heater, hot plate, window-type A.C unit, water supply, sanitary fittings, telephone, refrigerator, etc.

b) Site office(s) for Engineer(s) representative(s) either self contained mobile one(s) or temporarily built with cement sand blocks shall be in both cases be completed within one month from the date of receiving of the site(s). The contractor shall pay a penalty of KD.100/- (Kuwaiti Dinars One hundred only) per site office for each day delayed in the completion, furnishing and installations of services, etc for the site office(s). The total penalties so imposed shall not normally exceed KD.5,000/- (K.D. Five thousand only) for delaying of each site office.

c) Full time services of an attendant boy or farrash shall be made available for Engineer’s representative on each site to attend on him during his presence on site.

d) Site office(s) for Engineer’s representative(s) shall always be well maintained, floors swept, furnitures dusted and wiped clean, everything kept neat and tidy as per best standards.

e) Site office(s) whenever required by the Engineer in writing will either be removed from site(s) and/or demolished and the site(s) made good on completion of contract, all at no extra cost.

10.1.12 Protection of Works: a) The contractor shall protect the works from weather and from all other damages whether

by General Public or by workmen whether or not belonging to the Contractor, performing concurrent or subsequent operations in the execution of works. He shall provide and erect the necessary guard rails and barriers and clear them away on completion of works.

b) Fair-faced brickwork...etc shall be protected by means of polythene sheets or similar approved to ensure that the finished work is not damaged, splashed or stained by subsequent trades such as floor screening, tiling, grouting and grinding of same, casting of copings to perimeter walls...etc. Roofs shall be swept clean to ensure that there are no loose nails and the like which may damage the membranes.

c) Throughout the duration required by the works, the contractor shall construct and maintain where necessary, props and shuttering on the sides to protect same from collapse installations, property and public services from damage that may be caused by collapse of the dies or subsidence of the surrounding ground.

d) The contractor shall adopt all precautionary means for protecting public services. He shall be held responsible for the results of his operations during the execution, especially excavation, and in case damage is caused to any property or services due to a direct hit by the equipment used or due to sliding or collapse of the soil as a result of not supporting the sides of the excavation or any other reason.

e) The contractor shall be responsible for carrying out the works in a safe and sound manner so as to avoid risk or danger to all people employed on site(s) whether or not belonging to the contractor and the general public, to the satisfaction of the Engineer.

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10.1.13 Sign Boards: The contractor shall place a sign at each site of works and the sign should be white in

colour with red letters, without any line on the edges. The minimum dimensions of the sign shall be 1.50M x 1.20M and the bottom of the sign shall be at 1.20 metres above ground level. Both sides of the sign shall bear the following information:

Name of the Ministry Nature of work and reference Date of commencement of work Date of completion of work Name of the Contractor 10.1.14 Delayed Items of Work: Certain items of work such as sand and gravel fill, paving of the yard if required, final

coat of paint if so ordered or any other item intimated by the Engineer in writing shall not be carried out until such periods as shall be required by the Engineer and/or by the other contractors and the main contractor shall be made due allowance in his prices and rates to carry out all such delayed items of work whenever so ordered by the Engineer within the maintenance period. The contractor shall not be entitled for any compensation whatsoever for the delayed items which should be carried out within 15 days from the date the contractor receives instructions in writing from the Engineer to execute the same. On contractor’s failure to do so, the Engineer reserves the right to get them executed by other sources and all costs plus overhead...etc shall be debitable to the contractor.

10.1.15 Maintenance of Defect Liability Period: The contractor shall satisfactorily maintain all works included in and executed by him

under this contractor for a period of 12 (twelve) calendar months from the date of initial acceptance of same and he shall attend to and make good all defects appearing due to poor workmanship or improper material used whether or not supplied by the Employer. Maintenance of airconditioning works shall also be for 12 calendar months but to commence from the last date of test running of the plant. Date of initial acceptance of works shall be reckoned from the date of issuing of Taking Over and Acceptance Certificate as defined under the General Conditions of Contract.

10.1.16 Supply of Electric Energy: During the construction of works, the Contractor shall at his own expenses provide all or

any electric energy he may stand in need and under no circumstances the employer and/or the Engineer will be held responsible for supply of electric energy. Approved types of mobile “Generators” where required shall be supplied, installed and connected to services as directed by the Engineer.

10.1.17 Costs of Testing of Materials: The costs of testing of all materials such as cement, sand, shingle reinforcing steel,

structural steel and other metals, test cubes, cement sand blocks, floor and wall tiles, paints and decorative materials.....etc used in the permanent works under this contract shall be borne by the contractor who shall pack, transport and deliver the samples in such quantities as shall be required for testing purposes by the Government Research Station at Shuwaikh.

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10.1.18 Cleaning of Site(s): a) The contractor shall dispose of surplus construction materials, soil and other debris

from the site(s) gradually as the same accumulate, and cart away the debris to the dumping sites approved by the Municipality.

b) He shall make good all such previously concreted, paved and/or asphalted areas disturbed or damaged by himself/his workmen and/or by the other/his Sub-contractors during the execution of works and shall provide at his own expense and submit to the Engineer a certificate from Kuwait Authorities stating that the site(s) of works and the temporary working area have been cleaned as stated above and to the full satisfaction of the authorities concerned.

The works shall not be finally accepted unless the contractor fulfils the above obligations.

10.2 Specification for Civil Works: Materials: All materials are to be the best of their respective kinds and in accordance with latest

Kuwait or relevant British standard Specifications or equivalent. The contractor shall submit to the Engineer samples of all materials which he proposes to incorporation so that the Engineer may be able to obtain results of all or any tests he proposes to be carried out on such samples. All materials used for incorporated into the works thereafter shall fully conform with such approved samples.

10.2.1 Design Calculations: The contractor shall submit for approval fully detailed calculations in English for all

parts of the works including calculations to prove the bearing capacity of the ground, foundations, all slabs, beams, columns, brick and concrete walls, steel structure, etc.... The calculations shall prove all parts of the works to be in accordance with the standard relevant current British standard or British Standard Code of Practice (BSCP) pertaining at the date of tender being issued.

Calculations produced in the form of computer print-out, will not be accepted without prior written permission from the Engineer.

10.2.2 Loading: The loading to be used in the design of all parts of the works shall be in accordance with

BSCP 3 loading, and for wind loads, a basic wind speed of 40m/sec shall be used in conjunction with factors obtained from BSCP 3 Chapter V Part 2 ‘Wind Loads’. Superimposed loading or flat roofs shall be not less than 150kg/sq.M.

The design of the sub-station(s) shall be such as to minimize or prevent damage to both the equipment and the structure caused by explosion due to electrical faults which could occur in the substation equipment. The contractor shall state the measures he has taken in this respect and shall state the likely effects of such explosions.

Wall, separating transformers, shall be designed to resist blast damage. Foundation and structure supporting overhead line conductors shall be designed in

accordance with the Ministry of Electricity & Water specification for Overhead Transmission Lines.

10.2.3 Design and Protection of Substructure Works against Underground Water: B.S. 8110 shall be followed when preparing the designs for the buildings with or

without basements.

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The following items are required in all cases: 1. Floors and walls of basements shall be of cast-in-situ reinforced concrete and

shall be at least 20cm in thickness. Approved additives may be used to decrease permeability. Sulphate resisting cement shall be used in all cases.

2. Basements shall always be designed as a single unit without provision for expansion joints. Construction joints shall be minimum in number and shall be provided with rubber waterstops.

3. All basement floors shall be designed to resist a water head equivalent to at least one third the depth of the basement below finished ground level. When the water table lies above or at basement floor level, the floor shall be designed for a minimum of 1metre additional head of water over the existing or one third the depth, whichever is greater.

4. The basement walls shall be designed to resist a minimum water head equivalent to three quarters the depth of the basement. When the water table lies above or at basement floor level the walls shall be designed for a minimum of 1metre additional head of water over the existing or ¾ the depth whichever is greater.

5. The basement shall also be checked for uplift by checking the overall dead load of the structure against the upward water pressure at various stages of construction. In such cases a full water head may have to be considered.

6. All basements shall be protected by a continuous protective membrane, which excludes penetration of water and provides a vapour seal. The protective membrane if placed externally shall be protected by reinforced or plain concrete or protection board.

7. The bearing surface of all reinforced concrete footings including pile caps shall be protected by a layer or protective membrane sandwiched between two layers of plain concrete blinding.

Sulphate resisting cement shall be used in all cases. 8. Sides and tops of footings shall be protected either by protective paint or

continuous protective membrane, depending upon individual site conditions. 9. In case ground water table is 60cm below the basement floor level or any where

above this level cable ducts openings are not allowed below a height of 60cm above the ground water table, but an acceptable arrangement shall be required to avoid flooding of the basement in all cases and also to allow for laying, bending, crossing...etc of all cables and that the cable ducts structures shall also be protected with the same basement protection (continuous layers) and opening of the ducts should be sealed as described in clause 10.2.49 (b) and as approved by the Engineer.

10. A recommended specification for materials and construction of protective membrane and protective paint are as described in clauses 10.2.3.A & 10.2.3.B respectively.

10.2.3-A Protective Membranes: A-1 General: The following Specification covers the furnishing and applying of waterproofing

protective membrane to surfaces as shown on the drawings or where directed by the Engineer.

The contractor shall furnish the Engineer evidence that the personnel applying the material are qualified and the manufacturer is approved.

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A-2 Submittals: The contractor shall submit to the Engineer for approval three samples of each

type of the following materials, as applicable. a) Membrane waterproofing sheet : 300mm by 300mm b) Bituminous mastic : One liter containers c) Primer : One litre containers The contractor shall submit to the Engineer certificates that materials to be

furnished comply with specification requirements. A-3 Product Delivery, Storage and Handling: The contractor shall deliver products to the job site in their original unopened

containers clearly labelled with the manufacturer’s name, brand, designation, type and class as applicable, and the date of manufacture and expiration (if any).

Products shall be stored in an approved dry area with rolled goods laid flat, one pallet high, and protected from contact with soil and from exposure to the elements. Products shall be kept dry at all times.

Products shall be handled in a manner that will prevent breakage of containers and/or damage to the products.

A-4 Materials: A-4-1 Self Adhereing Protective Membrane: Protective membrane shall be a self-adhering composite sheet membrane

consisting of a rubberized asphalt compound coated to one side of a film made of polyethylene, PVC, polyester or other approved material. The composite membrane shall be manufactured specifically for the intended application and shall have a minimum overall thickness of 1.5mm and the film alone shall have a minimum tensile strength of 140Kg/sq.cm.

A-4-1-1 Rubberized Mastic: Rubberized mastic shall be a special compound provided by the self-adhering

membrane manufacturer, formulated for its intended use. A-4-1-2 Primer: Primer shall be a special compound provided by the self-adhering membrane

manufacturer, formulated for its intended use. A-4-2 Reinforced Asphaltic Protective Membrane: Protective membrane shall be a reinforced asphaltic membrane with polyester or

glass fabric and a minimum thickness of 3 mm. The membrane shall be attached to the concrete surface using a hot air or gas burner in accordance with the requirements of the manufacturer.

A-4-3 Plasticized PVC Membrane: Protective membrane shall be a plasticized PVC sealing membrane with a

minimum thickness of 1.5 mm. It shall be laid loose on floors and attached to vertical surfaces using approved resins. Hot air or electric welding shall be used for sealing the overlaps, all in accordance with the requirements of the manufacturer.

A-4-4 Alternative Membranes: Other membranes in accordance with British Standard C.P.102 (1973), may be

used when approved by the Engineer or specifically called for in the contract documents.

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A-5 Application: A-5-1 General Procedures a) Surfaces to which the waterproofing materials shall be applied shall be surface

dry, smooth and free from dirt, grease and oil. b) The contractor shall coordinate the waterproofing membrane work on the

blinding slab so that the placement of a protection screed or protection board where specified will follow the waterproofing membrane application by not more than five days.

c) Application of primer materials if required may be by brush or roller. The primer shall be allowed to dry before the membrane sheet is applied.

d) The contractor shall apply the membrane sheet with a minimum of 120mm overlaps at edges and ends and the sheet shall be rolled down firmly and completely.

e) The contractor shall follow the membrane manufacturer’s approved written recommendations for specific procedures, details and materials not specified herein.

f) If the work must be left partially complete, the exposed edges of outside strips of membrane shall be protected in compliance with the manufacturer’s recommendation and to the approval of the Engineer.

A-5-2 Application of Membrane to Concrete: a. Over the cleaned concrete surface to the extent shown on the drawings, the

contractor shall apply primer if required in a manner and using quantities in accordance with the membrane manufacturer's printed instructions. The surface shall be reprimed if not covered within 36 hours.

b. After the primer has dried, the customer shall apply the membrane to the concrete without stretching. The membrane shall be smoothed down with heavy hand pressure or a small roller. Edges and ends shall be lapped as specified.

c. The contractor shall double inside and outside corners by using an initial strip of 300mm wide membrane, centered along the axis of the corner. This strip shall be covered by the regular application of membrane. The exposed ends shall be protected in accordance with manufacturer's recommendations.

d. The membrane on blinding slabs shall extend to the outer edge of the slab and shall be protected as specified below. Sidewall membrane shall extend down and out of the edge of the previously applied blinding slab membrane.

e. Areas around drains, piping and protrusions shall be double covered with an additional layer of membrane for a minimum of 300mm in each direction. The membrane edges shall be protected and the gap between the membrane and protections shall be filled with mastic.

f. At expansion joints, and additional ply of membrane 500mm wide, centered on the joint and extending the full length of the slab and upto the membrane terminating point of the walls shall be applied.

A-5-3 Protection Layer: Before any work is allowed to proceed above a water-proof membrane, or within

five days of application whichever is the sooner, the membrane shall be protected by an approved protection layer as shown on the drawings or as otherwise directed by the Engineer. The protection layer against vertical surfaces shall be protection board with a minimum thickness of 6mm. Horizontal surfaces shall be protected by a sand/cement screed 50mm thick, or equivalent, approved by the engineer or as otherwise shown on the drawings.

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A-5-4 Repairs: The contractor shall repair gauges and other damage to the completed membrane

by means of membrane patches applied prior to placement of the protection layer.

A-5-5 Protection Board: The protection board shall be a semi-rigid board of 6mm minimum thickness,

subject to the approval of the Engineer and manufactured specifically for the intended use.

A-5-6 Installation of Protection Board: Within five days after membrane application, the contractor shall install the

asphalt protection board to membrane-on-concrete surfaces where specified. The board shall be stuck to the membrane by means of epoxy or other approved adhesive which will not damage the membrane. Sidewall protection board shall extend down and out to cover the horizontal blinding slab membrane.

10.2.3-B Protective Painting of Concrete: B.1 General: The following specification covers the furnishing and application of rubberized

bitumen to buried surfaces of concrete as detailed on the drawing. B.2 Submittals: The contractor shall submit to the Engineer for approval three samples in one

litre containers of the rubber bitumen emulsion. The contractor shall submit to the Engineer certificates that materials to be

furnished comply with specifications. B.3 Materials: The rubber bitumen emulsion shall be a water bound emulsion with a minimum

60% total solids content by volume, comprising bitumen with fine particles of rubber. Not less than 10% nor more than 20% of the total solids shall be rubber. The consistency shall be such that it can be applied to the surface by brush at normal temperature.

B.4 Application: a. Before the application of rubberized bitumen emulsion the concrete surface

shall be thoroughly cleaned and made free from dirt, dust, grease and other extraneous matter and lightly brush damped immediately prior to application of the emulsion.

b. The priming coat shall be made up by mixing 0.23Kg of approved powder detergent or the equivalent of liquid detergent, with 45 litres of clean water and adding this to 4.5litres of emulsion. The priming coat shall be applied at the approximate rate of 9 litres per 30metres square.

c. The second coat consisting of undiluted emulsion shall be applied as soon as the priming coat is dry, at the approximate rate of 9 litres per 15 metres square.

d. The emulsion shall be applied by brush, squeegee or spraying strictly in accordance with a manufacturer's instructions. It shall not be applied during, or when rain or dust storms are to be expected.

f. Backfilling shall not be commenced until the second coat of emulsion is quite dry.

10.2.4 Specifications: The contractor shall familiarize himself with all parts of this and other specifications and

documents issued to him and shall carry out the works in accordance with the true intent and meaning thereof. He shall submit for approval fully detailed specifications for any item which he proposed to incorporate within the works which is not included for in this and other specifications issued to him.

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10.2.5 Drawings: The contractor shall prepare and submit for approval his own working drawings fully

detailed and true to scale. Submitted drawings shall show the design working load on each floor. Drawings shall show any special construction sequence required such as where retaining

walls are designed to be restrained at the top or where precast slabs require propping until insitu topping has matured....etc.

Reinforcement drawings shall show the size, position and number of every bar in accordance with normal British Practice. A Schedule of reinforcement shall be submitted with each drawing, produced in accordance with B.S.4466.

Foundation drawing shall show the maximum load on each foundation and the design ground bearing pressure.

Steelwork drawings shall show all section sizes, bolt and weld details material types and paint or other finishes.

10.2.6 Datum: The datum levels will be determined on the site(s) by the Engineer but any checking or

approval by the Engineer or his representative does not relieve the contractor from his responsibilities under the contract. Moreover, forming the final substation yard level shall in no case entitle the contractor for any claim whatsoever. Tenderer should make his own site investigation for natural conditions before tendering.

10.2.7 Working Area: The contractor shall himself arrange immediately after signing the contractor with the

Municipality authorities to obtain an area, reasonably large enough to carry out all his activities within the site of works. He shall confine his operations within such working area as allotted to him and shall not encroach upon, occupy and/or extend his operations beyond without the Authorities written consent. The contractor shall be solely responsible to arrange for the same without having any claim whatsoever due to non-availability of such areas.

10.2.8 Storage of Materials: The contractor shall erect and maintain proper stores for the storage of all materials to be

used in construction of works. The stores shall be strongly constructed and shall be weather tight secure and capable of protecting the materials from deterioration and theft. The contractor shall submit to the Engineer his proposal for the stores before their construction is commenced. Suitable fire protection shall be provided for the stored material and equipments.

Cement shall be stored in sheds or buildings which shall be built and used solely for that purpose. The buildings shall be dry, well ventilated and so designed as to store the cement off the ground and to permit its use in the order of its arrival. The contractor must ensure particularly that rubber water stops and other rubber materials and perishable goods are stored so as to avoid exposure to sunlight.

10.2.9 Contractor's Plant and Method of Working: All mechanical excavators, pumps, concrete mixers, concrete distributing and conveying

plants and all other mechanical plants used by the contractor in the execution of works shall be of such types and sizes and shall be sued and maintained in such manners as acceptable to the Engineer. The contractor will be responsible for obtaining all such plants. The contractor shall prepare, and submit for approval, a "Method Statement" for the works which shall consist of the following:

1. A detailed programme, which may be in bar chart form, showing all items and critical dates for electrical installation.

2. Detailed description of proposed methods of working including sketches or marked up drawings showing sequence of excavation, casting concrete (showing construction

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joints) and striking shuttering, location of plant, access ways, scaffolding etc. (approval) of methods of working shall not relieve the contractor of his responsibilities for the proper execution and safety of the works.

3. Schedules of labour and resources demands giving ordering and delivery dates for materials and plant together with storage and handling proposals.

The above shall be submitted during the first two weeks of the contractor starting work on the site during which time modification may be made in accordance with the requirements of the Engineer or his responsibilities.

At the beginning of each week a proposed programme of work for that week shall be submitted to be subsequently compared with progress at the end of that week. The contractor shall modify his detailed civil programme and schedules in the light of current progress so as to meet the specified completion dates.

Formal site meetings shall be held at least once a month between the contractor and the Engineer representative in order to monitor the progress of the works. The contractor shall demonstrate his ability to speed up the works if progress has been slower than that programmed. Failing this the contractor shall be required to work additional hours in accordance with the general conditions of contract at no extra cost whatsoever.

If circumstances arise, which in the opinion of the Engineer necessitate a change in the method of working or the suspension of the plant or part of the plant either temporarily or permanently and notwithstanding the previous approval by the Engineer of the type, size and manner of using such plant, either on the affected portion of the works or on any other portion of the works the contractor shall immediately adopt another approved method of working with or without approved plant and shall have no claim against the Employer or Engineer for costs incurred by him in changing the method of working in the provision of other such plants.

10.2.10 Variation in Method of Construction: Where a method of construction for a particular section of work is detailed for specified

in the contract documents or is reasonable to be inferred therefore, the contractor shall at all times observe such method of construction unless he shall have previously obtained the approval of the Engineer to an alternate method of construction.

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EXCAVATOR 10.2.11 Nature of Excavation: The Engineer without any guarantee may make available for the contractor's guidance

information regarding the nature of the ground to be excavated. a) The contractor shall carry out all necessary excavation works in any type of ground

such as stone, lime stones, rock or in any other type of material including concrete plain or reinforced, masonry.....etc to levels, lines and profiles shown on the drawings or as instructed by the Engineer.

b) The excavated material is to be disposed off in the manner agreed and approved by the Engineer and all surplus is to be carried away to a tip to be provided by the contractor, with all necessary permits taken from Municipality or other Authority.

c) The contractor is solely responsible for the safety of the excavation and he shall provide all necessary planking and strutting required in the manner and method agreed by the Engineer.

d) All excavations shall be kept free from water by pumping, bailing sub-drains and sumps as required and approved at the contractor's expense unless otherwise described in the bill of quantities. The Term "excavations" shall mean under water excavation also.

e) The face and beds of all excavations shall be properly trimmed and all lose mud, dirt, sand and debris cleared away.

f) All excavations shall be inspected and approved by the Engineer prior to laying of any blinding or plain concrete for foundations.

g) The contractor shall take all necessary precautions against risks of subsidence, slips and falls and all other damages to excavations.

10.2.13 Backfilling: All materials taken out from the excavations and approved by the Engineer as suitable

for back-filling shall be kept in separate spoil heaps. Additional material required for back-filling shall be gatch bound sand obtained by the

Contractor from external sources in conformity with samples approved by the Engineer. The material for backfilling is primarily to be taken from the approved spoil heaps and

additional material if required it shall be imported gatch brought from external sources other than the spoil heaps and deposited in regular successive layer not exceeding 15cm thick, wetted and rammed by approved means upto the required levels and grades and to the satisfaction of the Engineer.

Any excavation carried out by the contractor to greater depths than shown on the drawings or back-filled with concrete 1:3:6 mix to the specified levels at the contractor's own expense.

10.2.14 Approval: The contractor shall obtain the approval of the Engineer for the bottom of each

excavation before laying the blinding concrete. 10.2.15 Reinstatement: On completion of the contract the Contractor shall reinstate all disturbed surface

whether within or without the curtilage of site(s) at his own expense and to the satisfaction of the Engineer.

10.2.16 Explosives: The use of explosives to remove rock met within the course of excavations will not be

allowed without the prior written consent of the Ministry of Interior and Ministry of Defense. The contractor shall be entirely responsible for all safety precautions concerned with the use of explosives.

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CONCRETOR

10.2.17 Cement: Cement used for concrete works either plain or reinforced and for mortars ...etc shall be

fresh ordinary portland cement and/or sulphate resisting cement complying with the current Kuwait Standards or British Standard Specification No.12:1958 or B.S.4027 respectively, supplied in sealed and branded bags and stored in dry and well ventilated stores.

All cement must be approved by the Engineer before work commences and certificates for each consignment are to be produced. All types of cement shall be tested in accordance with BS 4550, the contractor shall provide facilities for sampling & preparing cubes...etc at no extra cost. No cement is to be stored on the site(s) for more than 3 (three) weeks without the approval of the Engineer and all rejected cement promptly removed. A note of the order of arrival of various loads must be made and the cement used in the order.

10.2.18 Coarse Aggregate: Coarse aggregate shall be clean, crushed, hard store, gravel shingle or other similar

material, well graded to B.S.S 882 free from all dirt, clay, loam and other deleterious matters. It shall be approved by the Engineer who shall be informed of the sources of all aggregate. Coarse aggregate shall pass through a 1½ inch sieve and be well graded to range in size proportion varying from 1½ inch to 3/16 inch for concrete work generally and from ¾ inch for all other reinforced concrete. Storage of the fine and coarse aggregates shall be in separate bins set in a concrete base and protected from the wind-blown sand and other impurities and contaminations. Maximum permitted acid soluble chlorides (as NaCl) shall be 0.05% by weight and for acid soluble sulphates (as SO) shall be 0.4% by weight. Coarse aggregate shall be tested in accordance with BS 812.

10.2.19 Fine Aggregate: Sand also shall comply with B.S.S.882 amended 1957 Zone 1.2 or fine aggregate and be

composed of clean, sharp coarse concreting sand, structurally and chemically stable, free from loam, clay and other impurities and screened on site(s) as directed by the Engineer. All sieves shall be to British Standard Specifications. Maximum permitted acid as NaCl shall be 0.1% by weight and for (SO3) shall be 0.4% by weight and shall be tested in accordance with BS 812.

10.2.20 Testing of Aggregates.....etc. Both coarse and fine aggregate either already delivered to site(s) or which the contractor

proposes to deliver shall not be incorporated into the works until such periods as shall be required by the Engineer to obtain results of any tests which he proposes to be carried out on them by the Government Research Station.

The contractor shall provide samples of both coarse and fine aggregates in such quantities as shall be required for testing purposes.

Cost of testing of all materials such as coarse and fine aggregates, reinforcing steel, tiles, cement sand blocks, paints, decorative materials...etc used in the permanent works under this contract including the testing of test cubes shall be borne by the contractor. Tests shall be carried out by the Government Research Station only.

10.2.21 Water: Water to be used for mixing and curing shall be drinking water and shall not contain

vegetable matters, acid, excessive sulphates as to cause efflorescence on the face of the concrete nor adversely to affect the setting time or strength of concrete nor to instigate electro-chemical corrosion of the reinforcement. Fresh water or water containing not more than 4000 parts per million dissolved solids of which not more than 1000 parts per

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million may be chlorides and 2000 parts per million may be sulphates should be used for all concrete works and shall be tested in accordance with B.S. 3148. Water temperature shall be below 30ºC when added to mixer, in order to obtain a concrete temperature not more than 30 at discharge.

10.2.22 Steel Reinforcement: a) Mild steel bar reinforcement shall comply with BS.4449 and shall be stored on clean

concrete areas.

Tons/sq.in Lb/sq.in Kg/sq.cm Ultimate tensile 21.6 to 48,400 to 3,400 31.8 71,000 5,000 Minimum % elongation

8 in. gauge length: 10%

Bend Requirements d:dia. of bend) t:dia. of bar)

189 d 3.5 t

b) The contractor shall provide maker's test certificate or samples of reinforcing steel

for testing if directed by the Engineer. c) Mesh or fabric reinforcement shall comply with the requirements of BSS 4483 in all

respects. d) Rod reinforcement shall be cut to exact lengths and made truly straight or bent to

shapes and dimensions indicated in the drawings in accordance with BS 4466. Bending of rods shall be done cold and by application of a slow and steady pressure. Bent reinforcement shall be bundled, labelled clearly and stored as specified. e) All reinforcement shall be firmly maintained in positions shown on drawings by

means of tight and adequate tying of rods with binding wire at every intersection of rods. Minimum cover to reinforcement shall be in normal cases:

Substructures : 5cm from face in contact with soil or blinding External face : 4cm (to all steel) Internal faces : Columns and beams shall be 4cm to main steel, slabs and

walls shall be 2.5cm to all steel Minimum cover to reinforcement for fire resistance shall be as in BS 8110. f) Precast concrete blocks of the correct thickness and with tying wire cast in shall be

tied to the reinforcement to provide the correct cover and shall be of the same mix as the concrete in the relevant member. On no account shall blocks made of mortar or the use of wood or steel be permitted. Sufficient spacer blocks shall be used to ensure that the reinforcement everywhere has the correct cover both during the concreting and in the finished work. Particular attention shall be paid to slab and beam soffits and exposed fair faces. Plastic spacers may be used subject to the approval of the Engineer.

g) Welding of reinforcing bars will not be permitted. h) Steel bars which conform to BSS 4461:1969 amended 1976 cold worked steel bars,

or BSS 4449:1969 amended 1976 hot rolled steel bars or equivalent approved may also be used for the reinforcement of concrete.

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10.2.23 Measuring and Mixing: Fine and coarse aggregate and cement shall be measured separately by weight. The

weighing, device shall be an integral part of the mixer and shall be calibrated at regular intervals or as directed by the Engineer. Cement shall be added to the mixer in quantities of whole bags only if bagged cement is used. Water shall be added from a container with calibrated site glass and feeding directly into the mixing drum. The mixing time shall be such as to achieve a uniform color of the mix and normally shall be for a minimum of 1½ minutes but to be as agreed with the Ministry's representative depending on the type of mixing plant.

'Ready Mixed' concrete shall be in accordance with BS 1926 and this specification. Water shall not be added to the vehicles mixer drum until it arrives on site and in the presence of the Ministry's representative.

10.2.24 Casting Concrete: a) Concrete is not to be cast if the temperature is below 5ºC or when it is raining. The

water content in the concrete shall be as low as possible to allow workability and is to be to the Engineer's approval before casting. Concrete temperature shall not exceed 30ºC at discharge.

b) The method of conveying concrete from the mixer into positions shall be in clean receptacles deposited from a height of not more than 1.50 metres vertically. Concrete shall be placed within 15 minutes of leaving the mixer.

c) Concreting shall be continuous operation from construction joint without stoppage. d) Concrete shall not be disturbed after initial set has commenced, excepting where

approved finishing techniques are to be applied adopting a method approved by the Engineer in writing.

e) Concrete to raft foundation floor slab and roof slabs, etc. shall be placed as near as possible to its final position to reduce flowing and re-distribution to the minimum.

f) All mixers, tools, barrows, carts, pipes ...etc shall be thoroughly clean to all times. g) All castings of concrete shall be carried out during Ministry's working hours except

under emergencies whereupon Engineer's written approval shall be obtained. h) All concrete shall be cast in the presence of the Ministry's representative after his

proper inspection and failing to do so, such works shall not be accepted by the Ministry regardless of the workmanship or quality.

i) The contractor shall have to demolish, dismantle and recast all such works at his own costs, on receipt of written instructions from the Engineer.

j) Concrete with a slump in excess of 75mm recorded in the standard slump test will not be accepted and shall be removed.

k) 2cm x 2cm fillets shall be formed on all exposed external corners by means of planed red wood timber unless otherwise instructed by the Engineer in writing.

l) The proposed positions of construction joints for each pour shall be submitted to the Engineer in writing accompanied by sketches, where necessary, for approval prior to concreting.

m) Vertical construction and expansion joints in beams, walls, slabs, stairs, etc shall be truly vertical and properly formed by means of rigid formwork to the Engineer's satisfaction.

n) Horizontal joints in columns, walls...etc shall be uniform and visually acceptable. o) Special care shall be taken to ensure that concrete is properly compacted at joints. p) The concrete faces of construction joints shall be brushed with a wire brush while

still green to remove laitance (but not so as to disturb the aggregate in the set concrete) and to provide a good key for the next pour. This shall be done immediately after striking off the formwork.

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q) If this not done and the concrete is allowed to harden, scabbling of the joint shall be carried out using a purpose made scabbling tool. Hacking of the surface by hammer and chisel or the like will not be permitted.

r) Prior to casting fresh concrete against construction joints, the joints faces shall be slightly wetted with water. They shall be perfectly clean and free from loose material, sand oil...etc and special removable panels shall be provided in the formwork to permit the proper cleaning out of formwork and previously cast concrete by means of compressed air or other effective means immediately prior to casting to the satisfaction of the Engineer.

s) The written approval of the Engineer is required prior to casting any concrete without relieving the contractor of his obligations under contract.

t) Building tolerances shall be to Class I or better to BS 5606, accuracy in building. Drawings shall show any special tolerances to achieve the designed architectural and/or structural requirements.

10.2.25 Compaction: a) Compaction shall be carried out by mechanical vibration and the concrete shall be

thoroughly worked in the neighborhood of formwork and reinforcement to give even consolidation throughout and to leave no voids. All exposed surfaces to have a smooth and dense free from any honey-combing.

b) Honey-combed areas shall not be made good until inspection and approval of the Engineer has been obtained. They shall be cut back to sound concrete and made good to the satisfaction of the Engineer. If honey-combing is of an unlimited extent, the engineer may direct the whole of the member to be demolished and recast.

10.2.26 Testing: The contractor shall prepare 6 Nos. of 15cm x 15cm x 15cm cubes in steel moulds from

concrete as and when directed by the Engineer. Test cubes shall be stored as per B.S.S 1881 three cubes shall be tested at 7 days and three at 28 days. Cubes shall be properly marked for identification purpose. At least one set of cubes shall be prepared for each concrete mix being used for each day of concreting or from every 30 cu.m whichever is more frequent.

10.2.27 Concrete Mixes & Results: a) For all structural concrete work concrete mixes shall be standard or designed mixes as

defined in BS 8110 with minimum works cube strength of (25).Newtons per square millimetre. The mix proportions shall be adjusted to give low, medium or high workability in accordance with the above codes and as agreed with the Engineer for each item of the works. Mix proportions generally 1:2:4 BY weight and to fulfill the above requirements.

b) The results of cube tests shall be assessed in accordance with BS 8110. However the concrete shall have a crushing strength of at least 70% of the required 28 days strength when tested at seven days and the Engineer reserves the right to have all concrete, cast from the batch failing the 7 days test, broken out and precast at the contractors expenses.

c) Blinding concrete, mass concrete backfill and bedding to surrounds of cable ducts shall be of 1:3:6 mix and may be volume batched.

d) All concrete for foundations, wall columns and slabs in contact with the ground or blinding shall be made with sulphate resistant cement with a minimum cement content of 330Kg/cu.M.

e) Concrete for roadway slabs shall have a minimum strength of 25 New tons per sq.mm. f) No additives may be used in the mix without the written approval of the Engineer. g) The free water cement ratio for all structural concrete shall not exceed 0.55. h) The concrete must have 70% of the crushing strength within 7 days of pouring. Failure

to produce these results may mean the relative member be broken, cut and recast, if the engineer so desires, but at contractor's cost.

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10.2.28 Curing of Concrete: a) All concrete shall be cured for a minimum period of 7 days by keeping the surfaces

continuously wet with water by spraying or other means acceptable to the Engineer. b) All work must be well protected during curing period. 10.2.29 Surface Finishes: Basement floors shall be finished by power floating/toweling, Procedures for power

floating shall be agreed with the Engineer before commencing work depending on ambient conditions and concrete mix.

Roof and floor slabs which are to receive further finishing materials shall have an approved suitable finish and free of irregularity and be true to levels and falls as shown on the approval drawings.

Tops of transformer bases and other equipment bases/floors shall be finished with a steel float.

Roads shall have an approved non-slip surface. 10.2.30 Sundry Works: a) Great care shall be exercised by the contractor to build in bolts plates...etc or form

openings and holes...etc that may be required as shown on drawing or necessary for the proper execution of the works.

b) It is the contractor's responsibility to coordinate and cooperate with other contractors to ensure that all necessary built-in items such as conduits are fixed into the correct position prior to concreting. The contractor shall be held liable for all costs and/or delays resulting from incorrectly positioned or omitted items.

10.2.32 Precast Concrete: Precast concrete shall be designed and constructed in accordance with BSCP 110 or BS

8110. The moulds for all precast concrete works shall be to the accurate dimensions and

shapes as shown on the approved drawings and be off sound construction to the Engineers satisfaction. Moulds shall be thoroughly cleaned before each casting. Exposed faces shall be trowelled smooth or otherwise prepared to the Engineer's satisfaction.

The contractor may submit alternative mixes for use in precast work for the approval of the Engineer together with cube tests, etc. as required by BS 8110 or CP110 for standard or designed mixes applicable.

All precast units shall be vibrated. All precast units shall be properly marked and dated in a manner approved by the Engineer. Precast units shall be properly cured by methods to be agreed with the Engineer.

Stocking of precast units shall be properly carried out, after curing in a separate area set aside for that purpose and so arranged that the units may be removed and used in the order they were cast. No units may be placed in the works until such time after casting as agreed with the Engineer.

10.2.33 Expansion Joints: a) Expansion joints shall be incorporated in the works to allow for differential and

thermal movement where necessary. The position and detail of the expansion joints shall be clearly shown on the drawings.

b) Below ground level all expansion joints shall incorporate an approved type of water bar which shall be continuous with site joints kept to a minimum and there necessary made strictly in accordance with the manufacturer's instructions.

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c) Sealing of all expansion joints shall be carried out with an approved polysulphide

sealant to a minimum depth of 2.0cm when the adjacent concrete surfaces are quite dry. The joints surfaces shall be cleaned, primed where necessary and sealed in accordance with the manufacturer's instructions. Compressible joint filler of an approved type shall be used as a firm base which prevents loss of the sealant.

10.2.34 Sumps (if required): Sumps are to be formed to sizes and positions as and if shown with 15cm walls and floor

reinforced with rod reinforcement. The 5cm mild steel angle frames are to be cast in finishing level with the surrounding floor finish (see "Steel and Metal Worker" for covers).

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CARPENTER & JOINTER

10.2.35 Formwork: a) All wood used for sawn or wrought formwork shall be new and old wood of any kind

shall not be brought to the site(s) of work. All wrought formwork shall be of waterproof type 18mm. thick.

b) The contractor shall be solely responsible for the supply and erection, stability, centering, striking and removal of formwork in such manners as to preserve the concrete from damage or distortion during casting and setting. Formwork shall be so constructed as to bear its own weight, the full weight of the concrete and all other temporary weights and loads in the execution of casting and curing.

c) Formwork shall not be struck without Engineer's approval and the engineer will make himself sure that the concrete has hardened sufficiently to bear its own load and any other load or loads that will be placed on it immediately after removing the formwork.

d) In case of any premature removal of formwork, a especially from the sides of roof slabs and soffits of roof beams the contractor, if so ordered by the Engineer, shall cut, break, remove away such concrete and the reinforcing steel therein and refix new steel and recast all such concrete work at his own expense whether the damages caused by the premature removal of formwork is apparent or not.

e) Where finished surfaces of concrete are exposed and/or where formwork is described as "wrought" formwork shall be constructed with new plywood not less than ¾ inch thick so to leave a perfectly smooth and even surface of concrete when the formwork is struck. Each face of plywood to be used for one casting, i.e. each board of ¾ inch thick plywood shall be used only twice when it will be removed from the site(s) of work. The decision of the Engineer shall be decisive and binding on the contractor.

f) Formwork shall be so constructed that NO ties, wires, etc., pass through it. Special purpose made wall-ties, etc....may be permitted with the approval of the Engineer and they shall be of the type such that they are positioned within the concrete member with the correct cover. Holes left by cones or the like shall be made good immediately after the formwork is removed.

g) Where wires, etc., pass through sawn formwork, these shall be cut off below the concrete surface at a distance equal to concrete surface at a distance equal to concrete cover for the relevant member and the holes made good immediately after striking of formwork.

h) Prior to fixing of reinforcement, all wrought formworks shall be coated with one layer of approved mould oil, which in no account must be allowed to get in contact with the steel and it shall be such as will not stain the concrete, injure it by chemical action, be absorbed into the formwork or be soluble in water. All joints shall be finished with putty to get a perfectly smooth surface and to make the joint invisible.

i) Formwork, either sawn or wrought required for the works shall not be measured separately.

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BRICKLAYER

10.2.36 Brickwork: a) Bricks to be used shall be first choice class "A" to BS 5628 sand lime bricks, size

22x10.5x6.5cms obtainable from Sand Lime Bricks Factory, Kuwait. They shall be in two qualities : engineering quality for works below datum, common quality for all super structural works both to be tested to BS 187.

b) Above datum and as per drawings, walls shall be of cavity brickwork, fair-faced, both internally and externally laid in stretcher bond. Weep holes in vertical joints to be left at 2' - 0" centers in the first course to external walls of building. All brickwork in fair-faced walls to be perfect and chipped and cracked bricks shall not be used.

The cavities shall be kept clean of mortar droppings by lifting battens or other approved means. Openings will be left at the base of clean cavity at completion and subsequently these openings will be bricked up uniformly to match surrounding work.

c) Colors and shades or bricks to be used to works shall be green, white, yellow, grey, etc. strictly as shown in drawings or mentioned in the Bill of Quantities.

d) The brickwork during construction is to be carried up in uniform manner with no part being raised more than 3' - 0" above another. All perpends, quoins recesses, etc. are to be kept true, plumb and square and bonded together with the frogs facing upwards.

e) All bricks are to be wall buttered with mortar before being laid and laid down even and regular throughout with a total vertical height of four courses and four joints to every 30cms.

f) Bricks are to be carefully off loaded and stacked on level pavets or rigid wooden platforms and protected at all times form rain, direct sunlight, dirt and other damages. Obvious changes in color within any one section of wall will not be accepted by the Engineer and such walls shall be removed and otherwise made good to the satisfaction of the Engineer at the contractor's expense.

g) The top of all brick and block panels, unless shown to the contrary on the drawings, shall be finished 12mm below the soffits of slabs and beams over the gap being entirely filled with flex cell or similar approved.

h) The top of brick or block walls shall be tied to the concrete soffit over in a manner approved by the Engineer where shown on the drawings or required by the Engineer, the 12mm gap being filled as described above.

k) For insulation of cavity walling around air-conditioned rooms of the building, see Clause 10.2.102.

10.2.37. Treatment of Bricks: Great care must be exercised into the wetting of sand lime bricks which shall be

sufficient only to prevent adsorption of water from mortar and under no circumstances shall the bricks be immersed in water. Treatment of sand lime bricks shall be in accordance with the Engineer’s instruction which may vary according to temperature ruling at the time of execution of works.

10.2.38 Mortar for Brickwork: The cement and sand shall be the same as for “Concretor”. Lime shall be hydrated in accordance with B.S.S. 890 : 1966, Class “B” and to be

soaked in water for not less than 16 hours before use. Mix to BS 5628 to be used for all works but provisionally shall be 1:1:5

cement:lime:sand by volume and mortar for pointing shall be the same. Care shall be taken to ensure that all joints are completely filled as work proceeds.

Lime and sand shall be mixed by hand or in a mechanical mixer until the color is uniform starting with the dry ingredients gradually. This lime and sand mix shall be prepared 24-48 hours in advance and stored in a heap with the sides smoothed over and

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protected with hessian and must be kept continuously moist. Cement shall be added immediately before use. The quantities of finally mixed mortar within 30 minutes of mixing and the consistency at the time of laying shall be to the approval of the Engineer.

Concrete plasticizer, if permitted by the engineer shall be used in strict accordance with the manufacturer’s instructions. Mortar to be tested to BS 4551.

10.2.39 Wall Ties: Galvanized wire, butterfly pattern wall ties, size 20 cm x 10 cm to B.S.S.5628 shall be

supplied by the contractor and built into brickwork to cavity walls in every sixth course vertically and at 3’-0” centers horizontally staggered alternatively with extra ties at reveals and openings. Wall ties shall also be used to anchor the walls to concrete columns.

10.2.40 Expanded Metal Lathing: All cavity wall shall be reinforced with expanded metal lathing, gauge 26, starting from

third course and continued at every sixth course. But solid walls to have those at every third course. The metal lathing should be rebated 1.5 cm within the brickwork from both faces. Strips of expanded metal shall always be 3 cms narrow than the full width of walls within which these are

inserted (e.g. 29 cms for 32 cms cavity walls). 10.2.41 Pointing: Below datum level, all pointing is to be fair-faced, flush as the work proceeds unless

directed otherwise by the Engineer. Above datum level, internally and externally all pointing is to be barrel as the work

proceeds. Walls which are to be plastered shall be left with joints well racked out to provide a good key for plaster.

10.2.42 Expansion Joints in Brickwork’s and Concrete: Expansion joints between concrete and brickwork, if shown on the drawings are to be

2.0 cms thick and are to be filled with flexcell bitumen impregnated fibre board filler. Vertical joints are rebated within the thickness of the wall.

10.2.43 Blockwork: Cement and blocks shall be of the shape and sizes shown on the approved drawings to

BS 5628 and tested to BS 6073. Mortar for brickwork shall be as specified under clause 10.2.38.

10.2.44 Glass Bricks: Glass bricks will be used in positions shown on the drawings. The type to be used will

be P.B.32, size 15 x 15 x 10 cms or as shown. Every course is to be reinforced with expanded metal where those walls are flanked by brickwork, the expanded metal strips will be carried into the brickwork.

The mortar to be used is to be 1 (one) part white cement, 1 (one) part hydrated lime and 4 (four) parts sand by volume. The mix must be fairly dry and fatty and the sand must be clean. The pointing is to be carried out by racking the joint back slightly as the work proceeds. Clearance joints of ½" are to be provided to all panels in the top and sides. These are to be filled with fibre glass and pointed with a non-hardening compound.

10.2.45 Plastering: a) Cement, lime, sand and water shall be as specified under Clause 10.2.39 (Mortar for

brickwork). b) The whole of the works shall be executed in a workman like manner to the best

standards and to the satisfaction of the Engineer. Any work rejected through non-compliance with the specification shall be removed and replaced at the contractor’s expense.

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c) Mixing: All materials shall be measured by volume by means of approved gauge boxes on a

boarded platform and the ingredients shall be turned over twice dry and twice while water is added through a hose. Alternatively, mixing may be by means of an approved mechanical mixer.

Mixes shall be used up with within one hour of mixing. Materials which have started to set, shall not be mixed with additional water.

d) Plastering on concrete or concrete block shall consist of two coats of mix 1:3 cement:sand by volume to a total thickness of 10 cms. The under finishing coat is applied. A plasticizer where approved by the Engineer and used in accordance with the manufacturer’s instructions may be used to improve the workability of the mix.

All surfaces shall be treated with an initial application of spatter-dash to provide an adequate key for subsequent coats and shall consist of a mix 1:2 by volume cement: sand thrown wet into surface. This mix shall be allowed to dry thoroughly before applying the undercoat. Special care shall be taken to ensure that each layer of the work is protected from hot sun and drying winds to prevent too rapid drying out and each layer shall be cured for a minimum period of 3 days by continuously spraying with water.

The finished work shall be perfectly smooth and with sharp edges to all corners, etc. All joints except expansion joints, between concrete and brickwork or block work shall

be reinforced by fixing in an approved manner a 50 cms. wide strip of expanded metal lathing, 26 gauge, or similar approved 25 cms. on either side of the joint prior to plastering. all fixings shall be galvanized.

e) This shall be as specified for internal plastering above except that the surfaces finish required shall be as shown on the drawings or as instructed in writing by the Engineer.

10.2.46 Materials: a) Cement, sand, crushed aggregate and water are to be as specified for “Concretor”. b) Brickwork in manholes is to be as specified for “Bricklayer”. c) Salt glazed, spigotted stoneware pipes, bends, junctions, gullies, etc. for soil drain sand

rain water pipes shall be of 10 cms. internal diameter (except where otherwise shown on drawings or described in the Bill of Quantities) and shall be well glazed, free from cracks or other defects and shall be of tested quality complying in all respects BSS.65: 1952 and BSS.540, Part I: 1971. Flexible mechanical joints shall be as per BSS.540, Part 2: 1972 or equivalent.

d) Cast iron, heavy duty type manhole covers, 60 cms & 60 cms clear shall be as per BSS. 23: 1973 or equivalent approved.

e) Floor drainage traps, where shown on the drawings or described in the Bills of Quantities will be supplied by the Contractor.

10.2.47 Excavation: Trenches for drains shall be excavated to the lines and depths indicated on the drawings

or as directed by the Engineer. Care shall be taken to excavate only to depths as are required for correct and regular

gradients, and any excavation carried below the required depth shall be filled with concrete at the contractor’s own expense.

The bases of all trenches shall be formed to the required level or slope and grooves for pipe collars provided except where concrete bed is required.

The faces of excavation shall be upheld as required and the trenches shall be filled and rammed in layers not exceeding 15 cms, the finest material being filled in next to the pipes. Surplus soil shall be disposed off as directed.

The excavation shall be kept free from water by pumping, bailing or otherwise. The Engineer will inspect and approve the trenches before any concrete or pipes are laid.

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10.2.48 Concrete Surround to Drains: Concrete for foundations under drains, traps, gullies, etc. shall be of mix 1:3:6 and for haunching

and covers to manholes shall be of mix 1:2:4 as specified under “Concretor”. All ground floor and outside drainage shall be laid on 15 cms thick bed of concrete of the width shown on the drawings or as described in the Bill of Quantities but in no case shall width be less than 30 cms plus diameter of pipes.

All drains shall be surrounded with concrete mix 1:2:6 thickness 15 cms all around the pipes as shown on the drawings or as directed by the Engineer.

10.2.49 a) Laying of Drains: Every line of drain shall be accurately laid and perfectly true to line and gradient from

point to point. Every main drain shall be true to line from manholes and any change in direction shall

take place inside the manholes by the use of curved main channels. Change in the diameters of drains shall also be made in manholes by the use of tapered channels, straight or curved as necessary.

Fall to be 10 cms diameter, 30 cms, in 12.00 meter and 15 cm diameter 30 cms in 18.00 meters. Joints in salt glazed stoneware pipes are to be carefully made by pressing turns of tarred yarn into the socket to ensure concentricity. The socket is then to be completely filled with mortar (1 part cement, 2 parts sand and 2 % approved integral water proofer) and a fillet formed round the joint with trowel forming an angle of 45 barrel of the pipe. Flexible jointed stoneware pipes shall be laid strictly as per manufacturer’s instructions. Joints of these pipes shall not be surrounded in concrete.

b) Cable Pipes Ducts: Pipe ducts shall be laid by the contractor to lines and levels shown on the drawings. All

cable ducts shall be sealed with DENSYL MASTIC or similar approved material, unused ducts shall be sealed by inserting a 250 mm long filler plug of PVC or similar stable material and then sealing around the plug. Plugs shall be 5 cms less than the duct cables and plugs shall be held centrally in the duct by packing with hemp or hessian such that the sealing material can be pressed evenly around the cable/plug. Depth of sealing material shall be at least 150 mm. The exposed face of the sealant shall be set back 20 mm from the duct end and only after approval of the seal. The duct shall be flushed up with sand/cement mortar. The cable ducts to be encased with 1:3:6 concrete mix 15cm around the ducts body all around. Precautions against flooring shall be required as agreed by the Engineer. Arrangement to be as per attached drawing.

10.2.50 Manholes: Manholes are to be constructed as follows as shown and specified: a) Bottom to be of mix 1:2:4 concrete to 15 cms thick. b) Side walls to be of fair-faced flush pointed engineering bricks in mortar all as

specified under “ Bricklayer” unless otherwise required by the Engineer. c) Channels to be stoneware bedded benched (fall 1 in 10 ) in water proofed mortar as

described above for jointing but in 1:1 mix. d) Manholes are to be in fair-faced brickwork ( see “Bricklayer” ). e) A 15 cms thick reinforced concrete steel trowelled slab is to be cast over manholes (see “ Concretor ”). 10.2.51 Septic Tanks: a) Septic tanks shall be constructed true to details shown on drawings, complete with

concrete ramps, sloping beds, reinforced concrete walls, cover slabs, openings, baffles, inlets, outlets, etc. all as shown and depths of septic tanks shall be as indicated or as agreed with the Engineer.

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b) Facilities shall be provided for the Engineer to check the invert levels of both inlet and

outlet pipes and also the reinforced concrete baffle beams prior to casting. c) Form work to walls internally, bases and sides of baffles and to soffits of cover slabs

shall be wrought and top surfaces shall be trowel led smooth with steel float. 10.2.52 Soakaways: a) Soakaways shall be of cement : sand blocks to shapes and sizes shown on the drawings

and the depths of soakaways shall be as agreed with the Engineer. Mix to be used for casting of blocks shall be 1:3 and moulds shall be to Engineer’s approval. 30% of all moulds shall be perforated as shown on the drawings.

b) Circular ring beams for soakaways pits and cover to the same shall be of reinforced concrete with 1:2:4 and formwork to be used for soffits of cover slabs shall be wrought. The cover shall be trowel led smooth.

10.2.53 Workmanship Execution: All works to septic tanks and soakaways shall be executed in an efficient and workman

like manner and the respective trades concerned in the construction are to refer to their work specified elsewhere in the specification clauses.

10.2.54 Clean Drains: The contractor shall remove all silt and foreign matters from drains and manholes and

leave the whole system a clean and workable conditions. 10.2.55 Testing: a) All drains and manholes, etc. shall be tested with water under a minimum of 1.00

diameter head as directed by the Engineer or be tested with smoke. The contractor shall provide all labor and apparatus for carrying out the tests. In case of any default or leakage, the contractor is to repair this at his expense as directed by the Engineer and the test repeated until approved by the Engineer in writing.

b) The test shall be carried out by filling the drain with water and the 1.2 meter head obtained in a 10 cm diameter stand pipe fixed to the highest point and it shall be allowed to stand for two hours. After this period, the water level in the stand pipe shall not fall by more than 25 mm. per 50(fifty) pipe joints.

c) The Engineer may require further tests to be carried out by the contractor at the contractor’s expense after backfilling has been completed.

d) Drains shall be tested not less than 48 hours after laying and jointing but before the concrete casting (where required ) and the filling in are done. Connection shall be fixed temporarily to obtain the requisite head for the test.

e) The contractor shall ensure that no disturbances of the drains, etc. occur after they have satisfactorily passed the test.

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PAVIOR

10.2.56 Materials: Ordinary portland cement, sand, aggregate and water to be as specified for “Concretor”.

Mixing of mortar to be as specified for “ Bricklayer”. 10.2.57 Floor Tiles: Floor internal to substation(s) shall be tiled with 20 cm x 30 cm x 3 cm.s thick terrazzo

tiles except battery room and charger which shall be tiled with ceramic tiles cast with pigments to comply with pigments to comply with BSS: 1197-1955. Tiles shall be perfectly square and edges perpendicular to surfaces. Surfaces shall be smooth and plain, free from projections and depressions, arises, sharp and true. Type and color of tiles shall be as agreed with the Engineer. The contractor shall submit samples for approval prior to supply of materials to site(s).

10.2.58 Laying of Terrazzo Tiles: Tiles shall be laid on a clean and well swept sub-floor on cement sand, 1:3 mortar within

overall thickness of bed and tiles of 6 cms. The tiles shall thoroughly be soaked in water and laid within section of floor levels. The tiles must be leveled with a wooden beater to regulate the alignment of joints which shall be perfectly straight before the mortar bedding is initially set. The joint shall be grouted with neat white colored cement slurry unless otherwise required by the Engineer, spread over with a squeeze and the surfaces wiped clean immediately after. Newly tiled surfaces shall be protected from all other trades and not walked upon until fully set.

Expansion joints shall be provided in floor tiles as directed by the Engineer. 10.2.59 Ceramic Tiles: a) Battery room if shown on the drawings shall be tiled with ceramic tiles 20 cm x 10 cm x

1 cm thick as per BSS 1286 : 1945, quality and color be agreed. b) Like terrazzo tiles, ceramic tiles shall be also laid on a clean and well swept sub-floor

and on cement sand 1: 3 mortar with an overall thickness of 5 cms. c) No area of tiles, terrazzo or ceramic shall be laid to greater than 5M x 5M or as directed

by the Engineer. These to be separated by the dividing strip 2 cm thick vinyl fiber strip of a width sufficient to fill the full depth of the floor covering and finished flush with the surface of the tiles.

10.2.60 Levels and Damages to Tiles: a) Tiles shall be laid in workman like manner along the angle frames and shall be finished

flush to the top of angles, so that the 4.50 cm thick red wood covers also be flush with the tiling, if red wood cover is required.

b) Tenderer shall make due allowances in his rates for all wastes and damages to tiles during transporting, handling and laying and while cutting to sizes and making good around pipes and openings , etc. and during all other works of a like nature. Cracked, chipped and/or otherwise damaged tiles shall not be accepted.

10.2.61 Yard Paving: (if required ) The yard externally around the building(s) shall be paved with precast vibrated concrete

1:2:4 paving slabs of agreed dimensions edges with curbstones as shown on the drawings. Ordinary portland cement, sand, shingle, and water specified for ’concretor ‘ shall also be applicable for casting of paving slabs which will be cured for seven days by covering with hessian kept continuously wet. All paving slabs shall be cast with 1:2:4 cement sand 1 cm crushed aggregate.

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10.2.62 Delayed Paving Yard: The paving of yard around the substation can be delayed or postponed until such periods

as may be required by the Engineer and the contractor shall make all necessary arrangements whenever so ordered by the Engineer any time within the maintenance period. The contractor shall not be entitled for any compensation and loss or damages from the Employer as his rates for yard paving shall be deemed to include all such contingencies.

10.2.63 Inspection: The Engineer and/or his representative shall at all times be entitled to visit the factory’s

precast yard or premise to check, inspect and examine the mix proportions, method of casting precast slabs and means of curing the same to ensure that the work is being carried out as specified. Surfaces of all paving slabs shall receive a steel float finishing and damaged, cracked and chipped slabs shall not be accepted.

10.2.64 Laying of Slabs: The area to be paved shall be well prepared and the slabs laid on the fine but well

consolidated and leveled sand bed and finished to falls as directed by the Engineer and joints grouted in neat Portland cement.

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ROOFER

10.2.65 Insulation: a) The roof(s) to buildings shall be covered with one layer of light weight insulating

concrete consisting of one part of Portland cement to six parts of alveolite or exfolidated vermiculite passing through 6mm BSS mesh, but retained on 3 mm. mesh or any other approved equivalent materials. The insulation material to be used shall be mixed and laid in strict accordance with the supplier's printed instructions. It shall be laid and tamped lightly to a thickness from minimum and finished to falls as shown on the drawings including formation of angular fillets at junctions. Either of the materials shall not be used before it is approved by the Engineer.

b) The light weight concrete shall be laid strictly to minimum fall and cross falls of 1.5 % i.e., 1.5 cms in 1.0 meters to ensure proper drainage of water to outlets. Nothing shown to the contrary on drawings, etc. will nullify this requirement.

c) The entire roof slab of substation building shall be covered with 5 cms. thick extended polystrene or polyurethane heat insulation.

10.2.66 Topping Screed: This shall be ordinary portland cement and clean sand mix 1:4 by volume, laid and

spread over light weight concrete screed to a thickness of 2 cms. Immediately after spreading and lightly tamping the light weight concrete screed, the topping screed shall be laid over it and in no circumstances shall this be left over until the following day or any other later date. The topping screed shall be finished smooth with a steel trowel and curved by hessian kept continuously wet or by similar approved means for a minimum period of seven days.

The roof covering shall consist of 2 layers of approved water proofing membranes laid by a specialist approved by the manufacturer strictly in accordance with the manufacturer's printed instructions.

Proposals should be submitted for approval at least two months prior to the commencement of the roofing works.

Evidence of the specialist's credentials to carry out this work shall be given to the Engineer upon request.

Each step of the work shall be approved by the Engineer prior to the next step otherwise the Engineer will require the work to be removed and repeated at the contractor's entire cost.

10.2.67 Roof Treatment: Such approval given by the Engineer shall not relieve the contractor of his

responsibilities under the contract to ensure that the finished roof is completely leak-proof. The roof covering shall not be laid when raining or when ambient temperature is below 5 centigrade degrees.

Preparation of Slab: i) All edges and corners shall be rounded off with cement mortar. Upstand junctions

shall be formed with a cement filler where not already formed in the screed. The topping screed shall be fully cured and the entire area swept clean.

ii) The entire surface of roof slab to be water-proofed, including upstands with one layer of approved type of water proofing membrane laid as per manufacturer's instructions to render the roof and the parapets completely water-tight.

iii) All perimeters, upstands- etc. shall be fitted with two layers of water proofing membrane provided that the exposed portion of the top layer to be of mineral protection type both inserted at the top and in a suitable groove fixed and filled with approved sealant.

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iv) At drain-holes shall be placed centrally over the drain hole and cut crosswise in the

centre, the flaps being folded into the drainhole. The drain mouthpiece shall then be bonded into position, to ensure perfect sealing of the edges of the mouthpiece.

v) Gutters shall be treated prior to the work of the flat surfaces and shall be covered with approved membrane.

vi) The groove in the up stands shall be sealed using bituminous mastic or equal approved.

10.2.68 Aluminum Flashings: (if required) A continuous strip of aluminum shall be fabricated, supplied and fixed over the

expansion joints as shown on the drawings. The fixing shall be to the satisfaction of the Engineer by means of brass/aluminum screws 3cms long minimum.

10.2.69 Materials: Materials used for fabrication of items included in steel and metal worker action shall be

the best of their own kind complying fully with the requirements contained in BSS.15:1948.

10.2.70 Workmanship: The works shall be executed in the most efficient and workmanlike manner strictly in

accordance with the drawings and to the full satisfaction of the Engineer. All mild steel angles, plate and channels shall be true to alignment, perfectly plumb and work shall be of bolted and/or welded fabrication as shown in the drawings.

10.2.71 Aluminum Works and Internal Doors: a) All windows and internal doors shall be minimum 2 hrs. fire fighting doors

consisting of special frames as shown on the drawings. All doors and windows internally shall be subject to Fire Brigade's approval and requirement as detailed hereinafter. The successful tenderer is required to submit catalogues and testing certificate to prove the fire rating from BRI or equivalent.

b) Contractor will submit to the Engineer for his approval, sections which the proposes to use or fabrication of doors and windows and only approved sections shall be incorporated into works. All doors and windows shall be true to sizes shown in the drawings, suitable for single or double as shown, fabricated, supplied and fixed in workmanlike manner to Engineer's approval.

10.2.72 Steel Doors and Windows: a) Windows to Guard room and all external doors to building(s) shall be steel as shown

on drawings and mentioned in the Bill of Quantities. b) External windows and doors shall comply with BSS frames fabricated, supplied and

fixed in a workmanlike manner with all fittings and fixings true to sizes and dimensions as shown on drawings. All parts shall soundly and accurately be constructed with arrises clean and sharp, supplied, erected and mounted in position as shown, completion with channel frames, dowels, lugs, hinges, door steps, drop bolts, grip handles, archittraves and all other door and window furniture and fittings as per drawings.

c) All ironmongery and door furniture shall be stainless steel or equivalent, but approved by the Engineer.

d) All steel door frames, window frames, vents, etc. shall be primed with red lead as detailed under "PAINTER" prior to being fixed into position. All frames for external doors must be fixed on special concrete door joints connected to the main concrete skeleton as approved by the Engineer.

e) On no account will split brick courses be permitted above door and window frame.

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f) All external steel doors shall be provided with approved door steps cast into an external concrete landing wherever possible as shown on the drawings or otherwise as instructed by the Engineer.

g) The contractor shall also provide for approval, samples of all ironmongery and floor furniture which he proposes to incorporate into the works and all furniture and fittings used thereafter shall strictly conform to the approved samples.

h) Facilities shall be provided for Engineer's representative to check, inspect and examine the fabrication of doors in the contractor's workshops.

i) All the glazing and weather-proof materials shall be as shown on the drawings. Sample shall be submitted for approval by MEW.

10.2.73 Union Door Locks: All external doors excluding emergency exit doors and other doors as directed by the

Engineer to substation building(s) shall be each fitted with one number union lock pattern 2300, night latch and 2 keys each to pass, fit and suit master key HYWA single cylinder to be supplied by the Employer from his stores in Shuwaikh. Rates for doors shall include for collecting the union locks from employer's stores and fixing the same into the doors.

10.2.74 Internal Door Locks: Locks to all internal doors shall be supplied and fixed by the contractor. The locks shall

be Union or equivalent approved with 3 keys which will be handed over to the Engineer at the time of initial handing over of the substation(s). All internal doors shall be 2 hrs. fire resistant as specified in the Bill of Quantities. Covers for future openings and manholes shall also be 2 hrs. fire resistant.

10.2.75 Vents: (if required) These shall be welded H.D galvanized steel frames and two galvanized angles bolted to

each on all four sides and well stretched, galvanized fly screen netting fixed in a workmanlike manner. They shall be built into brick or blockwork with lugs as described in Clause 10.2.70.

10.2.76 Trench and Manhole frames: These shall be of mild steel angle to sizes shown on drawings with fish-tailed lugs

welded at 60cms centers to levels as shown on drawings. Tenderer's rates shall be included for all labour and material required to finish the works

in a workmanlike manner and to the Engineer's satisfaction. The grilles to the sumps are to be 45cms x 45cms overall and reference must be made to

the drawings for their exact sizes and positions, if shown. The grilles shall be placed on 5cms x 5cms mild steel angles frame cast into the floor in

similar manner as described above. The grilles will be made up of 1" x ¼" mild steel flat to surround with ¾" dia. mild steel rod at 3" centers. A further 1½ " mild steel flat will be welded across the bars at centers to act as stiffeners.

All work to be primed before being built and painted after in accordance with the specifications (see "PAINTER").

10.2.77 Rain Water Spouts and Down Pipes: The Guard Room is to be provided with rain-water spouts made from galvanized pipes

to sizes and lengths shown in positions indicated on approved drawings and the main building(s) to have mild steel down pipes firmly anchored to walls.

Rain water down pipes to main building(s) shall be supplied and robustly fixed with all fixings and fittings as shown on as required. Down pipes will generally be positioned centrally with columns unless otherwise shown on drawings or agreed with the Engineer.

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10.2.78 Vent Pipes:(if required) The Contractor shall supply and fix vent pipes in positions, shapes and sizes shown in

the drawings and the vent pipe is to finish 25 cms above the roof slab of the guard room and a copper wire ballon fixed over.

10.2.79 Sweet Water Feed Pipes: A 2" dia. galvanized screws jointed feed pipes for the water supply will run from

boundary fence at which point a gate valve will be required. (See "PLUMBER") 10.2.80 Plumbing Generally: All plumbing work is to comply with the PROVISIONAL BY LAW WITH RESPECT

TO WATER SUPPLY. The pipes and fittings are to be of the standards specified below:

Galvanized steel as Class 'C' - BSS.1387 with malleable fittings to BSS.143 or 1256. Where pipes are shown outside the building(s) under the ground, they are to be protected with 6" of concrete all around (mix 1:3:6). (See "CONCRETOR")

10.2.81 Gullies, Pipes and Pans: a) All pipe runs shall be true to lines and fixed with clips and straps of approved type and

shall be uniform throughout the work. b) The make joint between cast-iron and galvanized tube, a brass sleeve, 6" long shall be

brazed to copper and the same shall be fixed into cast iron pipe and joint caulked with lead.

c) All other services to be 2" copper and ½" copper and/or as detailed on the drawings. d) The waste pipe from the lavatory basins are to be 2" dia. copper. The traps are to be

15cms with brass cleaning screw caps. e) Floor gullies are to be provided with perforated removable brass cover plates. f) For the W.C. a front outlet 'S' trap will have to be provided as per drawings. 10.2.82 Cold Water Supply Internally: (if required) The whole of the supplies will be surface work and the Engineer to be informed and his

approval gained for all pipe runs before any work is put in hand. The contractor is to provide and fix one number storage tank of 600 gallons. The tank should be fibre glass fabrication to the best workmanship, fitted with 2" dia. galvanized over-flow pipe (discharge into the open air) to lavatory basins, waste water prevention and taps for washing the floors. A brass cock is to be allowed at the head of each down service. Tank shall be provided with two nos.10cms x 100cms x 100cms long teak batterns underneath any material required by the Engineer.

Copper pipes are to be obtained from an approved manufacturer. They are to be fixed with copper and brass pipe clips or bands of approved pattern and care must be taken to allow the pipes to move in the clips for a structural movement. Connections to copper pipes to be "Metco" pattern screwed couplings or other approved type of fittings including 'T' pieces, diminishing straight connection, bends, etc...all as necessary.

10.2.83 Cold Water Supply Externally: Water supply line is to be run from the boundary fence to the water storage tank in the

levels and positions as indicated on the drawings. The pipes are to be galvanized steel tube 2" diameter screw jointed. At the boundary fence, valve is to be provided in a pit and the pipe will stand vertically to a height of 2 feet and coupling for connection to the water house. At the end, pipes will pass through the wall (a flanged connection is to be cast in the wall and will rise to the tank).

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10.2.84 Sanitary Fittings: The contractor shall supply and fix all sanitary fittings and fixings as indicated and

detailed on the drawings and /or as is understood to be necessary by reference to documents and drawings. All fittings are to be assembled strictly in accordance with the manufacturer's instructions. All fittings shall be well and solidly installed, level and true throughout. The contractor shall be wholly responsible for covering and protecting of all sanitary from the time they are fixed upto the final delivery of works and he shall deliver the fittings in place, undamaged and in perfect working order.

In joining enamelled fire-clay or cast iron fixtures to floors, services piping, overflows, traps to soil and waste pipes, contractor shall use oil putty mixed with boiled linseed oil reinforced with hemp. No cement or gypsum will be allowed. The contractor shall test all fittings in relation to the plumbing and drainage in a manner to the satisfaction of the Engineer, and any defective portion shall be repaired or reinstated by the contractor before final acceptance is made.

10.2.85 Manhole Septic Tanks & Soakways: The contractor shall execute all manholes, septic tanks and soakaways pits with

necessary drain lines as indicated in the drawings and/or as agreed with the Engineer with heavy duty cover to B.S.S 497.

10.2.86 Testing: All cisterns, fittings and pipes, etc. to be tested on completion under water and all joints

left perfect and water-tight. 10.2.87 Paint to be Used: Ready mixed paint to be of first quality and to be approved by the Engineer prior to any

order being placed by the contractor. It shall be used strictly in accordance with manufacturer's instructions, or relevant instructions of the Engineer.

10.2.88 Special Instructions Generally: a) Brushes which have been used for emulsion paint are on no account to be used for any

other paint work. b) No thinners to be used other than those specified by the manufacturer. c) Every practical precaution must be taken to keep down and exclude dust before and

during application of the paint and during the whole of the drying period. d) No painting is to commence on any surface until to receive a perfect smooth surface,

which includes providing putties and the preparation of that surface has been approved by the Engineer and no finishing coat is to be applied without prior approval of the Engineer.

e) The contractor shall repair at his own cost any work where the paint finish is found to be in the opinion of the engineer unduly thin.

f) No painting is to be carried out when raining and all surfaces thoroughly dried before work commences.

g) All paint work must be protected during execution and dust sheets are to be make available if required by the Engineer.

h) The tints of undercoats are to be approximate to the finishing coat, but to be of sufficient difference in each succeeding coat to indicate and prevent missing areas.

i) Test samples of colours to be used are to be made for each coat and approved by the Engineer before the work commences.

j) All paint(s) are to be delivered to site(s) in the sealed and labelled containers produced by the manufacturers with the necessary instructions for use and on no account any mixing to take place without the prior approval of the engineer.

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A certificate or letter from the manufacturer must be also produced stating that hey have full confidence that their material will stand upto the exposure conditions in Kuwait.

10.2.89 Safety of Electric Gear: The contractor shall be responsible for the safety of all electrical equipment, switchgear,

transformers, etc., and should any of these be damaged, destroyed and/or scratched during his operations either by himself or his workmen, he shall, at his own expense make good all such losses incurred either by the employer, and/or his subcontractor.

The metal doors, frames, windows and ventilators, panels, etc....are all to be prepared as specified below.

10.2.90 Preparation: All metal work which is to be painted is to have all rust and scale entirely removed by

means of steel wire brushes or mordant solution and a perfectly clear surface obtained to receive undercoats. It is important that all the mordant solution is washed clear before priming. All priming is to be red lead.

10.2.91 Application: Each coat on a single area is to be carried out in uninterrupted operation. All coats of

paint must be thoroughly dry before subsequent coats are applied and each coat must be rubbed down before the succeeding coat is applied.

Any red lead priming coat applied to steel or other metal work shall be given four clear days to dry and harden before application of undercoat.

10.2.92 Metal Work Generally: To receive two coats of undercoating and two semimatt finishing coat of approved paint.

All coats to be approved before application of subsequent coating. 10.2.93 Schedule of Colours: a) Steel angles and channels, etc. Semi matt black b) Trench and manholes frames to be finished in semi matt black. c) Wood doors and frames surface to spirit varnish finished. 10.2.94 Creosote: (if required) Well creosote at all ends of red wood before building up. 10.2.95 Linseed oil: (if required) Three times oil, red wood trench covers of all faces. Allow two weeks lapse between

application, rub down with quality sand paper immediately prior to application. Last oil to be very slight. Creosoting and linseed oiling shall not be measured separately.

10.2.96 Silicone Paint: For the concrete and surfaces scheduled below, only paints for silicone and resin base

are to be used. All surfaces must be thoroughly dry and free of dust and on no account any paint to be

applied if the temperature is below 4ºC or when raining. All brushes used are to be new, of pure bristle or nylon minimum 5" width, 1½" length. Application is to be made by flowing the paint on and on no account is the paint to be brushed.

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Tinning is only to be carried out when the weather is excessively cool and then no more

than half pint of mineral spirit or turpentine per gallon of paint. Permission to do this must first be obtained from the Engineer. Surfaces of concrete shall be rubbed down, smoothed and puttied where necessary prior to commencement of painting. The puttying of walls prior to painting is only to fill small holes, shrinkage cracks, etc. in the concrete surfaces. Large holes are to be made good immediately after striking formwork and as described under "Concretor". Under no circumstances is putty to be spread over the concrete surface in order to remove irregularities, etc. and a two application of white silicone paint is to be made to all concrete surfaces as follows:

a) All exposed and visible concrete surfaces externally. b) Ditto do......internal including roof soffits, columns and beams. 10.2.97 'Fix Only' Items Generally: The tenderer's rates shall be deemed to include for any labour which is not specifically

measured or mentioned but which may be understood to be necessary by reference to the Bills of Quantities, Specifications and Drawings.

Tenderer's rates shown against "Fix Only" items shall cover collection, loading or assisting to load, transporting to the site(s), unloading or assisting unloading, placing in stores, taking from stores, unpacking, hoisting of position, building in or fixing necessary incidental materials and making good. His rates shall also cover for his being responsible for the safe custody of all materials and for which he deems himself to be entitled for.

10.2.98 Glazed Wall Tiles: a) Internal faces of wall to battery room up to 1.50M door heights or as shown shall be

glazed with tiles 15cms x 15cms in accordance with BSS.1391:1954 true to shapes even in surfaces free from all blemishes.

b) Samples are to be submitted by the contractor for approval. The vertical wall surfaces to receive glazed tiling are to be prepared with a cement sand screed (1:4), horizontally scratched and the tiles are to be bedded in cement and sand bedding (1:4) and grouted and pointed with white cement.

10.2.99 Kerbstones and Kerbraces: (if required) Foundations to kerbstones or kerbraces shall be concrete 1:3:6 and shall be minimum

size of 18" x 12". All haunchings too shall be finished in a workmanlike manner and to Engineer's approval. All precast kerbstones within the yard shall be of the sizes shown on the drawings, bull nosed type and built in a workmanlike manner true to levels and alignments and grouted with cement sand mortar 1:3. All kerbstones to be purchased from the Cement Products Factory, Kuwait.

10.2.100 Manholes and Future Openings Covers: All internal manholes and future openings for equipments shall be covered with

approved fire fighting (1Hr fire rating) both shall be fixed on a hot dip galvanized steel frames anchored properly to the concrete.

10.2.101 Insulations to Cavity walls: Should any of the air conditioned rooms, such as, control room, communication room,

charger room and room for the fire fighting control panel, be flanked by cavity walls, all cavities in these walls should be filled to full width and depths with rockwool, fiber glass or equal other approved insulating material to Engineer's satisfaction.

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10.2.102 Overhead Crane: A travelling overhead crane shall be provided in the 300/132kV switchgear room. The

working load of the crane shall not be less than 130% of the weight of the heaviest complete part of the switchgear that will be lifted during erection or dismantling for maintenance (presumably a complete circuit breaker pole with operating mechanism).

The contractor shall submit with his offer for the Ministry's approval, the manufacturer's catalogues showing the crane to be supplied and hoisted into position. However, provisionally the specification for the crane shall generally be as follows:

The plant shall be of a heavy duty type and of robust construction. All materials and workmanship shall be the best of their respective kinds. The equipment shall comply with all relevant British Standard Specifications or with equivalent standards.

All materials used must be suitable for erection in the 300/132kV switchgear room of dimensions that will be determined with the switchgear offered and the room plan submitted by the tenderer (called for under separate clause), all subject to amendment and final approval by the Engineer.

Type Overhead, hand-operated, suitable for longitudinal

and transverse movement. This shall be of the double

type Working load 130% of the maximum working load (as specified) Test Load 15% overload Headroom 0.90 meters Span Side Room (side clearance) Clear height (underside of These will be determined upon approval of the

Engineer hooks) When in height position Longitudinal travel distance End Carriage The end carriages shall be of the welded steel

construction, each mounted on two double flanged cast iron runners fitted with roller bearings.

Trolley The trolley should be guarded and hand-operated. It shall have travel wheels fitted with roller bearings and shall be designed to combine hoist and trolley units into one compact unit.

Chain The chain shall be of the finest quality obtainable accurate to pitch and free from twist. Both the hand chain and load chain shall be guarded and shall run on roller bearings to reduce friction and secure effective performance.

Load hook The hook should be forged from special steel and should swivel on ball bearings or similar.

Brake The brake shall be automatic in action and totally enclosed. It should offer no resistance when hoisting is in operation and should act immediately when hand chain is released.

Sundries All rails necessary, fish plates, clamps, holding nuts, washers, etc., shall be supplied.

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Pointing All unmachined surfaces must receive two coats of oil paint before despatch. Bright parts must be protected against corrosion.

Test Certificates Certificates of testing and examination of crane, hoisting chains and hooks will have to be supplied with the crane.

Erection & testing The crane shall be erected and tested on site and handed over ready for operation and test by the Ministry's Surveyor.

During the guarantee period any defective components and parts shall be replaced and

defects found or defected during this guarantee period shall also be rectified. 10.2.103 Importing of Production Equipments: a) Importing of production equipment for the manufacturing of construction materials

will only be allowed by an advance authorization from the Ministry of Commerce and Industry.

b) Locally manufactured construction materials should be used unless such materials do not conform to specifications set forth in the contract.

10.3 SPECIFICATIONS FOR THE SUPPLY AND INSTALLATION OF AIR-CONDITIONING EQUIPMENT IN 300/132/33/11kV SUBSTATIONS 10.3.1 General: 1. Main Contractor for the sub-station construction on "Turn-key" basis shall be

responsible for design, supply and installation, setting to work, testing, commissioning and delivery in perfect operating conditions as well as maintaining the complete installation for a period of one year from the date of testing and acceptance as detailed in the book of General Conditions and Safety Precautions for A/C works issued by MEW.

2. Specifications described hereunder are brief and therefore, the main contractor shall include for all equipments, materials, labour...etc for the complete installations to ensure best workmanship and operating conditions, whether detailed hereunder or not.

3. All builders works including foundations, cutting, opening, false ceiling...etc. required for the A/C installations shall be done by the contractor whether specified hereunder or not.

4. Where equipments offered are manufactured locally, the tenderers shall produce the relevant design data for scrutiny.

5. Where equipments offered are manufactured under license, tenderers shall enclose with their offers a written assurance from their principals for the design and quality of equipments produced by them, without which the offers shall not be considered.

6. If contractor during the guarantee and maintenance period fails to respond to any necessary repairs called for by MEW within 24 hours or contractor been notified by phone, MEW reserves the right to execute the necessary repairs under full responsibility of contractor and charge the contractor the cost of these repairs without accepting any claims from the contractor side.

7. If contractor is not the main agent of A/C equipment and if contractor fails to start and commission the A/C equipment (packaged units/mini split units) MEW reserves the right to call a specialist from the main local agent to start and commission the A/C equipment at the expense of the contractor without any claims from the contractor side.

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8. Scope of Air-Conditioning Works: a) Control room, communication room, battery charger rooms and Argon and dry

powder room shall be provided with Mini-split A/C units. b) Battery rooms shall be provided with minimum 350 cfm capacity exhaust fans

with automatic vane type shutters, and shall be treated as hazardous areas. c) Basement, mezzanine floors and 300kV, 132kV cable gallerys if any shall be

provided with aero foil type extract fans to provide ventilation rate of minimum six air changes per hour extract fans and air intake arrangements shall be properly located to ensure proper cross flow across the entire ventilated areas. A minimum of the two extract fans shall be provided in each basement fire zone.

9. Complete design calculations showing overall heat transmission coefficients, equivalent temp. differences, cooling load estimates, A/C installation drawings, filled in technical schedules (copy attached) for equipment being proposed, catalogues, schematic electrical control wiring drawings, details of A/C Sub-Contractor should be submitted by the main contractor and approvals obtained before commencing A/C installation and other installations in the substation shall not interfere with each other and main contractor shall be responsible for ensuring alterations in any of them in case of unforeseen alterations in approved A/C installation drawings at the time of installation work, at no extra costs.

10.3.2 General Technical Specifications for Mini Split Units: 1. Tenderers shall offer from one of the following makes, viz., National, Carrier,

Hitachi and Trane or equivalent, which shall conform to MEW specifications in all respects and do not require major field modifications to meet MEW requirements.

2. The following design data shall be taken into consideration by the Tenderers for equipment selection:

For summer Air-Conditioning: Outdoor temperature 115 degree Fahrenheit dry bulb 82 degree Fahrenheit dry bulb Indoor temperature 76 degree Fahrenheit dry bulb Indoor relative humidity to be maintained at 50ºF. Maximum saturated suction temperature 45ºC A) Works required under this specification shall be: supply and installation of the

following: 1. Mini split A/C Units: Mini split A/C unit shall consist of air cooled condensing unit and matching fan coil

unit, factory assembled, pre-wired, pre-charged and factory tested using R-22 refrigerant.

Condensing unit: a) Casing: Casing shall be constructed of heavy gauge M.S. sheet metal and shall be firm

and rigid. Casing shall have an approved anti-corrosive and heat resistant paint finish. b) Coil: 1. Condenser coil made of seamless copper tube with aluminium or copper

straight fins, mechanically expended over the tubes. 2. Condenser coil made aluminium tubes and aluminium spiral fins will be

accepted subject to the following conditions: - A five years warranty shall be given by the manufacturer for the coil and

compressor. - No joints within the individual refrigerant circuits. - Transition joints shall be easily acceptable and protected by pretinned zinc

rich aluminium solder.

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- Single row configuration shall only be accepted. - Tube fin gap shall be sealed properly without affecting the metal to metal

contact between tube and fin. c) Compressor:

Compressor shall be hermetic reciprocating or rotary type of appropriate capacity and shall be suitable for operation on 415V, 3-phase, 50Hz, or 240V single phase 50Hz supply with permissible voltage variation of +/- 6%. Compressors shall be inherent thermal protection or external thermal overloads.

d) Condenser Fan: Condenser fan shall be multi-blade type directly mounted on dip proof motor

with class A insulation and shall be suitable for operation on 415V, 3-phase, 50Hz, or 240V, single phase 50Hz supply with permissible voltage variation of +/- 6% condenser fan motor shall be provided with inherent thermal protection.

Fan Coil Unit: Fan coil unit shall be either floor mounted, wall mounted, ceiling suspended or cassette

type as mentioned in the schedule of Units or as shown on the drawings. a) Casing: Casing shall be of heavy gauge M.S. sheet, wall mounted, ceiling suspended or

cassette type as mentioned in the schedule of Units or as shown on the drawings. b) Evaporative Coil: Evaporative coil shall be made of seamless copper tubes with aluminium or copper

fins mechanically bonded to the tubes. Spiral fins are not accepted. c) Fan: Shall be multi-blade centrifugal, two or three speed impeller type, directly mounted

on motor shaft and shall be easily accessible for maintenance. Fan motor shall be open type class A insulation, provided with inherent thermal protection and suitable for 240V, 50Hz, single phase power supply.

d) Air Filters: Air filters shall be of permanent cleanable and washable type and shall be easily

accessible, thickness shall be minimum 12.5mm. Other Requirements: a) Pre-charged and pre-insulated refrigerant tubing as supplied by manufacturer of the

A/C unit shall be used. The insulation shall be wrapped with 8 oz. Canvas and painted with 2 coats of weather proof paint.

b) Drain pipe shall have minimum 19mm and the material shall be PVC. c) A remote switch and thermostat shall be provided for wall, ceiling and cassette FCU

type and built-in for floor mounted FCU. d) All mountings, brackets, bolts, nuts, fixtures, etc. for installing the condensing unit

and fan coil unit shall be provided. e) All mini split A/C units shall be provided with proper earthing as per MEW's

specifications. B) All works, under this trade, shall be executed by registered A/C contractor who is

acceptable to the Ministry. C) Make, model and type of A/C mini split units, proposed to be supplied shall be from

a well know manufacturer, priority for local make, and performance to all such units and the cooling capacity of same shall be checked by the Ministry to make sure whether or not the units offered meet the design conditions as well as the near extreme climatic conditions prevailing in Kuwait.

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D) Subsequent to completion of installation, the units shall be put to a durability test of

30 days during mid-summer, 15th June – 15th September at contractor's cost and should be durability test prove to be satisfactory, the contractor shall be required to maintain all such units for a further period of 12 calendar months therefore.

E) pars of building to be air-conditioned shall be control room, communications room, and battery chargers rooms and Argon and dry powder room.

F) Each ventilator equipped in basement will operate (in the normal case) automatically by thermostat switch and manually by override switch.

G) In case of using more than one ventilator in one zone of basement, those ventilators shall operate and stop automatically and manually altogether.

H) Each ventilator will be provided with an isolating switch located adjacent to the ventilator for the purpose of maintenance.

I) In the case of fire, all the ventilations in basement (where the fire is burning) shall be stopped by means of an arrangement done in conjunction with the Fire Alarm panel in the Station. Means of prevention against the automatic re-operating of ventilators unless the clear of fire (the manual operation could be fulfilled even the presence of fire).

J) Indication lamps to be provided in the control circuit of each ventilator to aid knowing the instant situation of the ventilator.

K) The above arrangement will be submitted in an integrated system for control of the operation of each ventilation, for approval.

L) The tenderer shall be taken into his account that the ventilation of the local transformers room should be adequate to keep the ambient temperature inside the room within the permissible limits (50ºC).

10.3.9 Work Execution: a) All insulation material being used by the contractor shall have manufacturer's test

certificate and shall be used only after the approval of the concerned Engineer. b) The contractor shall carry out the installation work strictly according to approved

specifications and drawings under the constant supervision of an Engineer of this Ministry. Any deviations in specifications and layout, etc. for any reason whatsoever shall be made by the contractor only after the written approval by the supervising Engineer concerned during installation.

10.3.10 Inspection and Testing: a) The contractor shall carry out the installation work to the entire satisfaction of the

Supervising Engineer. b) On completion of the installation by the contractor, the installation shall be

inspected by the component authorities in accordance with approved specifications and drawings. Any discrepancies noted shall be rectified within one week time and the installation re-inspected. Erection certificate shall be issued to the contractor only after ensuring that the installation work is done to the satisfaction of Engineer's concerned.

10.3.11 Operation Test and Handing Over/Taking Over: Operation test shall be carried out in satisfactory and continuous running of the

installation for a minimum period of one month. During the test, the contractor shall demonstrate the operation of all controls, performance of each component and the units capacity to meet the designed indoor requirements of temperature and humidity. Operation tests are usually carried out between the 15h June and 15th September.

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10.3.12 Guarantee: Guarantee shall be for a period of one year from the date of satisfactory operation test

and issue of handing over and taking over certificates. 10.3.13 Miscellaneous: a) The contractor shall submit three sets of the following separate folders at least one

week before the installation tests: i) Complete specifications and installation drawings and electrical diagrams, etc. as

tendered and approved variations if any. ii) Manufacturer's technical data regarding the installation, etc. iii) "As fitted" A/C system drawings. b) The contractor shall handover the following at the handing over the installation: i) Three sets of operation, maintenance and service engineering catalogues in separate

folders along with the electrical wiring and technical drawings. ii) Micro-Films: The contractor has to supply to the Ministry three sets of 35 mm silver halide micro-

film aperture cards from "as fitted" or "built" original drawings. The front face of these aperture cards should be left blank and on the reverse face, the following details should be shown by the contractor:

Supplier Contract No. Title of Project Drawing No. Reduction Ratio Date A sample of processed micro-film aperture card should be admitted to the Ministry

for approval. iii) Transparent polyster copy of each drawing to be supplied, a sample of which should

be submitted to MEW. 10.4 Specification for Electrical Installation Works: 10.4.1 Scope: 1.1 This specification covers the design, supply, delivery to site(s), erection and

commissioning of all materials and equipments required in connection with electrical installation work for the substation(s) required.

1.2 All work, equipment, accessories and fittings shall be designed and manufactured to operate continuously in the electrical supply system of 415 volts ±6%, 3-phase, 4-wire/240 volts, ±6% single phase, 50Hz, ±4% and the entire works shall be carried out strictly in accordance with this specification, the Bill of Quantities, the various electrical schemes, drawings and the rules and regulations for electrical installation of MEW R-1, and the general specification for electrical installations of MEW/SS/1, and amendment.

1.3 The contractor shall complete the forms and shall submit with the offer. 10.4.2 Materials: Attention of all tenderers is hereby drawn to the following: a) The successful tenderer shall furnish to the Ministry of Electricity & Water, all

particulars of all the equipments he proposes to install along with dimensional drawings, catalogues and specifications, before starting the work. At the request of the Engineer, the contractor shall also submit samples of all equipment for approval.

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b) No orders shall be placed by the contractor for any materials unless the written approval

of the Engineer has been obtained. c) Only approved material shall be employed at site(s) and all materials installed which

have not been approved shall be removed and reinstalled by approved ones at the entire cost of the contractor.

10.4.3 Electrical Contractor: The electrical works shall be carried out by an electrical contractor who is on the Central

Tenders Committee's approved list of electrical contractors. The electrical contractor must have an Electrical Engineer and an Electrical Supervisor for ensuring supervision of the works. The Electrical Engineer must be available for a minimum period of two(2) hours every second day at site/each site and the exact time shall be arranged between the contractor and the Ministry of Electricity & Water's Engineer. The Electrical Supervisor should be available at site during working hours.

The electrical contractor shall be wholly responsible for the proper execution and completion of the entire electrical works included under the electrical installation section of the complete specification and the MEW will not issue a certificate of acceptance until the entire works are completed in all respects.

The contractor shall replace the supervisor and/or any of his subordinates, technicians and unskilled labourers, etc. who, in the opinion of the engineer, are not carrying out the respective works in proper and efficient manner.

Main contractor must ensure that all services and electrical installation works in the substation shall not interfere with each other and the main contractor shall be responsible for ensuring necessary alterations of approved installation drawings at the time of installation works, at no extra cost.

10.4.4 Drawings: The tenderer shall prepare the drawings and schedules describing the electrical

installation at the site(s) of work. The position of all fittings, fans, equipment, apparatus, etc. indicated on the drawing

should be approximate only, and are to indicate generally the arrangement of works, but the final positions of all such equipments and apparatus shall be as agreed by the Engineer and with no extra cost to the Ministry due to any change made by the Engineer.

Should any portion of the works which should reasonably and obviously be inferred as necessary for the complete, safe and satisfactory operation of the installation as a whole but not expressly described or specified, the contractor shall provide and execute such works as part of the contract and shall not be entitled to any extra payment on that account.

10.4.5 Working Drawings: The contractor shall provide working drawings showing the exact routes of all

underground cables and ducts, the exact run of all conduits and trunking, drawings and junction boxes, then number and size of wires in each conduit or trunking, the final connection arrangements at distribution boards and switchboards and the details of ducts and the method of fixing final distribution boards for the approval of the Electrical Engineer before commencing any portion of the works.

4 sets of working drawings shall be submitted for approval within two months before starting the works.

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10.4.6 E.I. & E.I. Materials: Unless otherwise specified, all E.I and E.I. materials shall be carried out and supplied in

accordance with MEW Regulations – General Specifications – for Electrical installations and their amendments.

10.4.7 Emergency Distribution Boards (E.D.B.): The distribution board for emergency lights shall be double pole metal clad, and shall be

provided with H.R.C. fuses. The board shall be suitable for 110 volts D.C. supply and comply with B.S. 5486 PT II. The board shall be complete with earthing terminal block for taking one earth continuity conductor for each outgoing circuit, and one earth lead conductor which is to be connected to the substation earthing.

10.4.8 Switch Fuse or MCCB Units: For transformer bay, 300, 132, 33 and 11kV switchgear shall be surface type, metal clad,

heavy duty type a per B.S. 5486/4752, with glands to receive supply cable. 10.4.9 Lighting and Power Circuits: a) All lighting and power circuits shall be wired in accordance with the drawings as

originally approved by MEW. b) 110 volts d.c. circuits for emergency lights shall be carried out generally as normal

lighting emergency circuits and shall be enclosed in separate conduits. c) All socket outlets shall be complete with plug-tops. d) All light fittings shall be complete with lamps/tubes. All light fittings shall be as

described in Ministry of Electricity & Water's Standard General Specification MEW/SS-1.

e) The light fittings in the 33kV and 11kV switchgear room shall be suspended from steel trunking. The steel trunking and other accessories shall be factory fabricated, purpose made out of heavy gauge, galvanized sheet steel to receive lighting fittings in its underside providing a structural support for the wiring and adequate through wiring capacity. The trunking shall be closed on top and open at bottom.

Trunking shall be suitable for suspension by saddle brackets attached to down drops from the ceiling structure. The trunking mouth shall be closed by snap-on steel cover strip which is easily cut at site to fit between fittings.

The trunking shall be suspended from the ceiling by means of conduit as recommended by the manufacturer. Circuit wires shall enter the trunking through one/more of the suspension conduits and suitably bushed holes provided at top of the trunking. Suspension conduits shall be fixed at ceiling to ball and socket type dome-covers to conduit boxes.

Non-metal trunking may be employed, subject to MEW Engineer's approval. f) 300 and 132kV switchgear rooms to be illuminated with fluorescent and flood-light

fittings. Flood light fittings shall be complete with control gear and high pressure

mercury/sodium vapour lamps. Transformer area will also be illuminated by using flood lights as specified before. Number of light fittings shall be subjected to the prior approval of MEW Engineer. 10.4.10 Earthing: Various distribution boards, switch fuses and all other metal works in/above the main

building of substation shall be connected to the substation earthing system. All other annexed buildings may be connected to a separate earthing, complying with MEW Regulations and General Specifications for electrical installations.

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10.4.11 Micro-Film: 3 sets of standard 35mm microfilm aperture cards photographed from "as fitted"

drawings shall be submitted along with five sets of "as fitted" drawings, specified in MEW-S-1.

Details on the reverse side of the microfilm aperture card shall include: Supplier Contract No. Title of the Project Title of the Drawing Drawing No. Reduction Ratio Date The front face of the card must be left blank. N.B. Reduction ratio should be between 6X and 30X. 10.4.12 Amendment No.1: The tenderer shall take into his consideration, while pricing, the amendment No.1 of

regulations for electrical installations issued by Ministry of Electricity & Water to MEW/R-1 Fourth Edition 1983.

Amendment No.1 is as hereunder: I- Clause (415) – page (17): Insert the following note at the end of the last paragraph (as applicable). 3. In multi-occupancy buildings, all electrical installation for common service (i.e.

guardroom, staircase lighting, life, etc.) must be fed via one kilo-watt hour meter, for each surface intake.

Exceptions, if necessary, wil only be given for feeding lifts after obtaining prior approval from MEW.

II- Clause (611) page (21): In line 7, delete the work "lifts" Delete exception (2) and substitute the following: 2. For motors driving fire pumps and lifts, the provisions of current operated earth

leakage circuit breaker will not be permitted. Instead, an audio-visual alarm indicator for leakage (300 – 500mA) shall be provided at a readily accessible and easily noticeable location.

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