OHPC Balimela Volume 4

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ODISHA HYDRO POWER CORPORATION LIMITED

BALIMELA POWER HOUSE, BALIMELA UNITS # 1 to 6 (6x60 MW) R & M WITH NEW TG SET

ELECTRICS AND CONTROL & INSTRUMENTATION

INDEX TO VOLUMES

VOLUME – I : NOTICE INVITING TENDER

VOLUME – II : GENERAL CONDITIONS OF CONTRACT

VOLUME – III: TECHNICAL SPECIFICATION (MECHANICAL & CIVIL)

VOLUME – IV : TECHNICAL SPECIFICATION (ELECTRICS & C&I)

VOLUME – V : TECHNICAL SPECIFICATION (DRAWINGS)




TS VOL IV

VOLUME – IV

TECHNICAL SPECIFICATION ELECTRICS

ORISSA HYDRO POWER CORPORATION LIMITED

CHIPLIMA POWER HOUSE, CHIPLIMA UNIT # 3

R&M WITH NEW TG SET ELECTRICS AND CONTROL & INSTRUMENTATION�

VOL. – IV CONTENTS Page 1 of 3

CONTENTS 01. SPECIAL INSTRUCTIONS TO TENDERERS 01.01 Compliance with specification 1 of 5 01.02 Standards and Regulations 1 of 5 01.03 Make and Interchangeability 2 of 5 01.04 Safety 2 of 5 01.05 Coding/Numbering Scheme 4 of 5 01.06 Compliance with rules, regulations and obtaining

statutory approval 4 of 5 01.07 Instruction Manuals 5 of 5 02. BRIEF DESCIPTION OF SCOPE OF WORK AND

ELECTRICAL SYSTEM DESIGN CRITERIA 02.01 Description of Existing plant 1 of 21 02.02 Scope & Brief Description of work 2 of 21 02.03 Electrical System Design 8 of 21 03. PERFORMANCE REQUIREMENT AND GUARANTEE 1 of 1 04. TECHNICAL SPECIFICATION 04.01 Generator Control Equipment 1 of 160 04.02 Metering and Protection System 10 of 160 04.03 Generator Transformer 27 of 160 04.04 220/11 kV Station Transformer 36 of 160 04.05 Unit Auxiliary Transformer 50 of 160





04.06 11 kV Switchboard 59 of 160 04.07 Unit Auxiliary Board / Station Auxiliary Board 74 of 160 04.08 Electric Motors 87 of 160 04.09 uninterruptible power supply (U.P.S.) 90 of 160 04.10 Battery ,charger and DC distribution board 91 of 160 04.11 Cables 97 of 160 04.12 Miscellaneous 101 of 160 04.13 220kV Switchyard Bay Extension 114 of 160 04.14 Erection specification 143 of 160 04.15 Overhauling of 1000kVA, 11/0.433V 154 of 160 Transformer 05. INSPECTION & TESTING 05.01 Inspection 1 of 17 05.02 Testing 4 of 17 ` 06. LIST OF PREFERRED MAKE 1 of 5 07. LIST OF SPECIFICATION DRAWING 1 of 1 08. DRAWING & DOCUMENTS TO BE SUBMITTED

BY THE TENDERER 1 of 6 09. TECHNICAL PARTICULARS TO BE SUBMITTED

BY THE CONTRACTOR 09.01 General 1 of 32 09.02 Design Consideration 2 of 32 09.03 220 kV Equipment 3 of 32 09.04 HT Equipment 14 of 32





09.05 Relays 22 of 32 09.06 Transformer 22 of 32 09.07 Generator Busduct 26 of 32 09.08 LT Equipment 26 of 32 09.09 Motors 29 of 32 09.10 Cables 29 of 32 09.11 UPS System 30 of 32 09.12 DC System 31 of 32 ANNEXURE – I SELECTION OF POWER COMPO

NENTS FOR MOTORS 1 of 1

ANNEXURE – II LIST OF MANDATORY SPARES 1 of 7 SEC ‘B’ CONTROL & INSTRUMENTATION 01.00 General 1 of 46 02.00 Scope of work and Supply 2 of 46 03.00 Design Criteria 6 of 46 04.00 General Technical Rules 18 of 46 05.00 List of Measurement 27 of 46 06.00 Drawings and Documents 36 of 46 07.00 List of Spares 40 of 46 08.00 Inspection 43 of 46 09.00 List of Preferred makes 43 of 46


BALIMELA POWER HOUSE, BALIMELA UNITS # 1 to 6 (6x60MW) R&M WITH NEW TG SET

ELECTRICS AND CONTROL & INSTRUMENTATION�

TS – VOL IV SEC. A Ch- 01 Page 1 OF 5

01. SPECIAL INSTRUCTIONS TO TENDERERS

01.01 Compliance with Specification

01.01.01 All equipment and accessories covered under this specification shall conform

to `Technical Specifications' given in this document.

01.01.02 All equipment shall be suitable for voltage/freq. variations and other data

given in Electrical System Design.

01.02 Standards and Regulations

01.02.01 The design, manufacture, performance , testing and installation (including

safety, earthing and other essential provisions) of equipment and

accessories covered under this specification shall, in general, comply with

the latest issue of:

• Applicable Standards and Codes of Practices published by Bureau of

Indian Standards.

• Central Board of Irrigation and Power

• Indian Electricity Act.

• Central Electricity Authority

• Indian Electricity Rules.

01.02.02 Equipment complying with other recognised Standards such as IEC, BS,

VDE, DIN etc. will also be considered if it ensures performance equivalent to

or superior to Indian Standards.

01.02.03 Equipment and accessories for which Indian Standards are not available,

shall be designed, manufactured and tested in accordance with the latest

issues of recognised Standards such as IEC, BS, VDE, DIN etc.





01.02.04.1 In case of conflict between applicable Standards referred to in this part and

the Technical Specifications given in Chapter-04, the latter shall govern to

the extent of such difference.

01.03 Make & Interchangeability

01.03.01 The make of major equipment shall be limited to preferred makes indicated

under chapter `List of preferred makes'. Makes of all other equipment and

accessories are subject to prior approval by the purchaser.

01.03.02 Similar equipment and components shall be of same make; equipment of

same type and rating shall be interchangeable.

01.03.03 The purchaser has the option of selecting the manufacturers of electrical

equipment, instruments and controls and any other specialised items in the

interest of standardisation and the successful tenderer shall have to supply

equipment of the particular make, if so required. 01.03.04 The tenderer shall furnish division list of supplies from foreign and Indian

sources indicating the name of the agency or make against the respective

items. It shall be the responsibility of the successful tenderer to arrange the

import licence for the imported items offered and to Co-ordinate the supply of

equipment from foreign and Indian sources and execute the contract within

the agreed time schedule.

01.04 Safety

01.04.01 All equipment shall be complete with approved safety devices wherever a

potential hazard exists and with provision for safe access of personnel to and

around equipment for operational and maintenance functions. The design

shall include not only those usually furnished with elements of machinery





but also the additional covers, stairways , ladders, steel structural platforms

for operator's control panels , handrails, partitions etc. which are necessary

for safe operation of the plant.

01.04.02 All danger and caution notice boards' shall be both in English and Odiya

languages.

01.04.03 The Contractor must take sufficient care in moving his construction plants

and equipment from one place to another so that those may not cause any

damage to the property of the Purchaser particularly to the overhead and

underground cables and other service lines.

01.04.04 When the work is carried out at night or in the obscure day light, adequate

arrangements for flood lighting in the working area shall be made by

Contractor at his own cost and got approved by the Purchaser / consultant.

01.04.05 The safety posters/regulation for prevention of accidents shall be displayed

by the Contractor at appropriate places. Notices and warning signs shall be

displayed for all sources of dangers.

01.04.06 All electrical drives and equipment must be equipped with safety devices.

The safety provisions shall conform to the recognized standards, safety

codes and statutory regulations.

01.04.07 All safety measures as required to be adopted as per the statutory

regulations and the safety rules of the plant shall be strictly followed by the

Contractor during the execution of the Contract.

01.04.08 Adequate number of first aid boxes as defined in the State Factory Rules

shall be provided and maintained at all work sites.





01.05 Coding/Numbering Scheme

A coding scheme for identifying the drawings, plant and equipment,

structures, spares and shipping documents shall be adopted by the

contractor in a sequential manner. The objective shall be to provide the

following :

- Streamlined archives management

- Effective control with respect to identification of equipment and

drawings to be supplied by different contractors/sub-contractors.

- Identification of the spare parts for easier inventory control.

01.06 Compliance with rules, regulations, and obtaining statutory approval

All equipment/materials shall be installed in accordance with the

requirements of relevant standards, Indian electricity Rules and Acts and

also the Factories Act. It is the responsibility of the tenderer to see that the

electrical installation supplied and erected by him shall be to the entire

satisfaction of Chief Electrical Inspector, Central Electricity Authority or any

other statutory body having jurisdiction in the area and also to the owner/

consultant.

The responsibility for obtaining the Electrical Inspectorate’s approval for the

installation and modifications to be carried out rests entirely with the

contractor. It shall be the responsibility of the contractor to prepare and

submit all necessary drawings, calculations, test certificates and relevant

details (other than those given by the owner/consultant) to the Electrical

Inspector and obtain prior approval for commencing the work and for the

complete installation work done.





01.07 Instruction Manuals

01.07.01 Instruction manual shall give step by step procedure for :

1 Erection, testing and commissioning

2 Operation

3 Maintenance and

4 Repair.

01.07.02 Maintenance instruction shall include:

1 Diagnostic trouble shooting / fault location charts

2 Tests for checking of proper functioning.

3 Periodic Maintenance schedule.

01.07.03 Instruction manual shall also contain:

1 Manufacturer's catalogues with ordering specification for all items.

2 List of consumables with specifications, brand names and annual

consumption figures.

3 Drawings relevant for erection, operation, maintenance and repair of

the equipment.

4 Procedure for ordering spares.


BALIMELA POWER HOUSE, BALIMELA UNITS # 1 TO 6 (6x60 MW) R&M WITH NEW TG SET

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TS VOL IV Sec.A Ch-02 Page 1 of 21

02. BRIEF DESCRIPTION OF SCOPE OF WORK AND ELECTRICAL

SYSTEM DESIGN CRITERIA

02.01 DESCRIPTION OF EXISTING PLANT

Balimela Power House at Balimela consists of eight units of which Units 1 to 6 each of 60 MW and units 7 & 8 each are of 75 MW. .

Existing units 1 to 6 (for which renovation and modernization with new TG work is to be taken up) are connected to 220kV power system through 11/220 kV generator transformers. Generator transformers are located in transformer yard towards downstream side of power house . The important parameters of existing generator transformer for each unit are as follows.

Rating - 3x 23400 kVA (Three Single Phase Transformer per Unit Type of cooling OFWF (Forced oil circulation with forced water

cooling) Vector group - Delta/star-(DYn 11) Location - Outdoor Connection - Bus duct - 11kV side - Overhead conductor - 220 kV side

Generator output is taken through isolated phase bus ducts and connected to Generator step up transformer.. Neutral side terminal of generator has been shorted. Tapping has been taken for LA PT panel. For auxiliary supply, 11 kV is tapped from generator bus ducts of units 1,3,5 & 7 and connected to 11kV bus of auxiliary supply system through isolator, reactor, and MOCB. From the 11kV bus four auxiliary transformers ( named 11T, 12T, 13T and 14T) feed unit and station LT boards. These transformers are located upstream side of the Power House in the LT transformer yard Existing LT board is fixed type.

A common control room housing control, protection and annunciation panels for generators, generator transformer, generator aux. and turbine control desks is provided. For the indication & relays duplex type panels are provided. Summation MW, MVAR meters are also located in this control room. Generator is being synchronized at 220 kV through synchronization arrangement.



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The Main Control Room, Battery Room, Battery Charger Room and Unt Control Room (one per unit) located at EL 174.65 m.The HT and LT Switchgear room are located at EL 170.12m. Generator is synchronised at 220kV through synchronisation arrangement. 220 kV Switchyard has a switching scheme of double bus with bypass bus arrangement..

02.02 SCOPE AND BRIEF DESCRIPTION OF WORK

The job shall be done on turnkey basis. The scope of work for the R&M of Units- 1 to 6 with new TG and extension of 220kV Switchyard includes dismantling and proper storage of the dismantled equipment/facility. Design, detailed engineering, construction/manufacture or procurement of new electrical equipment(refer 02.02.01 below), shop testing, packing, transportation, loading and unloading, delivery at site, storage at site, handling, erection, pre-commissioning tests and commissioning of all equipment/system including preliminary acceptance test, performance guarantee, post commissioning services. Scope of contractor shall also include following :

� Supply of mandatory spares, commissioning spares � Supply of special tools and tackles for the equipment/systems

supplied

� Insurance during transit, storage, erection and commissioning

� Minor civil works required for fixing of electrical equipment/panels/cables, bus duct opening, support and reinforcement of existing foundation etc.

� Procurement of all necessary materials and also carrying out

fabrication work as specified in the respective sections of the specification.

The Contractor shall be responsible for complete satisfactorily working of system with guaranteed parameters. All the major equipment shall be installed, tested and commissioned under supervision of representative of manufacturer of respective equipment.



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The Contractor shall also include in their scope of work the fault level calculation for the complete network taking into account minimum/ maximum generation. The relay settings shall be recommended accordingly.

Tenderer shall visit the site and make himself aware of existing units, space for the aux. & Generator transformers, HT/LT Panels, Main Control Room etc. and shall take care of all aspects while designing/executing the work.

Miscellaneous Activities

Following miscellaneous works shall also be included in the scope of tenderer;

� Obtaining certificate from Chief Electrical Inspectorate of the state and CEA for installation and energizing the complete electrical system and equipment covered under the package. (Fees paid to statutory authorities shall be reimbursed to the contractor against production of receipt).

� Any modification or additional requirements by Statutory Authorities shall have to be carried out without time and cost implication to the purchaser.

� Arranging any other statutory approval, if required.

02.02.01 Supply, Erection, Testing Commissioning The scope of tenderer shall include all electrical equipment required for the power plant units and auxiliaries covered under their scope for R&M of units 1 to 6 with new TG and switchyard extension of Balimela Power House at Balimela. The broad scope is envisaged below and shown in Electrical Single line diagram.

The major equipment covered under scope of supply shall be as follows:

� Generator 60 MW, 11kV, 375 rpm 0.9 PF – 6 Nos.( Refer Vol III for scope of work)

� Static excitation system & Digital AVR with thyristor controlled dual channel – 6 set.. (Refer Vol III for scope of work)

� Generator line side terminal cubicles consisting of Surge suppressors, Voltage transformer, surge capacitor, etc. – 6 Nos.

� 11kV Current Transformers for metering, protection, AVR, synchronisation etc.

� Generator neutral side with suitable bus duct links for formation of STAR POINT. The Generator shall be grounded through neutral grounding



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transformer.

� Generator protection panel with numerical protection relays. Protection scheme shall also be hard-wired.

� Generator metering, synchronizing and annunciation panel.

� Microprocessor based control system as elaborated in Sec B of this Volume

� Unit control desk

� HT Bus duct

� 11/220 kV, 3x 23.4 MVA Generator Transformer

� 220 kV Bay Eqipment including extension of Bus, overhead conductor and associated hardwares

� 220 / 11kV, 20 MVA Station Transformer

� control & protection panel with numerical protection relays for Generator Transformer, 220/11 kV Station Transformer, Unit Auxiliary Transformer and Station Auxiliary Transformer

� High velocity water spray system for generator transformer and 20 MVA, 220/11kV Station Transformer.

� 11/ 0.433kV, 3 phase ,750 kVA cast resin dry type unit auxiliary transformer for each unit

� 11 KV Switchboard

� 415 V Unit Auxiliary Board consisting of incomer, bus coupler and out going feeders (Refer Single Line Diagram MEC/S/10FX/11/S3/E/01)

� Refurbishment of 2 nos. 11/0.433 kV, 1000kVA transformers and reuse as station service transformer.

� 415 V Station Switchboard consisting of incomers, bus couplers and outgoing feeders (Refer single line diagram )

� Electric Motors and Actuators including LT motors for drives and MOVs etc.

� AC distribution board / Power Distribution Board

� 2 sets of . 220V. battery bank of adequate capacity.

� 1no. float and float cum boost battery charger for each battery bank

� DC switchboard for each battery set

� Local Push Button stations for drive motors, Junction boxes etc.

� HT & LT Power and control cables, instrumentation and special cables as per requirement and accessories including their termination at both ends

� Cable supporting structures, GI cable trays (ladder type and perforated type), cable racks, other associated accessories and fire sealing materials for laying,



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termination and sealing of cables are under contractor's scope of supply. Cable trestles, if needed within the battery limit for supporting contractor’s cables, shall be in the contractor’s scope. Contractor shall lay separate trays for laying different type of cables like power, control and screened cables.

� All erection materials, required during erection of all types of electrical equipment under contractor’s scope.

� Complete earthing system for all the equipment/systems - equipment earthing and electronic earthing as per actual requirement. Earthing connection of all new equipment to existing network.

� Welding sockets (415V), Power receptacles, 240 V sockets, , 240V Industrial type sockets etc. are included in the scope of the contractor.

� UPS system complete in all respect.

� Illumination within battery limit including DC emergency lighting.

� Lightening Protection for area under extension of 220 kV Switchyard

In addition to above following are also the scope of bidder :

� .Supply of hand gloves and shock treatment charts in English and Oriya.

� Supply of rubber mats in suitable sections to be provided in front of all switch boards for their entire lengths.

� Supply of danger / caution notice boards in English and Oriya as per IE Rules.

� Supply of all foundation bolts, bolts of special design and special embedments as required for installation of all equipment covered under this specification.

� Preparation and submission of lists with specification and itemized prices for various spares, special tools & tackles for operation, repair and maintenance.

� Supply of all consumable materials such as lubricants, transformer oil, etc. required for first filling, commissioning, start-up and performance test ad submission of specification including brand names and quantities. The Tenderer shall also furnish details of yearly requirement for the above consumables or normal operation.

� Preparation and submission of all drawings and documents including progress reports as called or in this specification.

� Determination of electrical soil resistivity at the location of sub-stations by carrying out actual site test.

� Testing of all equipment and accessories covered under this specification at manufacturer’s works and / or recognized independent testing centers before dispatch of same to site as well as all tests at site before handling over the system, complete in all respects to the Owner.

� Arrangement of temporary work yards, material depots and access as required,



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as well as removal from site of all erection equipment, packing materials etc.

� Any item not mentioned in the specification, but considered by the tenderer necessary for satisfactory operation and maintenance of the plant shall be included by the tenderer in his scope of supply and installation.

Supply of gravel of uniform size of 50 mm and spreading it to thickness of 100 mm in the expanded portion of the switchyard. Soil shall be treated chemically to control growth of vegetation and sand shall be spread before spreading gravels. Supervision of erection, testing and commissioning of TG sets, their controls including electrics shall be by representatives of respective equipment manufacturer.Installation & testing of cabling system, including cable, trays/supports etc. Laying and termination of all interconnecting cabling required for completeness and commissioning of the Units All control metering and protection cables required for connection to relays, meters, signaling alarm, control, monitoring etc. at main station building shall be provided, laid and terminated at both ends by the tenderer e.g. control cables from HT transformer's marshalling boxes to MCR, junction boxes of 220 kV isolator, CB, earth switches, CT/PT of yard to marshalling box and marshalling box to MCR. A brief description of control philosophy and layout for complete power plant is given in the subsequent chapter for understanding of tenderer. Tenderer shall provide accordingly. Irrespective of the details provided, tenderer shall include complete electrics for the Units under his scope of work.

The detailed specification and schedule of quantities also covering the minor equipment shall be worked out by the tenderer for the total implementation of the job. The technical requirements of the main equipment involved as per the scheme are covered in technical specification section and other appropriate sections forming part of this specification. The technical requirement of the main equipment involved are covered in technical specification section and other appropriate sections forming part of this specification.

All other existing equipment and structures necessary to complete the work within battery limit.

02.02.02 Dismantling

The scope of the Tenderer shall also include the following;

� Dismantling of all equipment within battery limit



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Tenderer has to remove all the old/existing equipment along with cables. All the unused existing equipment shall be removed, packed and placed in a proper place as decided by the purchaser. Following major existing equipment shall be dismantled

• Generator Transformer

• 11 kV Isolators, Reactors

• All electrical panels including 11 kV Switchboards, Unit Aux. Board, Station Aux. Boards, and control cables pertaining to Units # 1 to 6

• All station switchboard

• Battery banks, battery chargers and DCDBs

• HT, LT and Control cables

• Cable trays, supporting structures, cable racks etc

• Excitation-AVR-PT Panel

• Generator Busducts

• Generator control & relay panel, generator metering panel, generator transformer control, relay & metering panel.

• CTs, PTs, LAs etc

• All steel structures required under battery limit to complete the job.

In addition to the above equipment dismantling and storage of other equipment / structures etc as required to complete the job is In the scope of tenderer.

02.02.03 Battery Limits and termination points

a) Generator Transformer Side Power evacuation up to generator transformer shall be included in tenderer’s scope. Connection of EHT conductor from transformer to 220 kV transformer LA is in the Tenderer’s scope. Control cable termination at both ends wherever signals are required to be tapped/transmitted including control cable termination in yard equipment as per the need.

Auxiliary Side

A new 220 kV Bay for Station Transformer including extension of existing 220 kV Buses to the new bay.

a. )

b) Existing DG set



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02.02.04 Exclusions

The following equipment have been excluded from the scope : Units 7 & 8.

02.03 ELECTRICAL SYSTEM DESIGN

02.03.01 General

Standards

The design, manufacture, assembly and testing as well as performance of the equipment shall conform to the relevant IS specifications (latest revision). In case the tenderer is not in a position to comply fully with certain IS specifications, or in respect of certain items for which there are no IS specifications, the tenderer may base his proposals on IEC/BS/VDE/DIN recommendations or other reputed national or international standards subject to the approval of the purchaser/Consultant.

All equipment supplied and all work done including system design and detailed engineering shall also comply with the statutory requirements of the Government of India, the Government of Odisha and with the Indian Electricity Rules.

Climatic Conditions

The climatic conditions generally prevailing at BALIMELA have been described in volume I.

Electrical Equipment selection and derating shall generally be based on ambient temperature of 50 deg. C.

02.03.02 Design Criteria

Standard Voltage levels The standardized voltage levels as given in table no. 02.02 shall be adopted.



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Table 02.01 Standard Voltage levels -------------------------------------------------------------------------------------------------------------------------

Sl.No. | Description | Voltage level | ------------------------------------------------------------------------------------------------------------------------

1. Generation 11kV, 3 Phase 2. Evacuation and Transmission 220kV, 3 phase, 3 wire

50 Hz, effectively earthed

3 11kV System 11 kV, 3 Phase, 50 Hz, Non effectively earthed 2. Station supply 415 V, 3 phase, 4 wire, 50 Hz, effectively earthed. 3. A.C. Drive motors 415 V, 3 phase, 4 wire effectively earthed 4. Metering 110 V, AC PT. voltage 5. Control & protection 220 V, DC 2 wire unearthed of EHV, LT switchgear, D.C. drives 6. Panel lighting and 230V, 1 phase, 2 wires space heaters 50 Hz, A.C. with

point earthed. Permissible variations

The system unit/plant equipment shall be designed suitably for variation in voltage and frequency as indicated in Table 02.03

Table 02.02

Variation in Voltage and Frequency ----------------------------------------------------------------------------------------------------------------------- Sl.No| Description Voltage Frequency -----------------------------------------------------------------------------------------------------------------------



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1. Permissible variation + 6% to - 6% , + 3% to - 5% For LT system with rated performance/ rated current and control + 6% to - 9% , + 3% to - 5% For HT system effectiveness system maintained +10% to -12.5% + 3% to - 5%For EHT

system 2. Permissible variations +/- 10% , +3% to - 5% for control and regulation

equipment with rated performance and control

quality maintained. 3. Permissible voltage dip - 5% at LT switchgear bus for starting of LT motors ----------------------------------------------------------------------------------------------------------------------

Basic Insulation Levels

Equipment shall be designed suitably for basic insulation levels as given in Table 02.03.

Table 02.03 Basic Insulation Levels

---------------------------------------------------------------------------------------------- Sl.No | Nominal voltage kV | BIL kV (peak) ---------------------------------------------------------------------------------------------- 1. 220 kV 1050 2. 11 kV 75 3. 415 V 1.1 ----------------------------------------------------------------------------------------------

Symmetrical short circuit ratings

The three phase symmetrical short circuit ratings of the switchgear at different voltage levels will be as indicated in Table 02.04.



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Table 02.04

Symmetrical Short Circuit Ratings -------------------------------------------------------------------------------------------------------------------------

Sl. Voltage Symmetrical Making No. level Breaking capacity

------------------------------------------------------------------------------------------------------------------------- 1. 220 kV 40 kA 100 kA 2. 11 kV 40 kA 100 kA 3. 415 V 30 kA 75 kA 4. 220 V DC 10 kA -

-----------------------------------------------------------------------------------------------------------------------

The rated short circuit withstand duration for switchgear of 220kV is 1.0 sec and for 11 kV it will be 3 Secs whereas for 415 V including MCCs it will be 1 sec.

Motor Starting and permissible voltage dips :

Voltage dip on starting of the largest motor shall be limited to 15% of the nominal voltage at the motor terminals.

System Earthing

220 kV systems is effectively earthed. 11 kV System is non-effectively earthed. 415 V system will be effectively earthed in line with IE Rules.

Other Requirements

The electrical distribution scheme to be provided will be subject to approval of purchaser/purchaser's consultants.

Miscellaneous items such as relays ,type of relays, relay ranges, number of poles for relays, scale of meters, CT ratios, links, fuses, switches, indication lamps, terminal blocks, aux. relays, timers associated with main relays, size of control cables shall be supplied as per the approved scheme/to achieve scheme requirements.

All HT and LT CTs shall be of 5A secondary and EHT CTs shall be 1 amp. secondary. Control cable from CT to panel shall of 2.5 sq.mm. copper.



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All erection/installation accessories, cable termination and jointing kits, cable fixing, dressing, tag numbers, route markers, supporting materials for all equipment shall be part of the tenderer's scope.

Motor space heater (if required) power supply shall be fed from respective shop MCC/Distribution board. Space heaters will be interlocked with motor main power supply.

Earthing mat is already provided for complete power plant area. Existing earthing connections/ strips needs to be checked for continuity and to be refurbished / extended if needed for making suitable to connect all equipment in the scope of tenderer.

Earthing mat shall be provided for the area of switchyard to be extended and it shall be joined with existing earthmat. Selection of components and cable size for MCCs shall be as per chart given in Annexure-I.

Tenderer to submit a system wise drive list indicating process interlocks, permissive conditions etc. with places and mode of control for each drive control system philosophy with provision of various control, indication, measuring devices at various places. This shall be approved by the purchaser/consultant. Based on above approved philosophy tenderer shall have to provide all equipment/materials and prepare a control scheme/logic diagram.

Above mentioned control philosophy and interlocking logic shall be prepared as per the technological requirement.

Tenderer shall include in his scope dummy panels for switchgear and control panels, wherever civil beam blocks cable entry to panel.

For control and protection requirement DC system shall be used.

220V DCDB shall be provided catering all the loads of units and tenderer to include incoming cable for the same. 220 KV System The relay and control panels for this transformer bay shall be provided in existing switchyard control room. A busbar differential protection scheme (analogue, not numeric microprocessor based) for working bays of the existing switchyard is functioning and the panel is installed in the control room of the existing switchyard. It is proposed to extend this existing busbar differential protection



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to cover the extension portion of the switchyard. The tenderer shall include in his scope all the equipment/relays/modifications as per requirement. Tenderer may use spare core of existing CTs. However, in case of non-availability, tenderer shall include CTs suitably as per site requirement.

The design of steel structure in the switchyard shall in accordance with the requirements of IS : 800 for steel. The design of concrete foundation for these structures will be done as per IS : 456. Wind load shall be as per IS : 875 (Part – III).

Outdoor yard shall be designed with consideration of following clearances.

• Minimum height of live conductor above ground level (mm) : 7000 • Sectional clearances (mm) : 4300 • Ground clearances for vehicle movement (mm) : 8000 • Phase to phase clearance between conductors (mm) : 4500

The basic system parameters for the 220 kV system are as follows.

• Nominal system voltage : 220 kV • Highest system voltage : 245 kV • No. of phases : Three • System frequency : 50 Hz • System earthing : Solidly earthed • Fault level (3 – Phase symmetrical) : 40 kA (for 15000 MVA) • Short time current rating (for all : 40 kA for 3 secs current carrying parts) : • Power frequency withstand voltage : 460 kV RMS (Switch

gear) • Impulse withstand voltage : 1050 kV peak (switch

gear) • 220 kV conductor : ACSR Zebra • Current carrying capability of bay bus : 1600 A

The Tenderer shall check the VA rating of metering and protective cores of all current transformers and potential transformers and satisfy himself thoroughly regarding their adequacy considering lead burden as well as burden of all relays, meters ad instruments offered. The successful Tenderer shall submit for Owner’s approval details of relays,meters, instruments and associated circuits as well as calculations for selecting knee point voltage of all PS class CTs.

Suitable interlocking shall be provided between various switchgear equipment in the 220kV switchyard to ensure safety of maintenance personnel working on one section of the equipment with other sections alive and to prevent



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incorrect switching sequence which could lead to damage to plant and equipment. The interlocking may be of electrical or mechanical or key type or any combination thereof, but shall be effective when the equipment is controlled remotely, locally or under emergency manual operation. However, in the selection and design of the interlocking scheme, the Tenderer shall give due consideration to the specific requirements of the Central Electricity Authority.

The relay and control panel for 220 kV switchgear, and DC distribution board for the 220 kV switchyard shall be located in the Switchyard control room and all these are included in the scope of this specification. 415 V ACDB shall be located at switchyard control room building.

02.03.03 Design of Electrical Auxiliary System.

The electrical auxiliary system shall be designed considering available short circuit levels, switchgear duties and voltage dips on auxiliary buses for the various operating conditions. The impedance values of transformer shall be selected with a view to limit the fault levels and voltage dips.

Manual transfer of auxiliary loads shall be provided during unit starting and during planned shutdowns, whereas fast automatic transfer shall be provided between the two incomer. buses of 415V switch boards.

02.03.04 Power Distribution Scheme

The electrical power distribution and control scheme shall be based on the scheme elaborated below. Tenderer shall follow the system design in general on these lines and design the equipment based on criteria given in earlier paragraphs. The generator shall generate power at 11 kV. The generator shall be directly connected to 220 kV systems through 3 phase 11/220 kV transformer. The electrical distribution scheme shall be based on unit and station auxiliaries system feeding separately. The unit loads shall be fed directly through 750 kVA, 11/0.433kV transformer for each unit. The scheme is shown in single line diagram and is further elaborated in the following paragraphs of this chapter.

Power Evacuation

The transformer yard and the switchyard are existing and located adjacent to power plant building to interconnect the power plant to grid at 220 kV for the purpose of power evacuation.



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02.03.05 Elaboration of Electrical Scope of Work

The scope of work and different design requirement have been given in different chapters, however, for ease of understanding it is briefed in following paragraphs.

01. Generator CT-PT- LA Cubicle

New Generator CT-PT- LA Cubicle shall be provided. All line side CT for metering, protection and AVR shall be provided in this cubicle. 11/ 0.110kV Potential transformer for metering, protection, AVR and for synchronization shall be provided

02. Neutral Grounding Cubicle

New NGC shall be provided. The generator neutral grounding equipment shall be housed in a metal enclosed cubicle. The high resistance grounding of a generator neutral shall be adopted by connecting the primary of a single phase distribution type earthing transformer between generator neutral and ground with the transformer secondary being shunted by resistance with a voltage relay and harmonic filter. Current transformers for metering & protection shall be provided in this cubicle.

03. Generator Transformer including HVWS System A new 3 phase, 23400kVA, 11/220/�3 transformer for each unit shall be provided by the tenderer. The new transformers shall be provided with the microprocessor based numerical transformer management protection systems.

High Velocity Water Spray System

High velocity water spray system shall be provided for generator transformer. System shall be designed as per TAC guidelines and shall have auto as well as manual starting features. For Detail specification refer Vol – 3 of TS.

04. Electrical Protection System

The protection required for the various electrical equipment e.g generator, generator transformer, 220/11 kV, 20 MVA Station transformer, unit aux. transformers, station auxiliary transformer, , auxiliary motor etc. All the relays including generator protection relays shall be microprocessor based numeric type irrespective of their use with communication facilities



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05 220 kV SYSTEM

• A new 220/11 kV, 3 phase, 20 MVA transformer shall be provided • Existing 220kV bus shall be extended to accommodate new station

transformer 220 /11 kV, 20 MVA. • New 220 kV transformer bay consisting of SF6 breaker, Isolator,

earthing isolator, CT, PT etc as per requirement shall be provided. • Foundation of 220/11 kV , 3 phase, 20 MVA transformer, switchyard

bay equipment etc within battery limit is in the scope of bidder • Earthing mat for extended portion of switchyard and connectivity of it

with existing switchyard is in the scope of bidder. • Lightning protection for extended portion of switchyard is in the scope

of bidder. • Illumination for the extended portion of switchyard is in the scope of

bidder. • New cable trench for extended portion of switchyard and connectivity

with existing cable trench is in the scope of bidder. • Approach road for materials and inspection during normal operation of

new transformer bay is in the scope of bidder. Connectivity of new road with existing road is in the scope of bidder.

• Arrangement of refilling of SF6 gas, compreesed air and fire fighting is in the scope of bidder.

• C& R panel for transformer bay shall be provided and modification in cable trench, if required, shall be done by bidder.

06 Generator Busduct

11 kV generator busduct shall be isolated phase with tubular shaped enclosure. Enclosure shall be continuous type. Tenderer shall include the Generator busducts consisting of following minimum items;

a) Generator main Busduct from generator terminals to generator

transformers and tap offs to unit auxiliary transformer

b) Generator neutral busduct to the neutral grounding transformer

c) Generator busduct tap off to surge protection & VT cubicle d) Generator busduct tap off to Excitation Transformer



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e) All associated equipment/items like flexible/rigid joints, required no. of bends, silica gel breather, space heater, etc

f) Set of maintenance tools and tackles as required.

g) Earthing of busducts with continuous run of conductors

h) Necessary support structures, erection hardware

07. 11kV Switchboard

New 11kV Switch board shall be provided as per 11kV single line diagram.

The switchgear shall be of metal clad, single bus bar, self standing, dust proof

construction, indoor cubicle type fitted with vacuum/SF6 circuit breakers, in

fully draw out execution.

08 LT AUXILIARY SUPPLY SYSTEM

Dedicated cast resin dry type Unit Auxiliary Transfomers (UAT) shall be

provided for each unit. Each UAT shall be of 11/0.433kV, 750 kVA. Each UAT

shall feed the respective Unit Auxiliary Board(UAB). The UAB’s will have back

ups incoming supply from existing 11/0.4 kV auxiliary transformers (11T and

12T) and will be called Station Service Transformers(SSTs). The Station

Service Board will meet the station load requirements as well as auxiliary load

of one unit..

7.01 Unit Auxiliary Transformer

New 750kVA, 11/0.433 kV, cast resin dry type transformer shall be provided for each unit.

7.02 11/0.433 kV Station Transformer

Existing 11/0.433 kV, 1000kVA transformers shall be reused after refurbishment

7.03 415 V Unit Auxiliary Board

415V Unit Auxiliary Board shall be provided for each unit. It shall have air

circuit breakers & shall be metal clad, indoor type floor mounted (in fully draw



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out execution).Switchboard shall be in single tier execution for incomers & bus

couplers and two tiers for outgoing feeders.

7.04 Station Auxiliary Switchboard New station auxiliary switchboard consisting of three incomers (incomers

from station transformers and from DG set), bus couplers and outgoing

feeders as per requirement shall be provided. The incomers will have auto

change over facilities. Switchboard shall be in single tier execution for

incomers & bus couplers and two tiers for outgoing feeders.

7.05 415V Switchgear (MCC, Aux. AC/DC Boards, Local Distribution Station)

415V draw out type switchgear / MCC shall be provided for feeding different auxiliaries, as required for the plant.

8 DC System 2x100%,220 V battery bank shall be provided to cater all the requirement of DC loads of power plant. The battery bank shall also take into account DC requirement of existing units 7 & 8.

One no. float and float cum boost charger shall be provided for each battery bank.

. One set with two sections DC distribution board shall be provided for each unit.

9 UPS

A dedicated UPS system of adequate capacity and redundancy shall be

provided to cater all requirement of control & instrumentation of unit 1 to 6.

This shall be consisting of battery banks (VRLA, SMF type), battery chargers,

inverter banks, static switches, manual bypass switches, 3 phase to 1 phase

transformer, ACDB and all other associated cabling and accessories.

Sufficient nos. of spare feeders shall be provided in the ACDBs of the UPS for



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purchaser’s use. The exact number of feeders shall be decided during

detailed engineering

10 Cabling (Cables, Cable supporting materials, trays etc)

All HT/LT power, control cables and cable accessories supporting structures, cable installation, cable terminations with necessary junction boxes and fire sealing are under the scope of tenderer for all areas covered in the package.

All control and protection cables required for connection to relays, meters, signalling alarm, control, monitoring etc. at main station building shall be provided, laid glanded and terminated at both ends by the tenderer.Existing cables shall be removed and placed in proper condition in a place identified by the purchaser's store.

All erection/installation accessories, cable termination and jointing kits, cable fixing, dressing, tag numbers, route markers, supporting materials for all equipment covered in the package shall be part of the tenderer's scope.

Selection of components and cable size for MCCs shall be as per chart given in Annexure-I.

Tenderer shall have to submit the layout indicating location of all major electrical equipment and cable routes including levels of floor, clearances, entry/exit points, cable structure details during detailed engineering stage.

11. LT Motors

AC squirrel cage industrial motors shall be fed at 415V, 3 phase, 50 Hz, with DOL start as applicable. For motors above 30 kW rating star delta starter shall be provided.

415 V AC energy efficient motors shall be provided to all auxiliaries covered under this package as per system requirement.

12 Illumination Illumination of Power House Area, Main Control room and extended switchyard area shall be in scope. Light fittings shall be selected considering aesthetic look and requirement. Light fittings near all equipment within battery limit shall be provided.



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13. Earthing Materials New GI flexible/flats are to be provided for connecting all equipment within battery limit to existing earth grid.

14 Ligtning Protection Lightning protection for extended part of 220kV Switchyard shall be

provided. All required materials shielding wire, down conductor etc are In the scope of tenderer.

15 Electrics of compressed air system, technical water facility, fire fighting

system, AC & ventilation system and EOT crane is in the scope of bidder

16 Control & Instrumentation

Control system shall be provided as detailed in Sec B of this Volume. Electronic portion of governor and AVR control shall be compatible to the over all system requirement.

The automation control shall have normal operation control, Governor control, process protection control.

The Control System among other things shall have .

- Automatic Control of the unit - Acquisition of operational data about generating units, transformer,

220 kV CBs. Unit Auxiliaries, Station Auxiliaries. - On line monitoring of partial discharge, vibration Temp, and trend

indication. - Indication & recording of faults - HMI with Technological equipment - Annunciation - Operation Documents

The control desk in the main control room shall have one VDU screen with keyboard, mouse etc. (OWS) for each unit with all the above controls and one engineering work station (EWS). Each OWS shall have complete computerized contriol facility. The main control desk of the unit in MCR shall have the following minimum analogue control, metering and indication.

MANUAL CONTROL

- Normal Start - Normal Stop - Emergency Stop



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- GCB switch ON/OFF - FCB switch ON/OFF - Load lower / raise - Speed Lower / raise - Voltage Lower / raise - Reactive power Lower raise - Synchroscope / Bus Selector Switch.


BALIMELA POWER HOUSE, BALIMELA UNIT # 1 TO 6 (6x60 MW) R&M WITH NEW TG SET


TS VOL IV Sec.A Ch - 03 Page 1 of 1

03. PERFORMANCE REQUIREMENT AND GUARANTEE

03.01 The tenderer shall study the specification and satisfy himself thoroughly regarding the workability of the plant, equipment and systems offered and also take full responsibility for the guaranteed operation and performance of the same as well as for their smooth, safe and reliable working.

03.02 All equipment shall be guaranteed for workmanship, materials design and

satisfactory performance to the parameters in accordance with the specification document and relevant clauses of the General Conditions of Contract (VOL II of TS). The guarantee for performance shall cover individual items and systems for their ratings / outputs.

03.03 The tenderer shall also guarantee the integrated operation of all the systems

and equipment covered in his scope as a whole including interfaces required to be established with other related systems and equipment.

03.04 The supplier shall conduct performance / acceptance tests on each of the major

items of equipment supplied to demonstrate that the equipment and system supplied are capable of achieving the performance parameters specified and contracted for, in accordance with the General Conditions of Contract. The total system performance shall also be guaranteed and demonstrated.

03.04 Should the tests specified show that the unit has failed to achieve the

guaranteed parameters, the supplier shall carry out necessary modifications or part replacements to achieve the guaranteed parameters and for successful demonstration the tests shall be repeated

ODISHA HYDRO POWER CORPORATION LIMITED BALIMELA POWER HOUSE, BALIMELA

UNIT # 1 TO 6 (6x60 MW) R & M WITH NEW TG SET

TECHNICAL SPECIFICATION ELECTRICS AND CONTROL & INSTRUMENTATION

TS VOL IV Sec .A Ch- 04 Page 1 of 160

04. TECHNICAL SPECIFICATION 04.01 GENERATOR TERMINAL CUBICLE 04.01.01 LINE SIDE TERMINAL CUBICLE

LAVT panel shall consist of Potential Transformer, surge protection equipment, Protective capacitor and current transformers for AVR and metering. Current Transformer for Generator metering and Automatic voltage Regulator shall be provided in isolated phase busduct Panel specification shall be as follows :

1. Panel Construction : Sheet steel not less than 2.0 mm thick 2. Gland Plate : 3mm CRCA 3. Type : Indoor, Floor mounted 4. BusBar : Main – 100x10x3R AL.(High tensile

fastners to be used for busbar joints. Earth Bus – 50x6 mm Cu. FLAT 5. Cable Entry : Bottom 6. Degree of Protection: IP-54 7. System Fault Level : 40 kA for 3 Sec 8. 11 kV clearance : Phase to Phase : 127 mm (Min)

Phase to earth : 90 mm (Min) 9. Name Plate : Black letters engraved on white

background Adhesive type 10. Wiring : 650 /1100 grade PVC insulated

multistranded Cu cable 11. Painting : Enclosure – Interior / Exterior

Generator Voltage Transformer To provide power supply for metering, synchronisation, AVR and protection purposes voltage transformer shall be provided in LA-VT panel. These will be connected after the generator outgoing terminals. VTs shall be of dry type cast resin design mounted in separate panels. High voltage side of VTs shall have fuses with MCBs on low voltage side. Low voltage star winding shall have all three phases and neutral connections brought out to terminals.





Accuracy class of this shall be 0.2. The technical parameters shall be as follows :

Rated continuous voltage : 11 kV

Ratio : 11 KV/√3 : 0.110 kV/√3

Burden : As per requirement Minimum

100 VA

Power frequency withstand voltage : As applicable for generator busduct

Impulse withstand voltage : -- do -- Surge Protection Equipment The surge protection cubicle shall comprise of surge divertor and protective capacitor on each phase to protect the generator from the effect of transient over voltages. Surge protection equipment and VTs as described above shall be mounted in dust proof isolated phase compartment with provision for entry of main bus tap off into the compartments. Protective capacitors shall be single pole units i.e. one per phase, non inflammable synthetic liquid impregnated type connected between each phase terminals and ground. Each capacitor shall be provided with a built in discharge resistor to drain the residual charge after being de-energized. Surge divertors shall be of station class type with 10 kA discharge current and shall be of design specifically meant for protection of rotating machines, other salient particulars of surge divertors should be chosen in accordance with relevant IS-3070,Part-I, 1974.

Generator Current Transformer To provide Protection and metering for generator, suitable current transformers shall be provided in the busduct. Separate cores of CTs shall be used for differential protection, over current protection and measurement purposes. CTs shall be bar pirmary type . Generally the measurement CTs shall have accuracy class as 0.2 whereas protection class shall be 5P30 and for differential CTs the class shall be PS. The knee point characteristics of differential CTs shall be matched with the relays. The technical parameters are elaborated below :





Type : Epoxy cast resin

Rated continuous current : 5000 amps

Ratio : 5000/5A

No. of cores : As per requirement

Short time rating (3 sec) : 40 kA

Power frequency withstand voltage : As applicable for

generator busduct

Impulse withstand voltage : -- do --

04.01.02 Generator Neutral Grounding Cubicle

The high resistance grounding of a generator neutral shall be adopted by connecting the primary of a single phase distribution type earthing transformer between generator neutral and ground with the transformer secondary being shunted by resistance with a voltage relay and harmonic filter. This will reduce transient overvoltage limit at the point of fault and contribute to a positive selective relaying in the event of generator stator E/F. The value of resistance shall be so chosen that the energy loss in the resistor equals the capacitive kVA of the generator windings, the generator surge capacitance, the capacitance of the isolated phase busduct and the associated generator transformer with respect to earth during ground fault conditions. The generator neutral grounding cubicle shall consist of Neutral grounding distribution transformer, Off load manual Isolator, current transformers for generator protection, resistance.





Panel specification shall be as follows :

1. Panel Construction : Sheet steel not less than 2.0 mm thick 2. Gland Plate : 3mm CRCA 3. Type : Indoor, Floor mounted 4. BusBar : Main – 100x10x3R AL.(High tensile

fastners to be used for

busbar joints. Earth Bus – 50x6 mm Cu. FLAT

5. Cable Entry : Bottom 6. Degree of Protection: IP-54 7. System Fault Level : 40 kA for 3 Sec 8. 11 kV clearance : Phase to Phase : 127 mm (Min)

Phase to earth : 90 mm (Min) 9. Name Plate : Black letters engraved on white background

Adhesive type 10. Wiring : 650 /1100 grade PVC insulated multistranded

Cu cable 11. Painting : Enclosure – Interior / Exterior :- RAL 7035

Panel shall also have marshalling box, space heater, thermostat MCBs etc as per requirement.

The earthing transformers shall be dry type for indoor installation. The generator neutral grounding equipment shall be housed in a metal enclosed cubicle. The metal enclosed neutral grounding cubicle shall be connected to the neutral compartment of the star point of the generator. Technical parameters of earthing transformer shall be as follows:

Primary voltage : 11.0 kV Secondary voltage : *





Continuous capacity based on 30 min. duty cycle : * * Final values to be decided during detail engg. stage.

04.01.03 GENERATOR BUS DUCT

The 11 kV generator busduct shall be phase isolated type. The busduct shall be installed inside machine hall.

The generator busduct shall comply with the requirements of the latest version of relevant IS / IEC standards. The busduct shall be designed to carry maximum continuous current under normal conditions without exceeding temperature rise limits

The bus assembly shall be designed to mechanically withstand a rated continuous current as well as the specified short circuit current without damage or permanent deformation of any part of the bus structure.

Tenderer shall include the Generator busducts consisting of following minimum items: 1. Generator main Busduct from generator terminals to generator

transformer with tap off to unit auxiliary transformer and excitation transformer.

2. Generator neutral busduct to the neutral grounding transformer through link.

3. Generator busduct tap off to LAVT panel. 4. All associated equipment/items like flexible/rigid joints, required no. of

bends, silica gel breather, space heater, etc 5. Surge protection, VT cubicles and Current Transformers located inside

busducts 6. Set of maintenance tools and tackles as required. 7. Earthing of busducts with continuous run of conductors 8. Necessary support structures, erection hardwares

9. Suitable canopy with proper slope for outdoor portion of the busduct





GENERAL TECHNICAL REQUIREMENT

1. Applicable Standard IS : 8084 2. Rated system voltage and frequency 11 kV, 50 Hz 3. System earthing Non effectively earthed 4. System short-circuit level, kA (rms)

85 kA (for 3 sec) for main run 152 kA (for 3 sec) for tap off

5. Type of busduct Phase Isolated

6. Service Indoor / Outdoor Indoor 7. Maximum voltage at which the

busduct can operate continuously 12 kV

8. Busbar material - Conductor Aluminium Alloy 9. Busduct support structure required To be provided 10. Current ratings 11. Rated continuous current 5000A

12. short time Current Rating for 1 sec

40kA

13 Dynamic current withstand rating kA (peak)

100 kA

14 Type of Cooling AN 15. One min. dry power frequency

withstand voltage 28 kV

16. Impulse withstand voltage 75 kV 17 Supporting insulator a) Type Porcelain b) Max. distance between supports To be worked out based on

short circuit calculation c) Rated Voltage 12 kV d) One minute power frequency

withstand voltage 35 kV

e) Impulse voltage withstand value with 1.2/50 micro sec. wave shape

75 kV





f) Minimum Creepage Distance 240 mm 18 Earth Bus a) Material Al b) Size As per requirement 19 Enclosure a) Type Phase Isolated b) Degree of Protection IP 52 c) Material of Enclosure Al d) Thickness 3 mm min. 20 Design Ambient Temperature 50oC 21 Maximum temperature when carrying

rated current continuously

a) - Conductor a) 1 Bolted Joints (Plain or tinned) 90oC a) 2 Bolted Joints (Silver Plated) 105oC b) Busduct Enclosure 80oC 22 Accessories a) Seal-off bushings As per requirement b) Silica gel breather To be provided

Length of the busduct shall be calculated by the tenderer based on approved layout and location of the generators and generator transformers. Generator bus duct shall be suitable for air and water tightness test as per IS : 8084 Rating, type and detailed technical particulars of the generator neutral bus duct shall be as per requirement and as per standards prevailing. GENERAL ARRANGEMENT

1. 11 kV generator busduct shall be phase isolated with tubular shaped

enclosure. Enclosure shall be continuous type. 2. Comprising of following sections, as applicable, to make the installation

complete and to match with the terminal equipment : � Generator lead-in section with flexible hood and links.





� Straight section in standard length. � Matching section (length as required). � Generator transformer lead-in section with flexible links � Corner sections (horizontal and vertical) � Phase cross-over section (If required to match phase sequence of the

board). � Link section.

3. Silica gel breathers at appropriate locations.

4. Space heaters and power supply arrangement for the space heaters

5. Earthing of busducts with continuous run of conductors 6. Generator neutral bus duct along with all the generator CTs, SAPT, NGT

and loading resistor, all associated accessories, etc CONSTRUCTION DETAILS

1. Degree of protection for enclosure IP 52 or better inside machine hall. 2. Enclosure material : Aluminium of minimum thickness 3 mm.

Tenderer shall include enclosure with the thickness required for the rectangular shape and mechanical/ electrical strength point of view.

3. Maximum temperature of enclosure under rated operating conditions limited to 800C

4. Bolted covers with gaskets for easy inspection and access to

insulators and bus bar joints.

5. Rubber bellows at transformer end to take care of vibration (Flange on which rubber bellow shall be seated shall seam welded to avoid ingress of water into the transformer).

6. Hinged and gasketed inspection access cover at suitable intervels. 7. Seal off bushings and frames complete with bolts

8. Provision for draining moisture.

9. Provision for mounting on brackets.





10. Supply of GI supporting structures with necessary hardwares.

Supporting structures shall be fabricated from standard steel sections and shall be hot dipped galvanised after fabrication.

11. For termination at generator end, suitable seal off bushings shall be

provided, if required 12. Necessary supporting foundation including civil works to be

provided Surface treatment

Two coats of epoxy paint for outdoor and synthetic enamel paint for indoor application, preceded by de-rusting, cleaning chemically, degreasing, pickling in acid, cold rinsing, phosphating, passivating and spraying with two coats of zinc oxide primer.

Shade of paint Interior : Black/white/light yellow Exterior : Light grey shade 631 of IS - 5 1978 (unless otherwise specified) and further stoved.

BUSBARS AND CONNECTIONS

1. Material EC grade aluminium alloy equivalent to E91E WP conforming

to IS 5082-1981.

2. Final operating temperature of both bus bars and joints under continuous operation in enclosure limited to 900C by thermometer method.

3. Bus bar arrangement as per IS 5578 (1991). 4. Phase identification by colour at ends and at regular intervals. 5. Busbars shall be of welded construction. 6. Copper flexible busbars surface shall be tinned 7. Contact surfaces shall be silver plated. 8. Flexible connections for termination on equipment. 9. Expansion joints on straight runs with joints staggered in adjacent

phases.





10. Bimetallic joints for jointing between dissimilar metals. 11. Busbar conductors shall be given coat of black mat. 12. Busbar support insulators of non-hygroscopic material having high

impact and di-electric strength with an anti-tracking contour. PROTECTIVE EARTHING

1. GI/Aluminium earth bus of size 50 x 10 mm running throughout the length of the busduct, positively connected to the body of the busduct.

2. Provision at each end of busduct for terminating external earth

conductor. INSULATORS

1. Bus support insulators shall be interchangeable.

2. The insulator shall be designed and mounted in such a manner so as to facilitate easy inspection, removal and replacement without disturbing the conductor.

SPACE HEATER

Adequate number of thermostatically controlled space heater shall be provided to maintain internal temperature above the dew point to prevent moisture condensation within the busduct. Supply for space heater shall be 240V, single phase, 50Hz.

BUSDUCT SUPPORT

The busduct shall be supported from floor / roof beams or steel inserts.All hardware shall be galvanised.

04.02 METERING AND PROTECTION SYSTEM Control, Relay and Mimic Panel

Complete control, monitoring, interlocking, sequencing, metering, annunciation and protection of complete TG sets and complete electrics of the unit shall be performed in DCS. Hardwired back up panels shall also be provided for turbines and generators.





Complete control, operation and metering requirements for the following :

- Generator, generator transformer, 220/11 kV station transformer, Station Auxiliary transformer, unit auxiliary transformers and associated circuit breakers, Turbine shutoff valve,

- 220 kV transformer bay equipment - 11kV Switchboard - 415V incomers and bus-coupler of unit Aux. Board

- 415V incomers of Station Aux. BoardControl Requirement

Refer Chapter 6

Metering

i) Generator The ammeters, voltmeters, MW meter, MVAR meter, frequency

meter, power factor meter, energy meter (MWH) meter, MVARH meter, exciter field voltage and exciter field current meters including necessary transducers shall be provided in the generator control desk located in control room.

Generator protection panel shall consist of numeric type protective

relays (microprocessor based communicable on open protocol like MODBUS/IEC, Password protected with fault recording facility and time stamping) and associated wiring. Tenderer shall provide state of art equipment system in the control room fulfilling the functional requirement of all the equipment for smooth and trouble free operation of the units. Minimum no. of control desks/panels shall be as per requirement to have control, monitoring, interlocking, sequencing, metering, annunciation and protection of complete TG set, and complete electrics of the unit.

Tenderer shall provide above annunciator windows at the top of operator's console. Number of annunciation alarm/trip points shall be finalised during detailed engineering stage and 20% spare windows shall be included for future use. Annunciations shall also be provided in the DCS / PLC.

Interlocking arrangement shall also be provided to take care of all the





approved logic schemes. Tenderer shall provide necessary wiring, control and required items to achieve the approved logic/ scheme. Local mode operation of the drives for test/trial etc. shall be carried out by selecting local/remote selector switch of panel in local position. Permissive conditions for start and tripping of various mechanism shall be provided as per approved logic diagrams.

A separate synchronization panel/desk shall be provided with synchroscope and necessary meters, indications, control switches, relays, etc.

04.02.01 Panel/Desks Constructional Features

Panels shall be arranged to form a continuous board with the mimic and control equipment type with rear hinged door except in MCR. Side terminal blocks, control signaling circuit breakers, resistors, fuses, links, isolating switches etc.

- Flush mounted meters, relays, switches, recorder, level indicators, temp. scanner, signal lamps etc. on front of the panel.

- Made of cold rolled pressed sheet steel thickness of not less than 2 mm.

- Provided with 75 mm base channel & 15 mm anti vibration pad. - shall have bottom cable entry, double compression cable glands, lugs

and gland plates. - Provided with space heater and interior illumination lamp with

switches. - Anodised aluminium inscription plate both at back and front side of

size to enable a person to read from 5 meter shall be provided. - Painted after proper degreasing, pickling and chemical phosphatising





- Lamp test facility to test all indicating lamps of the panel simultaneously.

- Earth bus securely fixed. 50 x 6 copper ground bus for all panels

-Control desk will have mosaic type construction and for relay panel rack type construction shall also be acceptable.

Technical Particulars

1. Panel : Sheet steel not less than 2.0 mm thick

2. Enclosure : IP 41 3. Provision of cable glands : Yes 4. Inscription front & rear : Both sides 5. Control supply : 220 V DC 6. Signalling bus isolation : ON/OFF switch 7. Control buses : As per circuit requirement 8. Relays : Numeric (self-diagnostic feature) With communication facility 9. Protective relays : Drawout type 10. Auxiliary relays : Non-drawout 11. Master trip relay : Yes 12. Auxiliary relays : As per circuit requirement 13. Instrument size : Minimum as per requirement 14. PT secondary voltage : 110 V 15. CT secondary current : 1A

Number of Panels Details of main control, monitoring, protection, interlocking, sequencing, etc have been described elsewhere. Tenderer shall prepare panel wise bill of materials considering SLD and the scheme requirement. Number of control relay and metering panel and their respective positions shall be finalised during detail engineering stage. Wiring - Wired with 1100 volt grade multistranded copper wire PVC insulation

having area 2.5sq.mm. External CT connections shall be made with 2.5 sq. mm copper wires. The

- CT & PT wiring shall be done with colour coded wires.





- Wire shall not be joined or tied between the terminal points. All wire

termination shall be made with insulated sleeved crimping type lugs.

- No bunch will contain more than 12 wires.

- Wire end shall be fitted with moisture and oil resistant insulating material having glass finish with identification number clearly engraved in black.

Terminal Blocks

- Stud type terminal blocks vertically mounted.

- Stud type terminal blocks shall be provided with brass studs.

- In each terminal block 10% spare terminals shall be provided. - CT terminal shall be suitable to terminate 4 sq.mm cable and shall be

link type to facilitate shorting of CT wires during testing etc. Control Supply

- The control voltage shall be 220V DC

- For switching off supply disconnecting devices with aux.contacts for

indication of control supply.

- One number 240 V single phase 5 A point in all panels for testing purpose. AC supply shall have single feeder

- DC supply shall have duplicate feeders with selection arrangement.

DC supply monitoring shall be provided in both control rooms.





Transducers

Various transducers (4-20 mA range) shall be provided either in separate transducer panels or mounted in control panels to facilitate remote monitoring of the parameters and to hook up with DCS/PLC /SCADA system. TRANSDUCER RATINGS

General

1. Make : Approved make 2. Output : 4-20 mA DC 3. Load Resistance capability : Suitable for DDC hookup 4. Accuracy : 0.5% of full scale 5. Repeatability : 0.1% of full scale 6. Linearity : 0.05% of full scale 7. Residual ripple in output current : 5% max. 8. Power frequency withstand voltage : 2 KV rms for 1 minute

between wires and case

9. Maximum burden on CT/PT : 1.0 VA Current Transducer

1. Nominal Input/Rated current : 1 Amp AC 2. Overload capacity without loss in accuracy

• Continuous : 120% of rated current • Short time : 10 times rated current for

0.5 sec. Voltage Transducer

1. Nominal Input/Rated voltage : 110/(sq.rt of 3) V AC 2. Overload capacity without loss of accuracy

• Continuous : 120% of rated voltage • Short time : 2 times the rated value

for 0.5 sec. Power Transducer

1. Nominal Input





• Rated voltage : 110VAC (3 ph PT supply) • Rated current : 1 A AC (3 ph CT supply)

2. Overload capacity without loss of accuracy • Continuous : 120% of rated voltage • Short time : 2 times the rated value

for 0.5 sec.

Auxiliary power supply, if required, shall be derived by tenderer from the 415 VAC, 3 ph/4-wire or 220V DC power supply provided at each switchgear.

04.02.02 Specification of Items

Indication lamps - Shall be panel mounted with rear terminal connection - Shall withstand 120% of rated voltage on continuous basis. - Bulbs and lenses shall be replaceable from the front. - Shall be LED type.

Semaphore indicators

- Shall rotate + 45 deg. on energisation.

- Shall be mounted in such a way that it forms part of mimic. - Shall withstand 120% of rated voltage on continuous basis. Control switches

- Generator breaker control switch shall have four position viz. Trip,

Close, Neutral after trip and neutral after close. - Other switches shall be as per the requirement of the scheme. - Type of operation handles of switches shall be spring return pistol

grip type. - All switches shall be provided with inscription labels. - All switches shall have a rating 10A/500V. - Switches shall be dust protected, heavy duty switch board type - Contacts shall be silver surfaced - Stay put type selector switch shall be provided for auto/manual, DC

source selection, local/remote etc.





Aux Relays

- Shall be contained in dust and moisture proof cases. - Close/trip circuit supervision relays (to be provided if features are

not available in numeric relays) shall be suitable for connection in series with close and trip coil of breaker and trip supervision relay shall be suitable for monitoring the healthiness of tripping circuit on both breaker open and close conditions. In protection circuit DC failure supervision relay shall be provided.

- The relays shall be suitable for operation between 70-110% of rated voltage.

Numeric relays

- Stringent measures including shielding of long internal wiring shall be taken to make relays immune to voltage spikes.

- Shall withstand 5 kV, 1/150 microseconds as per IEC.

- Shall be protected against transient/induced over voltage by

providing suitable surge arresting device. Annunciation

All electrical annunciations connectd with generator, generator systems and unit system Shall be displayed in DCS system.

The main annunciation points shall be as follows :

1. Generator - alarm/trip indication (separate for each electrical protection

/discrepancy).

FCB trip, Bearing-Stator temp. high/trip, overspeed alarm/trip, CO2 release, AVR failure, cooling coil temp, Duplicate annunciation shall be provided in UCR on occurrence of alarm/trip conditions as `warning' in MCR, and `Emergency in MCR'.

2. Generator transformer Buchholz, oil/winding temperature, oil level low - alarm Buchholz, oil/winding temperature - trip condition, oil pump trip, PRD





operated / cooling water valve closed / fire fighting operated. 3. Alarm/trip condition for 220 kV side protection (Protection points and low air pressure alarm). List of points shall be finalised during detail engg. stage, tenderer to

include all required points with accessories/wiring transducers etc needed to meet above requirement.

04.02.03 Electrical Protection System This section covers the details of the protection adopted for various electrical equipment, viz. generators and their auxiliaries, generator transformers, 220/11 kV Transformer, Station transformer, unit auxiliary transformers and all associated electrical equipment, etc. The protective relays used for protecting various equipment shall be numerical type with communication facilities and shall provide adequate redundancy. They shall be selected or grouped that in the event of non-availability of any relay or any one group, for any reason, e.g. power supply failure, on-line testing of any relay or many relays or any other reason whatsoever, the relays in other group shall completely protect the respective equipment since the same is expected to be energized / running. Selection of protective scheme will be based mainly on reliability (main & standby), sensitivity, selectivity. All main protections shall be fast acting type in order to clear the faulty system from the healthy system in earliest possible time to minimize damage to equipment and ensure continuity of power supply, if possible. Tenderer shall suitably design tripping system covering different protection under different class of trippings of generator and turbine. Numeric microprocessor based relays shall be provided suitable for communication to DCS / PLC / SCADA consisting of comprehensive protection with fault recording facility, metering provision and self testing facilities in line with present state-of-the-art system. The protection system will be in modular design comprising digital signal processing and a data bus for signal exchange, digital input / output units, analogue input-units, analogue / digital conversion units, field interface units, etc. All numeric relays shall be password protected and shall have sufficient





binary input/output contacts as per actual requirement plus 10 % spare. No auxiliary relays shall be used for contact multiplication. The relays shall have capability of capturing waveforms and disturbance recording at the time of fault. Moreover, all the relays shall have real time stamping facility. Complete relay co-ordination for the various systems and sub-systems shall be done by the tenderer. The system shall have necessary interface and compatibility with distributed digital type process control system. Protections for the various electrical equipment and generators are enlisted below;

1. Generator Protection The following protective schemes are proposed for the generators. a) Generator differential protection : This will offer selective and high

speed protection for generators against internal faults like phase to phase and three phase faults. The relay shall be ultra high speed, high-impedance type, immune to transients with operating time as short as 8 milliseconds for ultra high speed and 30 m sec for high impedance type relays. The relay shall be stable for all external faults.

b) Generator interturn fault protection : This protection will be provided for faults between turns of the same phase only if generator stator winding are double star type and leads of the same phase are separately brought out on the neutral side. For the above protection cross-connected CTs will be ultilised. The recommended relay shall be high speed, high impedance type, through fault stabilised, similar to generator differential relay.

b) Generator stator 100% earth fault protection : The neutral of the generator will be earthed through a distribution transformer, whose low voltage winding will be loaded by a suitably rated resistor. The recommended protection scheme shall detect earth fault at any point on stator winding to provide 100% protection. This relaying shall also be made to supervise the integrity of grounding system healthiness.

c) Standby stator earth fault (0-95%) protection : The protection scheme





shall include an inverse time or definite time neutral voltage displacement relay connected to the open-delta winding of the generator VT. This relay shall be immune to third and higher harmonics. This relay protects the winding only upto 95% from the phase side. This relay will also give earth fault protection for 11kV system during back charging of the generator transformer.

d) Generator field winding earth fault protection: The protection scheme

shall be in two stages. The field power supply is derived from unearthed DC source. The relay will be operating on the basis of monitoring insulation resistance by injecting subharmonic currents in field system. The first stage, shall operate when insulation resisance goes below 80 Kohms and gives alarm. The second stage will operate below 5 Kohms and will initiate tripping of the unit.

e) Generator negative sequence protection : Protection envisaged shall

protect the generator from harmful effects of negative phase sequence currents. Each negative phase sequence relay shall be having two stages of protection.

First stages shall iniate alarm and trip the unit after a definite time lag

(e.g. 1000 seconds). Similarly, second stage shall trip the unit when I sq.t = k exceeds preset value. The present limits shall be co-ordinated with that of the generator and also among themselves.

f ) Loss of excitation protection : The protection for loss of excitation

shall comprise of two stages. Both stages shall have offset mho relay characteristics. Stage I shall be set to respond for loss of excitation condition when load on the machine is 30-100% of rated value. The unit shall be tripped after a short time delay. The second stage shall trip the unit after longer time delay. It shall cater for loss of excitation condition when unit is lightly loaded (e.g 0-30%). Required undervoltages relay interlocks shall be provided.

g) Generator under frequency protection : Under frequency protection is

provided to protect the unit from prolonged under frequency with definite time delay plus cummulative time delays. Stepped under





frequency protections shall be provided for TG. No. of steps and their respective time delays shall be selected based on % of acceptable loss of life and load shedding/recovery curve of the grid.

h) Generator over voltage protection : The protection scheme shall envisage provision of two stage type definite time, high drop-off to pick up ratio over voltage relays. 1st stage shall be short time delayed high set type and second stage shall be long time delayed low set relay. The protection settings shall be choosen depending upon voltage regulator response characteristic and generator withstand capability. The setting of this relay alsoshall be based on withstand capability given by the manufacturer.

i) Generator stator over-current protection : This relay is voltage

restrain over current used for tripping of generators on short circuit.

j) Generator Reverse Power Protection: This protection is provided against motoring of the generator. Timer shall be provided in the scheme.

k) Generator VT fuse failure protection : The protection scheme shall

consist of voltage balances type relays whereby voltage between two sets of VTs shall be continuously monitored. The scheme shall be able to detect open circuit in any phase of the VT secondaries as well as primaries or fuse failure. This will give an annunciation and block the operation of AVR and voltage operated relays.

l) Generator field over voltage protection : This protection gives

protection of generator rotor due to rotor overcurrents caused by sustained system voltage depression or malfunction of the control system. The relay will be DC operated definite time delay over voltage relay and shall be used for alarm. Surge voltage protection shall also be provided for the field.

m) Generator, generator transformer over-fluxing protection : This protection shall be provided for overfluxing protection of generator, generator transformer. For this purpose two relays shall be provided (one high set and other low set). Both relays shall operate on the V/Hz ratio. The highset unit shall trip the unit for very high overfluxing





conditions after a short time delay and low set unit shall trip the unit inlonger time delay. Complete protection characteristics shall be coordinated with composite V/Hz withstand characteristics of all three equipment. If AVR is provided with under excitation limiters in manual mode, control functions shall be arranged from overfluxing protection to limit/control over- excitation at first stage and if V/Hz still persists tripping function shall be taking over.

n) Bearing failure protection : This is an alarm function. Upon occurence of alarm, bearings shall be inspected at the earliest opportunity.

o) Generator Overspeed : Two electrically operated and one mechanically operated Over speed shall be provided. Settings shall be finalized during drawing approval stage.

p) Generator breaker back up protection : Tenderer is to provide this protection system after study of existing system and (dedicated relays need) to be provided on scheme to be hooked up with existing protection system.

2. Protection for Generator Transformer

a) Generator transformer differential protection b) Overall generator & generator trafo and UAT differential protection

(for gen. Transformer only) c) Over current and earth fault protection on HV & LV side d) Backup over current and earth fault protection on HV & LV side e) Back-up earth fault protection on HV neutral f) Restricted earth fault protection on HT side g) Buchholz relay (alarm & trip) h) Winding temperature protection (alarm & trip) i) Oil temperature Protection (alarm & trip) j) Oil level alarm and trip k) Auxiliary relays for generator transformer for receiving transformer

alarm and trip (for generator transformer) l) Lightning arrestors on the HV side. m) Pressure release device with trip contact

3. Protection of 220 kV switchyard bays a) Time over current ground protection b) Directional over current protection c) · Directional over current ground protection





d) Local breaker back up protection e) Bus differential protection f) Protections of transformers as indicated above g) REF for transformers

Protection for Unit Auxiliary Transformer/ Station Auxiliary Transformer i) Back up over current protection

ii) stand by earth fault protection iii) Restricted earth fault on LV side iv) Auxiliary relays for UAT for receiving transformer alarm and trip. v) Winding temperature protection (alarm & trip) vi) Oil temperature Protection (alarm & trip only)

4 Comprehensive motor protection for motors of 75 kW and above

Comprehensive numeric motor protection including but not limited to the following;

a) Instantaneous over current protection b) Differential protection (for rating above 1000 kW) c) Instantaneous time over current protection in two phases and

definite time delayed over current alarm on the third phase d) Negative phase sequence protection e) Thermal overload taking -ve and +ve phase sequence into account f) Earth fault g) Locked rotor protection h) Winding temp monitoring and alarm for rating beyond 1000 kW i) Under voltage protection

5 LT motor protection (for motors less than 75 kW) The motors rated below 75 kW shall have bimetallic relays for thermal over load protection and MCCB for short circuit protection. Single phasing protection shall also be provided in the MCC modules

6 Generator Excitation System Excitation transformer

- Overload - Over current protection - Winding temp





Excitation system

- Load angle limiter - kVA & kVAR limiter - Stator current limiter - Rotor current limiter - Volt/Hz ratio controller - Slip stabilization - Cross current compensation

Thyristors

- Fuse failure / fan failure (Alarm) - Over current - Thyristor failure supervision & - thyristor overload

7. 415 V Switchboard

i) 415V Incomer

- Overcurrent - Earth fault Timers

ii) 415V Outgoing (MCC feeder)

- Overcurrent - Earth fault relays for selective tripping of feeder

iii) 415 V Motor Feeders (Above 110 kW) - Comprehensive motor protection relay

(Microprocessor based) iv) 415 V Motor Feeder (less than 110 kW)

, - Undervoltage - overload - single phase

v) Bus PT - U/V relays 415 V incomers shall have under voltage/timer relays for auto-





changeover as described in clause 04.05. 04.02.04 Protective Scheme Requirement General

- All required protection relays shall be provided. Auxiliary relays, timers switches etc. required to make the scheme complete shall be considered as part of the scope of work. Details of major relays and meters are highlighted in clause 04.02.03.(indicative)

- All CT-PT shall be suitable for the relay-meter requirement - lead

burden and as shown in the enclosed single line diagram. - All interfacing/essential interlocking cabling from existing units as well

as from 220 kV switchyard and bays are in the scope of tenderer.

- Aux. Relays shall be provided for each transformer fault. - Contact arrangement and number of poles/ways in control/selector

switches shall be as per the requirement/approved scheme.

- Generator tripping system shall be designed such a way so that on electrical faults only generators shall be tripped and on mechanical fault generator with turbine shall be tripped with signal to close the gate. Details of the scheme shall be finalized during detailed engineering stage.

- For control supply distribution, panel to panel separate set of terminal

blocks shall be provided at top of the control panel. All items/accessories required for above in each panel and in incoming panels shall be provided by the supplier.

- Wherever required supplier shall provide aux. relays for contact

multiplication.





- 04.02.05 Synchronisation Scheme

1. Synchronization arrangement shall be provided in control room for

closing of generator breaker.

2. Lockable syn-selector switches shall be provided on control panel.

3. One syn-bypass lockable type switch shall be provided to facilitate by passing of scheme if required.

4. Syn. complete and faulty indications shall be annunciated.

5. Required busbar/bus wires shall be provided in all panels (wherever

required) for synchronization scheme.

6. Generator control panel shall have voltmeter, frequency meter, to measure incoming and running voltage/ frequency and one synchroscope (with reversing voltage transformer RVT).

7. Check synchronisation relay shall be used to avoid human error

during breaker closing and shall be suitable to compare two signals (for measuring of voltage, frequency and phase).

8. One guard relay shall be provided with check-syn. relay to ensure operation of check syn. relay during breaker closing moment. Auto/manual synchronization selector switch shall be provided

9. In addition to above for generator closing automatic synchronising

shall be provided with facilities to hook up automatic operation of AVR and governor motor through DCS / PLC / SCADA.

Above technical features of synchronizing scheme shall be finalized during detailed engineering stage to suit the generator being offered.





04.03 GENERATOR TRANSFORMER 04.03.01 Electrical Design

- Generally as per IS 2026. - 3x single phase core type - Rated output voltage ratio, vector group shall be as specified in

Technical Particulars for design. - Rated frequency 50 Hz, +3% , -5% - Insulation level shall be designed according to the voltages specified

below. Nominal System voltage 11 kV 220 kV ------------------------------------------------------------------------------------------------------------------------------

1. Max. system voltage (kV) 12 245

2. One minute power 28 460 frequency withstand voltage (kV) 3. Peak impulse test 75 1050 withstand voltage (kV)

4. Clearance in Air (mm) Phase to Earth 110 5500 Phase to Phase 127 4500

----------------------------------------------------------------------------------------------------------------------------

- Transformers shall be capable of delivering rated current at an applied voltage upto 105% rated voltage without exceeding the temperature limits specified below.

- Overload capacity as per IS 6600 unless otherwise specified. - Shall be operable at its rated capacity at any voltage within + 10% of





rated voltage of the particular tap. - Transformer shall be Bi-directional - Temperature rise shall be as per IS 2026 Part-II.

a) Top oil (by thermometer) : 45 deg. C b) Windings (by resistance : 50 deg. C method) c) Maximum hot spot temp. : 55 deg. C

- Transformers shall be designed to withstand the thermal and dynamic

stresses due to short circuits at its terminals. Unless otherwise specified the duration of short circuit shall be 5 seconds.

- The max. temperature at the end of the specified duration shall not be

more than 250 deg. C with the temperature prior to short circuit corresponding to maximum permissible overload.

Magnetic Circuit

- Low loss CRGO silicon steel shall be used.

- Laminations shall be annealed in a non-oxidising atmosphere to relieve stresses and restore the original magnetic properties of CRGO sheets after the cutting and punching operations.

- CRGO sheets shall be coated with insulation varnish compatible with

the sealing liquid.

- Ducts to be provided to ensure adequate cooling.

- Core, framework and clamps arranged and tightened to securely hold laminations in order to prevent any settling of displacement in case of heavy shocks during transport, handling or short circuits.

- Flux density at normal over voltage or frequency shall be such that

under 10% over voltage condition it shall not exceed 1.6 tesla.





Windings - Material shall be electrolytic grade work hardened copper of high

proof stress with more numbers of radial supports. - Shall be pre-compressed, press board, pre-stabilization of coil. - Completed core and winding to be vacuum dried in full vacuum and

impregnated immediately. - Shall be braced to withstand shocks due to rough handling and forces

due to short circuit, switchings or other transients. - Permanent current carrying joints in winding and leads shall be

brazed. - Coils shall be supported using dried and high pressure compressed

wedge type insulation spacers. - Insulating materials shall be compatible with transformer liquid under

all service conditions. - Leads to the terminal board and bushings shall be rigidly supported.

Insulation - Interturn and inter coil insulation shall be designed such that

di-electric stress is uniformly distributed throughout the windings under all operating conditions.

Tank - Welded thick gauge plates stiffened and reinforced to withstand

without deformation all stresses applied during transport and operation or short circuit conditions.

- Oil tight welds and joints - Construction shall be bell type. - Fully assembled transformer with its radiators, conservator and other

fittings shall withstand for one hour a pressure corresponding to twice the normal head of liquid or to the normal pressure plus 35 kN/sq. m, whichever is lower, measured at the base of the tank.

- Plates shall be protected internally against corrosion due to insulating liquid.





- Provided with inspection opening and cover/with handling equipment) to provide acces to bushing connections.

- Form of cover shall be such as to prevent any stagnant water deposit and to drain gas bubbles towards the buchholz relay

- Transformer tank shall withstand the vacuum test for pressure of 100.64 kN/sq.mm.

Necessary type test certificate shall be furnished in respect of above. Conservator and Breather

- Conservator mounted on frame, integral with tank in such a manner that under all conditions and the lowest oil level the bushings remain under the head of liquid.

- Conservator volume shall be sufficient to maintain oil seal from ambient to oil temp. of 90 deg. C

- Oil filling hole with cap, a drain valve to drain the oil completely shall be provided one end of conservator shall be bolted into position so that it can be removed for cleaning purposes.

- Silica gel breather with inspection window and oil seal shall be mounted at suitable height from ground level and connected to conservator.

- Prismatic type oil level gauge with max. and min. levels marked. Tap and values shall not be fitted to oil gauge. 150 mm diameter dial type magnetic level gauge with alarm and trip contacts shall also be provided.

Buchholz Relay - Double float relay as per IS 3677. - 50 mm diameter of connecting pipe for transformers and shall have

minimum number of bends. - Shut off valves on either sides of the buchholz relay. - Pot cocks at the top and bottom of relay drain plug, inspection

window, calibrated scale, terminal box with oil tight double compression type brass gland.

- Potential free, self reset independent alarm and trip contacts rated to make, break and carry 2 amps at 220 V DC. No auxiliary relay shall be used to multiply the contacts. Contacts are to be wired to the marshalling box.





Cooling The cooling system shall be OFWF

Cooling system shall be designed and supplied with a concept of 2 x100% configuration to facilitate one working and one stand by. On tripping of oil pump, cooling water valve shall also be tripped to avoid ingress of water. The oil circuit of oil coolers shall be provided with the following : 1. A valve at each point of connection to the transformer tank 2. Removable blanking plates to permit the blanking off the main oil

connection of each cooler 3. A drain valve 25 mm lowest point of each bank cooler 4. A thermometer pocket fitted with a captive screwed cap on the inlet and

outlet oil branches of each separately mounted cooler bank 5. Air filter valve at the top and bottom of each cooler 6. Air release plug

In addition , the following are to be provided as per IS : 6088 a) A suitable differential pressure gauge fitted with electrical contacts b) Oil and water flow switches fitted with electrical contact c) Flow indicator

2 nos. Pump – motor set (1 working and 1 standby) shall be provided along with pipes, valves etc to facilitate water for cooling of oil

Transformer Oil Cooling System Complete new transformer oil cooling plant shall be installed / provided for all six units except embedded piping. Embedded piping if any to be reused after cleaning. Each new transformer oil cooling plant shall have four nos. oil coolers (3W+1S), 4 nos. oil circulating pumps(3W+1S) of suitable capacity with electric driven motor along with accessories, oil filters, adsorbent filters, necessary piping, valves. Provision for oil filter bypass system shall be provided. If any one of the working pump is failed then the standby pump shall be automatically started to maintain the oil level in the transformers. Latest BIS code/ international standards shall be followed for designing of the above system. Cooler tube materials shall be of Cupro-Nickel. Oil pipeline material shall be of stainless steel. Pressure gauge, flowmeter, flow relay etc instruments for local as well as remote shall be provided. Auxiliary relay, timer relay etc as per scheme requirement shall be provided. Auto change over power supply system shall be provided to have availability of





supply for operation of pumps as well as control. Draining of oil from oil coolers, adsorbent filters of each transformer shall be done to existing transformer oil tanks located at SRV floor. All pipes and valves shall be replaced by new one. Cooling water for coolers shall be tapped from nearest technical cooling water supply header. Tapping arrangement is in the scope of tenderer. Embedded pipelines shall be chemically cleaned. New Control panel /cubicle of transformer cooling plant shall be provided for complete control of pumps operation, emergency shutting down of pumps. It shall also have following protection –

• Transformer cooling failure

• Transformer cooling control circuit failure

• Transformer Cooler failure – Low water pressure, Oil temperature above the line

• Reserve supply failure

Indication of pump operation shall be provided. valves. Valves and Connections Valves shall be of sluice type with hand wheels. They shall be made of gun metal and shall be provided with padlocking facility to lock in closed/open position, blanking plates or screwed plugs and clear indication of open and closed position Terminations

It shall be possible to withdraw the transformer easily after disconnecting the connections without disturbing the OH line/cable/busduct terminations. For cable termination, air insulated cable box shall be provided which shall be suitable for the type and number of cables specified. Cable end box shall be self-supporting. For OH line termination, proper bushing shall be provided. For bus duct termination, proper matching flange arrangement shall be provided. Bushings - Conform to IS 3347 and 2099. - Minimum rated current of line and bushings shall be 1.5 times rated

current of the corresponding windings - Clamps and fittings made of steel or malleable iron shall be hot dip





galvanised. - - Neutral bushings shall be provided as required for earthing of neutral

point. Bushing current Transformers (Where applicable) - Removable at site without opening transformer tank cover/active part - Secondary leads of 4 sq.mm shall be brought to a weather proof

terminal box and from there to the marshalling box. Bushing Current Transformers Bushing CT shall be removable at site without opening transformer tank cover/active part. Secondary leads of 4 sq.mm shall be brought to a weatherproof terminal box and from there to the marshalling box Oil temperature Indicator 150 mm dial type thermometer with manual reset maximum reading pointer. there shall also be two potential free contacts for alarm and trip signals. The alarm and trip settings shall be independently adjustable. The temp. sensing element mounted in a pocket of oil, shall be connected to the indicator through capillary tubing. Contact rating at DC shall be minimum 0.5 amps. Winding Temperature Indicator Local winding temperature indicator (WTI) shall have a 150 mm diameter dial type indicator with a manual reset max. reading pointer. there shall be two potential free contacts for alarm and trip signals. Contact rating at DC11, 220V DC shall be minimum 0.5 amps. The device shall be complete with lamp, sensing element, image coil, calibration device, aux. CTs etc. as required. Marshalling box & Cooler Control Panel - All outgoing conections from the transformer i.e buchholz relay, temp.

indicators, level indicators, CT secondaries, alarm contacts for annunciations, including forced cooling system and OLTC, etc. shall be wired to a marshalling box.

- Degree of protection of enclosure shall be IP 52 for indoor and IP 55 for outdoor type respectively.

- Removable bottom gland plate with cable glands and cubicle illumination lamps.

The cooling system shall have duplicate power supply from two different sources with auto changeover arrangement.

- Cooler control box and motorized tap changer arrangement shall be





provided along with all the transformers Tenderer shall also provide dedicated remote cooler control cum tap chnager control panel for all the transformers with all indications, control, annunciations, etc. Earthing

- All metal parts of the transformer with the exception of individual core

laminations, core bolts, and clamping plates shall be maintained at fixed potential by earthing.

- Two tinned copper earthing terminals - One end of bushing CTs shall be earthed. List of fittings and Accessories - Name plate - First fill of oil as per IS - 335 with 10% excess in drums - Cooling system complete with accessories as per requirement

including radiators with shut off valves, filter valves, drain and sampling devices and air release device. For generator transformer, water cooling circuit shall be suitably connected to existing pipe network.

- Conservator - Dehydrating breather - Buchholz relay - Oil filter valves at top and bottom of tank - Off-circuit tap changer - HV side bushings for connection to overhead conductor. - Drain off valve at lowest location to allow complete draining. - Oil sampling device at top and bottom - Explosion vent with double diaphram - Pockets with thermometers for oil temp. and winding temperature

indicators. - Bushing CTs - Dial type oil and winding temp. indication(150 mm dia.) and alarm and trip contacts. Remote WTI/OTI shall be provided

in addition to local indicators. - Lifting lugs and jacking pads - Rating and diaphram plates - Earthing terminals





- Bidirectional wheel (flange type) - Inspection cover - Flat base and foundation bolts. - Marshalling kiosk

04.03.02 Technical requirements(indicative) For transformer

Voltage HV/LV : 220 kV/11 kV - Duty : Outdoor - Specification to be : IS 2026 compiled with - Continuous rating : 3x 23.4MVA - Cooling : OFWF - Vector group : YNd11 - Neutral grounding : 11 kV -High resistance grounded &

132kV Effectively grounded

- Percentage impedance : 10% - Termination HT : ACSR conductor

LT : Busduct - Bushing mounted CTs : PS class According

to requirement - Tap changer on primary : Off circuit type

a) Range +5% b) Total tap positions : 5 c) Taps above nominal : 2 voltage

d) Taps below nominal : 2 voltage

e) Voltage per step : 2.5% variation f) Tap change controls : Local- manual - Impulse test withstand voltage : As per IS 2026 - One minute dry and wet power : - do -

frequency withstand voltage - Induced over voltage : - do -

withstand voltage





- Withstand time without injury for : 5 secs. 3 phase short circuit at terminals

- Temp. rise above maximum ambient in oil by thermo meter. : 45 deg. C

- In winding by resistance : 50 deg. c - Auxiliary supply voltage : 220 V DC

- Parallel operation : Suitable for parallel operation with

transformers of similar Ratings - Overload capacity : As per IS 6600 - Radiator : Detachable type - Painting : Dark admiralty grey shade 632 of IS: 5. Epoxy based OVER VOLTAGE LIMIT

- Generator transformer shall be suitable for 140% over voltage for 5

seconds and 125% over voltage for one minute.

Note : Transformer design data and accessories shall be provided as per CBIP manual (Publication 275) except the data details mentioned here.

04.04 220/11kV STATION TRANSFORMER One (1) number 220/11 kV, 20 MVA ONAN / ONAF station transformer fitted with off-load tap changer and all other accessories shall be provided.

The Station Transformer shall be provided with the following; • Neural Grounding Resistor • �Oil collecting pit for the station transformer and it’s interconnection with owner’s

common sump pits • ��Complete civil works including foundations of adequate capacities along with

cable trench, road, fencing and gate etc • �Rail for transportation of the transformer and it’s interconnection with existing

network • �All the transformer accessories • �Complete earthing and shielding system





The core construction of station transformer shall preferably be of boltless technology. Construction/clamping shall be adopted so that hole through core laminations is avoided. Suitable tie plates and clamps shall be used so that core holes and core bolts are totally eliminated.

Tenderer shall clearly indicate in his offer whether he has considered and offered boltless core for the transformer in offer. Design Design shall be generally as per IS 2026. Transformer shall be suitable for rated frequency 50 Hz, -5%, +5%. Insulation level shall be designed according to the voltages specified below.

Sl. No.

Description 220 kV 11 kV

1 Nominal voltage (kV) 220 kV 11 kV 2 Max system voltage (kV) 245 kV 12 kV 3 Power frequency withstand

voltage (kV) 395

4 System Earthing Solidly earthed Non-effectively earthed

5 No. of phases 3 3 6 Frequency 50 Hz 50 Hz 7 Impulse test withstand voltage

(kV) 1050 75

8 Short time current rating (for all current carrying parts)

40 kA for 3 sec 40 kA for 3 sec

9 Fault level (3 phase symmetrical)

40 kA (15000 MVA)

40 kA

10 Clearance in air (mm) Phase to earth 2150 As per IS Phase to phase 2350 As per IS

Transformers shall be capable of delivering rated current at an applied voltage up to





105% rated voltage without exceeding the temperature limits specified below. Overload capacity shall be as per IS 6600. Transformers shall be operable at its rated capacity at any voltage within + 10% of rated voltage of the particular tap. The transformers shall be suitable for parallel operation with existing station transformers. Permissible maximum temperature at rated output and principal tap over an ambient temperature of 50o C.

• Top oil (by thermometer) : 45o C • Windings (by resistance method) : 50o C.

Transformer shall be designed to withstand the thermal and dynamic stresses due to short circuits at its terminals. Unless otherwise specified the duration of short circuit shall be 5 seconds. The max. temperature at the end of the specified duration shall not be more than 250oC with the temperature prior to short circuit corresponding to maximum permissible overload. Tenderer shall submit the calculation proving the same. Design for suppression of harmonics especially 3rd and 5th. Over voltage capability of the transformers shall be as per IS. Frequency response analysis shall be done on transformer during routine testing. COPS (Constant Oil Pressure System) shall be provided to avoid direct contact of oil with atmospheric air. One more drain valve with pipe of approximate diameter of 150 mm (for 10-15 mtr long) with bends shall be provided to facilitate draining of transformer oil in case of emergency. The exact arrangement shall be as per drawing to be furnished by the tenderer and approved by the owner during detailed engineering. Magnetic circuit The core construction of station transformer shall preferably be of boltless technology. Magnetic Circuit shall be made of low loss CRGO silicon steel shall be used. CRGO sheets shall be coated with insulation varnish compatible with the sealing liquid. Laminations shall be annealed in a non-oxidising atmosphere to relieve stresses and restore the original magnetic properties of CRGO sheets after the cutting and punching operations. Insulation shall be able to withstand annealing temperature as high as 850o

C and shall reduce eddy current to the minimum.





Suitable ducts shall be provided to ensure adequate cooling. Core, framework and clamps shall be arranged and tightened to securely hold laminations in order to prevent any settling of displacement in case of heavy shocks during transport, handling or short circuits. Flux density at normal over voltage or frequency shall be such that under 10% over voltage condition it shall not exceed 1.9 Tesla. Transformers shall be designed to withstand 110% over fluxing corresponding to rated voltage for 20 minutes. Windings Material shall be electrolytic grade work hardened copper of high proof stress with more numbers of radial supports. Completed core and winding shall be vacuum dried in full vacuum and impregnated immediately. Insulating materials shall be compatible with transformer liquid under all service conditions. Leads to the terminal board and bushings shall be rigidly supported. Winding shall be pre-compressed, press board, pre-stabilization of coil. Windings shall be braced to withstand shocks due to rough handling and forces due to short circuit, switchings or other transients. Permanent current carrying joints in the windings shall be brazed type. Joints outside the winding shall be crimped. Coils shall be supported using dried and high pressure compressed wedge type insulation spacers. Insulation Interturn and inter coil insulation shall be designed such that dielectric stress is uniformly distributed throughout the windings under all operating conditions. Tank Conventional tank design shall be provided. Welded thick gauge plates shall be stiffened and reinforced to withstand without deformation all stresses applied during transport and operation or short circuit conditions. Welds and joints shall be oil tight. Plates shall be protected internally against corrosion due to insulating liquid.





Fully assembled transformer with its radiators, conservator and other fittings shall withstand for one hour a pressure corresponding to twice the normal head of liquid or to the normal pressure plus 35 KN/sq. m, whichever is lower, measured at the base of the tank. Tank shall be provided with inspection opening and cover/with handling equipment) to provide access to bushing connections. Form of cover shall be such as to prevent any stagnant water deposit and to drain gas bubbles towards the buchholz relay. Transformer tank shall withstand the vacuum test for pressure as per CBIP guidelines. Necessary type test certificates shall be furnished in respect of above. Transformer tank shall withstand vacuum test for minimum pressure of 100.64kN/sq.m. Necessary type test certificates shall be furnished in respect of above. Conservator and Breather Conservator mounted on frame, integral with tank in such a manner that under all conditions and the lowest oil level the bushings remain under the head of liquid. Conservator volume shall be sufficient to maintain oil seal from ambient to oil temp. of 90oC Oil filling hole with cap and a drain valve to drain the oil completely shall be provided on one end of conservator. Conservator shall be bolted into position so that it can be removed for cleaning purposes. Silica gel breather with inspection window and oil level shall be mounted at 1.4 m from ground level and connected to conservator. Prismatic type oil level gauge shall be provided with max. and min. levels marked on it. Tap and valves shall not be fitted to oil gauge. 150 mm diameter dial type magnetic level gauge with alarm and trip contacts shall also be provided. Breather shall be connected with rubber bellow inside the conservator tank for expansion and contraction of oil. Buchholz Relay Buchholz relays shall be double float relay as per IS 3677. Shut off valves shall be provided on either sides of the buchholz relay. Pipe connecting the relay and tank shall be of suitable diameter for the capacity of the proposed transformers. Minimum diameter shall be 80 mm. Pot cocks at the top and bottom of relay drain plug, inspection window, calibrated scale and terminal box with oil tight double compression type brass gland shall also be provided. Potential free, self reset independent alarm and trip contacts rated to make, break and





carry 2 amps at 240 V AC shall be provided. No auxiliary relay shall be used to multiply the contacts. Contacts are to be wired to the marshalling box. Cooling The cooling system provided shall be ONAN/ONAF. Radiators shall be detachable type directly mounted and shall have flexible earthing arrangement. Bolted, gasketted and flanged connections shall be used for connecting the radiators to the tank. Additional spare radiator fins with isolation valves shall be provided with the transformers. The following accessories shall be provided for each radiator/radiator bank.

• Top and bottom shut off valves and blanking plates • Pumps and fans as required • Bottom drain plug and top filling plug, air release plug • Lifting lugs • Neutral bushing CTs • Thermometer pockets with thermometers in the inlet and outlet pipes (for

separately mounted radiator banks). • Top and bottom filter valves for each separately mounted radiator bank. • Pressure reducing devices with alarm • Air release devices • Earthing arrangement • Bi-directional rollers/rails • Rail for transportation with provision for extension for transformer • Spare radiator fins along with isolation valves • Any other accessories required.

Valves and connections Valves shall be of sluice type with hand wheels. They shall be made of stainless steel and shall be provided with padlocking facility to lock in closed/open position, blanking plates or screwed plugs and clear indication of open and closed position. Terminations It shall be possible to withdraw the transformer easily after disconnecting the connections without disturbing the OH line/cable terminations. For cable termination, air insulated cable box shall be provided which shall be suitable for the type and number of cables specified. Cable end box shall be self-supporting. For OH line termination, proper bushing shall be provided.





Bushings Bushing shall conform to IS 3347 and 2099. Minimum rated current of line and bushings shall be 1.5 times rated current of the corresponding windings. Clamps and fittings shall be made of steel or malleable iron shall be hot dip galvanized. Neutral bushings shall be provided as required for earthing of neutral point. All the bushings shall be provided with suitable connectors and clamps. Bushings shall have non magnetic clamps and fittings only. Neutral Bushing Current Transformers CTs for REF protection and back up earth fault shall be provided on the neutral end. Neutral Bushing CT shall be removable at site without opening transformer tank cover/active part. Secondary leads of 4 sq.mm shall be brought to a weatherproof terminal box and from there to the marshalling box. Neutral Bushing CTs of suitable ratio and adequate burden shall be provided by the tenderer to cater to the requirement of above earth fault protection associated with the transformer of this capacity. Separate bushing CTs may be used for winding temperature indications, if required and applicable. For differential protection of station transformer, CT in incomer of station board and CT in 220 kV station transformer bay shall be used. Oil temperature Indicator (OTI) 150 mm dial type thermometer with manual reset maximum reading pointer. there shall also be two potential free contacts for alarm and trip signals. The alarm and trip settings shall be independently adjustable. The temp. sensing element mounted in a pocket of oil, shall be connected to the indicator through capillary tubing. Contact rating at DC shall be minimum 0.5 amps. Remote oil temp. indication shall be provided. Additional 4-20mA signal for remote signal shall be provided. Winding Temperature Indicator (WTI) Local winding temperature indicator (WTI) shall have a 150 mm diameter dial type indicator with a manual reset max. reading pointer. there shall be two potential free contacts for alarm and trip signals. For transformers with forced cooling another two sets of contacts shall be provided to start / stop the forced cooling system automatically. The setting of closing / opining of each contact shall be independently adjustable. Contact rating at DC11, 220V DC shall be minimum 0.5 amps. The device shall be complete with lamp, sensing element, image coil, calibration device, aux. CTs etc. as required. Remote winding temperature indicator with resistance type temperature detector shall be provided additionally. Additional 4-20 mA signal for remote signal shall be provided. Marshalling box All outgoing connections from the transformer i.e buchholz relay, temp. indicators, level





indicators, CT secondaries, alarm contacts for annunciations including forced cooling system and OLTC etc. shall be wired to a marshalling box. Marshalling box shall be sheet steel vermin proof and weather proof. Degree of protection of enclosure shall be IP 55. Rain canopy shall also be provided over the marshalling box. Removable bottom gland plate with cable glands, cubicle illumination lamps and space heater shall be provided. Marshalling box shall be having following major accessories;

• Temperature indicators • Control and protection equipment • Terminal board and gland plate

Earthing All metal parts of the transformer with the exception of individual core laminations, core bolts, and clamping plates shall be maintained at fixed potential by earthing. Two tinned copper earthing terminals shall be provided. One end of bushing CTs shall be earthed. Off-Circuit Tap Switch - Externally hand operated - Designed for sustained over current of at least 150% of the rated current of the

winding. - Shall not occupy any intermediate position between clearly marked tap position. - Capable of repeated operation and withstanding short circuit forces. - Integral handle with pad locking facility at every tap position. - Tap position indicator - Inspection and/or repair shall not require removal of transformer from tank nor

major draining. Fitting & Accessories Transformers shall be provided with following auxiliary equipment/systems and accessories;

1. First fill of oil as per IS - 335 with 10% excess in drums 2. Cooling system complete with accessories as per requirement including

radiators with shut off valves, filter valves, oil filling valves, drain and sampling devices, air release device, lifting lugs, etc.

3. Off circuit tap changer with accessories as specified with tap position indicator and locking arrangement.

4. Bushing CTs, neutral bushing CT with terminal arrangement 5. Conservator with oil filling hole, cap and drain valve sump , drain valve and

detachable end plate.





6. Magnetic type oil gauge with low oil level alarm contacts 7. Dehydrating silica gel breather with oil-seal - 2 Nos., 100 per cent (In addition

to the silica gel breather, more advanced oil preservation system like air dryers like molecular sieve flexible membrane can also be considered.)

8. Buchholz relay with oil seal independent alarm and trip contacts with isolating valves on either sides

9. Required Nos. of pressure relief valves/vents or spring operated pressure relief devices with trip contacts

10. Pockets on tank cover for thermometers for WTI and OTI 11. Oil temperature Indicator with maximum pointer 12. Repeater dial of oil temperature indicator for remote indication (The remote

indication shall be a separate measuring system) 13. Winding temperature indicator with maximum pointer 14. Repeater dial of winding temperature indicator for remote indication (The

remote indication shall be a separate measuring system) 15. Oil filling hole with flange and bolted cover 16. Valves (made of stainless steel)

• Oil valve between cooler and main tank • Drain valve at lowest location to allow complete draining • �2 Nos. filter valves on diagonally opposite corner at top and bottom of tank

with locking arrangement • �2 Nos. sampling valves at top and bottom of main tank. The sampling valve

shall be provided with provision for fixing PVC pipe 17. Two nos. earthing terminals 18. Rating & diagram plate (One spare Rating and diagram plate shall also be

supplied loose) 19. Valve schedule plate 20. Jacking pads 21. Approach ladder to climb up the transformer tank 22. Air release devices 23. Inspection cover with neoprene gaskets 24. Haulage lugs 25. Earthing terminals 26. Marshalling kiosk 27. Flange wheel/rollers (bi-directional with lock and bolting device) 28. Special cables (other than standard power and control cables) 29. Bus and cable trays





The following minimum remote control/signaling provisions are to be made as applicable. • � �Voltmeter to read secondary side voltage of transformer • � �Signal lamps for ‘tap changing in progress’ for OLTC. • �Remote winding and oil temperature indicators • �Status indications for cooler fans running/off/tripped • �Status indication of cooling pumps • �Control supply fail, cooler fan bank fails to start, standby cooler bank running,

cooler pump fails to start, etc. Audio-visual annunciations for the following abnormal operating conditions shall be provided as applicable. • �Oil level in transformer low (from magnetic level gauge) • Buchholz relay operation for transformer • �High oil temperature in transformer • �High winding temperature • �Pressure relief device operated • ��Aux. AC supply failed. A solid state facia window type annunciation system having first sequence recording shall be provided for this purpose, with the following features. • �On incidence of fault, a hooter comes on and window lamp starts flashing • �On pressing ACCEPT button, hooter stops, lamp becomes steady • �On pressing RESET button, lamp goes off if fault is removed • �Lamp continues to glow, if fault persists The required alarm/trip contacts shall be wired to the marshalling box for connection to the annunciation system. INSTALLATION AND COMMISSIONING Installation of transformer shall generally conform to the requirements of Code of Practice for Selection, Installation and Maintenance of Transformers IS : 10028 as well as Manual on Transformers published by he Central Board of Irrigation and Power. The installation shall have to be approved by statutory government authorities like Central Electrical Authority, Factory Inspector, Insurance officials etc. Any modification in the equipment or installation that may be demanded by them shall have to be carried out by the successful Tenderer at no extra cost to the Purchaser. The responsibility of obtaining clearance from the Electrical Inspectorate of Orissa for commissioning of the complete electrical equipment / system covered under this specification shall lie solely with the contractor. The contractor shall carry out any modification if the same is required by the





statutory authority though their work is complete as per approval of the Purchaser / consultant. Technical requirement of transformer 1. Rated capacity : 12.5/20 MVA 2. Cooling : ONAN/ONAF 3. Nominal voltage (HV/LV) : 220 kV / 11 kV 4. Highest voltage (HV/LV) : 245kV/12 kV 5. Impedance : 12.5 % 6. Duty : Outdoor in open yard 7. Winding connection : Star/star 8. Vector group : YNyn 9. Specification to be complied with : IS 2026 10. Termination : HV : O/H ACSR conductor

LV : Cables

11. Tap changer : off Circuit Tap on HV 12. Range of tap changer : +2.5% to -7.5%in 2.5%Steps

13. Tap changer control : Local manual

14. Short circuit level : 40 kA at 220 kV for 3 sec 15. Neutral grounding (220 kV) : Effectively earthed





16. Insulation class : A 17. Bushing CTs : Required for HVN & LVN 18. Ratio of bushing CTs : HVN : To be provided by

tenderer : LVN : To be provided by

tenderer 19. Protection class of bushing CTs : PS for REF

PS for differential 5P20 for back up E/F

20. Impulse test withstand voltage (220/11) : 1050 kVp / 75 kVp 21. Power frequency rated short duration : 460 kVrms / 35 kVrms

withstand voltage (220 kV/11 kV)

22. Withstand time without injury for 3 phase : 5 Sec short circuit

23. Induced over voltage with stand voltage : 2xRated voltage 24. Temp. rise above 50o C

• In oil by thermometer : 45O C • In winding by resistance : 50o C

25. Overload capacity : As per IS 6600 26. Type of radiator : Detachable 27. Auxiliary supply voltage : 220 V DC / 240V AC 28. Suitable for parallel operation : Yes 29. Painting : Approved shade - 632

of IS-5 (Epoxy based) NEUTRAL GROUNDING RESISTOR The neutral of 11 kV winding of station transformer shall be grounded through low





resistance. NGR shall be used in 11 kV system to limit earth fault current within permissible limit of the plant. NGR shall be located in transformer yard fencing and connected to secondary side of transformer. Enclosure shall be of outdoor duty and with rain protection. Temp. shall be limited to 375oC at maximum ambient of 50oC. Temperature rise of enclosure shall be within safe limit. Material of the resistance grid shall be punched steel. NGR shall be designed for 30 second duty for current rating. Single pole isolator shall be provided on incoming side. Porcelain insulators shall be used to support the resistance grid. Isolator shall have locking provision. One end of the resistance shall be connected to ground grid by means of separate grounding conductor of sufficient size suitable for the above duty. The other end of the resistor shall be connected through a current transformer for earth fault protection to the transformer 11 kV winding neutral by means of cable of required size suitable for the above duty. NGR panel shall be supplied along with single core Aluminium HT cable and termination kits to connect primary side and to connect earth electrode. Technical Requirement of NGR 1. Rated system voltage : 11 kV 2. System earthing : Non effectively earthed 3. Resistance value : To be provided by tenderer 4. System short circuit level : 40 kA 5. Rating : To be provided by tenderer 6. Supporting /fixing structures : To be provided by the tenderer





7. Impulse withstand voltage : As per IS 8. Power freq. withstand voltage : As per IS INTERCONNECTION OF SWITCHYARD TRANSFORMER BAY WITH STATION TRANSFORMER 22O kV transformer bays of the extended portion of the switchyard shall be interconnected shall be connected with Station Transformer The above interconnection shall be consisting of the following major equipment/systems • �Conductors • Gantries • �198 kV lightning arrestors for station transformer (supply & erection) • �Droppers • �Insulators • �Clamps and connectors • All the accessories Complete civil and structural works for the above interconnection shall be under scope of the tenderer. Tenderer shall include all the civil works associated with these interconnections including foundations, sand, gravels, etc as per requirement. All the foundations required for the gantries, supporting structures of lightning arrestors, NGR, etc shall be under scope of the tenderer. Tenderer shall also include complete civil and structures work for fastening of overhead conductor (single Zebra) ST bays. Complete civil work of station transformer yard shall also be included. Complete interconnection of 220 kV switchyard bays with HT terminals of station transformer shall be done by the tenderer. Adequate quantity of GI structures for take off gantry at switchyard end and gantries at transformer end shall be provided. All other items like overhead conductors, jumpers, connectors, guard wire for road crossing shall be provided in adequate quantities as per actual requirement. The Tenderer shall supply and install lightning arrestors in all three phases near station transformer just below the gantry. All supporting structures for the lightning arrestors





shall be provided by the tenderer. The overhead interconnections shall be comprising aluminum conductor steel reinforced (ACSR). The sizes of the conductors shall be adequate to carry the required continuous current as well as to withstand the specified short-circuit currents. ACSR conductors shall conform to IS:398. The supporting structures shall be having adequate mechanical strength as required for the specified short-circuit level. Necessary jumpers, connectors, insulators, structural steelwork, hardware as required shall be supplied to make the installation complete in all respects. Fittings and accessories shall be in accordance with IS : 2121. Insulators shall be made of best quality porcelain and shall be brown glazed. All insulators shall be suitable for heavily polluted atmosphere and shall be able to withstand the duty requirements of the related equipment. Insulators shall be designed, manufactured and tested as per IS:731 and IS:3188. All fittings and accessories shall conform to IS:2486. The steel structures for gantries and for supporting lightning arrestors, etc. shall be designed, fabricated and supplied as a part of the work covered by this specification to make the installation complete in all respects. The structures shall be of adequate mechanical strength designed to meet the requirement of the equipment specified and shall be suitable for site and loading conditions as called for in this specification. The structures shall be of lattice type construction, fabricated from rolled mild steel sections and hot dip galvanised. Only bolted connections will be permitted. Steel members, bolts, nuts, fittings shall be hot dip galvanised except spring washers which shall be electro-galvanised.

04.05 UNIT AUXILIARY TRANSFORMER Standards

Copper wound Transformers shall comply with the following Indian Standards.

IS: 11171(1985) / IEC 60726 - Dry Type Transformers Mechanical Design 01 Transformer enclosure shall be welded/ bolted sheet steel construction, free

standing, with suitable size of louvers. Base shall be suitably reinforced to prevent





any distortion during lifting. Base channels shall be provided with flat wheels with pulling eyes and lifting hooks to facilitate handling.

02 All fasteners and bolts etc. shall be galvanised or zinc passivated. All surfaces to

be painted shall be thoroughly cleaned, made free from rust and given a primary coat of rust resisting paint followed by two finishing coats of approved shade. Paint shall be suitable to withstand specific climatic conditions.

03 The transformer shall be provided with separate weatherproof HV/LV terminal boxes and disconnecting links on the side of transformer so as to facilitate withdrawal of transformer without disturbing the HT busduct and LT cables connected to transformer.

04 Tank shall be suitably designed to withstand harmonics available in the system as well as generated by the transformer.

Electrical Design 01 3 Phase, Core type cast resin 02 Insulation level shall be designed according to the voltages specified as

applicable and as below. SN Description 11 kV System 1 Nominal system voltage (kV) 11 2 Max. system voltage (kV) 12 3 One minute power frequency withstand voltage (kV) 35 4 Peak impulse test withstand voltage (kV) 75 03 Transformers shall be capable of delivering rated current at an applied voltage up

to 105% of rated voltage without exceeding the temperature limits. 04 Overload capacity of the transformer shall be as per IS 6600 – 1972 unless

otherwise specified. 05 Shall be operable at its rated capacity at any voltage within + 10% of rated

voltage of the particular tap.





06 Permissible maximum temperature at rated output and principal tap at the ambient

temperature of 50°C . Windings (by resistance method) 120°C Core and other parts not adjacent of winding Within safe limits of core and adjacent materials

07 Transformers shall be designed to withstand the thermal and dynamic stresses due to short circuits at its terminals or symmetrical/asymmetrical fault on any winding. Short circuit withstand capacity for the bolted fault at the terminals shall not be less than 5 second duration with respect to fault level specified.

08 The maximum temperature at the end of the short circuit duration shall not be

more than 250°C with the temperature prior to short circuit corresponding to maximum permissible overload.

09 Transformer shall be designed for minimum no-load and load losses within the

economic limit. 010 Rated output, voltage ratio, vector group shall be as specified in technical

particulars for design. MAGNETIC CIRCUIT

i) Low loss CRGO silicon steel shall be used. ii) Laminations shall be annealed in a non-oxidizing atmosphere to relieve

stresses and restore the original magnetic properties of CRGO sheets after the cutting and punching operations.

iii) CRGO sheets shall be coated with insulation varnish compatible with the

sealing liquid. iv) Insulation to withstand annealing temperature as high as 850 Deg. C and

shall reduce eddy current to minimum. v) Ducts to be provided to ensure adequate cooling.





vi) Core, framework and clamps arranged and tightened to securely hold laminations in order to prevent any settling or displacement in case of heavy shocks during transport, handling or short circuits.

vii) Flux density under specified over voltage or frequency conditions shall be

within the maximum permissible for the laminations. However it shall not exceed 1.6 tesla.

viii) Transformers shall be designed to withstand 110% over fluxing

corresponding to rated voltage.

ix) Magnetising current shall be maximum 1% of the rated current.

WINDINGS

i) Material shall be electrolytic grade copper with 99.9% purity. ii) Shall be subjected to shrinkage treatment.

iii) Completed core and winding to be vacuum dried in full vacuum,

impregnated immediately, then dried before casting in resin.

iv) Shall be braced to withstand shocks due to rough handling and forces due to short circuit, switching or other transients.

v) Permanent current carrying joints in winding and leads shall be brazed.

vi) Coils shall be supported using dried and high-pressure compressed wedge

type insulation spacers. vii) Insulating materials shall be compatible with transformer liquid under all

service conditions. viii) Leads to the terminal board and bushings shall be rigidly supported. ix) Neutral shall be solidly earthed in case of Distribution Transformer.

TERMINATIONS It shall be possible to withdraw the transformer easily after disconnecting the connections without disturbing the Busduct/cable terminations. Cable termination box shall be bolted type and supported from bottom so that after withdrawing the transformer,





it remains at its same position. Winding shall be brought out and terminated on external /cable boxes as specified in the Technical Particulars.

i) In case of Cable termination a) Air insulated cable end box suitable for the type and number of

cables specified.

b) LV side terminal arrangement : Three insulated terminals housed within a flanged intermediate Air insulated disconnecting chamber (with inspection opening ) for connecting cable. It shall be possible to remove the transformer without disturbing the cable terminal chamber.

c) Shall be provided with earthing bus for termination of XLPE cable

screen and shall be with necessary disconnecting link. d) Compression type brass cable glands with finned copper lugs of

non soldering crimped type. e) Bolted type gland plated ( non magnetic material wherever

specified). f) Sealing kits with associated accessories like stress reliving ,

insulating type, bi-fercating boot, HT insulating tape etc. ii) Bus duct termination

HV side termination arrangement : When bus bar termination is required -

Provided with Porcelain bushing suitable for termination of HT open bus bars with flanged termination .

iii) Neutral terminal arrangement Full capacity LV terminal to be brought out side as a fully insulated terminal for solid earthing and provided with a CT for standby earth fault protection.





iv) Aux Terminal Box Embedded thermistors/ RTD's for winding temperature monitoring with alarm and trip contacts shall be provided in a separate aux. terminal box.

BUSHINGS j) Conforming to IS 3347 part-1,2 & 3 – 1979, Part 3&4-1988 and IS:2099-

1986 for HT and IS 7421 for LT system. ii) Minimum rated current of line end bushings shall be 1.5 times rated current

of the corresponding windings. iii) Clamps and fittings made of steel or malleable iron shall be hot dip

galvanized.

iv) Bushings rated 400 amps and above shall have non- magnetic clamps and fittings only.

v) Bushings shall be solid porcelain type. In case rating of porcelain type

bushings exceeds beyond IS rating & not available from approved manufacture, Epoxy type to be used.

vi) Neutral bushings shall be provided as required for earthing of neutral

point. This shall be connected to brass/tinned copper bar and brought to outside the body through porcelain insulator.

NEUTRAL CURRENT TRANSFORMERS i) Removable at site without opening transformer enclosure cover/active part. ii) Secondary leads shall be brought to a weatherproof terminal box and from

there to the Marshalling box with 4 sq.mm copper armoured cable. WINDING TEMPERATURE INDICATOR

i) Local winding temperature indicator (WTI) shall have a 150-mm diameter dial type indicator with a manual reset maximum reading pointer. There shall be two potential free contacts for alarm and trip signals. The settings for closing/opening of each contact shall be independently adjustable. Contact rating at DC11, 110V DC shall be minimum 5 Amps. The device shall be complete with lamp, temperature sensing element, image coil, calibration device, aux. CTs etc. as required Temperature indicator dials shall have linear gradations to clearly read atleast every 2°C. Accuracy shall be better than ±1.5%.





ii) Remote Winding temperature indicator with Resistance type temperature

detector shall be provided additionally. Output in terms of 4-20 mA signal corresponding to temperature measurement shall be interfaced with plant automation system.

MARSHALLING BOX i) All outgoing connections from the transformer viz temperature indicators,

level indicators, CT secondaries, fault contacts for annunciation, etc. shall be wired to a Marshalling Box.

ii) Degree of protection of enclosure shall be IP55 .

iii) Removable gland plate with cable glands , illumination lamp and space

heater shall be provided. RATING PLATE Each transformer shall be provided with a rating plate giving the details as per IS:2026 (Part-I). The marking shall be indelible and the rating plate shall be located on the front side. Exact value of transformer % impedance, as determined by tests shall be engraved on it and also on the final submission of name plate drawing. NOISE Noise level shall be low and shall be within limit depending on the rating of the transformer as per IEEE-141. EARTHING i) All metal parts of the transformer with the exception of individual core lamination

core bolts and clamping plates shall be maintained of fixed by earthing. ii) Two nos. of tinned copper earthing terminals shall be provided. iii) One end of bushing CTs shall be earthed. LIST OF FITTINGS AND ACCESSORIES i) Identification plate ii) Rating and diagram plates. iii) Off-circuit tap switch as specified.

iv) Dial type winding temperature indicators with max reading pointer and alarm & Trip contacts.

v) Bushing CTs with terminal arrangement in Neutral.





vi) Bi-directional rollers/flanged wheels with loading arrangement. vii) Lifting lugs and jacking pads viii) Earthing terminals. ix) Inspection cover with neoprene gaskets x) Pockets for thermometer for winding temperature indicator (WTI). xi) HV, LV and Neutral bushings xii) Marshalling box. xiii) Winding temperature indicator with remote indication xiv) Provision of skidding , lifting and jacking xv) Any other accessories required as per IS-2026.

TECHNICAL PARTICULARS Sl. No. Particulars Specifications

1 Type Three phase, core type, cast

resin dry type 2 Duty Indoor 3 Degree of Protection of

Enclosure IP42

4 Voltage HV 11 kV LV 0.433 kV 5 Frequency 50Hz 6 No. of Phases 3 7 Continuous Rating 750 kVA 8 Conductor Copper 9 Insulation Class Class F but temperature rise

limited to Class B 10 Cooling AN 11 Winding Connection Delta / Star 12 Vector Group DYn 11 13 Neutral Grounding Solidly earthed 14 System Earthing HT Resistance Eatrthed LT Effectively Earthed 15 Permissible temperature rise Refer Clause 3(Electrical





Design) above 16 Bushing mounted CTs CT in LV Neutral bushing for

standby earth fault protection Ratio : Primary calculated as per fault current requirement with secondary as 5 amp. Class : 10P15

17 Off Circuit tap changer bolted link type a Range ±2.5% , ±5% b Total tap positions 5 c Taps above nominal

voltage 2

d Taps below nominal voltage 2 e Voltage per step

variation 2.5 %

f Tap change controls Manual (Shall not occupy any intermediate position between clearly marked tap position)

g Rating Designed for sustained over current of at least 150% of the rated current of the winding and withstanding short circuit forces

18 . Impulse test withstand voltage As per IS 2026, Part III – 1981

19 One minute dry and wet power frequency withstand voltage

- do -

20 Short circuit level on HV side 40 kA for 3 Seconds 21 Time duration to withstand 3 phase short circuit

at secondary terminals, without any injury. 5 Sec

22 Auxiliary supply voltage 240 V 23 . Parallel operation Suitable for parallel

operation with transformers





of similar ratings 24 Overload capacity As per IS 6600 –1972 04.06 11 kV SWITCH BOARD

The switchgear shall be of metal clad, single busbar, self standing, dust proof construction, indoor cubicle type fitted with vacuum circuit breakers, in fully drawout execution.

- The circuit breakers shall be suitable for the duties :

i) To withstand in rush magnetizing currents of transformers, and capacitor

bank 'ON' and 'OFF' operation.

- The controls, indicating lamps, shall be mounted on breaker cubicle itself and relays & meters shall be mounted in the remote cubicle in the control room..

- Operation counter, close/open mechanical indications spring charged/dischared indication shall be provided.

- All circuit breakers shall have motor operated spring charged independent

closing and shunt tripping from 220V DC. Closing coil shall be suitable to operate between 85-110% of voltage and tripping coil between 60-110% of rated voltage. Spring charging motor shall operate between 80-110%.

- A manually operated device to enable charging of closing springs. - All circuit breaker trucks shall have service, test and draw out positions.

Test position shall engage only the auxiliary (control) contacts to close the CB during testing.

- Anti pumping features shall be provided. - All live parts shall be insulated by tapping supported by suitably designed

insulators. Proper insulation of bus bars upper and lower contacts of breakers, vacuum bottles (for VCB) and sealing of opening of bushings shall be provided to eliminate accidental contacts. Switchboard busbars shall be tapped by proper grade of insulating material by Reychem sleeving.

- The cubicles shall be provided with a position changing gear arrangement in such a way that by engaging detachable device from outside the front





door, it shall be possible to move the breaker truck and change positions without opening the cubicle door. Facilities for pad-locking in each position shall be provided. In the design of the switchgear the following positive interlocking shall be provided.

- It shall not be possible to move the truck from the Isolated to the Service Position unless low voltage plug and socket connections have been made.

- It shall not be possible to disconnect the low voltage plug and socket as long as the circuit breaker truck is in service position.

- It shall not be possible to withdraw the truck past the Isolated Position without disconnecting the low voltage plug and socket.

- It shall not be possible to move the truck from the service to the Isolated position or vice-versa with the circuit breaker in the ON position.

- It shall not be possible to switch on the circuit breaker when the truck is in between the Isolated and the service positions (except in Test position).

- It shall be possible to switch on the earthing switch only when the truck is in the isolated position, where an integral earth switch is provided.

- It shall not be possible to open the circuit breaker enclosure when the breaker is ON on to have access to any part of the drawout assembly which is live when the circuit breaker is in the Service position.

- Shutters shall be lockable in closed position. - Where local/remote selector switches are called for, it shall be ensured

that:

� The breaker can be closed locally only if the breaker truck is in the test position and the local/remote selector switch is in local position.

� The breaker can be operated from remote panel (in control room)

only when the breaker truck is in service position and the local/remote selector switch is in remote position.

� the breaker can be tripped locally regardless of the position of the

breaker truck. - Each cubicle shall have mimic diagram with metal strip.

- Each cubicle shall be of compartmentalized construction and shall have

separate compartments for busbars, CTs and outgoing cables, metering





protection devices. - All circuit breaker trucks of same rating shall be identical in all respects

(except metering and protective devices) and shall be interchangeable with similar breaker panel.

- Continuous earth bus shall be provided throughout the board. Operating Mechanism

- The operating mechanism parts shall be designed to give longer life trouble free operation, and minimum maintenance.

- The material and components used shall have chopping current limited to

minimum. Insulation Level - Corresponding to the rated voltage as below : - Nominal voltage (kV) : 11.0 - Highest system voltage (kV) : 12.0

- One minute power freq- : 28.0

uency withstand voltage (kV)

- 1.2/50 micro second : 75.0 impulse withstand voltage (kV) Short Circuit Strength

- Rated short time withstand current not less than the system short circuit level specified for the stipulated duration.

- Rated peak withstand current not less than 2.5 times the system short circuit level.

- Auxiliary buses for control & protection - Buses shall be formed by wire looping. - Control supply buses for AC and DC - Signalling supply - PT secondary voltage - Spare buses - 2 nos.

Provision of surge suppressor

- In case of breakers like VCB that give rise to overvoltage surges due to current chopping phenomenon, surge suppressors to be provided at the





load side terminals of the breakers to limit the switching surges to value limited for as per IEC.

Annunciation scheme - Flag indications for all faults for which individual protective relays have

been specified. - 'Alarm' signalling (as applicable) on individual panels :

a) All transformer warning/signalling condi-tions (group signal from

corresponding transformer control panel/substation) b) Loss of trip circuit supply c) Earthfault d) Control supply failure e) PT fuse failure/MCB tripping

- 'Emergency' signalling for tripping of HT breakers on fault

- One common signal for alarm and one signal for emergency from each panel to be wired to a common annunciation panel of the switchboard, where specified.

- Annunciators for alarm warning and emergency signalling conditions on

individual panels of solid state facia window type. Common audio signalling with Accept, 'Reset' and 'Test' push buttons for the switchboard where common annunciation panel not specified. Audio signalling to have distinct tones for 'warning' and 'emergency'.

Busbar and connections

- Power buses of EC grade aluminium alloy equivalent to E91E WP as per IS 5082 - 1981 or high conductivity electrolytic grade copper as per IS : 613 - 1984.

- Control and auxiliary buses of electrolytic grade copper - The continuous rating of the main horizontal bus not less than the rating of

the incomer specified, where not specified, the rating to be selected for at least 125% of the maximum demand of the switchboard taking into account spare feeders.

- The vertical bus rating :

= For incomer : Not less than that of





horizontal bus

= For outgoing : not less than that of the outgoing breaker, irrespective of releases setting.

- Final operating temperature under continuous operation in enclosure limited to 90 deg. C by thermometer method.

- Both horizontal and vertical bus bars to be designed and supported to withstand the thermal anddynamicstresses corresponding to rated short time and peak withstand current specified.

- Cross section of main horizontal bus to be uniform throughout the switchboard and continuous in one transport unit.

- Bus bar arrangement as per IS-11353 - 1985, IS-5578 - 1985. - Phase identification by colour in each panel. - Busbar joints and tap off connections of bolted type with zinc bichromated

high tensile steel bolts, nuts and spring washers, fish plates with accessories at the end of a transport unit for site connections.

- Busbar support insulators of non-hygroscopic material having high impact and dielectric strength with an anti tracking contour.

Internal control wiring - Control wiring by 1100V grade PVC insulated, single core copper wire of

minimum cross section 2.5 sq. mm - Flexible wires protected against mechanical damage for wiring to door

mounted devices. - Wires identified at each and in accordance with schematic diagrams by

interlocked type ferrules.

- Color code for control wiring : AC - black DC - light Grey

- All connections external to a feeder, all the auxiliary contacts of the HV breaker and at least 1 NO + 1 NC spare contacts of the relays, brought on to terminal blocks.

- Interconnection between panels of adjacent shipping sections to be brought out to a separate terminal block.

- Control wires shall be run in earthed metallic flexible conduits when laid in HV bus chamber.





- Not more than two connections on any one terminal. - All telemetering signals wired to terminal strips.

External Terminations Control Terminations

= 650V grade multi-way terminal blocks of non-tracking moulded plastic complete with insulated barriers, stud type terminals, washers, nuts and lock nuts and identification strips.

= Control terminals of minimum rating 10 amps and suitable to receive 2.5 sq. mm copper conductor.

= 20% spare terminals in each control terminal block. Power Terminations

= Suitable for accepting cable/bus trunking as specified. = Sufficient space and support arrangement inside each panel to accomodate

HT cable termination kits and sealing kits suitable for the type, size and number of cables to be terminated.

= Dummy panels to be provided adjacent to the switch panel, where the required

number of cable terminations can not be accomodated in the cabling chamber of the main panel

= Where more than one cable have to be terminated per unit, the arrangement shall permit connection and disconnection of cables separately without disturbing other cables.

= Where specified, the following cable termination accessories, suitable for the type, size and number of cables to be terminated, to be supplied with the switchboard.

= Cable sockets with all HT terminals. (socket set at such an angle that cable tails can be brought up for termination with minimum bending and setting.)

= HT cable termination and sealing kits. = Double compression type, brass cable glands and crimping type tinned heavy

duty copper lugs for HT, LT power and control cables. Current Transformers

- Separate sets of current transformers shall be used for differential protection, over current protection and measurement purposes.

- Short time rating and insulation levels of CTs shall be similar to the rating of associated breakers.

- CT ratios specified are provisional. Where outputs and accuracies are not





specified, these shall be such as may be required by the circuits in which they are used. Generally the protection CTs and metering CTs shall have 10P15 and 1.0 class respectively.

- CTs shall be window/bar primary type - CTs shall have shorting link on secondary side to facilitate insertion of

meters on secondary side without opening CT circuits. Voltage Transformers

- Voltage transformers shall be provided in incomer panel of the switchboard.

- High voltage side of VTs shall have fuses and low voltage side shall be provided with MCCBs.

- Low voltage star winding shall have all three phase and neutral connections brought out to terminals and one phase shall be earthed.

- Insulation levels shall be similar to the rating of associated board. - Accuracy class 1.0 shall be used. - Shall be mounted on withdrawable truck. - Preferred VA burden 100.

Relays - All relays shall be flush mounted in dust proof cases and shall be mounted

on rear side of cubicle. The relays shall be micro processor based numerical relays with communication system.

- All protective relays shall be draw out type.

- All timers and protection relays shall have flag indicators.

- Master trip relay shall be hand reset type and shall have 3 NO and 3 NC contacts in addition to those required by the protection/control scheme.

Indicating instruments

- All indicating instruments shall conform to IS : 1248 - 1983 and IS - 2419 -

1973. - Shall be capable of withstanding system fault current taking account CT

saturation. - Shall be located in the upper part of the panel.





- Shall have 144 sq. mm square flush case, non-reflecting bezels, clearly

divided and indelibly marked scales, sharply out lined pointers and zero adjusting device.

- The full load reading of each ammeter shall occur at the most prominent

part of the scale. The minimum scale reading shall not be more than 10%. Maximum reading shall be 15% full load for transformers panels and 600% full load for motor panels.

- Each voltmeter shall be calibrated with coil hot. The scale shall be open

between 60% to 125% of normal volts and shall be suppressed below 60% of normal volts.

Annunciators

- Solid state facia window type with white heat resistant plastic material, inscriptions, engraved in black.

- Lighting unit with dual lamps in parallel. - Facia window and lighting unit in `plugin'type assembly. - Control circuits of individual channels on glas epoxy coated plug in type

PCBs in bin assembly, plug/sockets mechanically coaded, to avoid wrong insertion.

- Fault ACCEPT, system RESET and TEST push buttons common for the

system. - Sequence of operation - On incidence of fault - hooter ON, lamp FLASH . On pressing ACCEPT PB - Hooter OFF, lamp STEADY - On pressing RESET PB LAMP OFF if fault has been cleared. Otherwise





LAMP Persists Control Supply

- Control supply buses shall run through the switchgear. - Two DC feeders shall be taken in each board controlled by MCBs. - In each panel for controlling of its DC supply MCCB shall be used. - 240V AC supply shall be taken from a substation aux. board. - Each section shall have separate feed with automatic changeover scheme. - Each panel shall have one MCB for controlling its AC supply. - Sub circuits shall be protected with HRC fuses.

Voltage Selection Circuit

- Voltage selection circuit shall be formed to ensure that only one PT feeds the entire load of PT consumers. This shall be necessary to avoid paralleling of PTs, when more than one voltage source in 'ON'.

Earthing Devices

- Either integral earthing switch or a separate earthing switch shall be provided to facilitate earthing of busbars and any feeder circuit.

- Earthing truck (if included) shall have PT and alarm provision. - Rating of earthing device shall be in line with associated board.

Terminal Blocks

- Stud type suitable to accommodate 2 cores of 2.5 sq. mm copper control cables.

- Size of terminals for bus wires - AC/DC incoming supplies shall be as per





requirements. - 20% spare terminals shall be provided in each panel. - All terminals going out of the switchboard shall be brought to a separate

terminal board marked 'External Connections'. Small wiring and ferrules

- All small wiring shall be carried out with 650 V grade single core cable having copper conductor, preferably stranded, of not less than 1.5 sq. mm cross section. However, wires going outside the switchboard shall have minimum 2.5 sq. mm cross section.

- Wiring across the hinges shall be through flexible cables.

- The wires shall be identified by numbered ferrules at each and, all in

accordance with connection diagram.

- All ferrules shall be made of non-deteriorating materials.

- The ferrules shall be firmly located on each wire so that they cannot move freely on the wire.

Transducers for telemetering

- DC analogue signal output of 4-20 mA for continuous parameters like

voltage, current, power etc. - Pulse/BCD output for energy monitoring. - Provision of adjustments to compensate errors in primary circuit.

Indicating Lamps - 7 watts, screw type filament lamps with series connected resistors,

preferably built in the lamp assembly.





- Color : ON - RED

OFF - GREEN

CIRCUIT HEALTHY - WHITE FAULT/WARNING - AMBER

Control and selector switches - Control switches for circuit breaker ON/OFF control-3 position spring

return to neutral with lost motion device and pistol grip handle. - Other control and selector switches - stay put type with wing type knobs. - Ammeter selector switches - 4 position, make before break - Voltmeter selector switches - 4 or 7 position as required. - Rating : continuous - 10 amps AC - 4 amps, 240V DC 11 - 0.5A, 220V, L/R - 40 ms

Colour : Black Push Buttons

- Rating : continuous - 10 amps AC : 1.5 amps, at 240V DC 11 : 0.5A, 220V, L/R - 40 ms

-Color : ACCEPT - BLUE





RESET - BLACK

TEST - YELLOW Control Circuit Protection

- Preferably with MCBs, alternatively HRC link type conforming to IS 9224. Protective Earthing

- Continuous earth bus of minimum size 50 x6 mm copper or equivalent aluminum/galvanized steel section, designed to carry the peak short circuit and short time fault current as specified.

- Provided at the bottom extending throughout the length of the board,

bolted/brazed to the frame work ofeach panel, with an earthing terminal at each end, for terminal at each end for terminating external earth conductor.

- Vertical earth bus for earthing individual functional units. - All non-current carrying metal work (including metallic cases of instruments

and other panel mounted components) effectively bonded to the earth bus.

- Hinged doors earthed through flexible earthing braid. - Looping of earth connection resulting in loss of earth connection to other

devices when the loop is broken, not permitted. - Withdrawable units provided with selfaligning, spring loaded, silver plated

copper, scrapping earth contacts, of make before/break after type,ensuring earth continuity from service to the test position.

Test and maintenance equipment

- Each board to be supplied with





1 set of test plugs

1 common transport trolley for interchanging with drawable units, height of

the trolley lifting arm adjustable for raising/lowering the units.

Any other special purpose tools for maintenance.

Construction features : Mechanical Design Mechanical Design

- Sheet steel clad, floor mounted, free standing design. - Minimum sheet steel thickness : doors & covers - 2 mm cold rolled, other

members - 2.5 mm - Degree of protection IP53

- Assembled on base channel of structural steel of minimum height 50 mm,

painted black. - Earthed metallic barriers between compartments and between vertical

sections. - Seal-off bushings wherever bus bars pass through metallic partitions. - Zinc bichromated and passivated hardwares. - Transport unit not larger than 3.2 meters. - Removable lifting arrangement for each transport unit - Lockable front doors with concealed hinges with the door not forming part

of the drawout truck. - Extensibility on both sides of the panel.





- Screwed wire mesh for bus bar and CT chambers to prevent accidental

contact with live parts. - Removable sheet steel covers at rear - Explosion vents for different chambers. - Pressure relief flaps which can not be opened from outside to release

pressure that builds up in the event of arcing faults inside the cubicle. - All similar units should be electrically and mechanically interchangeable.

Labels

- Switchboard designation name plate at the center of the board with letters

not less than 25 mm high. - Panel designation number on each panel, both in front and rear - Inscription plate for each feeder on the door. - Door/front mounted devices to have labels directly below them. - Labels made on non-rusting metal or 3 ply lamicoid with engraved

inscriptions of white letters (minimum 3 mm high) on black ground. - Label designation and size of lettering subject to approval. - Bus side and cable side shutters labeled for identification.

Surface Treatment

- All metal parts of the panel to undergo surface treatment that includes de-

rusting, cleaning, chemically degreasing, pickling in acid, cold rinsing, phosphating and passivating followed by spraying with two coats of zinc





oxide primer and baking in oven. - Shade of paint :

Panel interior : Off white shade

Exterior : 2 coats of light Grey enameled paint of shade 631 of IS-5 (unless otherwise specified) and further stoved.

Technical particulars and design parameters

1. Type & Service : Indoor, metal clad, Draw out.

2. Enclosure : IP-4X

3. Nominal system voltage : 11 kV

4. Highest system voltage : 12.0 kV

5. No. of phases and : 3, 50 Hz frequency

6. System earthing : Non effectively earthed

through resistance. 7. Circuit breaker rating :

a) Continuous current :

rating at 45 deg. C

b) Short circuit rating : 40 kA for 3 sec.





c) Dynamic system : 100 kA stability

8. Bus-bar rating : 3000A, 40 kA (3 sec)

9. Power frequency with- : 28 kV rms for 1 min. stand voltage

10. Impulse withstand voltage : 75 kV

11. Control voltage : 110V DC for s/s

12. Termination : XLPE cables

13. CT ratio : Secondary current 1A

14 PT ratio : 11000 110

- ------ / ------- Sq.rt 3 Sq.rt 3

15. No. of aux. contacts : 4 NO & 4 NC.

for purchaser's use.

16. Details and type of : As per details feeders .indicated in schedule of components

. 04.07 UNIT AUXILIARY BOARD /STATION AUXILIARY BOARD

Constructional Features :

- Metal clad, indoor type front mounted panels, free standing design, with dust proof construction. The construction shall be compartmentalised with metal / insulation partitions between compartments.





- Sheet steel of not less than 2 mm thickness for cold rolled sheets cold rolled and 2.5 mm for Hot rolled sheets.

- Circuit breaker shall be mounted on fully drawout truck with service,

test and isolated positions and complete with following safety interlocks and safety shutters with padlock facility :

Truck cannot be moved in or out of cubicle when the breaker is

closed.

CB compartment door shall be mechanically interlocked so that it will not be possible to close the CB in plug position when the door is open.

Truck cannot be pushed in close position if either of the safety shutter is not free and not in close position.

Name plate for each incoming, buscouplers and outgoing at front and back both on the fixed portion of the panel.

- All panels shall have space heater with switch and cubicle

illumination lamp with door switch - The back door shall be hinged type. - Enclosure shall be confirm to IP54 - Operating height shall be 450-1800 mm - All panels shall be suitable for pollution degree three environment.

Insulation Level :

- Rated insulation voltage 1100V

- One minute power frequency withstand voltage :

• 2.5 kV for power circuits • 2 kV for control circuits

- Clearance in air (minimum) :





• Phase to phase - 25.4 mm • Phase to earth - 19.0 mm

Short Circuit Strength :

- Rated short time withstand current not less than the specified short circuit level for 1 second.

- Rated peak withstand current not less than 2.1 times the specified short circuit level.

Busbars : - Three phase, neutral (with atleast 50% rating of main buses) and

continuous earth bus. Bus bar and tapping shall be provided with PVC sleeve.

- Rating of horizontal buses shall be in line with incomer rating and

vertical bus bar for the compartment shall commensurate with all outgoing feeders.

- Temperature rise of bus bars shall not be more than 35o C above ambient of 50o C.

- Bus bar and connection shall be of high conductivity Aluminium /

Aluminium alloy of suitable hardness and purity complying with as per IS 5082.

- All bus connectors shall be Silver plated.

Cable Termination Requirement :

- Extension bus links properly spaced for terminating single cables of size 120 sq. mm and above as well as for terminating multiple cables of all sizes.

- Where more than one cable have to be terminated per unit, the





arrangement shall permit connection and disconnection of individual cables separately without disturbing other cables.

- Double compression type brass cable glands and crimpping type,

tinned heavy duty copper lugs suitable for the type, size and number of cables to be terminated, to the bottom to be supplied with the switchboard for all LT power and control cables and cable accessories.

AIR CIRCUIT BREAKERS :

Electrical Features : - Air break triple pole drawout type conforming to IS 13947(1993).

- Rated continuous current as specified. - Symmetrical breaking capacity and 1 second short time rating shall

be specified. - Performance catagory : B (100%) - Auxiliary contacts : 6 NO + 6 NC minimum convertible from NO to

NC and vice-versa at site.

Ratings : Continuous - 10 amps AC - 4 amps at 240V DC - 0.5 amps at 220V

Operating Mechanism :

- Motor operated mechanism as applicable - Spring charged stored energy mechanism to ensure high speed

closing and tripping independent of the operating forces. - Anti pumping and trip free feature. - Emergency tripping by mechanically operated trip push button

(shrouded to prevent accidental closing) acting directly on the trip bar.

- Closing operation of the breaker will charge the spring. - Mechanical indication to show :





� Closing spring charged � Breaker ON/OFF/TRIP indication.

- Breaker to close only when spring fully charged

- Non-reset type operation counter

� Charging of closing spring by motor � Closing by closing coil (operating range 85% to 110% of rated

voltage) � Tripping by trip coil (operating range 70% to 110% of rated

voltage). � Spring charging motor and closing coil suitable for rated control

voltage.(220 V DC) � One opening and one closing operation without control supply. � Provision also for manual closing with spring charging motor

automatically decoupled as soon as charging handle is inserted.

Drawout Features :

- 3 distinct positions viz. service, test, and isolated with the door closed.

- Mechanical position indication and locking/latching facility for all 3

positions.

- Power connections - self aligning, plug-in type contacts between silver plated copper and silver plated copper.

- Control connections - sliding or plug socket type, mechanically

coupled to prevent wrong insertion, continuous rating 16 amps minimum.

- Automatic safety shutters to prevent accidental contact with live parts

when the breaker is withdrawn.

- The break contact shall be on the breaker side.





Safety Interlocks :

- Breaker can not be closed in any intermediate position other than the 3 fixed positions.

- With the breaker closed, it cannot be racked in from any of the 3

position to another.

- Mechanical stopper to prevent accidental falling while withdrawing.

- Breaker cannot be racked in from isolated to `test' postion with the door open together with provision for defeat of this interlocking, however, the door can be closed only when the breaker is brought back to 'isolated' position.

- Door can be opened only when

• breaker is OFF and • is in `Isolated' position.

- Remote closing of breaker not permitted with door open.

- Insertion of breaker into 'Service' position not possible if the shutters are not free.

Internal Control Wiring

- Control wiring by 1100V grade PVC insulated, single core stranded copper conductor of minimum cross section 2.5 sq. mm.

- Flexible wires, protected against mechanical damage for wiring to door-mounted devices.

- Wires identified at each end in accordance with schematic diagrams by interlocked type ferrules.

- Colour code for control wiring : AC – black DC - light grey

- All connections external to a feeder, all the auxiliary contacts of the





LT breaker and at least 1 NO + 1 NC spare contacts of the relays brought to terminal blocks.

- Interconnection between panels of adjacent shipping sections to be brought out to a separate terminal block, wires for interconnection properly labelled, looped and bunched inside the panel for connection at site.

- Not more than two connections on any one terminal. - All spare contacts wired upto terminal block of the panels

a) Protective relays - withdrawable type b) Auxiliary, timer relays - fixed type

External Terminations Control Terminations

- 500V grade multiway terminal blocks of non-tracking moulded plastic complete with insulated barriers, stud type terminals, washers, nuts and lock nuts and identification strips.

- Power and control terminals segregated.

- Open type control terminals of minimum rating 10 A suitable to

receive 2.5 sq. mm copper conductor.

- 20% spare terminals in each control terminal block.

Power Terminations:

- Suitable for accepting cables/bus trunking as specified.

Protective Devices

The circuit breaker shall be provided with the following protective devices with suitable setting ranges. Alternatively self powered relays can be offered. Preferably these shall be static type.

A. Incoming Circuit Breaker





• Built-in direct acting type series over current release

instantaneously operating and tripping the circuit breaker against short circuit with adjustable minimum definite time delay 0.1 - 0.6 seconds through electornic - timer independent of line current and voltage.

• Built-in-direct-acting type series overcurrent release having

long time delayed inverse-time current characteristics for protection against overloads.

• Earth fault protection through an over current relay

connected across a CT mounted on the neutral busbar. The earth fault relay shall operate to trip the breaker through the shunt trip coil rated for 220V DC. The earth fault relay shall have a mechanical operation indicator.

• Under-voltage tripping shall be provided through under-voltage relays/timer relays for the following operating conditions.

a) The circuit breaker shall trip for voltage less than 50% of rated

system voltage (with an adjustable time delay in the range of 1-10 seconds).

b) The system under voltage shall not prevent manual closing of

circuit breaker above 80% of rated system voltage. c) The relay shall not prevent remote closing of circuit breaker when

the control circuit voltage is 85% - 100% of nominal control circuit voltage.

d) The under voltage relays shall not trip the breaker in case the

substation is operating on single transformer or with the control selector switch set in MANUAL position.





Current Transformer The thermal and dynamic stability current for CTs will be same as for the air circuit breakers. CT ratio shall be as per requirement. Protection and measuring current transformer shall be bar primary/ window type with 5A secondary conforming to IS-2705 Part-II-1992 and Part-III-1992respectively. Measuring CTs shall conform to accuracy class-I of IS 2705 part-II-1992 and burden of CTs shall be as required by the associated measuring equipment. The CT ratio shall be as required by the associated measuring instrument. The CTs shall have saturation factor of not less than 1.5 and higher limit shall be compatible with the overload capacity of the instrument connected on the secondary side. Protection CTs shall have their accuracy and burden as required by the protection circuits in which they are used and shall have saturation factor of not less than 10.

CT shall be of cast resin type. Potential Transformers (PTs) PTs provided on each incomer/ feeder shall be of draw out type. The PTs shal be dry epoxy resin moulded type. High voltage windings of voltage transformer shall be protected by current limiting HRC fuses. The voltage transformer and fuses shall be completely disconnected and visibly grounded in fully drawout position. Low voltage fuses, sized to prevent overload, shall be installed in all ungrounded secondary leads. Fuses shall be suitably located to permit easy replacement while the switchgear is energised. The technical particulars and accuracy class of the PT shall be as per requirement.





Relays:

- All the Aux. relays to suit the requirement of scheme operation and interlock of equipment

- Flush mounted type. - Shall withstand impulse voltage in accordance with IS/IEC

recommendation. - Diagram plate at the back of case to identify connections. - All spare contacts shall be wired upto terminal block.

Control Supply Two DC feeders shall be provided in each board for power supply of control, shunt tripping and annunciation purpose. Control supply shall have supervision facility, alarm shall be provided for non availability of any one of the control supply. MCBs shall be provided on incoming sides of suplies Control buses of two sections shall be connected through auto changeover scheme. L.E.D 's shall be provided for the indication purpose.

Isolation arrangement shall be provided on each panel to facilitate fault location and testing. Separate fuses shall be provided for spring charging motors, for indication lamps and for closing/tripping circuits of each cubicle. Metering Instrument & other components/Equipment specification Indicating Instruments( Ammeter, Voltmeter, Kilowatt hour meter :





- Square size : Incomer and sectionalizer - 144 sq. mm Outgoing - 96 mm square - Flush mounting : in front of the cubicle - Accuracy class : 1.0 - Ammeters shall be compatible with CTs of 5A secondary and read

actual currents. - For motor feeders ammeters shall have cramped scale after 1.2

times full load current and shall have red mark on full load value. Contactors:

Contactors shall break without damage 10 times rated current upto 100 amp rating and 8 times rated current for above 100 amp rating. Continuous current shall not exceed 2 amp and initial pick up shall be limited to 9 amp. Class of insulation shall be E or better. Drop out voltage shall be 45-65% of rated voltage and pick up shall be 85-110% contactor duty shall be AC3 unless otherwise specified in design paramters. Indicating Lamps:

- L.E.D indication shall be provided as detailed below:

- Colour : ON - RED

- OFF - GREEN FAULT/WARNING - AMBER TRIP HEALTHY - WHITE Control and Selector Switches:

- Control switches for circuit breaker ON/OFF control 3 position, spring return to neutral with lost motion devise and pistol grip handle.





- Other control and selector switches - stay put type with wing type

knobs.

- Auto/Manual selector switch shall be lockable Push Buttons:

- Rating : Continuous - 10 amps

AC 11 - 1.5 amps at 240V DC 11 - 0.5 amps at 220 V DC L/R - 40 mS

- Colour : Red - ON

Green - OFF Yellow - Test Red - Emergency P.B

Protective Earthing

- Continuous earth bus of minimum size 50 x 6 mm copper or equivalent aluminium/galvanised steel section, designed to carry the peak short circuit and short time fault current as specified.

- Provision at the bottom extending throughout the length of the board,

bolted/brazed to the frame work of each panel with an earthing terminal at each end for terminating external earth conductor including provision for termination of cable armouring at earth bus.

- Vertical earth bus for earthing individual functional units. - All non-current carrying metal work (including metallic cases of

instruments and other panel mounted components) effectively bonded to the earth bus.

- Hinged doors earthed through flexible earthing braid.





- Looping of earth connection resulting in loss of earth connection to

other devices when the loop is broken, not permitted. - Withdrawable units provided with self-aligning, spring loaded, silver

plated copper scrapping earth contacts of make before/break after type ensuring earth continuity from service to the test position.

Auto-Changeover Scheme Auto Changeover Scheme for Unit Aux. Supply In case of failure of unit transformer incoming supply, to be sensed by under voltage relay the incoming breaker of the de-energised section shall be tripped after a pre-set time delay. Through the normally closed auxiliary contacts of the tripped incoming breakers, the station supply breaker shall close provided the other section is healthy. The automatic transfer scheme shall be such that the automatic closing of the bus section can be done only once and in case the reserve breaker trips during auto-changeover, no further auto closing shall be permitted. Auto changeover shall not take place if the incomer breaker trips on fault. The restoration of power shall be manual.

The automatic transfer circuit shall be controlled over by an auto-manual change-over switch located in MCR. The bus section breaker shall be allowed to close only if there is no earth fault or O/C fault on affected section of the 415V switchboard busbars.

Breaker Handling Truck

- One for each switch board, for withdrawing the breakers from the

switch board.

- Height of platform adjustable to suit the levels at which the breakers are mounted.

- Adequate mechanical strength for handling the largest breaker.





- Guide rails and stops. their work is complete as per approval of the owner / consultant. 04.08 ELECTRIC MOTORS 04.08.01 Low voltage squirrel cage induction motors :

Constructional features:

- Frame sizes and ratings and other facilities as per IEC

- For motor frames upto 315, cast iron or steel construction body; for frames above 315,steel construction shall be used.

- Casing feet to be integral with the motor body.

- Degree of protection for motor, bearings and terminal box to be IP-55.

- Cylindrical shaft ends, unless otherwise specified - Shaft extension as per requirement.

- For motor of rating upto 5 kW, Ball bearings shall be used for both DE & NDE end. For ratings above 5 kW the DE end shall be provided with roller bearing and NDE end shall be provided with ball bearing.

- Bearings shall be suitable for running of motor in either direction.

Terminal box:

- Terminal box suitable dimension to receive copper cables and provided normally on the right side as viewed from drive side or on the top as per the requirement.

- Terminal box frame with opening for cable rotatable by 4x90 deg.





- A suitable earthing stud shall be mounted inside the terminal box.

- Terminal Box shall be suitable to receive the aluminium cables as given in Table-I.

- Extension of Terminal box as required shall be done to receive the

Aluminium cables to avoid cramping of the cables in the terminal box.

Cooling:

- Motors shall be of TEFC design

- Ventilation shall be effective irrespective of direction of rotation.

Quality of operation:

- Motors shall be dynamically balanced with full key on the shaft- end and fan.

- Vibration intensity shall be limited as per IS 4729. - Continuous noise level should not exceed 85 db A at a distance of

1.0 m from motor body Electrical design - Suitable for DOL starting

- Motors suitable for being switched on to a solid main even at phase opposition at a maximum residual voltage of 50% i.e. the motor shall be capable of withstanding 150% of the rated voltage.

- Motors capable to start and run-up at a minimum of 85% of rated

voltage at its terminals with the driven mechanism/equipment connected.

- Capable of operating satisfactorily at full load for 5 minutes without





injurious heating with 75% of the rated voltage at its terminals.

- Starting torque shall be not less than 160% of rated torque. - Starting current shall be less than or equal to six times the rated current.

- Motor shall be capable of withstanding locked rotor current for at least 5 seconds longer than the starting time at 80% voltage under rated load conditions.

- Continuous duty motors shall be capable of three equally spread starts

per hour under normal condition or two starts in quick succession from cold or one hot start, under rated load condition.

- All continuous duty motor (S1-100%) shall be of high efficiency to Eff 1 class as per IS 12615- 2004.

- Motors provided with class 'B' or class ' F' insulation. Permissible

temperature shall be limited to 120 deg. C in case of class'B'insulation and in case of class F insulation, permissible temperature shall be 130 deg.C as measured by resistance method. Class H insulation shall be considered in specific cases. Limiting temperature shall also be limited to 130 deg C in case of Class H insulation as measured by resistance method.

- Motors selected shall be of normal starting torque type, high starting

torque type, high slip type or stall torque type as required for the specific application.

- Four pole motors to be used for all general applications, unless

specific drive requirement or economy calls for other poles. Valve Actuators

- The actuator shall be designed for operation on 415V, 3 phase, 50 Hz system.

- The actuators shall be suitable for voltage frequency variations as indicated in Chapter Electrical design criteria.





- The actuators shall consists of motor, torque/ position limit switches, clutch, hand wheel, position indicator, space heater.

- The actuators enclosure shall be totally enclosed dust tight, water proof without the necessity of any canopy.

- Insulation of the drive shall be class `B'. - Two torque limit switch one for each direction and four for end of

travel limit switch (two for each direction) shall be provided. - Hand wheel shall declutch automatically when motor is energised. - Position transmitter, potentiometer type shall be provided for remote

indications wherever required. - Internal wiring shall be of 1.5 sq.mm copper wire, however, terminals

for external connections shall be suitable for 2.5 sq.mm - Motor data sheet for each type of motor actuator shall be furnished

alongwith internal wiring diagram, suggested control schematic and torque limit switches contact development.

04.09 UNINTERRUPTIBLE POWER SUPPLY(U.P.S.)

- A UPS of adequate capacity shall be provided for Control and instrument system of Units 1 to 6 . The UPS shall be a static type and shall have dual redundancy of electronic parts/system. UPS shall be ON LINE back up facilities

- Two nos. 110% capacity converters shall be provided which shall

consist of dry type transformer and rectifier panels.

- Output of converters shall be connected to DC bus and through rectifier DC battery supply shall also be connected to the above bus. Battery capacity shall be for 2 hour back up

- Two nos. 110% rated inverters shall be connected to DC bus and

output of inverters (IGBT based) shall be connected to AC bus of UPS.

- Tenderer to calculate the requirement/capacity of the system and





furnish alongwith the bid.

- UPS batteries shall be sealed maintenance free type (Lead Acid) and shall be suitable for site condition.

- All equipment shall be naturally air cooled.

- All active device shall be solid state.

- The nominal AC input supply shall be 415 V 50 Hz, 3 Phase. - A bypass static switch with transformer etc. shall be included to

provide continuity of supply in the event of UPS failure and transfer time shall be less than 1/4 cycle.

- For abnormal operating conditions alarm shall be provided in CR

panel and as well as on UPS Panels.

System shall be suitable for 125% rated output for 15 minutes 04.10 BATTERY ,CHARGER AND DC DISTRIBUTION BOARD 04.10.01 Codes & standard

03.07.07.01 IS : 266 Specification for sulphuric acid IS : 1069 Specification for water for storage batteries IS : 1146 Specification for rubber and plastic containers for lead acid

storage batteries IS : 1652 Specification for stationary cells and batteries, lead acid type

(with plant positive plates). IS : 3116 Specification for sealing compound for lead acid batteries. IS : 8320 General requirements and methods of tests for lead acid

storage batteries IS : 6071 Specification for synthetic separators for lead acid batteries

ANSI-C 37.90a Guide for surge withstand capability tests IS:5 Colours for ready mix paints.





IS : 694 PVC Insulated Cable for working voltages upto and including 100V

IS : 1248 Specification for Direct acting indicating analogue electrical measuring instruments.

IS:13947 Pt-1 Degree of protection provided by enclosures for low voltage switch gear and control gear.

IS : 13947 Specification for low voltage switch gear and control gear IS : 3231 Electrical relays for power system protection. IS : 3842 Application guide for Electrical relays for AC System IS : 3895 Mono-crystalline semi-conductor Rectifier Cells and Stacks IS : 4540 Mono crystalline semi-conductor Rectifier assemblies and

equipment. IS:6005 Code of practice for phosphating of Iron and Steel IS:6619 Safety Code for Semi-conductor Rectifier Equipment. IS:6875 Control switches (switching devices for control and auxiliary

circuits including contactor relays) for voltages upto 1000 VAC or 1200VDC

IS : 9000 Basic environmental testing procedures for electronic and electrical items.

IS:13703 Low voltage fuses for voltages not exceeding 1000 V AC, 1500VDC.

EEUA-45D Performance requirements for electrical Alarm Annunciation system

04.10..02 Scope and mode of operation

The battery system will include:

� DC 220V battery set (2 sets) � Identical automatic Float and float-cum-boost chargers 2 sets for

220V battery

� DC distribution switchgear ( 1 set with two sections) for each 220 V battery

� All interconnecting cables/wiring with connection accessories and





other required items to make the system complete.

� Complete battery maintenance equipment required for convenient and safe handling and preparation of electrolyte will be supplied with the battery bank. These will include but not be limited to items like syringe type hydrometer, mercury in glass thermometer calibrated 0 to 100oC, wall mounted holder for one hydrometer and one thermometer, syringe, level testing tube, 150 mm dia glass funnel, spanners, centre zero cell testing voltmeters 3-0-3 V, PVC apron, PVC gloves, PVC jug, battery impedance tester, etc

Mode of operation:

i. Normally the chargers connected to the battery will supply the DC

load and also keep the battery under float charge. On failure of supply from charger, the battery will be taken over without any interruption.

ii. When the battery requires boost charging, the charger will operate

on boost charge mode while the second battery will supply the DC load on float mode through changeover arrangement.

iii. The DC distribution switchgear will feed the power from the

charger/battery to the various consumers of the plant.

04.10.03 Battery and accessories

Nominal voltage is 220 V DC. The no. of cells will be chosen accordingly. Battery cell will be Plante type lead acid. Ampere hour capacity (minimum) will be as per requirements of the plant at 10 hours discharge rate. Each Battery bank shall be capable to cater the 220 V DC loads of Units 1 to 6 and emergency lighting loads of power house.

Following accessories will be supplied





� Battery stand � Cell booster for charging 1 to 5 cells � Copper cell connectors (5 nos.) � Spanner for cells � Bridging clamps for cutting out individual cells in the event of defect � First aid box

04.10.04 Battery Chargers

i. Float and Float cum boost chargers for battery will be comprised of

the following; a) Microprocessor based IGBT/thyristor based battery charger b) MCCB, line contactor and overload relay on the AC side c) Dry type double wound rectifier transformer with copper conductor

and class `B' insulation d) Filter circuit at the output e) MCCB on DC side f) Control and protection circuits

ii. In float mode, the charger operates with a constant voltage

controller and the output voltage of the charger will be maintained within + 1% of the set voltage for + 10% input AC voltage variation, or 0 - 100% load variation, or both occurring simultaneously. The output voltage required can be set externally through potentiometers in the range 90-120% steplessly.

iii. In boost mode, the charger will be suitable to operate in a constant

current as well as constant voltage mode with manual selector arrangement, controller suitable for two-rate charging. The charging current will be externally adjustable from 20% to 100% steplessly.

iv. Provision of charging with manual control of output voltage will also

be provided. Electronic current limit, adjustable between 85-105 percent of rated current will be provided. During boost charging, the charger will be cut-off as soon as over voltage occurs. Ripple





content in the charger's output voltage will not exceed 0.5% in float mode and 3% in boost mode.

vii. The supply to the charger will be at 415V + 10%, 50 Hz +3% and

-5% unless otherwise specified. viii. The following relays will be provided:

a) AC input supply to charger failure b) Earth fault c) Float bus over and under voltage d) Boost bus over voltage e) Boost over current for each charger circuit f) All relays will be in draw out cases and with mechanical hand reset

operation indicator.

ix. The following indications will be provided.

a) AC supply ON (for 3 phases separately) for each charger b) DC supply ON for charger c) Boost/float mode ON for charger d) Supply ON for each outgoing distribution feeder

x. Instruments for the following measurement will be provided;

a) AC input voltage and current of each charger (through voltmeter/ammeter selector switches)

b) DC output voltage and current of each charger c) Battery charging/drain current of each charger with necessary shunt d) Battery trickle charging current (through amplifier) e) DC bus voltage (through selector switch) to measure between

Positive to Earth, Negative to Earth & positive to negative. xi. Static type annunciation will be provided for the following;

a) AC supply failure to charger





b) Battery earth fault (+ve & -ve separately) c) Float bus over/under voltage d) Boost bus over voltage e) Boost over current for each charger f) Failure of thyristor/diodes for each charger g) Failure of blocking diode h) Output MCCB open for each charger i) Battery MCCB open j) Battery room exhaust fan OFF k) D.C.Voltage Low l) D.C.Voltage High m) A.C.Input Under Voltage

xii. One repeat alarm point for all above annunciations will be provided

to facilitate annunciation of "Fault in Charger" in control room. .

04.10.05 DC Distribution board i. The DC distribution board will have single bus bar arrangement.

The DCDB will be provided with all the instruments, AC/DC meters, indicating lamps, relays and other accessories.

ii. Each outgoing circuit will be connected to bus bars. Each outgoing

circuit will have MCCB. The no. of outgoing circuits will be as per the requirement plus 10 nos. for purchaser’s use and 20 % spare.

iii. Switch board will be floor mounting type sheet steel enclosed with

degree of protection IP 52 or better. Board will be compartmentalized design.

iv. All power wiring will be done through single core PVC insulated

copper wires/buses. All control wiring will be done through single core; PVC insulated copper wire of 2.5 sq. mm. All connections external to the panel/switch board will be terminated in suitable terminal blocks. Inter panel wiring will be only between terminal blocks.





04.11 CABLES 04.11.01 Cable Specification

Types of cables of following grades and general specifications shall be used taking into consideration the application requirements. All cables shall have FRLS (Fire Retardant Low Smoke) PVC compound for inner and outer sheath.

Type 1 : 11 kV (UE) XLPE Cables 11 kV (UE) heavy duty power cable, 3-core, with compact circular stranded (rm/V) copper. conductor with extruded conductor shielding of semiconducting material, XLPE insulated, with insulation shielding over individual cores consisting of extruded semiconducting compound followed by lapped semi conducting material and copper tape, cores stranded together with a holding tape provided with a common covering of extruded inner sheath, galvanised steel wire armoured and FRLS PVC outer sheath of type ST2 compound as per IS : 7098 (Pt-II)-1973 as ammended upto date. Copper screen shall be suitable to carry 1 kA E/F current for one second.

Type 2 : 1.1 kV, heavy duty power cable multicore with standard sector shaped (sm) or with compact circular stranded (rm/V) or circular stranded (rm) Aluminium conductors as applicable, PVC insulated type A suitable for 70 deg. C. operation, core stranded together provided with a common covering of FRLS PVC inner sheath of type ST1 PVC compound, galvanised round steel armoured and FRLS PVC outer sheathed of type ST1 PVC compound conforming to IS:1554 (Part-I) - 1976, as ammended upto date.

Type 3 : 1.1kV circular stranded (rm) annealed copper conductor, PVC insulated of type A PVC compound suitable for 70 deg.C operation,as per IS:5831 - 1970, cores stranded together provided with a common covering of PVC inner sheath, galvanised steel armoured and overall FRLS PVC sheathed of type ST1 PVC compound and multi-core to IS : 1554 (Part-I) - 1976,





04.11.02 Cable Selection

- In general, cables for LT drives shall be selected as per Annexure-I, however, size and type of cables for specific applications shall be selected giving due consideration for the following:

- Thermal heating effect/permissible current carrying capacity. - Voltage drop - Short time current/overload requirement - Protection system grading and short circuit current carrying capacity. - Ambient conditions - Cable grouping factors

In selection of the cable following ambient conditions shall be taken into

account.

Cables laid directly in ground in single way ducts or pipes buried underground.

- Thermal resistivity of soil : 150 deg.C cm/W - Soil temperature : 40 deg.C

- Depth of laying (to the : 75 cm for 1.1kV

highest point of cable or grade cables and top surfaces of ducts) 90 cm for HT cables

- Horizontal formation axial : 15 cm in case of spacing cables

laid directly in ground in a group and

approximately touching in case





of single way ducts or pipes. Cables laid in free air/in conduits in free air.

Ambient air temperature : 40 Deg.C & As specified for the respective shops. Cables laid in ventilated ducts/gallery

Ambient air temperature : 40 Deg.C.

The minimum cross sectional area for HT power cables shall be 185 sq.mm. The minimum cross-sectional area of the cables used in LT power circuits shall be 6 sqmm per core if with aluminium conductor or 4 sqmm per core if with copper conductor. Maximum cable size shall be 185 sq mm for motors and 240 sqmm for incomers to MCCs, PCCs etc. For power supply to moving mechanisms subject to vibrations, flexible copper cables preferably single core should be used. In these cases, a separate core should be provided for earthing. Cables used for circuits of tachogenerators, brakes, solenoids, field windings and secondary windings of measuring transformers shall be copper conductor with cross-sectional area not less than 2.5 sqmm per core. All control cables shall have copper stranded conductors except for mobile and portable equipment where control cables shall be of flexible type. Copper cables shall be used for all cranes/hoists. For control circuits, PVC insulated and FRLS PVC sheathed multicore cables with copper conductors having a minimum cross-sectional area of 2.5 sqmm per core shall be used. The number of cores may be standardized as 2,3,4,5,7,10,14,19,24.Each core of control cable with 7 core and above shall be numbered at every 1 meter intervals. In multi-core control cables, the following minimum reserve cores shall be kept at the engineering stage:

Upto 7 cores - One reserve core





10 cores - Two reserve cores 14,19 & 24 cores - Three reserve cores

Sequential length marking shall be provided in outer sheath of all power and control cables. Standard drum length for all types of power and control cables shall be offered. ISI marking at every meter of cable length shall be provided. Cores of multi-core control cables shall be serially numbered. For all cables, extra length of 2 metres will be left before jointing. Additional Tests on cable To prove the fire retardent low smoke characteristics, the following additional tests shall be conducted at works on any size of each type of cable namely, H.T/ power, L.T. power, control and instrumentation cables. Oxygen index test as per ASTM D 2863. Minimum value of Oxygen index shall be 30. Flammability tests on finished cable as per the requirements of IEEE-383 and IEC-332-1. Smoke generation by inner/outer sheath fire as per ASTM D 2843. The cables shall meet the requirements of light transmission of minium 40% after the test.

04.11.03 Cable termination & joints

Following type of cable termination and joints shall be used for XLPE cables in indoor and outdoor applications :





1. Tapex type 2. Heat shrinkable type 3. Pre moulded push on type

Tapex type system : The stress grading material shall be wrapped around the cable core, over lapping the edge of the outer conducting layer. The tape layer shall fuse together to form a compact rubber body around the stress grading material and cable core and thereby excert an active pressure on cable. Heat Shrinkable type system : The stress control and grading wherever necessary shall be by means of semi conducting heat shrinkable tubing. Environmental sealing between heat shrinakable material and cable surfaces shall be achieved by using hot melted sealants or adhesives. Where such sealents or adhesives shall be exposed to high electrical stress, same shall be track resistant type. Premoulded Push On type system : Premoulded refers to moulded Ethylene Propylene Diene monomer rubber components. Sealing between the premoulded push on material and cable surface shall be achieved by semi conducting pad which has cold flow properties. The termination and straight joints for HT/LT cables shall be supplied in kit form. The kit shall include all insulating and sealing material apart from conductors fittings and consumable items. Necessary devices required for termination and joints shall be provided.

04.12 MISCELLANEOUS 04.12.01 Illumination 1.0 Genearal





The lighting system inside and outside power house units are designed based on the desired minimum illumination levels recommended by IS and the practices followed in industries, architectural arrangement, building dimensions including mounting height, environmental considerations, ease of maintenance and reliability of the lighting distribution network.

2.0 Illumination will be provided in all premises of power house peripheral

lighting, area lighting, street lighting, etc within battery limit. The illumination system will include the following in required quantities;

� Lighting DBs � Light fittings with lamps � Lighting fixtures and accessories � Cables and wiring � Ceiling fans � Receptacles

� Switches � Conduits � Brackets � Hangers � Clamps � JBs

3.0 The illumination system shall be designed as per IS:3646-1992. The

minimum level of illumination, type of fittings, maintenance factor to be considered is as given below:

Area Type of Light Fittings& Lamps Lux level (min) Control room with false ceiling

Decorative mirror optic luminaire for recessed mounting with energy efficient CFL 2x36W of Philips type FBS 450/236 M2 HF (with MASTER PL-L 36W/840/4P ICT lamp) OR equivalent.

300

Conference room with false ceiling

Decorative mirror optic luminaire for recessed mounting with energy efficient T5 lamps 2x28W of Philips type TBS 669/228 D6 HF (with MASTER high efficiency TL5-

300





28W/840 lamp) OR equivalent. Office Room without False Ceiling

Surface mounting luminaire suitable for 2x28 Watt TL-5 lamp ( Philips model TCS 3502 XTL5 – 28Watt EB C5 or Equivalnt)

300

Civil Staircases of plant building

General purpose batten luminaire with energy efficient T5 lamps 2x28W of Philips type TMS 122/228 E HF (with MASTER high efficiency TL5-28W/840 lamp) OR equivalent.

100

Flood lighting Weather proof non integral type (integral type in case of high mast) flood light fittings suitable for 1x250/400W HPSV lamps of Philips type SNF 114 250/400W wide beam /narrow beam as per requirement OR equivalent.

70

Machine Hall Surface/Suspended type high performance integral open medium bay luminaire with prismatic diffuser comprises of polycarbonate reflector & separate control gearbox complete with 1 No. HPIP 250 Watt Lamp etc as required (Philips Model HPK 205 1xHPI – BU250W PR or Similar)

200

Electrical rooms without false Ceiling

Surface mounted / Suspended luminaires suitable for T5 lamps 2x28 W of Philips type TPS 814/228 D8 HF/ TPH 824/228 I HF (with MASTER high efficiency TL5- 28W/840 lamp) OR equivalent.

200

Battery Room Surface mounted luminaire with energy efficient T5 lamps 2x28Watt of Philips type TMS 122/228 E HF with GMS 122 /228 Reflector (With MASTER high efficiency TL5 – 28 W/840 lamp) OR Equivalent

100





Toilets General purpose batten luminaire with energy efficient T5 lamps 1x28W of Philips type TMS 122/128 HF (with MASTER high efficiency TL5-28W/840 lamp) OR equivalent.

100

In addition to above following light fittings shall be used as per architectural requirement / as per requirement 1. Recess mounting direct lighting luminaire suitable for Compact

fluorescent lamps PLL 36 Watt anti glare, D-6 optics, pearl white wing (Philips model FBS 580 2xPL – L36W EB TOD DF-WH or Similar)

2. Recess mounting accent light suitable for 1 no. 50 Watt halogen lamp (Philips Model QB 026 XMA/ 50 Watt/12GU5 3WH or Similar)

3. Surface mounting type mirror luminaire suitable for 13 Watt CFL lamp (Philips model No. 13W / 34094 /11/86 or Similar)

4. Indoor Bulk head luminaire suitable for 1no. 9 Watt CFL lamp complete with all accessories like reflector, protection guard, holders (Philips model FXC 101 1xPL-5 Watt or Similar)

The light fittings shall be complete with all accessories like electronic ballast, reflector etc. External area lighting including street/road lighting / tower lights shall be fed from Out door type Feeder Pillar located at suitable places. Automatic switching ON/OFF of these circuits shall be done through timers. Flood light towers shall be fed through 415/240V, 3 phase, 4 wire circuit with individual fittings distributed at 240V, single phase, with control and protection located at bottom of each tower. DP MCB in a sheet steel box shall be provided near each fitting to facilitate removal of lamp in off position.

4.0 Lighting Power distribution

The distribution of lighting power supply for the individual areas within battery limit shall be done at 415V, 3 phase, 4 wire bus system through Main Lighting Distribution Boards (MLDB). The outgoing feeders of the MLDB shall feed the required numbers of Sub Lighting Distribution Boards (SLDB)





for lighting. Each SLDB shall receive power at 415V AC, 3 phase, 4 wire and distribute it into 240V, 1 phase circuits for connection to the lighting fixtures and 240V receptacles. The SLDBs shall be located in the rooms, bays, etc preferably near entry/exit. covering the respective zone. The SLDBs shall be located in the electrical rooms in the respective area. Separate neutral chamber shall be provided for neutral busbar inside SLDB.

5.0 Control room illumination -

Control room illumination shall be provided with decorative fittings mentioned in above table flushed to the false ceiling. Decorative type two numbers 60 watt light fittings shall also be provided as emergency lights. Lux level of control room shall be 400. Light fittings layout and their type shall be approved during detail engineering. Cables/Wiring and switches - In control room, wiring shall be above the false ceiling and PVC conduits shall be used on side walls. 3 nos, 240V, 3 pin socket outlets with plug tops and switches shall be provided. In switch board 16 Amp MCB as incomer shall be provided and decorative type ON/OFF switches shall provided for each fitting.

6.0 Emergency lighting

Dedicated & separate Emergency lighting MLDBs & SLDBs shall be provided for power house indoor & outdoor areas as per requirement to feed emergency lighting circuits.

Emergency MLDBs shall be fed through DCDB so that in case of failure of normal power also the Emergency SLDBs can be powered & Emergency lights can continue to glow. 20% lights shall be connected through Emergency SLDBs

7.0 Outdoor lighting

Flood lights for area lighting shall be mounted on towers/poles or building structures. Tower height shall be kept to an average of 22m.





Street/road lighting and boundary wall lighting shall be provided with HPSV/fluorescent lamp fittings mounted on poles of 9m to 11m height. For street lighting, necessary control gear shall be provided for reduced voltage running during off peak traffic for energy conservation .

8.0 Illumination of other areas

In existing power house indoor and outdoor illumination has been provided however at certain locations within battery limit additional fittings needs to be provided during erection stage to facilitate the work.

9.0 SPECIFICATION OF MAIN LIGHTING DISTRIBUTION BOARD (MLDB) A. General

Type : - Metal clad - Shall be suitable for 415/240V, 3

phase and neutral. - Non draw out type

Construction : - Modular Construction.

- Fully Compartmentalized with metal/ Insulating material partition.

Enclosure class : - IP52 .

Type of execution : - Single front

Mounting : - Floor mounting - Free standing with ISMC 75

Installation : - Indoor





B. Constructional Features 1.0 Sheet Steel Thickness : - 2 mm for load bearing members.

- 1.6 mm for non load bearing members.

2.0 Cable entry

Incomer :- Bottom cable entry. Outgoing :- Top / Bottom cable entry.

3.0 Design

- Separate bus alley and cable alley on opposite side of the

outgoing modules - All the components shall be accessible from front - Each module to have covering at the bottom.

- Minimum 200mm shall be left blank at bottom through the length

of panel - Interlocking & protection : - Module door interlocked with

main powerIsolating devices.

- Power circuit isolation device to have Pad locking in the OFF position with

door closed. - Operating Height - Minimum : 300 mm Maximum : 1800 mm

- Gland Plate - Undrilled removable bottom gland plates (3 mm thick)

- Miscellaneous - Neosprene rubber gasket

shall be provided for all the doors , removable covers & between adjacent covers .





- Lifting hooks for the panel

- Doors shall have concealed hinges

.

. - Earthing - - Two separate earthing terminals shall be provided.

- Bolted joints with tooth spring washers for good earth continuity.

- Earth bus to run in all cable alley of the panel .

- Limiting dimensions - Width of Module :- 500 mm (min) - Width of Cable alley :- 300 mm (min) - Depth of MLDB :- 600 mm - Height of MLDB :- 2400 mm (max) - Width of Bus alley :- 300 mm (min) - Height of module :- 300 mm (min)

C. Busbars (i) Main horizontal & vertical busbars

1.0 Arrangement - Three phase & neutral. Bus Bar chamber on the

top.

2.0 Material - High conductivity electrolytic aluminium alloy confirming to grade E91E as per IS-5082 –

1981.

3.0 Phase Busbar Rating - Minimum rating shall be same as incomer MCCB rating

- Shall be able to carry continuously the connected load (considering all derating factors) plus a 25% margin .

4.0 Neutral Busbar Rating 50 % of phase busbar rating 5.0 Short circuit rating 50 KA for 1 sec. 6.0 Busbar configuration Red-yellow-blue from front to back or top to





bottom or left to right as viewed from front. 7.0 Busbar insulation Heat shrinkable PVC

- R,Y,B coloured sleeves for phases - Black for neutral.

8.0 Max. temp. rise of bus - Not to exceed 35 deg. C. above ambient of 50

deg.C.

9.0 Air clearance for bare busbar Phase to phase :- 25.4 mm (minimum) Phase to earth :- 19.0 mm (minimum)

10.0 Joints and tap off points - Busbar joints and tap off points shall be shrouded and bolted ( with cadmium coated bolts with plain and spring washers and locknuts).

(ii) Earth bus 1.0 Material GI/AL at bottom through the panel length. 2.0 Size Minimum 50 x 6 mm with extension at both ends . (iii) Control bus 1.0 Material Copper. 2.0 Size Minimum 25 x 3 mm or equivalant. D. Insulation level 1.0 Rated insulation voltage 1100 V 2.0 Impulse withstand voltage 4 KV as per IS-13947 (Part I) 1993 3.0 One minute power 2.5 KV for power circuit & 500 V for control circuit

frequency withstand voltage





F. Feeder arrangement Incomers 1.0 Isolating Equipment 3 pole microprocessor based MCCB (for rating

upto 630 A) with LSIG protection

2.0 Quantity Two incomers & One Bus coupler 3.0 Auto changeover - Through Power contactor logic with suitable

timer and auto manual selector switch. - Power Contactors of AC3 rating same as

incoming MCCB

4.0 Indication Lamps LED type indicating lamps for :- - MCCB ON/OFF/TRIP. - Power ON R / Y / B .

5.0 Meters - 144 sq.mm size voltmeter - 144 sq.mm size ammeter - MFM with communication features.

6.0 Current transformer 3 numbers for metering . Outgoing feeder arrangements 1.0 Circuit breaker Three pole microprocessor based MCCB with

LSIG release.

2.0 Indications ON/OFF/TRIP indication lamp. G. Panel wiring Power / current 1.1Kv grade single core, black colour PVC

transformer circuit insulated , stranded copper conductor of.





minimumsize 2.5 sq.mm 10.0 SPECIFICATION OF SUB LIGHTING DISTRIBUTION BOARD (SLDB) A. General :-

Type : - Metal clad - Shall be suitable for 415/240V, 3

phase and neutral.

Construction : - Totally enclosed. - Dust & vermin proof. - Welded back and sides

Enclosure class : - IP54 . - IP 55 (with canopy) for outdoor

installation

Type of execution : - Single front

Mounting : - Wall mounting .

Installation : - Indoor / Outdoor (with canopy)

B. Constructional Features :- 1.0 Sheet steel CRCA, Thickness 2 mm . 2.0 Cable entry

- Incomer :- Bottom cable entry. - Outgoing :- Top / Bottom cable entry.

3.0 Design

- One Incomer and outgoings . - All the components shall be accessible from front - Access to the operating handle of the incoming isolating switch

shall be from the front of the cubicle without opening the front





door. - Operating knobs of outgoing MCBs shall be accessible only after

opening the front door of the cubicle. - Protective insulated cover plate (3 mm thick bakelite sheet ) shall

be provided inside the cubicle to shroud all the live parts .

4.0 Gland plate :

Undrilled detachable gland plates (3 mm thick) shall be provided at the top and bottom with suitable gaskets for cable entry

5.0 Earthing

Two separate earthing terminals shall be provided

04.12.02 Power Distribution Board (PDB) / ACDB / DCDB

- 415V, 3 phase, 4 wire, 250A, 40 kA (short time rating for 1 sec.) indoor type.

- Board shall be single front, metal clad, front matched, dust and

vermin proof fully compartmentalized and extensible on both sides, IP51 type enclosure.

- Shall have base channel of size ISM 75.

- Shall have isolated busbar chamber for main busbar at the top, running through out the length of the board. Chamber shall have removable cover.

- Cable alley shall have sufficient space for aluminium power cables

and bottom cable chamber shall be left free completely isolated from the vertical busbars.

- Busbars shall have same cross section through out the length .

Rating of the neutral busbar shall be 50% of the main busbar. Earth bus bar shall run in bottom chamber throughout the length of the





panel.

- The number of PDBs and their locations shall be decided based on consumers and shall be finalised during drawing approval stage.

- Generally all boards will have following feeder arrangement :

• Incomer - 250A load break switch

• Outgoings - 32A - 4 nos. MCB (TPN)

16A - 4 NOS. MCB (TPN) other as per the need of tenderer.

DCDB shall have two incomers with ammeter, voltmeter, & in outgoing one of each type of feeder shall be provided as spares.

04.12.03 Local Control Stations

- Near all drives local control stations shall be provided.

- Sheet steel construction, dust and vermin proof, wall/structure mounting.

- Control switches, push buttons and indication lamps mounted on front

hinged gasketted and lockable door.

- Suitable knockouts with glands on the bottom or top cover for cable entry.

- Terminals to be suitable for 2 cores of 2.5 sq.mm conductors with

20% spare terminals.

- Readily accessible shrouded terminals.

- Wiring with extra flexible wires.

- Stop push button to be lockable type with mushroom head.





- Inscription in English on corrosion resistant metal strips.

- Enclosure conforming to IP-54 class for indoor and IP55 with canopy

for outdoor.

04.12.04 Erection, installation accessories

All support structures required for cables, busducts and for electrical equiment including conduits, inserts, shall be provided to complete the erection job in all respect. Cable tag markers, clamps, sealing compound, pull boxes, marshalling boxes etc. shall be considered as part of the tenderers scope.

04.12.05 Other items

- All required safety items like rubber mats in front of LT board, shock treatment chart, Two nos. first aid boxes shall be provided in each electrical premises.

04.13 220kV Switchyard Bay Extension General

The supply of equipment and services covered by this specification shall include, but not be limited to, the following :

1. 220 kV SF6 breakers 2. 220 kV isolators and earth switches (all types as specified and as

per existing bays) 3. 220 kV CTs 4. 198 kV Lightning arrestors 5. Control and protection panels for the switchyard bay/equipment 6. Main bus conductors 7. Bay bus conductors 8. Insulators 9. clamps and connectors 10. Marshalling box 11. Complete structural work within battery limit including supply and





erection of all GI Structures, bus work and gantries 12. Complete civil works for the above including foundation, cable

trenches, Roads, Boundary wall, etc 13. Complete earthing and shielding system 14. All hardware including jumpers, connectors, etc. as per requirement 15. Any other equipment/systems required for smooth functioning of the

switchyard bays/equipment 16. DC distribution board as per requirement 17. AC distribution board as per requirement

18. Lighting Distribution Board as per requirement 19. HT & LT power and control cabling including their termination at

both ends and cable accessories 20. Cables other than power and control cables 21. Power socket cabinet and lighting cabinet 22. All erection materials, required during erection of various equipment

under scope of tenderer 23. Safety items

220 kV SF6 CIRCUIT-BREAKER

The 220 kV circuit-breaker located in the outdoor switchyard shall be outdoor, SF6, electrically operated, remote controlled, trip free design, complete with local control, operating mechanism with all associated auxiliaries.

220 kV SF6 circuit breaker operating mechanism shall be pneumatic type with individual compressor. The compressor mechanism shall be provided with AC motors.

Circuit breakers shall be totally restrike-free under all duty conditions and shall be capable of performing their duties without opening resistor.

Circuit breaker shall be capable of making and breaking any fault currents up to and including those specified without any undue strain. Interrupting capacity for short line faults shall not be less than the rated rupturing capacity for terminal faults.

The circuit breaker shall be capable of;





• Breaking the steady and transient magnetising current of transformer of rating shown in single line diagram • Breaking line charging current as per IEC 56-2, 1987 with a temporary

over-voltage of 1.5 p.u. without the use of opening resistors • Breaking inductive currents of 1 to 10A without switching over-voltage

exceeding 2.3 p.u. • Breaking 25% of the rated fault current at twice rated voltage under phase

pposition condition • Clearing short time faults (Kilo metric faults) with source impedance behind bus

equivalent to specified symmetrical fault current.

The circuit-breaker shall have specified current ratings and shall be capable of making and breaking the specified fault current. No part of the circuit-breaker or any other part of the equipment carrying the fault current or any supporting structures shall be unduly strained or damaged when making or breaking fault current up to and including that specified.

All current carrying parts of the circuit-breaker shall be of adequate size. Are control devices shall be capable of rapidly and effectively extinguishing the arc with negligible stresses on the enclosure. The circuit-breaker shall satisfactorily interrupt transformer magnetizing current, line charging current and short-line faults.

Each circuit-breaker shall operate as one complete 3-phase unit with minimum vibration. It shall be possible to make independent adjustments of each phase unit. The arrangement shall allow for easy access to all contacts for inspection, repair and replacement. Insulating barriers and arc control devices shall be of approved material not affected by tropical climate.

Constructional Features

All making and breaking contacts shall be sealed and free from atmospheric effects. The contacts shall be permanently under pressure of SF6. The gap between open contacts shall be such that it can withstand the rated dielectric stresses at zero gauge pressure of SF6 gas due to its leakage.





Main contacts shall be the first to open and the last to close so that there will be little contact burning and wear. Arcing contacts shall be the first to close and the last to open and shall be easily accessible for inspection and replacement. Main contacts shall have ample area and contact pressure for carrying the rated current and the short time rated current of the breaker without excessive temperature rise which cause pitting or welding. Tips of arcing and main contacts shall be silver plated or have a tungsten alloy tipping.

Operating mechanism The operating mechanism of outdoor circuit-breaker shall be housed in weather-proof and dust-tight sheet steel cabinet with padlocking facilities. Suitable space heaters with automatic thermostat control and ON / OFF switch shall be provided inside the cabinet. The cubicle shall be complete with control circuit isolating switch, lockable stay-put type local / remote selector switch to select local or remote electrical control of breaker, pushbuttons for local electrical OPEN / CLOSE as well as manual tripping operation, ‘ON’ and ‘OFF’ position indicators, operation counter, 3-pin, 240 V, 5 A plug socket with ON / OFF switch, necessary number of auxiliary contacts for protection, interlocking and signaling purposes suitably wired and terminated in control cable terminal board with 10% spare terminal, provision for cable entry for multi-core, PVC insulated, PVC sheathed and armored, power and control cables etc.

Operating mechanism shall be of electro-pneumatic, electric motor-wound spring charged type. Failure of any auxiliary spring shall not prevent tripping and shall not cause trip or closing operation of the power operated closing devices.

Means shall be provided for manual operation of the breaker under emergency or for testing and adjustments. Only well tried-out and robust operating mechanism which is proved and tested for frequent operations shall be provided. Anti-pumping and trip-free electrically and either mechanically or pneumatically under every method of closing (except during manual closing for maintenance ) shall also be provided. Trip circuit healthiness shall be continuously monitored and in the case of fault, an alarm shall be generated.

The mechanism shall be suitable for remote control from the electrical control room and electrical tripping by shunt trip coils. A local control switch with locking arrangement shall be provided for each breaker for local operations i.e. tripping





and closing during maintenance, test etc. It shall be possible to trip the breaker even in the event of auxiliary supply failure. Local/remote selector switch shall be provided in the mechanism cabinet. No. of tripping coil shall be two.

Breaker shall be interlocked to prevent remote operation when the selector switch is in the local position. Provision shall be provided for individual pole closing/opening for maintenance purpose shall be provided.

Cabinet for operating mechanism and its accessories shall be of IP-55 protection with pad-locking facility and suitable space heaters with automatic thermostat control.

Closing circuit to operate correctly from 80% to 120% of the rated control voltage. Each circuit-breaker shall have duplicate shunt trip coils. The trip coils shall be

designed to operate satisfactorily when the voltage at the terminals of the shunt trip coils is between 50% and 110% of the specified control power supply voltage.

Following features shall be provided in SF6 Gas Circuit Breakers;

• There should not be any condensation of SF6 gas on internal insulating surfaces

• In the interrupter assembly, absorption filters shall be provided for absorbing

gaseous SF6 decomposition products resulting from arcing and for limiting residual moisture content.

• Each pole shall form an enclosure filled with SF6 independent of the other two

poles and the pressure of each pole shall be monitored and regulated by individual pressure switches.

• Double O-ring seals with test holes for leakage test of the internal seal shall be

provided on each static joint. • Shall include facilities for remote low pressure/density alarm over suitable

temperature compensated monitoring devices when SF6 gas pressure/density of any pole falls below a predetermined value.





• Provision shall also be made for automatic tripping of the breaker and to prevent further breaker operation if the pressure/density decreases to a value below which the breaker cannot perform satisfactory operation at the specified rating.

• The position of vents, diaphragms and pressure relief devices shall be so

arranged to minimise danger to the operators in the event of gas or vapour escaping under pressure.

• Sufficient gas shall be provided to fill all the circuit breakers plus an additional

20% of the quantity to compensate for losses.

Circuit-breaker shall be provided with necessary auxiliary switches for indication, control, interlocking, protection or other purposes. Four spare sets of auxiliary contacts, six normally closed and six normally open, shall be left free in each unit wired up to the control cable terminal board. The auxiliary contacts shall be mounted in an accessible position and the design of the contacts shall be such that they can be easily converted from normally open to normally closed type and vice versa.

The circuit-breaker shall be of single pressure puffer type and shall consist of three separate identical phase units linked together for simultaneous operation of all three phases. The circuit-breaker shall have adequate hermetically sealed are quenching and operating system as well as gas-tight and arc-proof bushings. All relevant devices for pressurising, controlling and monitoring the gas pressure shall be provided with facilities for remote alarm over suitable temperature compensated monitoring devices when SF6 gas pressure / density of any pole falls below a predetermined value. Provision shall also be made for automatic tripping of the breaker and to prevent further breaker operation if the pressure/density decreases to a value below which the breaker cannot perform satisfactory operation at the specified rating. The circuit-breaker shall be provided with such safety devices as gas density monitor for SF6, pressure switches to block closing / opening / re-closing in the event of low pressure, phase discrepancy control, antipumping device and mechanical close interlocking.

Operation of circuit-breaker shall comprise pneumatic controlled mechanism. The mechanism shall be complete with all accessories as required. Each mechanism





shall be so designed as to enable a continuous sequence of circuit-breaker opening and closing operations.

The various parts forming the operating mechanism shall be of robust construction and carefully fitted so as to ensure free and definite operation. The design shall be such as to reduce mechanical shock to a minimum and to prevent inadvertent operation due to vibrations or any other causes.

Insulators/bushings Insulators/bushings shall be of either oil filled condenser type, hermetically sealed to prevent ingress of moisture and with leak proof magnetic indicator at the top to indicate oil level or polycone or solid core type or SF6 gas filled depending upon application. Insulators/bushings shall be free from radio interference. All iron parts shall be hot dip galvanized and all joints shall be airtight.

All current carrying contact surfaces shall be silver plated. Silver plating shall not be less than 25 microns in thickness.

Sulphur Hexafluoride Gas ( SF6 Gas ) SF6 gas shall comply with IEC : 376 and be suitable in all respects for use in the switchgear under the operating conditions. Means shall be provided for treating the SF6 gas by the use of desiccants, driers, filters etc to remove impurities in the gas. These shall be provided as permanent facilities. Portable plant for filling and evacuating the SF6 gas, shall be supplied. This shall include all the necessary devices for measurement of moisture content of SF6 gas and gas cylinders of adequate capacity for temporarily storing the evacuated SF6 gas. Suitable SF6 gas pressure monitoring device to give “Low Pressure Alarm” if SF6 gas pressure falls to a predetermined value. If pressure falls further, it shall block the breaker operation at certain value.

Technical Particulars of 220 kV Breaker 1. Type : Outdoor 2. Construction : Three identical single pole units linked





Together for simultaneous operation

3. Arc quenching medium : SF6 gas 4. Standards : IEC Publications 56 - BS116 & IS:2516 5. Rated voltage, kV (rms) : 245 6. Rated frequency, HZ : 50 7. Current rating, A : 2000 A 8. Number of poles : Three 9. Continuous current : As per SLD 10. Rated short circuit capacity : 40 kA for 3 sec 11. Rated peak withstand capacity : 105 kA 12. Pole discrepancy relay : Required 13. Rated operating duty cycle : O-0.3 sec - CO - 3min CO as per IEC-561987 14. System neutral earthing : Effectively earthed Operating mechanism 1. Type : Electro-pneumatic with electrical and

mechanical trip free device

2. Number : One per 3 - pole group/One per pole 3. Trip coil and closing voltage : 220 V DC 4. ON/OFF indicator : Mechanical as well as electrical





5. Emergency tripping mechanism : Mechanical 6. Anti pumping relay, operation ctr : Shall be provided 7. Local control panel, L/R S/S : Shall be provided

220 kV ISOLATOR (DISCONNECTING SWITCH) The isolators shall be outdoor, triple-pole, off-circuit, fault make, horizontally mounted, gang-operated and double-break type, designed, manufactured and tested as per IS:9921. The switches shall be center post rotating type. The switch contacts shall be high pressure, self aligning, self-cleaning, adjustable type, made of corrosion resistant copper alloy and silver plated. The switch blades shall be one-piece, corrosion resistant, copper alloy. The isolators shall be electrical motor operated with provision of local manual operation also. All isolators shall have provision for padlocking both in open and closed position. Isolators shall be capable of carrying rated current continuously as well as specified short-circuit current for the duration stipulated, without causing mechanical damage to any part and undue temperature rise damaging the insulation. Isolator shall be suitable for interrupting small inductive and capacitive currents such as those, which occur while disconnecting lines at no-load, busbars/voltage transformers under energized condition. Isolators shall be electrically interlocked with the associated breaker and earth switches to prevent their operation when the breaker is in closed position. The isolators shall be complete with supporting insulators, adjustable double point arcing horns, galvanised steel bases, operating down rod of requisite length, phase and earthing terminals etc. The operating mechanism shall be housed in a weather-proof and dust tight sheet steel cabinet with padlocking facilities. Suitable space heaters with automatic thermostat control shall be provided inside the cabinet. The cubicles shall be complete with control circuit isolating switch, lockable stayput type local / remote isolator, push-buttons for local electrical control of isolator , push-buttons for local electrical OPEN / CLOSE operation, ON and OFF position indicators, 3-pin, 240 V, 5. A plug socket with ON-OFF switch, necessary number of auxiliary contacts for protection, interlocking and signalling purpose suitably wired and terminated in control cable





terminal board with 10% spare terminals and provision for cable entry for multi-core, PVC insulated, PVC sheathed and armoured, power and control cables etc. Necessary provision shall be made for disconnecting the motor control circuit as well as the motor drive from the linkage mechanism in case of manual operation. All the interlocks shall be of fail - safe type. Suitable individual interlocking coil arrangements shall be provided. The interlocking coil shall be suitable for continuous operation from DC supply to the voltage variations stipulated. Isolators shall be able to bear on the terminals the total forces including wind loading and electrodynamic forces on the attached conductor without impairing reliability or current carrying capacity. Where required, isolators shall be provided with single or double earthing switches as specified and as per existing bays. Types of isolators shall also be as per existing bays and as specified in the specification. Following types may be applicable here;

- Isolators (normal) with two numbers earth switches - Isolators (normal) with one number earth switch - Isolators (normal) without earth switch - Isolators (tandem) with earth switch - Isolators (tandem) without earth switch

Tenderer shall design as per requirement and include the isolators/earth switches accordingly. The earthing switch shall have independent operating mechanism with suitable mechanical interlock so that it will not be possible to operate the earthing switch with the isolator in CLOSE position and vice versa. The earthing switches shall be manually operated and single-break type. Earthing switches to be provided on both sides or on one side of isolator, as per requirement, forming an integral part of the isolator. Earthing switches shall be only locally operated and shall be power operated but interlocked with the isolator. Earthing switches shall be able to carry the same maximum fault current as the main blades of the isolators and shall be able to withstand the same dynamic stresses. Each





earth switch shall be provided with flexible copper braids for connection to ground mat. These braids shall have the same short time current carrying capacity as the earth blade. Following features shall be provided for isolators;

• Triple - pole, off-circuit, fault make, horizontally mounted, gang operated, suitable for outdoor installation, in open yard · Centrally rotated, double break type with contacts moving in horizontal

• Common actuating mechanism shall be provided for all the poles. • Single pole units shall be interchangeable. • Supply shall be complete with supporting insulators, adjustable double point

arcing horns, galvanized steel bases, operating down rod of requisite length, phase and earthing terminals etc.

• Switch contacts shall be of high - pressure self-aligning, self-cleaning, adjustable type, made of corrosion resistant copper alloy and silver-plated.

• Contact pressure shall be released before any movement of the blades in the opening direction takes place and shall be applied after the closing travel is completed.

• Sufficient wiping action to make contacts self cleaning

Operating Mechanism of isolators shall have following features;

• Motor (3 phase, 415V, 50 Hz) operated including reversible starter cum hand operated.

• Shall be suitable for remote and local electrical operation with provision for

manual operation in case of necessity • Each pole of isolator shall have individual drive for main blades and earth switch.

The operating mechanism of the three poles shall be well synchronized and interlocked.

• Operating mechanism and its controls shall be so designed that under no

circumstances the travel of the switchblades is interrupted before it reaches the fully closed or open position.





• Signaling device for all poles both for closed position and open position for remote as well as local indication.

• Housing for the operating mechanism and its controls shall be of sheet steel,

weather and dust-proof construction with rubber gaskets conforming to enclosure protection class IP-55, and with padlocking facilities.

• Suitable reduction gearing shall be provided between the motor and the drive

shaft of the isolator.

• Shall be complete with a quick-acting electromechanical brake on the higher speed shaft to effect rapid braking.

• Limit switches shall be provided on the isolator shaft, within the cabinet, to sense

the open and closed positions of the isolator.

• Space heater with thermostat, panel illumination lamp, 240 V socket in local control panel.

Technical Particulars of Isolators 1. Type of isolators : Outdoor duty, centre post rotating blade vertical plane 2. Pole : 3 pole 3. System Voltage Nominal : 220 kV

Rated : 235 kV

4. Short time rating : 40 kA for 3 sec 5. Peak short time current : 105 kA 6. Rated current : 2000 A 7. Standard : IS 9921





8. Operating mechanism : Motor operated/manual reversible starter 9. Earth switch : Hand operated 10. Control voltage : 220V DC 11. Auxiliary supply : 240V AC 12. Auxiliary supply for motor : AC 415V 13. Standards : IEC-129/IS:1818, IS-9921-1985 14. Installation : Outdoor Required NO/NC auxiliary contacts of isolator shall be provided along with 20 % spare contactor. 220 kV CURRENT TRANSFORMER Current transformer shall be of electro-magnetic wound type, dead tank type, single- pole, separately mounted, hermetically sealed, oil filled units, designed, manufactured and tested as per IS:2705. Bottom tank shall be made of GI. The current transformers shall be complete with bushing insulators, adjustable double point arcing horns, oil gauge, pressure release device, nitrogen filling valve and cover, spark gaps, pressure release device, nitrogen filling valve and cover, spark gaps, suitable phase and earthing terminals, power factor testing terminals, drain valve, lifting lugs, rating and diagram plate, secondary terminal box etc. Explosion vent provision at top shall be there to minimize the destructive effect on surrounding equipment in event of any CT bursting. The current transformer shall be suitable for instruments, meters and relays offered as well as burden of secondary leads. Knee-point voltage, resistance and magnetizing current of class PS cores of CTs shall be suitably matched with the requirements of relevant relays offered and secondary leads used. The instruments security factor of metering cores shall be such as not to cause any damage to the related meters and instruments in the event of system fault current flowing through the primary.





The current transformer shall be provided with weather-proof and dust-tight sheet steel secondary terminal box complete with secondary terminals, shorting links, entry and termination of multi-armoured control cables etc. All CT metering cores shall be of 0.2 accuracy class. The technical parameters of the current transformer shall be as follows: Design Outdoor single-pole, electro-magnetic wound type

current transformer to be mounted on steel structures and suitable for short-time rating of 40 kA for 3-secs. and dynamic current of 105 kA peak, complete with all associated fittings and accessories.

Standard followed IS:2705

Ratio, accuracy class and VA burden

As per single line drawing enclosed

198 kV LIGHTING ARRESTORS LA shall be designed to provide maximum protection against over voltages occurring during switching of unloaded transformers against lightning and switching surges. Lightning arrestor shall be station class, heavy-duty, gapless, zinc-oxide type for use on solidly grounded system. LA shall be self-supporting type in single-pole assembly for line to earth connection. The dismountable units of the arrestors shall have the characteristic elements hermetically sealed under dry air or inert gas. The isolator shall be designed, manufactured and tested as per IS:3070 (Part-1). The installation shall be complete with line and earth connections, operation counter, leakage current indicator and other accessories and devices, including grading rings for improving voltage distribution. The discountable units of the arrestors shall have the characteristic elements hermetically sealed under dry air or inert gas. The lightning arresters shall be fitted with pressure relief devices and arc diverting ports suitable for preventing shattering of porcelain housing and providing path for the flow of rated fault current in the event of arrester failure. Grading corona rings shall be provided on each complete arrester unit as





required for proper stress distribution. Magnetic blowout coils shall also be provided for effective extinction of power frequency follow current. The insulator housing of the arrestor shall be made of brown glazed, wet process, electrical porcelain, free from all manufacturing defects. Spacers for and non-linear resistor elements or non-linear resistor blocks shall be of ceramic material. These shall be provided in such a way as to obtain robust construction, with excellent mechanical and electrical properties even after repeat operations. The grading network should contain both capacitors and non-linear resistors. Uniform voltage distribution should be maintained under all service conditions. Following fittings and accessories shall be provided along with LAs;

• Discharge counter with ammeter • Guarding rings • Pressure relief device • Supporting structures • Mounting insulators • Clamps and connectors on arrestor terminals : Suitable for existing conductor • Insulating bases having provision for bolting to flat surface of structure.

Technical Particulars 1. Standards : IEC 99-4/IS:3070-1993 for LA IS 5621-1980 for LA housing 2. Service : Outdoor in open yard 3. Class : Station class heavy duty 4. Type : Gapless nonlinear resistor 5. Nominal system voltage : 220 kV 6. Max. cont. op. voltage kV (rms) : 198 kV 7. Nominal discharge current rating : 10 KA





8. Standard : IS:3070 (Part-I) BUSWORK The overhead busbars / jumpers shall be swing type comprising aluminum conductor steel reinforced (ACSR) 54+7/3.18 “ZEBRA”. ACSR conductors shall be used for both Main bus-I and Bus-II . The sizes of the conductors shall be adequate to carry the required continuous current as well as to withstand the specified short-circuit currents. ACSR conductors shall conform to IS:398 The busbars shall be supported with fully insulated support having adequate mechanical strength as required for the specified short-circuit level. Necessary bus-supports, jumpers, connectors, insulators, structural steelwork, hardware as required shall be supplied with the busbars to make the installation complete in all respects. Provision shall be made in the busbar installation to allow for expansion and contraction of the busbars. The busbar system shall be so designed as to prevent any visual corona formation and possibility of causing radio interference. The busbar system shall be so supported and fastened as to withstand forces likely to be developed by the specified 3-phase symmetrical short-circuit current. INSULATORS Supporting insulators of circuit-breaker, isolators and lighting arrestor, bushing insulators for instrument transformers as well as well post type insulators and string insulator assemblies for supporting buswork shall be made of best quality porcelain and shall be brown glazed. Porcelain shall be homogenous, free from any laminations, cavities, flaws and imperfections and shall be thoroughly vitreous so that the insulation does not depend on the glaze. The glaze shall be of uniform shade, smooth, hard and shall completely cover all exposed parts of insulators. All insulators shall be suitable for heavily polluted atmosphere. All insulators shall be suitable for heavily polluted atmosphere and shall be able to withstand the duty requirements of the related equipment. Individual disc insulators as well as complete insulator strings for supporting ACSR busbars shall be designed, manufactured and tested as per IS:731 and IS:3188. All fittings and accessories shall conform to IS:2486. Insulators shall be of ball and socket type. The socket shall be malleable cast iron and the pin shall be of steel. After





machining is completed, the balls and sockets shall be of steel. After machining is completed, the balls and sockets shall be hot dip galvanised. The zinc coating shall be smooth, clean, of uniform thickness and free from defects. Ball and socket connections shall be provided with adequately strong retaining pins of locking devices of suitable material. Individual units of each string shall be identical and interchangeable and shall so designed as to prevent formation of any defect due to expansion or contraction in porcelain or metal fittings. Porcelain shall not exchange directly with metal but shall be mounted with suitable non-deteriorating interposing material. STEEL STRUCTURES Complete structures of the 220 kV switchyard shall be made of galvanized Iron. Tenderer shall include accordingly. The steel structures for mounting various equipment such as circuit-breaker, isolators, instrument transformers, lightning arrestor, busbars, and accessories etc. as required shall be designed, fabricated and supplied as a part of the work covered by this specification to make the installation complete in all respects. The structures shall be of adequate mechanical strength designed to meet the requirement of the equipment specified and shall be suitable for site and loading conditions as called for in this specification. The structures shall be of lattice type construction, fabricated from rolled mild steel sections and hot dip galvanised. Only bolted connections will be permitted. Necessary nuts, bolts, washers including foundation bolts etc. shall be supplied with the structures. Steel members, bolts, nuts, fittings shall be hot dip galvanised except spring washers which shall be electro-galvanised. Galvanising shall be done after fabrication is completed but the nuts may be tapped or re-run after galvanising. Threads of the bolts may be under cut to provide for increase in diameter because of galvanising. Re-running of the bolt threads is not permitted. Before galvanising, the steel section shall be thoroughly cleaned of any paint, grease, rust, scale, acid or alkali or such other foreign matters as are likely to interfere with the galvanising process or with the quality or durability of the zinc coating. Galvanising of each member shall be carried out in one complete immersion. The galvanising bath shall contain only the approved standard spelter. The galvanised surface shall consist of a continuous and uniformly thick bright coating of





zinc, minimum weight of coating being 910 gm / sq m, firmly adhering to the surface of steel. The galvanising shall be from any defect which may affect or tend to affect its anticorrosive properties. The finished surface shall be clean and smooth and shall be free from defects like discoloured patches, bad spots, uneven coating, zinc which is loosely attached to the steel globules of zinc, spiky deposits of zinc, blistered surface, flaking or peeled off zinc etc. The presence of any of the above defects or deformation noticed on visual inspection even without carrying out any test shall render the material liable for rejection. Defective galvanised steel sections requiring re-galvanising shall have the zinc coating entirely removed by suitable acid treatment without damaging the steel surface and regalvanised only after proper picking. Galvanised articles, zinc to be used for galvanising, method of testing etc. shall conform to the relevant standards. MARSHALLING KIOSK Marshalling kiosk shall conform to IS : 5039. Size of marshalling kiosk shall be adequate to work freely during maintenance. It shall be minimum of size 1600 mm x 970 mm x 600 mm. Marshalling kiosk shall be sheet enclosed and shall be dust, weather and vermin proof. Sheet steel used shall be at least 2.0 mm thick cold rolled/2.5 mm hot rolled and properly braced to prevent wobbling. The enclosures of the marshalling kiosk shall provide a degree of protection of not less than IP 55 (as per IS :2147) and one kiosk of each type shall be tested for the same. Lighting arrangement inside the marshalling kiosk shall be provided which shall be interlocked with kiosk door. Marshalling kiosk shall be of free standing floor mounting type or pedestal mounting type as per requirement. Marshalling kiosk shall be provided with double hinged doors with padlocking arrangement. The distance between two hinges shall not exceed 350 mm to ensure uniform sealing pressure against atmosphere.





All doors, removable cover and plates shall be gasketed all around with neoprene gaskets. Ventilating louvers if provided shall have screen and filters. The screen shall be fine wire mesh made of brass or GI wires. The neoprene gaskets shall be tested in presence of Owner's representatives. The cable entries to the marshalling kiosk shall be from the bottom. Suitable cable gland plate, projecting at least 150 mm above the base of the marshalling kiosk shall be provided for this purpose. Necessary number of cable glands shall be supplied and fitted on this gland plate. The gland shall project at least 25 mm above gland plate to prevent entry of moisture in cable crutch. Gland plate shall have provision for some future glands to be provided later, if required. The glands shall be dust proof screw on, double compression type for outdoor use and made of brass. The gland shall have provision for securing armour of the cable separately and shall be provided with earthing tag. The glands shall conform to BS 4121. The gland shall be cadmium plated. All sheet steel work shall be phosphated in accordance with IS : 6005, Code of Practice for phosphating Iron & Steel. Oil, grease and dirt shall be thoroughly removed by emulsion cleaning. Rust and scales shall be removed by pickling with dilute acid followed by washing with running water rinsing with slightly alkaline hotwater and drying. After phosphating thorough rinsing shall be carried out with clean water followed by final rinsing with dilute dichromate solution and oven drying. Then two coats of zinc cromate primer and two coats of oil and weather resistant varnish of a colour distant from primer shall be applied. Final coats of glossy, oil and weather resistant nonfading paint be applied. Primer paint shall be as per IS : 104 and intermediate and final coat of paint shall be as per IS-2932. All paint shall be carefully selected to withstand heat and extremes of weather. The paint shall not scale off or wrinkle or be removed by abrasion due to normal handling. Suitable heaters shall be mounted in every compartment of the kiosk so that cubicle temperature is always maintained approximately 10 deg.C above the outside air temperature to prevent condensation. On-off switch and fuse shall be provided. Heater shall be suitable for 240V AC supply. Marshalling kiosk shall be supplied complete with inter-connecting wiring provided between all electrical devices mounted therein. All internal wiring shall be carried out with 650V grade single core 2.5 sq.mm stranded copper conductor, PVC armoured insulated wire. The internal wiring shall be securely supported neatly arranged and readily accessible.





The wiring shall be colour coded. For illumination each compartment of the kiosk shall be provided with door switch controlled incandescent lamp. The marshalling kiosk shall also be provided with incoming switch-fuse or MCB and one 15 Amp interlocked switched socket in addition to a MCCB. The terminals shall be numbered as desired by Engineer-in-Charge and shall be so staggered that the connection of external cable to any terminal block should be possible without disturbing the rest of the connection. The terminal block arrangements shall be such as to provide maximum accessibility to all conductor terminations and any arrangement preventing ready access to other terminal screws shall not be accepted. The terminal block shall be made of moulded, non flammable thermosetting plastic. The terminal block to be provided shall be fully enclosed with transparent removable covers and made of moulded, non-inflammable thermosetting plastic material with blocks and barriers moulded integrally. The material of terminal block moulding shall not deteriorate because of varied conditions of heat, cold humidity, dryness etc. Such blocks shall have a white marking strip for circuit identification and moulded plastic cover. All terminals shall be clearly marked with identification numbers or letters to facilitate connection to external wiring. The terminals shall be made such that maximum contact area is achieved when a cable is terminated. the terminal shall have a locking characteristic to prevent cable from escaping from the terminal clamp unless it is done intentionally. The conducting part in contact shall be tinned or silver plated. Bay marshalling kiosk shall have three separate distinct compartments for the following purposes;

• To receive two incoming and distribute three outgoing 220V DC supply for various elements in switchyard.

• To receive two incoming 415V, 3 phase AC 100A supplies with auto changeover and MCCB units and distribute five outgoing supplies, 3 nos. 63A and 2 nos. 32A controlled by MCCB with remote, indication for tripping.

• To receive one incoming 240V, 1 phase, AC supply and distribute ten outgoing supplies.

• 200 nos. terminal blocks in vertical formation for interlocking facilities.





• CT terminal shall have disconnecting type shorting links. CLAMPS & CONNECTORS Clamps & connectors shall conform to IS : 5561. The clamps and connectors shall be made of materials listed below : • For connecting ACSR conductor : Aluminium alloy casting conforming to

designation A6 of IS : 617 and shall be tested for all tests as per IS : 617. • For connecting equipment terminals made of copper or ACSR conductor :

Bimetallic connectors made from aluminium alloy or casting, conforming to designation A6 of IS:617 with 4 mm thick Cast copper liner.

• For connecting G I Shield wire : Malleable iron casting • Bolts, nuts and plain washers - Hot dip galvanized mild steel • Spring washers : Electrogalvanised mild steel as per service conditions at least 3

of IS:1573. All casting shall be free from blow holes, surface blishters, cracks and cavities. All sharp edges and corners shall be blurred and rounded off. No part of a clamp or connector shall be less than 15 mm thick. All ferrous parts shall be hot dip galvanised conforming to IS : 2633. For bimetallic clamps or connectors, copper alloy, liner of minimum thickness-2mm shall be cast integral with aluminium alloy body. Flexible connectors, braids or laminated strips shall be made from tinned copper sheets or aluminium laminates depending on the clamp. The terminal clamps for busposts shall be suitable for both expansion as well as fixed/sliding connection. Size of the terminal/conductor for which the clamp/ connector is suitable shall be embossed/punched (i.e indelibly marked) on each components of the clamp/connector, except on the hardware. Clamp shall be designed to carry the same current as the conductor and the temperature rise shall be equal or less than that of the conductor at the specified ambient





temperature. The rated current for which the clamp/connector is designed with respect to the specified reference ambient temperature, shall also be indelibly marked on each component of the clamp/ connector, except on the hardware. All current carrying parts shall be designed and manufactured to have minimum contact resistance. Clamps and connectors shall be designed corona controlled. Corona extinction voltage for 220 kV clamps shall be 154 kV. OTHER HARDWARE Tenderer shall include complete 220 kV transformer bay including all conductors, jumpers, bus bars, supporting structures, connectors, clamps, and other accessories required for completion of job. CIVIL WORK Complete civil works shall be included for the switchyard extension including new bays in existing portion of the switchyard, Extension of cable trenches and road of existing switchyard to the extended portion, illumination, rail track for transportation of station transformer ,foundations, gravels, oil pits, cable channels, pipe grouting, cable ducts etc as per requirement Construction of foundation for the station transformer and bay equipment is in the scope of tenderer. Fencing and structural gate of 20 MVA, 220/11kV Transformer is in the scope of tenderer. Dismantling of existing wall and gate for extension of bay and construction of wall alongwith fixing of dismantled gates is in the scope of tenderer. Approach road upto extended part of the wall is in the scope of tenderer. RELAY AND CONTROL PANELS All equipment required for control, monitoring, interlocking, sequencing, metering and protection shall integrated in separate control cum protection panels to be installed in the existing switchyard Control Room. The panels shall be provided with required mimic, indications, control equipment, indicating meters, annunciators, protective relays, etc.The relays shall be numeric type with communication port. Relay and control panel shall have provision for metering, relaying, alarm annunciation, control and mimic diagrams for the double main bus with bypass bus arrangement and





220 kV bay. This shall be of duplex design and shall be installed in the Switchyard control building. Dimension (height and width) of relay and control panels shall match with existing panels. The relays and control panel shall be of floor mounted, free standing, dead front design fabricated out of minimum 2 mm thick sheet steel and with IP50 degree of protection. All meters, mimic diagrams, control switches, indicating lamps, annunciator facia etc.shall be provided on the front of the panel and all protective and auxiliary relays shall be mounted at the rear. NIT (Normal, Intermediate, Tie) switch shall be provided in control panel. NIT switch shall be lockable at “N” position. Key shall be able to come out only at Normal position not at “I” or “T” position. All internal wiring of panel shall be carried out with 1.1 kV grade stranded copper conductor, PVC insulated wiring cable of core size 2.5 sq mm for control circuit wiring. Terminal blocks shall be located in easily accessible positions and more than two wires shall not be connected to one terminal. Each terminal block shall be provided with at least 20% spare terminals. Space heater shall be provided in cubicle at the bottom with necessary thermostat switch to prevent condensation. Internal illumination with fluorescent lamp for convenience of access and maintenance work shall be provided. These lamps shall be provided with door operated switch. Four (4) Nos. 5 A, 240 V single-phase AC, 3-pin socket outlet shall also be provided. Earth bus of bare aluminum strip of adequate size shall be provided all along the length of the panel at the bottom. The structure of cubicle and non-current carrying metallic parts of all panel mounted devices shall be connected to earth bus for effective earthing. All protective and auxiliary relays, instrument, indicating lamps, push-buttons, control switches, alarm annunciators, semaphore indicators etc. shall be provided in the relay and control panel. Energy meters shall be of 0.2 accuracy class.





All instruments shall be robust design vibration-proof and suitable for flush mounting on vertical panels. Indicating instruments shall be 144 mm x 144 mm size of parallax free design with glare front glass covers. The instrument shall be provided with zero adjustment facility and magnetic screening. Solid state alarm annunciator with flasher and horn shall be provided for drawing attention of operator abnormal operating conditions. Annunciation window shall be mounted on the top of the control panel with black engraving on milk white translucent covers. Separate windows shall be provided to annunciate the following abnormal conditions: Trip and alarm annunciations shall be differentiated in separate alarm facias with different type of buzzers.

• Circuit-breaker auto trip. • Operation of each type of protective relay including inter-trip relay. • PT fuse failure. • Fault in DC control power supply equipment. • Circuit-breaker tripped due to transformer fault. • Buchholz relay-alarm. • Buchholz relay- trip. • Winding temperature-alarm. • Winding temperature-trip. • Oil temperature-alarm. • Oil temperature-trip. • Oil level low-alarm. • Oil level low-trip. • Earth-fault-trip. • Trip circuit faulty (Pre-close and post-close annunciation) • Air pressure low-alarm • Air pressure low-trip • SF6 gas pressure low-alarm (in each phase). • SF6 gas pressure low-trip (in each phase) • Trip relay circuit faulty (for supervision of lock out relay) • Breaker tripped on Pole Out of Step





The above is indicative and minimum. The same shall be finalized during detailed engineering. Alarm and annunciation shall be immune to Radio Frequency noise. Each annunciation window shall be provided with two lamps and a minimum of 20% spare window shall be provided. The annunciation system shall have push-button for alarm acknowledgement, re-set and test purpose. The annunciation system shall be built on plug-in type glass epoxy printed circuit boards of modular design. The alarm annunciator shall be immune to RE noise and hum noise of 50 cycles. The annunciator must be tested for impulse voltage withstand and high frequency disturbance tests as per IS:8686 and Tenderer shall furnish test certificates to this effect. The indicating watt meters and VAR meters shall be digital meters. These meters shall have the facility to communicate to a PC. The MWH & MVARH meters shall be of numeric type with facility to communicate to PC. The accuracy class shall be 0.2. In addition to various indicating meters, a multifunction meter with load read out facility and remote communication facility shall be provided. The multifunction meters shall have battery back up for memory. In addition to the metering and protection requirements as stated above, the relay and control panel shall be provided complete with mimic, diagram, semaphore indicators for position indication of circuit-breaker, isolators and earthing switches, spring-return to neutral type OPEN / CLOSE control switches for circuit-breakers and disconnecting switches, stayput type bus selection switches, lockable stayput type trip transfer switches, ON / OFF / AUTO TRIP / READY FOR OPERATION indication lamps for circuit-breaker, space-heater, illumination lamps and all other accessories as required to make up a complete installation. The mimic diagram with semaphore indicators shall be so arrange as to give the actual position of 220 kV circuit-breakers, isolators, etc. The arrangement adopted shall be subject to approval by the Purchaser / Consultant. The mimic shall be made of 12.5 mm wide and 3 mm thick enamel painted aluminum strips and different colours shall be used to identify different voltages fuses. The semaphore indicator shall have two separate operating units with provision of holding the semaphore disc in neutral position when both units are de-energised.





All standard protections shall be as per requirement for the 220 kV switchyard bay. The same shall be finalized during detailed engineering. MISCELLENEOUS Minimum sizes of GI structures for the proposed 220 kV system shall be as per existing 220 kV switchyard. The new system shall match with existing corresponding one in height, width, clearances, etc. Difference in FFLs shall be bridged by making the main bus with proper slope above road between existing and extended switchyard keeping all the statutory clearances. STATION AUXILIARY POWER SUPPLY EQUIPMENT The 415 V AC distribution board (to fed from the Owner’s 415 V station PCC) shall be floor mounted metal clad, totally enclosed cubicle type. It shall be single front drawout type. The AC distribution board shall be suitable for 415 / 240 V, 3-phase, 50 Hz, 4-wire system and shall have two incoming feeders. The incoming feeders shall be mechanically interlocked such that only one of the two can be closed at a time. The board shall have adequate number of feeders to cater to the station auxiliary power requirements. Feeders shall also be provided to cater to future equipment envisaged in the outdoor yard. Additional minimum six (6) Nos. fully wired spare feeders for owner’s use shall be provided in the AC distribution board. The board shall also have a minimum of 10% spare feeders (with minimum one number of each type and rating) in addition to feeders for owner’s use. DC CONTROL POWER SUPPLY EQUIPMENT 220 V DC shall be adopted as control voltage for the operation of circuit-breakers. One (1) set of floor mounted, cubicle type DC distribution board shall be provided with requisite number of incoming and outgoing feeders for supply of DC power to various equipment in the new yard. The feeders shall comprise adequately rated Moulded Case Circuit Breaker (MCCB) units. The minimum rating of MCCB units shall be 25 A. The board shall have minimum four (4) Nos. fully wired spare outgoing feeders for owner’s use. The board shall also have minimum 10% spare feeders (with minimum one number of each type and rating) in addition to feeders for owner’s use. The board shall be single front design.





AUXILIARY POWER AND CONTROL CABLING The Tenderer shall include in his scope, laying of one (1) lot of power and control cables required for complete interconnection of all equipment supplied which are included in the scope of this specification. The power and control cabling shall be complete with all laying, supporting, jointing and termination materials and accessories including cable racks, trays, supporting brackets for trays and racks, conduits, conduit fittings, cable tags, identification ferrules etc. as required to make the installation complete in all respects. All cabling materials and accessories shall be of quality to be approved by the Owner. EARTHING One (1) lot of earthing stations, earth conductors and accessories shall be offered for providing complete earthing of the following systems and equipment as required to meet the stipulations of Indian Electricity Rules to the full satisfaction of Chief Electrical Inspector to the Government of Orissa (CEIG) Central Electrical Authority (CEA) and the Owner. System Earthing Primary and secondary side neutrals of transformer are bought out and while primary side neutral is solidly earthed secondary side is earthed through resistance. Equipment Earthing All indoor and outdoor equipment and devices covered under the scope of this section including lightning arrestors, shielding spikes, outdoor steel structures, transformer rails, substation fencing and gate, cable boxes, trays, racks, conduits etc. Individual earth pit for each lightning arrestor shall be provided. Earthing system shall be designed as per the requirements of IS : 3043. The earthing system shall be so designed as to keep the touch and step potentials within permissible limits. The substation main earth mat shall be extended up to 1.5 meter beyond the substations in order to avoid dangerous potential difference developing between he fence and the surrounding ground. The electrical resistivity of soil shall be measured at site and taken accordingly. All earthing system shall be so designed as to ensure effective operation of protective gears in case of earth faults. Actual measurement of soil resistivity shall be done to





determine the number of earth electrodes to be provided. The total earth resistance at any point of the earthing system for the substation shall not be more than one ohm. The method of earthing the substation fence shall be considered from the view point of touch and step potentials in the area outside the fence. All fencing shall be separately earthed with the earth grid completely segregated from the station earth mat. Shielding and Lighting Protection The outdoor switchyards shall be properly protected against direct lighting strokes in accordance with IS : 2309. Vertical air terminations (lighting masts) shall be adopted for the outdoor switchyards erected on sub-station gantry column as well as on separate structures erected for masts. The size of shielding wire used in case of 220 kV transmission line shall be 7/9 SWG galvanised steel conductor. The lighting protection for outdoor equipment shall comprise of air terminations installed on sub-stations / structures / separate structures. Air terminations shall be copper rods mounted on substation steel structures. The cone of protection shall be 450 maximum for single masts and 600 maximum for multiple masts. The Tenderer shall critically examine the layouts and include masts that may be required to adequately protect the switchyards against direct strokes. The height of structures as well as masts shall also be suitably selected. The Tenderer shall indicate in his offer details of masts considered and height of masts. Down conductors from lightning masts and shielding wires shall be as short as possible and shall follow the most direct path possible between the air-termination and earth termination avoiding sharp bends, up-turns and kinks. Joints shall be avoided in down conductors. Each down conductor shall have an independent earth termination which shall be interconnected with the station earth mat. Each gantry column shall be provided with at least two earth connections to the station earth mat. The base of lightning arrestors shall be directly connected to the earth by conductor which shall be as short and as straight as practicable. Individual earth electrode shall be provided for each lightning arrestor. These earth electrodes shall be connected not to be taken through steel pipes. The size of the down conductor shall be 65 x 6 mm galvanized





MS flat. The method adopted for protection of buildings and allied structures against lightning shall be in accordance with IS : 2309. INSTALLATION AND COMMISSIONING The successful Tenderer shall carry out at site complete erection of equipment supplied by him (including those procured from fabricated by others based on his drawings, specification and bill of quantities) as well as start-up and commissioning including performance tests of the same. The contractor shall be completely responsible for the satisfactory erection, testing, commissioning, start-up, and performance tests of the equipment notwithstanding that he may be assisted by the Owner’s authorized representative. For complete erection and commissioning the successful Tenderer shall be responsible for providing at his cost all necessary tools, tackles and instruments as required. The installation shall be carried out only by electrical contractor, holding a valid H.T. electrical license, issued by he Government of Orissa for carrying out installation work of 220 kV voltage class under the direct supervision and person holding valid certificates of competency for the same voltage classes, issued or recognized by the State Government. The Tenderer shall furnish with his tender the particulars of the license held by him / the electrical contractor he proposes to engage for carrying out the installation work against this specification. The successful Tenderer shall furnish to the Owner the names and particulars of certificates of competency of the supervisors and workmen to be engaged for carrying out the installation work against this specification. The work shall be executed in a workman – like manner with the best engineering practices. The installation shall have to be approved by statutory government authorities like Central Electrical Authority, Factory Inspector, Insurance officials etc. Any modification in he equipment or installation that may be demanded by them shall have to be carried out by the successful Tenderer at no extra cost to he Owner. The responsibility of obtaining clearance from the Electrical Inspectorate of Orissa for commissioning of the complete electrical equipment / system covered under this specification shall lie solely with the





contractor. The contractor shall carry out any modification if the same is required by the statutory authority though 04.14 ERECTION SPECIFICATION 04.14.01 Guidelines for design of system and engineering the layout of electrical

equipment

General The tenderer shall prepare the layout drawings taking into consideration the requirement listed below. Electrical premises All electrical premises shall have adequate space to accommodate the electrical equipment from the point of view of operation and maintenance, and conform to IE Rules & Regulations. The clearance between the ceiling of the electrical room and top of the tallest equipment shall not be less than 1m, 2m where the equipment are to be maintained from top and additional height of lifting tackle wherever required. Air tight door arrangement shall be provided for electrical control rooms. Cable Installation Cables will have to be run partly along the structures and columns of the buildings, wherever it is necessary i.e. to a nearby shop cable trench /chan-nel or surface duct shall be provided. Cable channels inside turbine floor shall be avoided. Installation of cables directly buried in ground shall generally conform to the requirement given in IS: 255. If the cables are crossing the road/rail track, cables shall be laid in concrete cable ducts, G.I. pipes. 25 % spare conduits/pipes/duct openings shall be provided.





Cables in trenches shall be laid on 8 cm of riddled sand and covered with 8 cm of riddled sand. RCC slabs shall be provided for covering these trenches. The maximum trench depth shall normally be 1.5 m and thickness of top cover of 75 mm. If the trench is to cross railway tracks/roads or any load bearing area the cables shall be taken through suitable GI con-duits/pipes/ducts. Laying in surface ducts / on structures Cable racks for cable trays shall be fixed at a maximum interval of 1.5 m. Cables leaving the ground/floor shall be protected upto 2 m height by conduits/metallic guards. Galvanised prefabricated ladder type cable racks and trays shall be provided to lay cables in shafts/cable basements. Cables shall be laid in separate racks according to the voltage/application classification. The cables shall be laid from top to bottom in order of HT on top rack followed by LT cables and other cables on lower racks. All necessary frame works and fixings for the support of cables and accessories shall be supplied. Cables shall be suitably protected against heat, and mechanical damages. Structures for cable laying Cables shall be laid on ladder type cable trays. Ladder type cable trays shall be selected from sizes 200 mm, 400 mm & 600 mm and shall be fabricated from 40x40x3.1 mm GI slotted angles for longitudinal members and 25x5 mm perforated flats for cross members placed at an interval of 250 mm along the length of cable tray. Supporting vertical racks and horizontal hooks shall be of 50x50x6 mm angles.Cable racks and hooks shall be of welded construction. To avoid damage during cable laying, cable structures shall have no scales, abbrasive or rough surfaces or cutting edges.





Transformer installation Mineral oil filled transformer shall be installed at transformer yard. Earthing Entire system shall be earthed in accordance with the provisions of the relevant IEC recommendations/ IS code of practice IS 3043-1987 and Indian Electricity Rules, so that the values of the step and contact potentials in case of faults are kept within safe permissible limits. Parts of all electrical equipment and machinery not intended to be alive shall have two seperate and distinct earth connections each to conform to the stipulation of the Indian Electricity Rules and apparatus rated 240 V and below may have single earth connections. Earthing mat consisting of earthing electrodes and cross connecting conductor is already provided by the purchaser and tenderer has to connect equipment earthing to the grid. Existing earth pits shall be renovated and rusted materials shall be replaced with equivalent material and bimetal washers shall be provided wherever GI strips shall be connected to existing copper network. For protective earthing separate conductor shall be used for flow of earth fault current as elaborated below. The LV side neutrals of the distribution transformers shall be connected to two separate earthing electrodes. They shall also be connected with the neutral bus of the corresponding switchgear and in turn switchgear neutral bus shall be connected to the earthing bus of the switchgear. The protective conductor for connection from switchgear earthing bus to MCCs/DBs and further to motors shall be either through fourth core of cable or armouring of cable. In case of armouring on cable, same shall be double steel wire armouring. The fourth core or armour of cables and all conduits for cables shall also be connected to the earthing mains. A continuous earth strip shall run in each side of cable channel and in cable ducts and trenches. All joints in the run of the main earthing conductors will be welded or brazed





type. Connection to equipment structure shall be bolted type. Conductor sizes for earth connections : High voltage systems - 75 x 5 mm GI flat for :

- Transformers - Earthing resistors - Earthing leads to earth electrodes. LT system where the voltage does not exceed 650V normally : - 6 Sq.mm Stranded GI wire for : - Motors and starters upto and including 2.2kW, shunt limit switches,

push buttons and master controllers, Light fitting,JBs,PBs, etc. - Instruments and miscellaneous small items protected by fuses of

ratings not exceeding 15A.

- 16 Sq mm Stranded wire for : • Motors and starters above 3.7 kW and upto and including 15

kW.

25 x 3 mm GI flat for:

• Motors and starters above 15 kW, and upto and including 45 kW

• Control desks, cabinets, LCB, socket outlet isolators, SLDBs/DBs.

50 x 6 mm GI flat for :

• Motors and starters over 45 kW • Switchboards, MCC,PDB,PCC MLDB.





50 x 6 mm GI flat (minimum) for :

• Main earthing ring in plant buildings • LT transformer neutral • LT Switchboards and other equipment protected by circuit

breakers.

Sheet metal enclosed panels control desks and boxes The base frames of all panels, desks, posts etc., shall be welded to structures or to the civil inserts provided on the floor/walls. Fabrication of supports/frames, wherever required, shall be done by the tenderer. The shipping section shall be placed in position before removing the protective covering to eliminate scratch/damage. The shipping section shall be moved by using rollers under the shipping skids wherever lifting cranes are not available. The contractor shall do the assembly at site as per manufacturer's general arrangement drawings and installation instruction. While assembling a complete board comprising several unit type cubicles, the board as a whole shall be aligned. The panels shall be properly levelled prior to grouting the holding down bolts or welding the panels to the inserts. All interconnection of busbars and wiring between the panels shall be done as per manufacturer's instructions and drawings. Welding work on the panels shall only be carried out after consultation with the purchaser. Damage to the paint due to welding shall be rectified by the contractor. Transformers The transformer and its accessories and mountings like radiators, conservator, thermometers, silicagel breathers, marshalling box, rollers etc., delivered at site in separate packages, shall be assembled at site after cleaning by the contractor in proper sequence as per manufacturer's drawings. Jacks shall never be placed under valves or cooling tubes.





Suitable stopper shall be provided both in front as well as rear of transformer to keep the transformer stationary in its position. The oil conservator and the pipes shall be erected as shown in the manufacturer's drawings. All radiator tubes shall be cleaned before installation. Before the transformer is filled/topped with oil, oil samples shall be checked by the tenderer from each container. The oil shall possess the dielectric strength as per relevant IS. Oil shall be filled upto the mark shown. The contractor shall also test the oil from each transformer to determine its suitability for use. If required, the contractor shall carry out drying and filtering operations as per IS code of practice to ensure that moisture is completely removed and the oil is free from impurities. This may be carried out by using oil filtering equipment to be provided by the tenderer having vacuum as well as heating arrangement. Only after the dielectric strength of oil and other parameters are checked and approved, the external connections shall be made to the transformers. The dial thermometers shall be screwed to the thermometer pockets after removal of the blind plugs. All necessary cabling shall be connected before charging of the transformer. This will include signalling cables upto marshalling box and from marshalling box to meters, if not already done. Any modifications to HT and LT terminal box to accommodate the number of cables or bus duct to be terminated shall be carried out by the contractor. Naked light and flame shall never be used near the transformer. Instructions given by the manufacturer’s erection & commissioning manual shall also be followed. Busbar Busbar installation shall be commenced from the middle section and the buses shall be fastened without tightening the bolts. The buses shall lie freely on the insulators without warping and if necessary, suitable packing





shall be provided at the insulators. Final tightening of the bolts shall be done after the complete laying of buses. Approved means shall be used for tightening of the bolts. Bimetallic strips/washers shall be used wherever aluminium busbars or aluminium cables are terminated on copper busbars. Limit switches The places of installation shall be seen from the engineering drawings and the switch shall be secured by means of adjustable bars. Any modifications required in positioning of limit switches as per site conditions shall be done by the tenderer. Miscellaneous equipment Cables Installations Cable shall be fixed to racks or trays or cleats as required for proper support, accessibility and neatness of installation. Cable tags shall be provided at a regular interval of 30M. For cable run shorter than 30M one cable tag shall be provided in the middle. These tags shall be in addition to end cable tags. The cable tags shall be marked with cable number, size and voltage grade. Middle tag shall be indicated with destination. The end tag shall be with second terminal point. Cables shall be clamped rigidly at an interval of not more than 1500 mm in horizontal,and 1000 mm in vertical & inclined run and at bends. In the cable galleries, cable structures shall be properly arranged giving sufficient clearance for movement of personnel from one part of the gallery to the other. It shall also be possible to escape easily in case of fire. Cables laid in over ground structures shall be protected from the direct solar radiation. Road crossing points sufficient clearance shall be provided with due consideration to road traffic. In outdoor structure cat ladder and walkable platform shall be provided to facilitate cable removal/addition on the cable trays.





Perforated trays shall only be used where necessary for the support of a number of small cables. Each tray shall be firmly supported at suitable intervalsand shall carry the weight of its cables without sagging. Trays shall be painted and where the surfaces or edges are cut or otherwise impaired during erection, they shall be made good by coating with aluminium paint. Small cables may be bunched together under one saddle provided that in any bunch all cables have sheaths of the same material. The number of cables shall not exceed four wide and two deep. Not more than one cable shall be drawn into one conduit unless otherwise agreed. After the cable has been drawn in, the conduit shall be sealed by an approved means. All cables shall be tested for proper insulation before start of laying work. Cables shall be laid in conduits, racks/trays, cable trenches, along with structures or buildings, as per cable routing drawing and cable list. Suitable adjustment shall be made in cable routes, if required at site, with a view to avoid any interference with any part of building, structures, equipment, utilities and services with the approval of the purchaser. While laying cables, care shall be taken that kinks, twists or mechanical damage do not occur to the cable. All bends in cables shall be made with due consideration to the minimum permissible bending radius of the cables. On being pulled, the cable shall not be allowed to drag drawing along the ground or over a second cable already laid. Special care shall be taken while pulling through an opening where other cables have already been laid. Only approved cable pulling devices shall be used. No joints shall normally be made at any intermediate point in through run of cables unless the length of the run is more than the standard drum length. In





such cases where jointing is unavoidable, the same shall be made inside proper bases having plastic moulds and shall have moulded epoxy resin construction. Provision shall be made for earthing continuity at the joint. Cable splicing and jointing shall be done in accordance with the relevant IS code of practice and manufacturer's instructions. Insulation resistance of cables shall be checked before cable jointing. Adequate length of cables shall be pulled inside the switch boards, control panels, control desks, etc. so as to permit neat termination. All cables shall be neatly dressed without interlocking or cross over. While laying the cable vertically, these shall be clamped at suitable intervals. Horizontal runs shall be rigidly secured to trays on racks/hangers in all the places where the direction of the route changes as well as at cable terminations or joints. The clamps shall not be done up so tight that the insulation is damaged or deformed. Cable markers shall be provided on either side of road crossing at each turning and at 30 m intervals at straight runs for underground cables. Where cables are required to cross roads, surface drains and water, oil, gas or other pipe lines, they shall be taken through reinforced spun concrete or steel pipes. Entry of cables from underground to the buildings or trenches shall be through pipe sleeves. After laying of cables, the sleeves shall be sealed with bitumin or epoxy compound with sand matting and cement plaster to make them fully water tight. Special consideration shall be given for protection of cables against chemical and mechanical damage. All cable entry openings in the equipment shall be sealed with fire proof materials. All cable openings in walls and floors shall be sealed after laying of cables by water and fire proof materials.





All cables shall be provided with identification tags indicating the cable number in accordance with cable lists. Tags shall be fixed at both ends of the cable and at 30 m spacing for straight runs as well as on both sides wherever cables are crossing walls/floors. The tags shall be of aluminium/PVC with numbers punched/painted on them and securely attached to the cables by non-corrosive wires. The shape of tags shall be round, triangular and rectangular for control, medium voltage and high voltage cables respectively. Glanding shall be done for direct entry of both power and control cables into the panels by the contractor. Double compression type brass cable glands shall be used. The cables shall be terminated in accordance with relevant connection diagram. Termination and clamping shall be carried out in such a manner as to avoid strain on the terminals. All power cable terminations shall be by means of crimping type cable lugs. For flexible conductors, soldered termination shall be adopted. In case of aluminium power cables termination on copper bus bars, suitable aluminium copper bimetallic washers shall be used. Corrosion inhibiting grease shall be used for aluminium cable terminations. Suitable numbered and coloured letter interlocking type ferrules shall be provided for end termination of power and control cables. Control cable entering switch boards, control panels, control desks etc. shall be neatly bunched and strapped with PVC perforated straps and suitably supported to keep it in position at the terminal blocks. All spare cores of each cable shall be segregated, marked spare, neatly dressed and suitably taped at both ends. When the cores of two or more multicore cables take a common route, cores of each cable shall be separately bound and the separate bundles neatly bound together. Individual cores of control cables shall have plastic interlocked type coloured





ferrules with engraved numbers at both ends of the circuit for identification. The contractor shall be responsible for correct phasing of motor power connections and shall interchange connections at the motor terminals box, if necessary, after each motor is test run. The trays shall be earthed and rendered electrically continuous by welding the trays to the grounding strip at not less than two places from both sides of the tray. Exposed conduits Exposed conduits shall be laid along walls, floors, ceilings, on steel supports etc. as per working drawings/site requirements in consultation with the supervisory personnel. The conduits shall be neatly run and evenly spaced. Fixing of conduits to the supports on wall, column, structure shall not be done by welding. Exposed conduits shall be adequately supported by racks, clamps, straps etc. Jointing of conduits shall be done only in straight portion and not in bend portion. The contractor shall have available at site bending facilities for conduits as well as dies for threading conduits of diameters and threads corresponding to the standards. The threaded ends of conduits shall be painted with anticorrosive paint. The outer ends shall be smoothened free of burrs and sharp edges. Sealing shall be at both ends of conduits. Flexible metallic conduits shall be used for termination of connections to motors and other electrical equipment like pressure switches etc. which need to be disconnected at periodic intervals. All conduits shall be effectively connected to the earth terminal of the equipment where it terminates. Both ends of conduits shall be suitable earthed. Earthing continuity to be maintained by means of flexible wire wherever two conduits are joined with sockets.





Approved conduit bending machines to be arranged by the contractor shall be used for bending conduits in the field. The radius of any conduit bend shall be as per standards for cabling. Bends shall be free from cracks, crimps or other damage to the pipe or its coating.

04.15. OVERHAULING OF 1000 kVA, 11/0.415kV TRANSFORMER

2 Nos. 1000kVA, 11/0.415 kV transformer shall be overhauled and reused as Station Auxiliary Transformers. Before dismantling of transformer, oil shall be drained and handed over to the Owner in Owner’s container.

04.15.01 The following work are to be carried out during overhauling of the transformers to enhance the life of transformers for trouble free operation in future.

04.15.01.01 Core and Winding Core and winding shall be retained

04.15.01. 02 Bushing All the bushings of the transformer shall be retained however all the connectors shall be replaced.

04.15.01.03 Off-Circuit Tap Switch Off Circuit shall be refurbished.

04.15.01.04 Tank, Radiator & Conservator

Cleaning of tank, radiator and conservator shall be done. Oil leakage shall be completely sealed to prevent any loss of oil. Also ingress of moisture into the tank shall be stopped.





Painting The primers and finishing paint shall conform to latest Indian Standard or equivalent International Standard. Surface preparation shall be done properly. Colour of finished painting shall be dark admiralty grey shade 632 of IS :5 (Epoxy based). The colour scheme, however, may be changed, if necessary, by the purchaser at any stage before start of the painting of the equipment. A single coat paint when dry shall have minimum thickness of 25 to 30 microns. Total thickness of 4 coats (2 Primer + 2 Finish) shall be 100 to 125 microns.

04.15.01.05 Pressure Relief Device

Pressure Relief Device shall be provided in place of Explosion vent of the transformer.

04.15.01.06 Dehydrating Breather Dehydrating breathers shall be replaced.

04.15.01.07 Pipes, fittings, Gaskets and valves All pipes, valves and fittings shall be replaced by new one. All gaskets shall be replaced with new neoprene gaskets.

04.15.01.08 Marshalling Box Refurbishment of marshalling box, junction boxes etc. including replacement of contactors, switch fuse units, terminal blocks etc shall be





carried out. Rewiring of all the cabinets/ boxes shall be done. All the connecting clamps, cable lugs, ferules, cable markers, push buttons etc. shall be replaced.

04.15.01.09 Oil Transformer Oil as per IS: 335 – 1983 (with latest Amendment 1 & 2) shall be replaced. 10% excess oil shall be provided by Contractor.

04.15.01.10 Other Accessories

All accessories like OTI, WTI, magnetic oil level gauge, Buchholz relay etc. shall be replaced.

All the nuts & bolts, washers, valves, door locks etc. shall be replaced by bidder. Earthing strips shall be replaced.

Transformer specifications of some of the major items which are to be replaced during overhauling are given in section 4.2 and shall be followed

04.15.02 General Technical Specification

Electrical Design - Generally as IS 2026. - Rated output, voltage ratio, vector group shall be as specified in

original design.

- The oil used shall be transformer oil confirming to IS 335 – 1983 (with latest Amendment 1 & 2)

- Rated frequency 50 Hz, + 3%, - 5%.





Buchholz Relay

- Double float relays as per IS 3677. - 50 mm diameter of connecting pipe for transformers and shall have

minimum number of bends.

- Shut off valves on either sides of the buchholz relay.

- Pot cocks at the top and bottom of relay drain plug, inspection window, calibrated scale, terminal box with oil tight double compression type brass galnd.

- Potential free, self reset independent alarm and trip contacts rated to

make, break and carry 2 amps at 110V DC. No auxiliary relay shall be used to multiply the contacts. Contacts are to be wired to the marshalling box.

Valves and connections - Valves of sluice type hand wheels. - Made of gun metal - Clear indication of open and closed position.

- Provided with blanking plates or screwed plugs.

- Padlocking facility to lock in closed/ open position.

Oil temperature Indicator 150 mm dial type thermometer with manual reset maximum reset maximum reading pointer. There shall also be two potential free contacts for alarm and trip signals. The alarm and trip setting shall be independently adjustable. The temp. sensing element mounted in a pocket of oil, shall be connected to the indicator through capillary tubing. Contact rating at DC





shall be minimum 0.5 amps. Winding temperature Local winding temperature indicator (WTI) shall have a 150 mm diameter dial type indicator with a manual reset max. reading pointer. There shall be two potential free contacts for alarm and trip signals. The setting of closing / opining of each contact shall be independently adjustable. Contact rating at 110V DC shall be minimum 0.5 amps. The device shall be complete with lamp, sensing element, image coil, calibration device etc. as required. Remote winding temperature indicator with resistance type temperature detector shall be provided additionally. Earthing - All metal parts of the transformer with the exception of individual core

laminations, core bolts, and clamping plates shall be maintained at fixed potential by earthing.

- Two tinned earthing terminals.

Painting Dark admiralty gray shade 632 of IS : 5 (Exposed based). Refurbished Transformer shall fulfil following design criteria. Insulation level shall be according to the voltages specified below.

Nominal System voltage 11 kV 0.433 kV

1) Max. system voltage (kV) 12 kV 1.1 kV

2. One minute power 28 kV

frequency withstand





voltage (kV)

3. Peak impulse test 75 kV withstand voltage (kV)

- Transformers shall be capable of delivering rated current at an applied voltage upto 105% rated voltage without exceeding the temperature limits.

- Overload capacity as per IS 6600 - 1972 unless otherwise specified. - Shall be operable at its rated capacity at any voltage within + 10%

of rated voltage of the particular tap. - Permissible maximum temperature at rated output and principal tap

Ambient temperature of 45 deg. C

a) Top oil (by thermometer) : 85 deg. C b) Windings (by resistance : 95 deg. C method) c) Maximum hot spot temp. : 98 deg. C

- Transformers shall withstand the thermal and dynamic stresses due to

short circuits at its terminals. Unless otherwise specified the duration of short circuit shall be 5 seconds.

- The max. temperature at the end of the specified duration shall not be more than 250 deg. C with the temperature prior to short circuit corresponding to maximum permissible overload.

04.15.03 Erection of Transformers

Jacks shall never be placed under valves or cooling tubes.





Suitable stopper shall be provided both in front as well as rear of transformer to keep the transformer stationary in its position. For the front wheels such stoppers shall be screwed on the rails.

The oil conservator and the pipes shall be erected. All radiator tubes shall be cleaned before installation.

Before the transformer is filled/topped with oil, oil samples shall be checked by the contractor from each container. The oil shall possess the dielectric strength as per relevant IS. Oil shall be filled upto the mark shown.

After filling oil in tank up to required level, it shall be filtered till moisture content within permissible limit as per IS and dielectric strength as per IS achieved.

Empty oil drums shall be handed over to Owner.

Filtration M/c, vacuum pump and heating arrangement, if required, shall be arranged by contractor.

The dial thermometers shall be screwed to the thermometer pockets after removal of the blind plugs.

All necessary cabling shall be connected before charging of the transformer. This will include signalling cables upto marshalling box and from marshalling box to meters, if not already done, as well as inter-cabling between surge suppressor cubicle and transformer secondaries.

11kV and 0.433 kV terminal connection shall be done to form delta and star connection respectively.

All neutral points shall be connected to earth grid.



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TS VOL IV Sec. A Ch – 05 Page 1 of 17

05. INSPECTION AND TESTING 05.01 Inspection 05.01.01 General

Manufacturing progress review, inspection & testing of equipment covered under the technical specification shall be carried out by the Purchaser at the manufacturers' works/premises prior to despatch to ensure that their quality & workmanship are in conformity with the contract specifications and approved drawings.

These instructions are in addition to provisions laid down in other tender documents of the Purchaser.

05.01.02 Inspection & testing stages and finalisation of quality assurance plan (QAP)

Within 12 weeks of the award of contract the Contractor shall furnish the quality assurance plan as per proforma given to successful tenderer for electrical equipment. separately with suggestive stages and hold points for undertaking inspection and testing by the Purchaser/Consultant. Total list of plant & equipment of the order shall be submitted to the Purchaser/consultant prior to submission of QAP

After receipt, scrutiny and rendering into acceptable mode of above documents, a mutually agreed programme of inspection & testing of equipment shall be fina-lised with the Contractor by the Purchaser/consultant.

Inspection & testing of plant & equipment shall be undertaken by the Puchaser/consultant after finalisation & approval of QAP.

05.01.03 Responsibility for inspection

Any inspection by the Purchaser does not replace the responsibility of quality assurance and quality control functions, as expected of the Contractor to be performed by him for supply of plant & equipment as part of the contractual obligations. As such, any approval which the Inspecting Engineer of the Purchaser may have given in respect of plant and equipment and other particulars and the work or workmanship involved in the contract (whether with or without test carried out) shall not bind the Purchaser to accept the plant and equipment, should it on further test at site be found not to comply with the requirements of the contract.



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The Contractor is to meet the inspection & testing requirements for the equipment coming under statutory regulations e.g. weights & measures, safety, IE rules, etc. and submit certificates and documents from appropriate authority to Inspecting Engineer for the same.

05.01.04 Extent of inspection

The extent of inspection & testing by the Puchaser shall vary from equipment to equipment as per design requirements.

However, indicative extent of inspection for electrical equipment is furnished below. Extent of inspection to be carried out shall be finalised withthe Contractor after award of the contract on the basis of scope of supply, technical specification and approved GA drawings. However, in case of similar bulk manufactured items, methods of sampling for inspection of different lots shall be governed by relevant Indian or international standards.

In case of critical components, the Purchaser reserves the right to undertake 100% inspection.

Extent of Inspection Categories of (as applicable from Equipment equipment to equipment) ------------- -----------------------

i) Bought-out items Following standard bought-out items shall be

accepted on the basis of manufacturers' test certificates:

- LV current transformers

- Standard AC motors

- AC /DC DBs

- Push button station in manu-facturers' standard enclosure

- LT power, control & instrumentation cables

and cable termination / jointing kits

- Starters in manufacturer's standard enclosure



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- Light fittings - Field instruments

- Conduits

- Cable trays

ii) Final inspection & testing:

- Verification of test certi-ficates - Visual & Workmanship - Dimensional - Witnessing of routine tests as per relevant

standards. Manufacturers' test certi-ficates for type test to be submitted for verification.

- Witnessing of proto-type tests, as applicable.

05.01.05 Tests, test certificates and documents

For each of the items being manufactured, following test certificates and documents (as applicable for each of the equipment) in requisite copies shall be prepared and submitted to the Inspecting Engineer for scrutiny & records.

i) Materials identification & physical and chemical test certificates for all

materials except IS:2062 -1992 and FG 150 IS:210-1978 materials used in manufacture of the equipment.

ii) Welding procedures and welder's qualification test certificates, wherever applicable.

iii) Routine/type/calibration/acceptance/special test certificates for electrical items.

iv) Surface preparation and painting certificates.

v) Certificates from competent authority for the items coming under statutory regulations.

The Contractor shall be required to produce the specimen and test pieces on which tests were carried-out by his sub-contractors and if called for, samples and specimen shall become the Purchaser's property.



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Where facilities for testing do not exist in the Contractor/sub-contractor's laboratories or in case of any dispute, samples and test pieces shall be drawn by the contractor/sub-contractor in presence of Inspecting Engineer and sealed samples shall be sent to any approved laboratories for necessary tests at Contractor/sub-contractor's cost.

The Purchaser/consultant shall have the right to be present and witness all tests being carried out by the Contractor/sub-contractor at their own laboratory or approved laboratories. Also, the Purchaser/consultant shall reserve the right to call for conformatory test on samples, at his discretion.

Should the result of tests not come within the margin specified, the tests shall, if required, be repeated at Contractor's cost without any liability to the Purchaser.

05.01.06 Method of giving inspection calls

Inspection calls shall be given by the Contractor. All calls shall accompany four sets of relevant test certificates and inspection report of the Contractor/sub-contractor after satisfactory completion of internal inspection and tests by them as per approved QAP.

05.01.07 Obligations of the Contractor

The Contractor shall provide all facilities and ensure full and free access of the Inspecting Engineer of the Purchaser to the Contractor's or their sub-contractor's premises at any time during contract period, to facilitate him to carryout inspection & testing of equipment during manufacture of equipment.

This clause shall be read along with Vol.I for further details.

05.01.08 Stamping and issue of inspection memo & certificate & waiver 05.02 Testing 05.02.01 General

Test of all equipment shall be conducted as per latest IS. Tests shall also confirm to International Standards IEC/VDE/DIN/BS.

All routine tests shall be carried out at manufacturer's works in presence of purchaser or his representative.



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The tenderer shall submit type test certificates for similar equipment supplied by him elsewhere. In case type test certificates for similar equipment is not available, the same shall be conducted in presence of purchaser or his representative if purchaser so desires, without any financial implications to pur-chaser. Heat run test shall be conducted in one of HT transformer. Special Test on FRLS cables also to be carried out.

The site tests and acceptance tests to be performed by contractor are detailed below.

The contractor shall be responsible for satisfactorily working of complete integrated system and guaranteed performance.

05.02.02 Site Tests And Checks General

All the equipments shall be tested at site to know their condition and to prove suitability for required performance.

The test indicated in following pages shall be conducted after installation. All tools, accessories and required instruments shall have to be arranged by contractor. Any other test which is considered necessary by the manufacturer of the equipment, contractor or mentioned in commissioning manual has to be conducted at site.

In addition to tests on individual equipment some tests/ checks are to be conducted / observed from overall system point of view. Such checks are highlighted under miscellaneous tests but these shall not be limited to as indicated and shall be finalised with consultation of client before charging of the system.

The contractor shall be responsible for satisfactory working of complete integrated system and guaranteed performance.

All checks and tests shall be conducted in the presence of client's representative and test results shall be submitted in six copies to client and one copy to Electrical Inspector. Test results shall be filled in proper proforma.

After clearance from Electrical Inspector system/ equipment shall be charged in step by step method.

Based on the test results clear cut observation shall be indicated by testing



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engineer with regard to suitability for charging of the equipment or reasons for not chargings are to be brought by the contractor.

05.02.03 Site Tests

The tests to be carried out on the equipment at pre-commissioning stage shall include following but not limited to the following :

1.0 Transformer

1. IR test on each winding to ground and between windings. 2. Turns ratio test on each tap

3. Polarity and vector group test

4. Measurement of winding resistance by Kelvin bridge

5. IR, wiring and operational tests on all control devices in control cabinet, oil level indicator, winding and oil temp. indicators, cooling fan etc.

6. Checking of earthing wrt transformer tank (flexible from top cover to tank)

other parts, neutrals and tank to electrodes of LAs (for LAs located near to transformer)

7. Testing of buchholz relay for alarm and trip conditions.

8. For bushing CTs, tests applicable shall be as for current transformers.

9. Setting of oil/winding temperature indicators, level gauge and checking of alarm/trip circuits.

10. Check insulators for cracks.

11. Checking for oil leakage and arresting of leakages (if there)

12. Checking of operation of all valves.

13. Checking for open position of all the valves (except drain and filter valves)



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14. Filteration of oil by using line filter, vacuum pump, and heater set.

15. BDV test on oil samples from top and bottom.

16. Checking of oil for acidity, water content tan delta etc. as per IS 335.

17. Measurement of magnetising current and no load loss.

18. Measurement of PI value.

19. Checking of silicagel breather.

20. Checking of noise level at no load and at full load.

21. Checking of air circulation conditions for indoor transformers.

22. Conducting magnetic balance test

23. Checking of other points given in manufacturer's commissioning manual.

24. Back charging of the transformer and checking of voltages at different tap positions.

2.0 220 kV CIRCUIT BREAKER

1. IR test on each pole by Megger (Between poles and lower poles to

ground). 2. IR tests on control circuits. 3. Functional check of breaker operation on minimum and maximum

specified control voltages 4. Checking of interlocks with isolators & earthing switches. 5. Checking of remote operation and tripping from protection relays and

from other devices as per approved scheme. 6. Measurement of contact resistance 7. Checking tightness of termination connectors. 8. Checking tightness of earthing connections. 9. Checking of insulators for cracks etc. 10. Checking the settings of pressure switches. 11. Check operation of breaker at minimum specified pressure. 12. Check for closing and opening time and simultaneous closing of all poles

through oscillograph 13. Tripping of circuit breaker at reduced or over voltage i.e. at 70% & 110% .



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3.0 220 kV ISOLATOR & EARTH SWITCH

1. IR test by HV Meggar on main poles. 2. IR test on control circuits. 3. Measurement of contact resistance for all three phases. 4. Functional checking for electrical and manual operation. 5. Checking of interlocking with breakers 6. Setting and checking of auto trip operation of motor on complete close /

open position of isolator (close/open operation are to be repeated ten times to observe).

7. Testing of overload relay of motor 8. Checking for remote operation. 9. Checking of operation on minimum and maximum specified voltages

(local as well as remote). 10. Checking tightness of earthing connections. 11. Checking of insulators for cracks.

4.0 198 kV ARRESTOR

1. Continuity check (for metal oxide type only) 2. Check for connection to ground. 3. Check insulators for cracks. 4. Check working of counters 5. HT and IR test of each element

5.0 Current Transformer

1. IR test on each winding, winding to earth and between windings.

2. Checking of winding ratios by primary injection set.

3. Polarity check on each winding.

4. Continuity check for all windings.

5. Check for connections to correct taps.

6. Measurement of knee point voltage and secondary winding resitance for

the CTs used for differential protection. 7. Checking of continuity and IR values for cables from CT to Marshalling

box.



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8. Checking tightness of earthing connections.

9. Check output after loading of the main circuit.

6.0 Potential Transformer

1. IR test of primary winding by HV megger between windings and earth

2. IR test of secondary winding by LV megger between windings and

winding to earth

3. Checking of voltage ratio

4. Verification of terminal markings and polarity

5 Checking of continuity and IR values for cables from PT to Marshalling Box

6. Checking tightness of earthing connections

7. Checking of insulator for cracks

8. Check output on charging of the system with connected meters/relays

7.0 N G T

1. Measurement of resistance 2. IR test by HV megger between terminal and earth. 3. Checking of earth connection for terminal and for body 4. Check for isolator operation and continuity of aux. contacts (if applicable) 5. Check for temp. rise of enclosure and current flow in the resistances.

8.0 Bus duct

1. IR measurement before and after HV test

2. Checking tightness of bolts with torque wrench

3. Checking for phase sequence marking



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4. Check for clearances between phase to phase and phase to earth

5. Check for minor damages/cracks in supporting insulators/bushings

6. Checking of busbar cracks on bends by DP method and rectification of

same

7. Checking for inspection openings/accessibility for replacement of

insulator etc.

8. Check tightness of earthing connections on enclosure

9. Checking of silica gel breather

10. Checking of working of space heater (if there)

11. Hot air blowing to remove moisture if required

9.0 HT Switchgear

1. IR test before and after HV test.

2. HV test with HV testing kit.

3. Functional test for all feeders

4. Testing and calibration of all meters

5. Checking and calibration of overload relays and protective relays as per supplier's commissioning manuals.

6. Check operation of contactors from local and remote points

7. Checking of interlockings between incomers/bus coupler and other

feeders.

8. Test to prove interchangeability of similar parts

9. Tests to prove correct operation of breakers at minimum and maximum specified control voltages.

10. Checking operation of RC circuit (if there) for tripping of circuit breaker

after disappearance of control voltage

11. Checking of earthing connection for neutral-earth bus, cable armour,



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location of E/F CT etc. as per the scheme.

12. Check test, service and drawout position of all the breakers and operations of mechanical flag indicator and electrical indication lamps.

13. Check functioning of various elect. schemes like autochangeover

signalling etc.

14. Contact pressure test 15. Testing of CT as per CT testing details given below. 16. Breaker : IR value checking with breaker ON. Phase to phase & phase to earth and between phases in off position

10.0 LT Switchgear/MCC

1. IR test 2. HV test with 1.1 kV megger 3. Functional test for all feeders 4. Testing of all meters 5. Checking and calibration of overload relays and protective relays as per

supplier's commissioning manuals. 6. Check operation of contactors from local and remote points 7. Checking of interlockings between incomers/bus coupler and other feeders. 8. Test to prove interchangeability of similar parts

11.0 PDB/DCDB

1. IR test before and after HT test 2. HV test by 1.1 kV megger



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3. Checking for functions of components for each module 4. Checking for interchangeability of similar components 5. Checking of tightness of earth connection. 6. Testing and calibration of all indicating meters 7. Check output of each feeder after energisation.

12.0 AC Motors

1. IR test of stator and rotor windings.

2. Check tightness of cable connection 3. Winding resistance measurement of stator and rotor. 4. Check tightness of earth connections. 5. Check space heaters and carryout heating of winding (if required) 6. Check direction of rotation indecoupledcondition during kick start 7. Measure no load current for all phases. 8. Measurement of temperature of body during no load and load conditions. 9. Check for tripping of motor from local/remote switches and from

electrical/technological protection including differential protection. 10. Checking of vibration. 11. Checking of noise level. 12. During load running , measurement of stator and bearing temperatures (if

applicable) for every half an hour interval till saturation comes. 13. Checking tightness of foundation bolts 14. Check continuity of temp. detectors. 15. For actuator drives following shall be checked/tested :



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- Visual and dimensional - IR and operation of limit switches - Winding resistance

13.0 Battery

1. Checking for completion of civil/ventilation requirement of battery room. 2. Checking of adequacy of charger output/requirement wrt current required for

battery charging as per the manual. 3. Check availability of safety devices, water and first aid box. 4. Check polarity of connections between battery and charger. 5. Visul inspection test for level and leakages. 6. Checking of layout as per approved drawing. 7. Checking of IR value from positive to earth and negative to earth. 8. Checking of voltage per cell and total voltage between positive negative and

earth to positive/negative and also tap call voltage (as applicable). 9. Checking of tightness of connectors on each cell. 10. Checking of capacity test and hourly measurement of specific gravity and

voltage for each cell 14.0 Battery Charger

1. IR test 2. HV test 3. Checking voltage ratio of boost and float mode transformers 4. Checking for charging mode of batteries, constant current and constant

voltage mode. 5. Load test on chargers by running of DC drives and by liquid resistance

system. 6. Checking of tightness of earthing connections.



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7. Check for all alarm conditions. 8. Checking and calibration of all indicating meters. 9. Check functional operation of charger, auto/manual change over from float to

boost and boost to float etc. 10. Checking and setting of all relays 11. Check AC ripple in boost and float mode after charging. 12. Check polarity of cables connected to battery.

15.0 UNINTERRUPTED POWER SUPPLY

1. Visual check

2. IR value by megger 3. Current limit test 4. Ripple test 5. Supply variation 6. Functional test 5. Capacity test wrt time

16.0 Cables & Cables Supporting Structures

1. Checking of continuity/phasing and IR values for all the cables before

and after HV test. 2. HV test and measurement of leakage current after termination of cable

kits (for HT cables). 3. Checking of earth continuity for armour and fourth core (if applicable). 4. Check for mechanical protection of cables. 5. Check for identification ( tag numbr system) distance placement of cable

marker, cable joint etc. as per the cable layout drawing.



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6. Check earthing of cable structures. 7. Check clearances from ventilation duct and light fittings for cable

structures. 8. Check proper fixing of cable structures.

14.0 Indoor Lighting

1. Check dressing of cable 2. Measurement of lux level at various places 3. Check accessibility for replacement of lamps 4. Checking for black spots or poor visibility near operating and indicating

equipments 5. Check for mechanical protection of cables 6. Checking for adequacy of emergency DC light 7. Checking for starting system of periphery lighting 8. Check for auto switching of battery supply on failure of AC 9. Checking of earthing of light panel, socket boards, light fittings 10. Checking of type of fittings wrt specification at various locations 11. Check adequacy of support of fittings

12. Check water tightness of outdoor located panels

15.0 Earthing

1. Check tightness of all earth connections 2. Check earthing of all metallic equipments, cable trays, busbar supporting

structures, yard fencing steel structures of yard, rails, gates, building column (if steel) all elect. equipments, gas/oil/water pipe lines etc. as per



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the drawing /specification 3. Measurement of earth resistance for each electrode. 4. Measurement of total earth resistance. 5. Measurement of earth loop resistance for E/F path of biggest LT drive.

16.0 Control, Relay & Metering Panels

1. IR value test by megger 2. Checking of control cable connection. 3. Operational test of all components mounted on control panel. 4. Testing and calibration of indicating meters 5. Testing of all relays including aux. relays for their pick up drop up values,

operation at all taps (current, voltage and time) etc. as per the manufactuerr's commissioning manuals with the help of relay testing kits.

6. Setting of relays as per approved setting table and checking its operation

for one below and one upper settings, in the scheme. 7. Measurement of current and voltage in relay operating coils by secondary

injection in CT and PT circuit at switchboard. 8. Measurement of current and voltage in relay and meter circuits during

loading of the primary circuit/system 9. Testing of all schemes for their functions as per approved drawings 10. Checking stability of differential protection schemes 11. Checking inter changeability of similar equipments 12. Verification of accessibility of all operating points including resetting knob

of relays 13. Check operation of each annunciation facias, operation of bell/hooter etc.

and sequence of the system 14. Check operation of relays at minimum/maximum control voltage as per



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the specification 15. Integrated testing of protective relays for operation of master trip relays

and tripping of breakers from operatin of master trip relay 16. Check dressing of cables, sealing of openings in gland plate and for

provision of double compression glands 17. Check earthing connection of panels, fixing of panels and openings from

side and bottom. 18. Checking and adjustment in trivector meters as per the manufacturer's

instructions. 17.0 Miscellaneous

1. Checking of continuity of the system 2. Checking of phase sequence from overhead line to consumer end 3. Checking safe accessibility of all operating points 4. Check availability of emergency lighting 5. Check availability of control/aux. supply 6. Ensure availability of first aid box, fire fighting equipments, earth

discharge rods, rubber mats, rubber glove 7. Check working of ventilation system for battery room - transformer room

etc. 8. Check proper covering of cable channels. 9. Placement of shock treatment chart, danger boards, provision of boards

indicating 'Man on Work, Do not switch ON', 'Do not switch OFF', 'EARTHED' etc.

10. Check proper dressing of cables, mechanical protection of cables,

placement of cable markers 11. Check sealing of all cable openings including conduit opening with fire

resistance material 12. Check sealing of all openings at bottom of elect. panels.




TS VOL IV Sec. A Ch - 06 Page � of �

06. LIST OF PREFERED MAKES

HT(11KV) SWITCHGEAR ABB/ AREVA/ BHEL/SIEMENS TRANSFORMERS

a) GENERATOR TRANSFORMER *CGL/BHEL /KEC / TR / EMCO / ALSTOM

b) LT Transformer BBL/CGL/ALSTOM/ KEC/EMCO

/ INDCOIL / VOLTAMP/TR

CURRENT TRANSFORMER AE /ABB/ JYOTI / KAPPA /

WSI/INDCOIL

POTENTIAL TRANSFORMER AE /ABB/ JYOTI / KAPPA / WSI / INDCOIL

415V SWITCHGEAR L&T / SIEMENS / CONTROL &

SWITCHGEAR /GE (ALSTHOM) / SCHNEIDER

MOTOR CONTROL CENTRES SIEMENS/BCH/GE-POWER / L&T / C&S/ECC/ SWITCHING CCIRCUIT/ HCE/TECHNOCRATS/TECHNO-COMMERCE/SEN & SINGH/M K Engineers/POWER & PROTECTION/ SCHNEIDER

LT CIRCUIT BREAKER, SIEMENS/ BCH/ DISTRIBUTION

BOARD GE(ALSTHOM)/ L&T/ C&S/ SCHNEIDER / FULLY DRAWOUT SINGLE FRONT

UPS SIEMENS / HIREL / EMERSON/GE /

DB POWER CONTROL SOLID STATE ANNUNCIATOR APLAB/ L&T/ ELECMECH/

PROCON/ MINILEC/ CONTROL-





AND DYNAMICS

NUMERICAL PROTECTION RELAYS SIEMENS/ ABB/ AREVA FOR LT SYSTEM SCHNEIDER/ L&T(MM30)/ ASIDA

NUMERICAL PROTECTION RELAYS AREVA / SIEMENS / ABB / L&T

FOR HT SYSTEM AUXILIARY RELAYS AREVA/ EASUN/ ABB/ L&T/

GE/ SCHNEIDER/ SIEMENS/ BCH/ ROCKWELL

AMMETER/ VOLTMETER/ AEP/ IMP/ MECO AE/GEC//

L&T WATTMETER/ VAR-METER

VOLTAGE/ POWER/ CURRENT/ ABB/ AEP/ SIEMENS/ FREQUENCY/ ENERGY TRANSDUCER ELSTER / ADEPT

MOULDED CASE CKT BREAKER SIEMENS/ GE POWER/ L&T/

ABB/ SCHNEIDER/ BCH/ ANDE-RW YULE

INDICATING LAMP SIEMENS/ VAISHNO/ TECHNIK/

(CLUSTER LED TYPE) BINAY/ J-AUER

HOOTER/ BUZZER/ BELL GETCO/ KHERAJ/ EDISON/ KAKKU HT CABLES RPG/ UNIVERSAL/ CCI/

NICCO/ TORRENT CABLES/ INDUSTRIAL/ INCAB/ CRYSTAL/ UNIFLEX / ASIAN / CRYSTAL

LT CABLES RPG/ UNIVERSAL/ CCI/

NICCO/ TORRENT CABLES / INCAB/ CRYSTAL/ UNIFLEX/ POLYCAB/ FINECAB/ INCAB/ RADIANT/ KEI

CONTROL CABLE RPG/ UNIVERSAL/ CCI/





NICCO/ TORRENT CABLES/ INDUSTRIAL/ INCAB/ CRYSTAL/ UNIFLEX/ POLYCAB/ FINECAB/ INCAB/ RADIANT/ KEI/ SPECIAL/ DELTON/ CORDS/ CAPCAB

LOCAL PUSH BUTTON STATIONS SIEMENS/ L&T/ BCH/ BHEL/

C&S/ TECHNOCRAT/ B&C/ MEDITRON/ ELECTRO FABRIC/ HCE/ SEN & SINGH /TECHNO COMMERCE/ SWITCHING CIRCUIT/ VIJAY SWITCHGEAR

LIGHTING FITTINGS PHILIPS/ GE/ BAJAJ/

(SV/MV/MH/FLUROESCENT/CFL) CGL/ WIPRO/ FLOROCRAFT HIGH MAST TOWER BAJAJ/ BP PROJECTS/

PHILIPS/ CGL/ VENTURA STREET LIGHT POLE - OCTAGONAL TYPE BAJAJ/ BP PROJECTS/

PHILIPS/ CGL/ BMW - TUBULAR TYPE ELECTRO STEEL/ QUALITY

STEEL/ CULCUTTA POLES & TUBES/STEEL POLE CORPORATION/ BMW/ JINDAL

HT CABLE JOINTING KITS & RAYCHEM/ 3M/ DENSONS// M

– SEAL TERMINATION KITS CONTACTORS SIEMENS / ALSTHOM / L&T /

CGL / SCHINDIR/BCH/ABB HT HRC FUSES AREVA/ DP/ S&S/ COPPER-

BUSSMAN





TEMPERATURE SCANNER JYOTI / APLAB/SYNTECH / MASIBUS

HV BUSDUCT ECC (KOLKATA)/ STAR DRIVE

NOW KGS ENGINEERING LIMITED (CHENNAI)/ ENPRO (CHENNAI)/ BEST & CROMPTON/ SIEMENS/ BHEL/ CONTROL & SWITCHGEAR

MCCB SCHNEIDER (MG)/ L&T/ ABB/

SIEMENS/ GE POWER CONTROL / CONTROL & SWITCHGEAR/ BCH /MDS( LEGRAND

MINIATURE CIRCUIT BREAKER SIEMENS/ L&T/ GE POWER

CONTROL/SCHNEIDER (PROTEC / MG)/ STANDARD/INDOASIAN/ HAVELLS/ MDS (LEGRAND)/ ABB

LT SQUIRREL CAGE MOTOR ABB/ BHARAT BIJLEE/ CGL/ KEC/

LAXMI HYDRAULICS PVT LTD./ MARATHON/ SIEMENS/ ELGI/ JYOTI/ WEG

TERMINAL BLOCK EPCC/ ELMEX/ PHOENIX

CONTACT/ CONNECT WELL/ ESSEN DEINKI/ WAGO/ LAPP/ S&S/ HANSEL

MIMIC PANELS & ANNUNCIATION PANELS L&T / ADVANI OERLIKON / GE

POWER CONTROL/ BHEL/ BCH/ TRANSRECT/ MINLEC/ TIRUPATI ELECTRONICS/ ADVANCE POWER CONTOL/ CONTROL DEVICES

Battery (Lead Acid) CHLORIDE (EXIDE) /AMCO /

STANDARD /HBL-NIFE (SABNIFE)/ AMAR RAJA

Battery Charger HBL-NIFE(SABNIFE)/ CHHABI

ELECTRICALS/DEBIKAY/ CALDYNE / AMAR RAJA/ HCE





Sl. No. Items Preferred Make 1 220 kV Breaker 1. BHEL

2. Alstom 3. CGL 4. ABB 5 TELK

2 220 kV isolator 1. S&S 2. ELPRO INTERNATIONAL 3. HIVELM 4. GR POWER, Hyderabad

3 198 kV Lightning arrestor 1. CGL 2. Elpro 3. Oblum 4. WSI 5. ABB

4 220 kV CT 1. BHEL 2. TELK 3. WSI/ALSTOM 4. AEP

5 220 kV PT 1. BHEL 2. CGL 3. TELK 4. WSI

6 Insulator/Bushing 1. WSI 2. MODERN 3. BHEL

7 HT Transformer 1. Crompton Greaves Limited 2. BHEL 3. Alstom 4. ABB 5. TELK

8 Control and relay panel 1. Siemens 2. ALSTOM 3. L&T 4. BHEL 5. ABB

9 ACSR Zebra conductor 1. APAR, Mumbai 2. Smita Conductors 3. Deepak Cables 4. Gupta Conductors 5. Alind Corporation


BALIMELA POWER HOUSE, BALIMELA UNITS # 1 TO 6(6x60 MW) R&M WITH NEW TG SET


TS VOL IV Sec. A Ch- - 07 Page 1 of 1

07. LIST OF SPECIFICATION DRAWINGS For specification drawings refer Volume V.




TS VOL IV Sec. A Ch - 08 Page 1 of 6

08. DRAWINGS/DOCUMENT TO BE SUBMITTED BY THE TENDERER 08.01 Drawings/Data alongwith tender

1. Scope of work with general description of the system and equipment offered specifying the important features.

The description to be accompanied by single line diagrams, and equipment layout to enable the Purchaser to have a proper appreciation of the equipment offered and its operation.

2. Bill of Quantities ( unpriced ) in specified format, with division list of supplies

from foreign and indigenous sources.

3 Specific exclusions, if any, from scope of work.

4. Questionnaire as asked in Vol III for generator and Chapter-09 of this volume duly filled-in.

5. List of deviations from technical specifications, if not included under individual

equipment in Chapter 04.

6. List of commissioning spares and consumables included with the main offer.

7. List of 2 years operation spares, recommended by the tenderer equipment wise (unpriced), in addition to the mandatory spares asked by the purchaser.

8. List of special tools and tackles, test jigs and special instruments required for

operation and maintenance of generator static excitation system, AVR, protection relays. For all other electrical equipment, individual list of special tools and accessories required is to be furnished for each item.

9. Phase-wise requirements of power for construction, erection/testing activities.

10. Technical catalogues of equipment offerd.

11. List of total aux. drives for unit and common system including Air condition etc.

for main plant with kW rating, enclosure class, class of insulation, cable size, frame size, duty cycle, places of control, rpm, type of drive (cage, slip ring etc.) starting method, technological interlocking etc. in a format.

12. Construction/ Erection Plan.





16. Electrical layout of Control Room and main plant indicating location of all LT switchgears, LT transformers control/relay panels and main cable routes, cable gallery, cable shafts, with equipment entry approaches etc.

17. Dimensional details & weights of each equipment offered (tentative)

18. Any other information tenderer feels to submit to understand the quotation in

complete.

Note : FAILURE TO COMPLY WITH ABOVE MAY BE ITSELF SUFFICIENT REASON TO REJECT THE OFFER.





08.02 Data/Drawings to be submitted by supplier after placement of order 08.02.01 GENERAL

- Name of co-ordinators with address, telephone/FAX numbers for all sub-contractors, pertaining to electrical job.

- List of equipment/tools and manpower proposed to be arranged for

installation erection and site handling of the equipment.

- Name of site incharge with office/organisation and date of opening of site office.

- Quality control manuals

- Detailed list of drawings and documents containing information on current

state of the project.

- Monthly progress report furnishing status of

• Planning • Manufacture • Transport • Erection • Testing & commissioning

08.02.02 FOR APPROVAL

A. Calculations

1. Relay settings with calculations and graph for justification of all relay settings (current, voltage and time).

2. Calculation to justify generator CT/PT parameters like VA burden, knee point

voltage etc. for all cores. 3. Calculations for Required battery capacities of the UPS system.

5. Calculations for voltage drop and short time rating of cables to prove adequacy

of sizes.

6. Calculation of resistance values of NGTR & kVA of earthing transformer.





7. Calculation of lux levels of Control Room. 8. calculation w.r.t. generator busduct sizing, temp rise and insulator spacing

9. Calculations for short time withstand of transformers.

10. Capacity calculation of Battery and charger

B. Drawings and Documents

1. Single line diagram indicating transformers , breaker, CT/PT, all relays, meters, LA, cable sizes, details of CT/PT ratio, VA burden, Vk value, type and make of all relays, their range, nominal and short time ratings of breakers, busbars etc. for all equipment.

2. Front view and GA diagrams for all panels.

3. Control and schematics drgs. for local/remote control/protection for each

equipment and drives.

4. Drive list.

5. Synchronisation schemes.

6. Auto change over arrangement

7. Logic diagrams for start/stop of various mechanism/drives

8. Lighting layout for Control Room and other areas. Type of fittings, wiring arrangement, switching of fittings and single line diagram from board to fittings.

9. Details of protection logic (class A,B&C tripping) indicating list of electrical and

mechanical protection leading to tripping of turbine generator, field breaker etc.

10. Equipment Earthing layout drawing

11. Electrical equipment layout for all electrical premises.

12. Cable structure layouts with size of structures for gallery and cable channels of different places





13. Sequence of inspection plan and despatch of materials to site.

14. List of drawings, numbering system, size, proposed date of submission (To be submitted just after LOI).

For Information 1. Details of painting for all equipment

2. Bus wire arrangement for control/signal/annuncia-tion and heater supplies of control panels and switch boards.

3. Cable schedule indicating type of cables, from to via. route, total length, size of

each cable and a final summary sheet indicating total requirement of all types of cables (for control and power both).

4. Core wise control cable termination details indicating ferrule no./terminal block

no. for each cable/each equipment.

5 .Internal wiring diagrams for all panels.

6. VI characteristics and RCT values of CTs used in differential protection.

7. Cable layout drawings.

8. Technical particulers of all LT motors and recommended protection.

9. Catalogues for each type of equipment, relays, meters etc.

10. Installation and commissioning manuals for each equipment, relay etc.

11. Operation and maint. manuals indicating trouble shooting procedure for all equipment.

12. Type test certificates for all the major equipment.

13. Details of test results conducted at works for all equipment in bound Volume

14. Details of test results conducted at site for all equipment in bound Volume

15. Spare part list number and ordering procedure for all recommended spares.





16. Details of transport arrangement and maximum size of transportable section (weight and overall dimensions).

17. Details of agency proposed to be fixed for doing erection commissioning job.

18. Panel wise bill of material indicating type make and brief technical particulars of

all items/ accesssories mounted on the panels.

19. Overall GA of all the panels/equipment

20. Fixing details of all the panels/equipment, supporting structures, etc.

21. Heat loss for each equipment. 22. Static and dynamic loading of each equipment

23 .Floor cutouts and wall opening details for cables bus duct, air conditioning

ducts, light conduits, exhaust fans etc.

24. Details and location of various inserts base plates, bolts etc. required to be provided for support of cable structure, bus duct elect. panel etc.

25. Conduit layout drawing indicating type, size, length and locations of conduits

required to be placed in RCC wall/floor, brick wall. 26. Technical data sheet for each type of motors and characteristic curves for protection

settings. 27. As built drawings incorporating site changes along with soft copies in CD.



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TS VOL IV Sec. A Ch -09 Page 1 of 32

09. TECHNICAL PARTICULARS TO BE SUBMITTED BY THE TENDERER 09.01 GENERAL

1. Instructions

The data called for below is to be furnished by the bidder and in case the bidder becomes the supplier, the data shall form part of the contract covering the work. The performance figures quoted shall be guaranteed within the tolerances permitted in the relevant standards.

2. Bidder's Name (For Electrics)

1. Trade Name of Bidder : 2. Address for correspondence :

3. General conditions

Is it the Bidder's intention, if awarded the contract, to comply fully and in all respects with the Owner's

specification ? Yes/No If 'NO' is answered to any of the above questions, the

biddershallstatethe exceptions in details, clausewise, partwise

and chapter wise.

4. Tenderer to submit all data/ information / drawings / spare part list pertaining to electrics, generator, static excitation &AVR system in one volume. - Agreed

5. Tenderer visited the site and under stood the job & location of various stood.

equipment. - Yes



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09.02 DESIGN CONSIDERATIONS 1.0 Loading (unit wise) :

1.1 Cold start up : 1.2 Hot start up : 1.3 Full Aux. load on one unit :

2.0 Battery capacity required : Number AH (for the equipment/system of tenderer's scope)

3.0 Any other aux. supply required : Indicate with (other than 415 V AC & 220 DC) purpose. 4.0 List of drives/mechanism with kW : List to be enclosed

needs DC power supply

Spares and tools & tackles

1. List of commissioning spares : List to be submitted 2. List of special tools and tackles : List to be submitted

Summary Of Technical Parameters Of Major Electrical Euqipment

Sl. No.

Equipment

Description

& Qty.

Make & type

Country of manufactu

re

Total Weig

ht.

Single largest

package dimensions

& wt.

Applicable std.

Rating as per design conditions of tender

Guaranteed tech. Data



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09.03 220 kV EQUIPMENT

220 kV CIRCUIT BREAKER 1. T y p e :

2. Service :

3. P o l e :

4. Rated Voltage :

5. Maximum permissible voltage corresponding to rated breaking current, kV :

6. Rated Frequency :

7. System Neutral Earthing :

8. Insulation Level :

8.1 Impulse withstand voltage :

8.2 One minute power frequency withstand voltage :

9. Rated Current :

9.1 Continuous at 50o C :

9.2 Short time current for 3 Secs. : 10. Rated transient recovery voltage for terminals

Faults :

11. Rated line charging breaking current :

12. Rated low power factor, small inductive

breaking current :

13. Rated Breaking Capacity :

13.1 Symmetrical :

13.2 Asymmetrical :

14. Rated making capacity :

15 Creepage distance :

16. Rated short-time current characteristics :

17. No. of breaks in series per phase :



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18. Total break time (from the instant of trip coil

energisation), ms :

19. Make time (from the instant of closing coil

energisation), ms :

20. Reclosing :

21 Operating Duty :

21.1 For gang - operation :

21.2 Operating Mechanism :

22. Auxiliary Voltage :

22.1 Closing :

22.2 Tripping :

22.3 Spring Charge Motor :

22.4 Compressor Motor :

22.5 Heater/Lamp/Socket :

23. Type of operating mechanism :

23.1 Motor operated spring charging :

23.2 Pneumatic :

23.3 Shunt trip coils :

23.4 No. of coils :

23.5 Voltage rating :

23.6 Permissible operating voltage limit :

23.7 Power requirement, W :

24. Mounting :

25. Phase to Phase spacing :

26 Terminal Connector :

27. Type :

28. Suitable for :

29. No. of spare NO & NC auxiliary contacts :

30. Whether specified interlocks provided :



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31. Total / protected creepage distance of

supporting insulators, mm / mm :

32. Photostat copies of type test certificates for :

32.1 Breaking capacity :

32.2 Short-time rating :

33. Weight of each complete circuit-breaker unit, kg :

34. Overall dimensions of circuit-breaker assembly,

mm x mm x mm :

35. Pneumatic operating mechanism :

35.1 Type (whether centralised) :

35.2 Make and model number :

35.3 Capacity of each compressor :

35.4 Type of compressor motor :

35.5 Voltage ratings of compressor motor, V :

35.6 Continuous kW rating of compressor motor :

35.7 Temperature rise of motor winding above 500 C

Ambient :

35.8 Protective devices provided for compressor

Motor :

35.9 Volume of air storage reservoir, cu m :

35.10 Normal operating pressure for closing the

circuit-breaker, kg / sq mm :

35.11 Minimum pressure at which the breaker will operate, kg sq mm :

35.12 Quantity of free air required for one O-CO-CO sequence of operation of one breaker at minimum allowable operating pressure, cu m :

35.13 Quantity of free air required for one O-CO-CO sequence of operation of one breaker at minimum allowable operating pressure, cu m :



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35.14 Pressure in kg / sq mm at which low pressure

alarm is given :

35.15 Pressure in kg / sq mm at which circuit-breaker is automatically tripped and locked out :

35.16 Whether duplicate piping system provided : 35.17 Material of air piping : 35.18 Enclosed catalouge No. for compressed air system : BUSHINGS/SUPPORT INSULATOR

1. Rated Voltage :

2. Impulse withstand voltage :

3. Power frequency withstand voltage :

4. Creepage :

5. Pollution level as per IEC 71 :

6. Insulators shall also meet the requirement

Of IEC-815 having alternating sheds with

creepage factor less than or equal to four (4). :

220 kV ISOLATOR

1. Type :

2. Service :

3. Pole :

4. Rated voltage :

5. Rated Frequency :

6. System Neutral Earthing :

7. Insulation Level :

7.1 Impulse Withstand Voltage :

7.1a To Earth & Between Poles :



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7.1b Across isolating distance :

7.2 One Minutes Power Frequency withstand Voltage :

7.2a To Earth & Between Poles :

7.2b Across isolating distance :

8. Rated Current :

8.1 Continuous at 50`C ambient :

8.2 Short time current for 3 Secs :

8.3 Peak Short time current :

9. Creepage distance :

10. Operating Mechanism :

10.1 Main blade :

10.2 Earth Switch :

11. Auxiliary Voltage :

11.1 Motor :

11.2 Control & Interlock :

11.3 Heater/Lamp/Socket :

12. Mounting :

13. Phase to Phase Spacing :

14. Operating type :

15. Corona extinction Voltage :

16. Terminal Connector

16.1 Type :

16.2 Suitable for :

17. Material of earth blade :

18. Whether specified interlocks provided :

19. Type of operating mechanism (whether motor

operated spring charged) :

20. Voltage rating of closing mechanism, V :

21. Permissible operating voltage limit :



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22. Power required by closing mechanism, W :

23. No. of spare NO & NC auxiliary contacts :

24. Total/protected creepage distance of

supporting insulators :

25. Photostat copies of type test certificates for :

25.1 Short time rating :

25.2 Peak short-circuit current :

26. Weight of each complete unit, kg :

27. Overall dimension of each complete unit, mm x

mm x mm :

28. Enclosed catalogue No. :

220 kV CURRENT TRANSFORMER

1. Type :

2. Service :

3. System Details :

3.1 Voltage :

3.2 Frequency :

3.3 System Neutral :

4. I nsulation Level :

4a 1 minute 50 Hz withstand :

4b Impulse withstand :

5. Short-time Current :

5a Rated 3-second current :

5b Rated dynamic current :

6. Type of insulation :

7. Creepage distance :

8. Mounting :

9. Terminal Connector :

9.a Ty pe :



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9.b Suitable for :

10. Make and model number :

11. Standards followed :

12. Temperature rise over 500 C ambient while

carrying rated primary current :

13. Total / protected creepage distance of

supporting bushing insulator, mm x mm :

14. Ratio, accuracy class, VA burden :

15. Photostat copy of type test certificate for shorttime

Rating :

16. Overall dimensions of one single- pole unit,

Mm x mm x mm :

17. Weight of one complete single-pole unit, kg :

198 kV LIGHTNING ARRESTOR

1. Type :

2. Service :

3. Make and model number :

4. Standards followed :

5. Voltage :

6. Nos. of phases :

7. Frequency :

8. L.A. Rating :

9. Nominal discharge current :

10. Discharges class :

11. Level :

11.1 1-minute 50 Hz withstand :

11.2 Impulse withstand :

12. Maximum continuous operative voltage ( MCOV) :



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13. Spark Over Voltage :

14. Minimum power frequency :

15. Maximum 1.2/50 micro sec :

16. Current for pressure relief test :

17. Mounting :

18. Terminal Connector :

19. Suitable for :

20. Ground terminal :

21. Whether the results of various tests like voltage

withstand tests etc. conform to those specified in

IS:3070 :

22. Whether all specified fittings and accessories,

leakage current indicator etc. have been provided :

23. Total / protected creepage distance of supporting

insulator, mm / mm :

24. Enclose catalogue No. :

25. Overall dimensions of one single-pole unit,

mm xmm x mm :

26. Weight of one complete single-pole unit, kg :

ACSR CONDUCTOR

1. Make :

2. Standard followed :

3. Diameter of complete conductor, mm :

4. Weight of complete conductor, kg / m :

5. Characteristics of protective grease :

6. Ultimate tensile strength, kg :

7. Modulus of elasticity, kg / sq cm :

8. Coefficient of linear expansion per 0 C :



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9. Standard drum length, m :

GALVANISED STEEL WIRE

1. Make :


3. Ultimate tensile strength, kg :

4. Diameter of complete wire, mm :

5. Weight of complete wire, kg / mm :

6. Modulus of elasticity, kg / sq cm :

7. Coefficient of linear expansion per 0C, kg / sqcm :

8. Standard drum length, m :

INSULATORS

1. Make :


3. Manufacturer’s type designation :

4. No. of discs used per string insulator assembly :

5. Total creepage distance of :

5.1 Each disc insulator unit, mm :

5.2 Complete string insulator assembly, mm :

STRUCTURAL STEELWORK

1. Grade of steel for :

1.1 Steel members :

1.2 Nuts and bolts :

1.3 Other fasteners :

2. Minimum thickness of steel used for various

Members :

3. Galvanized details :



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4. Minimum diameter of bolts :

5. Maximum tension considered, kg :

5.1 phase conductor :

5.2 Shield wire :

CONTROL & RELAY PANEL FOR 220 kV EQUIPMENT

Control Panel Relay panel

1 Make :

2 Type :

3 Reference Standard :

4 Degree of protection :

5 Equipment Mounting :

a. All relays, meters and switches are flush mounted:? :

b. Relays furnished in drawout cases with built-in test

facilities? :

6 Overall dimensions & weight :

7. Control switches for circuit breakers

a) Make :

b) Type :

c) Type of handle provided :

d) No. of positions :

e) No. of contacts

i. Normally closed :

ii. Normally open :

8. Indicating lamps

a) Make :

b) Type :

c) Operating voltage :

d) Size of lamps :



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e) Wattage of lamps :

f) Colours of lamps :

9. Switch board wiring

a) Insulation of wiring :

b) Size of wiring conductor for the following :

i. PT circuits :

ii. CT circuits :

iii. DC supply circuits :

iv. Other circuits :

c) Size of earthing bar for safety earthing :

d) Type of terminals provided on wiring :

e) Wiring conductor material :

10. Indicating meters :

a) Type of instrument :

b) Size :

c) Whether magnetically shielded or not :

d) Limits of error in the effective range :

e) Max. scale length :

f) Whether tropicalised :

g) Short time over load capacity :

h) VA burden :

i) Temp. at which the instruments are

calibrated :

j) Maker’s name :

k) Description leaflets / references submitted :

11. PROTECTIVE RELAYS (To be furnished for each relay)

a) Make :

b) Type :



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c) Current coil rating :

d) Tap range :

e) VA burden :

i) Highest tap :

ii) Lowest tap :

f) Power consumption

i) Highest tap :

ii) Lowest tap :

g) Time of operation of max. time setting at

i) 5 times tap setting current :

ii) 10 times tap setting current :

h) Type of characteristics (Amp) :

i) Trip contact rating :

j) Whether seal in contact provided or not :

12. Space heaters in control cubicle

a) Rated voltage :

b) Power consumption at rated voltage :

13. Enclosures

(a) Whether relevant drawings for all the

Equipments enclosed :

(b) Whether all the type test reports for all the

equipments enclosed :

(c) Whether descriptive technical features for

All the equipments enclosed :

09.04 HT EQUIPMENT

09.04.01 11kV Circuit Breaker



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01 Make :

02 Type :

a) Manufacturer’s Type Number

:

b) Type of Circuit Breaker :

c) Closing Mechanism : Motor operated spring assisted

d) Trip free/fixed trip : Trip free

03 Standards followed :

04 Rated Current at

a) Design temp, Amp :

b) 50oC ambient temp, Amp

:

05 Indoor/Outdoor : Indoor metal clad drawout type

06 Service voltage :

07 Maximum voltage at which breaker can operate continuously

:

08 Making Capacity kA (peak)

:

09 Breaking Capacity

a) Symmetrical kA (RMS) :

b) Asymmetrical kA (RMS)

:

10 Short time current for 3 seconds kA (to be not less than symmetrical breaking

:



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current)

11 Total make time Milliseconds

:

12 Total break time Milliseconds (5 cycles or less)

:

13 Make break time Milliseconds

:

14 Poles : 3

a) No. of breaks in circuit per pole

:

b) Total length of breaks per pole

:

c) Speed of closing :

15 Insulation Level

a) One minute power frequency with stand voltage kV (RMS)

: 27

b) Impulse withstand voltage (1.2 x 50 micro sec. Wave) kV (PEAK)

: 60

16 No. of contacts with auxiliary switch

a) Normally open (NO) :

b) Normally closed (NC) :

c) Whether it is possible to change NO contact to NC contact & vice versa at site

:

17 Type of arc control device :



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18 Arc duration time

a) 100% breaking capacity

:

b) 10% breaking capacity :

19 Does magnetic effect of load increase contact pressure

:

20 Control supply voltage and permissible operating range

a) For spring charging motor

: 220 V DC, 85% - 110%

b) For closing and tripping coils

: 220 V DC, 85%-110% for close coil 220 V DC, 70%-110% for trip coil

21 Details of spring charging motor

a) Rating of spring charging motor at 220 V DC

:

b) Nominal current :

c) Starting current and duration of run of spring charging motor for full charging of closing spring

:

d) Type of spring charging motor

:

22 Power required at 220 V DC

a) For closing coil Watts :



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b) For tripping coil Watts :

23 Weight of circuit breaker and truck kg

:

24 Weight of cubicle (without truck) kg

:

25 Minimum number of operations for breaker without need for inspection or replacement of circuit breaker pole units

a) Off/On operation at rated current

:

b) Off/On operation at rated short circuit current

:

26 Contacts type and materials

a) Main :

b) Arcing :

c) If silver plates, thickness of silver plating

:

27 Maximum temperature rise over designed ambient in the cubicle oC

:

28 Overall dimensions (LXDXH) for different type of cubicles

:

29 Type of enclosures for switchgear

:

30 Degree of protection :



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offered by the cubicle

09,04.02 GENERATOR CT-PT-SURGE PANEL, NGTR

CURRENT TRANSFORMER Current Transformer Gen. Gen. Neu. Ph. C.T. C.T. ---- -----

1. Name of the manufacturer : 2. Type & Service-Indoor/Outdoor : 3. Insulation level, KV :

4. Rated short time thermal current for three (3) sec. KA, rms :

5. Temperature rise over an ambient temperature of 50 deg. c at -

a. Rated primary current : b. Rated short time thermal current for three(3) secs. :

Voltage transformer

1. Insulation class, KV : 2. Basic insulation level, KV peak :

3. Rating a. Voltage ratio : b. Rated output, VA : c. Accuracy class :



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d. Connection :

4. Over voltage factor - a. Continuous : b. 30 seconds :

5. Temperature rise above 50oC ambient

a. At 1.2 x rated primary voltage continuous : b. At 1.9 x rated primary voltage for 30 secs. :

LIGHTNING ARRESTOR

1. Make : 2. Service : 3. Type : 4. Voltage rating, KV rms : 5. Minimum power frequency spark-

over voltage, KV rms :

6. Arrestor insulation withstand test voltage -

a. Impulse, KV crest : b. Power frequency, KV rms 1 minute dry : 1 minute wet : SURGE CAPACITORS

1. Name of the manufacturer : 2. Service :

3. Type : 4. Rated voltage, KV :



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5. Rating -

a. Capacity in micro farad/ pole : b. Guaranteed tolerance :

6. Insulation class, KV : 7. Test voltage between terminals- a. A.C. for 1 min. : b. D.C. for 10 sec. :

8. Catalogue furnished? : 9. Details of Discharge resistor :

NEUTRAL GROUNDING TRANSFORMER

1. Name of the manufacturer : 2. Service : 3. Type & catalogue no. : 4. Transformer cooling type :

5. Rating

a. Rated KVA : b. Rated high voltage, KV : c. Rated low voltage, Volt : d. Rated frequency, C/s. : e. Phase, No. : f. Impedance, % :

g. Reactance, % : h. Resistance, % :

6. Details of Tapping a. Type : b. Rating : c. No. and range of taps :



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7. Temperature rise above 50deg.c: 8. Basic impulse level, KV peak : 9. One (1) minute power frequency test withstand voltage, KV rms : RESISTOR

1. Name of the manufacturer : 2. Type : 3. Service : 4. Referred standard : 5. Rating a. Voltage, volts : b. Current, Amps : c. Time rating, min. : d. Resistance, Ohms : e. Guaranteed tolerance, % :

6. Temperature rise above 50deg.c : 7. Material used

09.05. RELAYS

Indicate type & make of relays proposed to be provided for

- Generator Protection - Static excitation Transformer Protection - Generator Transformer Protection - Auxiliary Transformer Protection

09.06 TRANSFORMER

(Tenderer to fill up for HT & LT transformer separately)



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A. Guaranteed data

Rating

a. Rated KVA :

2. a. Temperature rise above 50 deg. C ambient for oil filled type

i. Oil by thermometer, Deg. C : ii. In winding by resistance deg.C :

b. Hot spot temperature in winding limited to deg. C :

3. Losses

a. No.load loss at rated voltage and frequency : b. Load-loss at rated current and at 75 deg.C :

4. Impedence at rated current frequency at 75 deg. C, % :

5. Zero sequence impedance, % :

6. Efficiency at 75 deg. C and

0.8 p.f. lag % :

a. at 100% load : b. at 75% load :

c. at 50% load :

B. General Details LT HT

1. Name of manufacturer :



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2. a. Service-whether indoor or outdoor: b. Type-core or shell :

3. Reference standard :

4. Type of cooling :

5. Rating

a. Rated current, amp (rms)

HV : LV :

b. Rated voltage, KV

HV : LV :

c. Generator Transformer capable of withstanding 125% rated voltage for 1 minute and 140%rated voltage for 5 secs.? : Yes/No

6. a. Terminal arrangement i. HV : ii. LV : b. Winding insulation category i. HV : Uniform/Non-uniform ii.LV : Uniform/Non-uniform

c. Insulation level as per IS:2026 (Part-III) or IEC-76-3 :

7. Type of tap changer :

8. Taps a. Capacity :



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b. Steps and range : c. Tapping provided on HV side ? : Yes/No

9. No load current referred to H.V and 50 c/s 100 % rated current : voltage.

10. Withstand time without injury for

a. Three phase dead short circuit at terminal with rated voltage maintained on the other side, sec. : b. Single phase short circuit at terminal with rated voltage maintained on the other side, sec. :

11. Insulation strength

a. One minute power frequency test KV rms i. H.V. : ii. L.V. : iii. L.V.Neutral : b. Impulse withstand voltage, KV i. H.V. : ii. L.V. : iii. L.V.Neutral :

12. Insulation oil a. Approx volume of oil, liter : b. Whether first filling of oil with 10% excess furnished ? :



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c. Oil conforms to IS:335 ? :

13. Marshalling Box a. Weatherproof, suitable for outdoor for oil filled type ? : Yes/No b. Degree of protection : 14. a. Type of valve : b. No. of valve comprising one complete set (break up of valves shall be given) :

09.07 GENERATOR BUS DUCT

1. Make : 2. Rated voltage frequency : 3. Continuous current rating (main & tap off) : 4. Busduct material & cross section : 5. Bus duct enclosure material & thickness : 6. Heat loss in bus duct at rated current :

Middle phase kW/m : Outer phase kW/m : Total heat loss kW/m : Loss in bus bar kW/3 phase/m :

Loss in busduct enclosure kW/3 phase/m : 7. Short circuit rating : ……KA………Sec : 8. Insulation level KV (RMS)/KV peak : 9. Bus duct Wt/m :

09.08 LT SWITCHGEAR,MOTOR CONTROL CENTRES, AC DISTRIBUTION

BOARDS, DC DIST. BOARDS, DC STARTER PANEL & RESISTORS AND LOCAL AC STARTERS

NOTE : Tenderer to furnish the following data separately for each of the above equipment.



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- EQUIPMENT ASSEMBLY - Make: - Type: - Reference Standard: - Short Circuit Rating:

a. Interrupting Symmetrical KA rms. b. Short-time for 1 Sec. KA rms. - Metal enclosed: construction? Yes/No - Degree of Protection: - Thickness of sheet metal: a. Front b. Back c. Side d. Bottom/Top - Dimensions of vertical: section in mm (LxDxH) - CONSTRUCTION:

- Drawout features provided for: a. Circuit breaker with SERVICE, TEST & ISOLATED position Yes/No : b. Voltage Transformers Yes/No : c. Protective Relays Yes/No : d. MCC modules Yes/No : - MCC completely compart-: mentalised ? Yes/No



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- All meter, switch and relays flush mounted type Yes/No : - CIRCUIT BREAKER - Make: - Continuous current rating a. As per manufacturer's

standard: b. Derated factor (if any) for: site condition - Symmetrical interrupting :

capacity(MVA) - Making current (peak), KA :

- Rated 1 second current, :

KA (rms) - Whether drawout, semi-drawout, : or non-drawout type ? - Closing mechanism a. Type: b. Rated voltage of coil: c. Emergency closing mechanism: provided ? - Rating of motor used in breaker closing mechanism - Shunt trip coil a. Type : b. Rated voltage of shunt trip : coil



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- Total opening time (measured from : trip coil energisation) cyc/m.sec

09.09 MOTORS 09.09.01 LT MOTORS (AC)

1. Make and type, reference standard : 2. Class of insulation : 3. Enclosure class : 4. Frame size : 5. Temp. rise over max. site ambient : for winding for enclosure 6. Min. volt to start : 7. Whether all motors are from one make 8. Type of protections envisaged : Electrical/Technological

9. Deviations if any on technical : design data

09.10 CABLES (HT/LT Power control cables)

The bidder shall indicate the following for each type and size of cables:

1. Make : 2. Type : 3. Shielding on Conductor



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(H.T. Cables) a. Material : b. Type : c. Thickness mm : d. Whether extruded : Yes/No

4. Insulation a. Material : b. Type : c. Thickness mm :

09.10.01 Cable Termination kit

XLPE PVC cable cable Make : Type : Complete with all accessories ? :

09.11 UPS SYSTEM:

Make :

Capacity :

Overload :

Capacity of convertor :

Overload capacity : of Invertor



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Battery Make : Type AH Capacity

Harmonics at rated load

- with battery :

- without battery :

Overall dimensions of the : panels

Schematic diagram : (to be enclosed)

09.12 DC SYSTEM

09.12.01 DC BATTERY

1. Make & type & applicable standard : 2. No. of battery sets : 3. Rated cell voltage & no. of cells/battery : 4. AH capacity :

09.12.02 BATTERY CHARGER

1. Make & Type & applicable standard : 2. Rated input voltage :

3. Rated output voltage & current

a) Float :

b) Boost : 4. % Ripple content DC Bus

without battery :



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At No load : At full load :

5. Type of SCR control :

6. Control & Protection Features Float charger :

Boost charger : 7. Enclosure type :

8. Overall dimensions :

9. No. of float cum boost chargers :


UNITS # 1 TO 6 (6x60 MW) R&M WITH NEW TG SET


TS VOL IV SEC A ANX – I Page 1 of 1

ANNEXURE-I

SELECTION OF POWER COMPONENTS & WIRING FOR CONTINUOUS DUTY CAGE MOTOR DRIVES

Motor Rating at S1 Duty (KW)

Minimum Rating of MCCB

*

Minimum rating of Contractor (AMPS) AC3 duty

Minimum size for internal power connections

Minimum size power cable (Copper) termination (sq. mm)

Copper wire (mm2)

Aluminum Flat

** ( mm x mm)

Up to 3.7 25 4 4 x 2.5 (Copper)

5.5 100 40 4 4 x 2.5 (Copper)

7.5 100 40 6 3 x 6 11 100 40 6 3 x 16 15 100 63 10 3 x 16

18.5 100 63 16 12 x 2 3 x 35 22 100 30 100 100 25 12 x 2 3 x 35 37 100 100 35 15 x 3 3 x 70 45 200 160 50 15 x 3 3 x 70 55 200 160 70 20 x 3 3 x 95 75 200 200 95 20 x 5 3 x 150 90 400 400 - 20 x 5 3 x 150

100 400 400 - 30 x 5 2(3 x 95) 125/135 400 400 - 40 x 5 2(3 x 95)

160 400 400 - 40 x 5 2(3 x 150) * MCCB rating shall be finalised in consultation with manufac turer of MCCB to

achieve type `2' protection. ** Copper flat of equivalent size can be used instead of aluminium flat

Number of cores on cables shall depend on earthing system.


UNIT # 1 TO 6 (6x60 MW) R&M WITH NEW TG SET

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TS VOL IV SEC A ANX II Page 1 of 7

ANNEXURE II 11. LIST OF MANDATORY SPARES FOR EACH UNIT (Six sets for six Units) 11.01 Generator LAVT

1. Lightning arrestor with complete : 1 set

assembly

2. PT assembly : 1 set

3. PT primary HT fuse : 5nos.

4. MCB : 10 nos.

5. Fuse : 20 Nos.

11.02 Generator CT

1. Phase CT of each class & type : 1 no. each

11.03 11 kV Bus Duct

1. Epoxy resin insulators used for main bus : 5 Nos.

2. Epoxy resin insulators used for tap off connection : 5 Nos.

3. Seal off bushings of each type in use : 2 Nos

4. Complete set of gaskets used in bus duct : 1 Set

assembly for 1 unit

11.04 Generator Transformer / 20MVA Transformer / Unit Auxiliary

Transformer (As Applicable)

1) H.V. side bushing. : 1 No.



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2) L.V. side bushing. : 1 No. 3) H.V. neutral bushing. : 1 No. 4) Buchholz relay (with alarm/trip contacts). : 1 No. 5) Oil surge relay (with alarm/trip contacts). : 1 No.

6) Magnetic oil level gauge (with alarm/trip contact). : 1 No. 7) Current Transformer of WTI. : 1 No. 8) Dial type oil temp. indicator with alarm/trip contact. : 1 No. 9) Winding temperature indicator with alarm/trip contacts. : 1 No. 10) Silicagel breather with silicagel charger. : 1 No. 11) Set of Gaskets for bushings. : 1 No.

12) Differential Pressure gauge of each type : 1 Set

13) Pressure gauge of each type : 1 Set

11.05 Neutral Grounding Cubical

01. Supporting insulators : 5 nos. 02. Resistor unit : 2 sets of banks

11.06 Control Relay Panel / Desk

01. Indication Lamps 50 Nos.

02. Semaphor Indicator 4 Nos.



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03. Control Fuse 50 Nos

04. Control Switches / Selector Switches (Each Type) 2 Nos.

05. Meters (Indication Only) (Each Type) 1 No.

06. PLC Card 1No. for each type

07. Relays (Protective and Aux.) (Each Type) 1 No.

08. Power Supply Card / units for relays (Each Type) 2 Nos.

(If applicable)

09. Hooter / bell etc 2 Nos. each type

10. Isolating switch

a) AC supply : 1 no. of each type b) DC supply : 1 no. of each type

11. Terminal blocks : 3 sets

12. Timers of each range : 2 nos.

11.07 11 kV Switchgear

01. Breaker Closing coil & Trip Coil 1 each

02. Breaker Spring charge Motor 1No.

03. Breaker Contacts (Fixed & Moving) 1 each

04. Current Transformer of each type 1Set each

05. Potential Transformer 1Set

06. HT & PT Fuses 10 Nos.

07. Control Fuse 50 Nos.

08. Vacuum Interrupter 1 No.

09. Aux. Relays / Contactor (Each type) 2 Nos.

10. Push Buttons and selector Switch 1No. each type



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11. Indication Lamps, holder with resistance 15% of Qty. used

12. Test / Service Position Limit Switch 2 Nos.

13. Meters (each Type) 1 No.

14. Transducers (Each Type) 1 No.

11.08 LT Switchboard

01. Breaker Closing coil & Trip Coil 1 each

02. Spring charge Motor 1No.

03. ACB Contacts 1 Set

04. Current Transformer of each type 1Set each

05. Potential Transformer (Each Type) 1Set

06. Fuses 50 Nos.

07. ACB Arc Chutes 1 Set

08. MCCB / MPCB (Each Type) 5 Nos.


10. Push Buttons and selector Switch 1No. each type


12. Contactors Complete (each Type) 3 Nos.

13. Aux. Contacts of Contactors (each Type) 5 Nos.

14. Close Coil of Contactors (each Type) 5 Nos.

15. Transducers (Each Type) 1 No. 16. O/L Relay (each Type) 3 Nos.

17. Meters (each Type) 1 No.



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11.09 Uninterruptible Power Supply System

01. Electronic Cards (Each Type) 1 No.

02. Meters (Each Type) 1 No.


04. Switch / Push Buttons (Each Type) 2 Nos.


06. Control Fuse 50 Nos.

. 11.10 AC Motors

1. Valve drive 1 of each type 2. Bearings 3 set of each type 3. Fans 3 nos. each type

11.11 220 KV CIRCUIT BREAKER Sl. No. Item Quantity 1 Compressor with motor 1 No. 2 Solenoids/valves 1 set 3 Support insulator 2 Nos. of each type 4 Closing coil 1 set 5 Tripping coil 1 set for complete

replacement 11.12 220 KV ISOLATOR Sl. No. Item Quantity 1 Moving blade 2 sets of each type and

rating 2 Fixed blade 2 sets of each type and

rating



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3 Earth switch moving blade 2 sets of each type and rating

4 Earth switch Fixed blade 2 sets of each type and rating

5 Arcing contacts 2 sets of each type and rating

6 Support insulator assembly 2 sets of each type and rating

7 Motorized operating assembly 1 set of each type and rating

11.13 CONTROL AND RELAY PANEL FOR 220 kV EQUIPMENT Sl. No. Item Quantity 1 Control switches 2 Nos. of each type 2 Selector switches 2 Nos. of each type 3 Push buttons 2 Nos. of each type 4 Indication lamps assembly (LVGP LED

type) 10 Nos. of each type

5 Power and control contactors 2 nos. of each rating and type

6 Multifunction meter 1 no. of each type 11.14 220 KV OVERHEAD LINE Sl. No. Item Quantity 1 Tension insulator string assembly complete

with deadend compression clamp etc. suitable to “Zebra” ACSR

i. Single tension type ii. Double suspension type

6 Sets 1 Set

2 Suspension insulator string assembly complete with suspension clamp suitable for “Moose” conductors covered with armour rods for :

I Single tension type

2 Sets



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Ii Double suspension type 1 Set 3 Preformed armour rod suitable for :

a) 54/7/3.53mm “Zebra” ACSR 10 Nos.

4 Vibration damper suitable for “Zebra” ACSR

10 Sets.

11.15 MAINTENANCE TOOLS & TACKLES

01. Breaker lifting/handling truck : 1 nos. 02. Breaker racking handle : 2 nos. of each board 03. MCC tray racking handle : 3 nos. of each board 04. Panel keys : 5 nos. for each board 05. Test cabinet with coupling cables : 2 nos. for each board for testing breaker in withdrawn position 06. Indication lamp extractor : 2 nos. for each board 07. Programming device for programming

and changing setting of relays for numeric relay: 1 set




TS VOL IV

VOLUME – IV

TECHNICAL SPECIFICATION CONTROL & INSTRUMENTATION


BALIMELA POWER HOUSE, CHIPLIMA UNIT #1 TO 6 (6X6OMW) R & M WITH NEW TG SET


TS VOL IV Sec .B Page 1 of 46

CONTROL & INSTRUMENTATION

01.00.00 GENERAL

a) This specification is intended to define the basic requirements of

instrumentation & control system for R&M with New TG for the Unit- 1 to 6

along with their auxiliaries as specified in the tender document.

The basic philosophy of C&I system should cover entire 6 units in totality and

shall be based on the state–of– the–art microprocessor based control system.

The C&I system shall ensure safe, efficient and smooth operation of the plant

and equipment with minimum intervention of the operating personnel during

normal working of the plant, load fluctuation/shut-down and start-up of the

unit.

The Tenderer shall furnish the complete Control and Instrumentation system

including Distributed Control System (DCS) or Programmable Logic Control

(PLC) based system, Primary and Secondary Instruments, Panels, Control

Desks, Alarm Annunciation System, Electric Power Supply System, Actuators,

Instrumentation Cables and Process Connection impulse tubing,

Actuators/MOV(Motor Operated Valve),

b) The Tenderer shall provide all material, equipment and services so as to

make a totally integrated Instrumentation and Control System together with all

accessories, auxiliaries and associated equipments ensuring operability,

maintainability and reliability. This work shall be consistent with modern

power plant practices and shall be in compliance with all applicable codes,

standards, guides, statutory regulations and safety requirements in force.





c) Further, Tenderer shall also include in his proposal and shall furnish all

equipment, devices and services, which may not be specifically stated in the

specification but are needed for completeness of the equipment/systems

furnished by the Tenderer and for meeting the intent and requirements of the

specification.

d) Standardisation and Uniformity of Hardware to ensure smooth and optimal

maintenance, easy inter-changeability and efficient spare parts management

of various C&I instruments / equipment like vibration monitoring systems, all

4-20mA electronic transmitters/ transducers, control hardware, control valves,

actuators and other instruments/ local devices etc. being furnished by the

Tenderer for TG and station auxiliaries for similar applications, the Tenderer

shall ensure that they are of the preferable same make, series and family of

hardware.

f) The equipment shall employ latest- state- of the- art technology to guard

against obsolescence. In any case, Tenderer shall be required to ensure

supply of spare parts for mininum10-15 years. In case, it is felt by the

Tenderer that equipment / component is likely to become obsolete, the

Tenderer shall clearly bring out the same in his offer and indicate steps

proposed to deal with such obsolescence

02.00.00 SCOPE OF WORK AND SUPPLY

The scope of work shall include design, engineering, procurement, inspection,

supply, packing, transportation to site, storage, calibration, erection, testing

and commissioning of all instrumentation and control equipment, cables,

pipes, auxiliaries and erection hardware necessary for completion and





handing over of instrumentation and control work for the unit after integrated

final commissioning.

02.01.00 The scope of work shall also include all civil works, like chipping, digging,

concreting including filling material etc. associated with erection of

instruments and associated equipment.

02.02.00 Measurement and control equipment offered will be complete in all respect

and any equipment / accessories not explicitly indicated in this specification,

but considered essential for proper functioning of equipment and process will

be included in the Contractor’s scope of supply and work

02.03.00 The scope of work and supply shall also include but not limited to the

following:

02.03.01 The instrumentation system shall cover for New TGs and its auxiliaries as

covered in this specification.

02.03.02 A proven dedicated 1:1 Hot redundant centralised Distributed Control System

(DCS)/ PLC based system for each unit shall be envisaged with this package.

02.03.03 Redundant Electro Hydraulic Turbine Control system with redundant actuator

shall be envisaged for each turbine.

02.03.04 Electro – Hydraulic control unit will be envisaged for Servo Rotary Valves.

02.03.05 The instrumentation equipment for all units of hydel power plant with their

auxiliary facilities as covered in the specification and also as felt necessary by

the successful Tenderer for the completeness of the job.





02.03.06 Fully wired panels, cabinets, desks, racks, transmitter cabinets and junction

boxes

02.03.07 All signal, control & Power cables shall be FRLS armoured types or

manufacturer standards cables required for instrumentation work.

02.03.08 All field instruments (4-20mA) shall be replaced by new SMART type 2 wire

transmitters.

02.03.09 All local field mounted instruments for New TGs shall be newly envisaged.

02.03.10 Turbine Vibration monitoring system and measurements with sensor and

converter box shall be provided for New TGs as per manufacturer standards.

02.03.11 All existing Impulse tubes, conduits shall be replaced by new SS impulse

tubes and conduit.

02.03.12 All Erection materials Like as Cable tray, cables fittings joints etc shall be

under scope of bidder

02.03.13 Submission of drawings and documents as per clause no. 05.03.00

02.03.14 Arranging of inspection of DCS/PLC & governor, excitation system at the

Original equipment manufacturer premises (Refer electrical inspection clause)

02.03.15 Erection, calibration, testing and commissioning of the total equipment included

in this specification. All tools and tackles, special testing equipment and

consumables required for erection and commissioning activities shall be

arranged by the tenderer.





02.03.16 Supply of C&I Mandatory spares for trouble free operation as per the list

enclosed in clause no 06.02.00

02.03.17 Commissioning spares.

02.03.18 Maintenance platforms and access ladders for instrumentation equipment

installed at inaccessible heights.

02.03.19 Compliance with `General Technical Rules' as indicated under clause no.

04.00 of this specification.

02.03.20 Tenderer may please note that for all imported instrumentation /equipment

selection of vendors shall be made in such a way that the provision of after

sales service and supply of maintenance spares for at least for ten years shall

be ensured.

02.03.21 All skid mounted instruments shall be as per OEM standards

02.03.22 In case of offshore vendors, It is preferable to select offshore sub-vendors,

who already has an associate/subsidiary/service agency in India who will give

after-sales service.

02.03.23 Names of offshore vendors considered shall be given in tender.

02.03.24 The client reserves the right of selecting the manufacturer / model of control &

instrumentation items in the interest of standardization wherever necessary

and the Contractor will agree to supply equipment of particular make if so

desired by the client without any cost implication. Manufacturer / model of





control & instrumentation items will be as per Contract. Any specific

requirement for change shall be approved by the Customer before finalization.

02.03.25 Any C&I equipment required during any stages for the efficient / safe / reliable

operation of the plant either during detail engineering / commissioning will be

supplied, installed and commissioned by the successful Contractor without

any additional cost as per technological and operational requirement at any

stage of project implementation.

03.00.00 DESIGN CRITERIA

03.01.00 In general, instrumentation equipment considered shall be electronic type and

micro-processor based. Signal from primary field transmitters to remote

instruments in the control room shall be 4-20 mA DC. The pneumatic signals

from converters to actuators shall be 0.2 - 1.0 kg/cm2 i.e.( 3-15 psi). if

required.

03.02.00 Same transmitters shall be used for measurements and control .

For critical measurements tenderer shall provide 2 out of 3 voting (Two out

of three philosophy shall be adopted for the control of all the critical loops).

The control system shall select the median value for the control purpose. .

03.03.00 Metering Bases

Pressure above 0.1 kg/sq. cm kg/sq. cm

Pressure below 0.1 kg/sq. cm

and draft

mm WC

Vacuum mm Hg or mm WC

Differential pressure mm WC





Temperature Degree Celsius

Flow (liquid) Cu.m/hr.

Flow (lub. oil) litres (totalised)

Level mm, cm, m

03.04.00 Instrument tapping points, root valves and connections shall

be followed as :

Root valves of reliable and rugged construction shall be provided at the

tapping points of process pipeline. Connection sizes to be adopted for the

instrumentation tapping points for measurement, control and test shall be as

follows:

Pressure measurement 1/2" NB SW

Temperature measurement On 1 1/2" flanged thermowell

with rating 300 # as minimum

Flow, level and differential

pressure measurements

1/2" NB SW

External displacer level

instrument

1 1/2" flanged 300 # minimum

Internal displacer level

instrument

4" flanged

Level gauge on vessel 1" flanged 300 # minimum

Level gauge on stand pipe 1" flanged / SW

Pneumatic connection for

signal and air supply

1/4" NPTF

Electrical connection 1/2" NPTF





03.05.00 Transmitters and Primary Elements

SMART transmitters providing a 2 wire output of 4 - 20mA DC shall be

provided with Digital local display indicators, for pressure, flow, level and

differential pressure measurements along with on line calibration and shall be

communicated with HART calibrator. The accuracy of these transmitters shall

be of minimum ± 0.1% of span or better. These shall be installed as close to

tapping points as possible from layout consideration for important signals

control and indication measurements shall be with separate transmitters.

The measuring elements of the transmitter shall be designed to withstand a

minimum static pressure of 1.5 times the maximum span without damage or

permanent deformation. For pressure / differential pressure transmitter, proof

pressure shall be 2 times of maximum static pressure of the process.

All pressure transmitters shall have easily accessible span and zero

adjustments. A range suppression/elevation facility shall be built-in.

Sensing elements and internal parts shall be made of material that is

corrosion resistant to process fluid. In general SS 316 may be used. All

pressure and differential pressure instruments shall be provided with block

and bleed, bypass, drain/vent valves etc. as per installation requirement of

the manufacturer. Direct mounted pressure switch shall be of either

diaphragm or bellow type of SS 316 or better with 1/2" NPT (F) connection.

For selection of level transmitters/controllers, the following type shall be

offered:





• External displacer type instrument with routable head shall normally be

used for level measurement up to 1219 mm. Displacer shall be of SS-

316 with inconel torque tube. Side connections shall normally be used.

• Differential pressure transmitters shall be used for level measurement

above 1219 mm or for services requiring purge or where liquid might

boil in external portion.

• Level switches shall generally be external ball float types with flanged

head.

All level gauges / transmitters shall be provided with drain connection to be

ultimately taken to ground level.

For temperature measurement using Resistance Temperature detector (RTD)

or thermocouples, the measurement shall be provided with cold junction

compensation. Compensating cables shall be brought up to the control room.

All the thermocouples and RTD's shall be as per manufacturer standards.

Local temperature gauges shall generally be bimettalic type with 150-mm dial

size. Wherever chances of vibration are present, filled type gauges with

additional capillary extension shall be used.

Flow measurement shall normally be done with concentric orifice plate

mounted between a pair of weld neck flanges of minimum 300 lbs ANSI rating

with flange taps.





03.06.00 Instrument Cables

Fire retardant low smoke (FRLS) PVC cables (IEC-60332.1, 1993) having

solid 7 strand conductor of 1.0 sq. mm twisted pair have been considered for

control and signal cables from field /junction box (in field) to marshalling rack

in the control room. This signal cable shall be of overall screened or as per

manufacturer standards.

a. Instrument cables shall be 660V grade with annealed and tinned electrolytic

grade solid copper conductor of 1.0 sq. mm dia insulated with extruded

PVC, suitable for conductor temperature of 70 deg. C - outlet sheathed by

extruded FRLS PVC colour (Blue/Orange) as per manufacturer standard

practice.

03.07.00 Power Supply

Power supply for entire C&I system shall be from Un-interruptible Power

Supply System (UPS) with battery backed. The input power to UPS shall be

415 volts, 50 Hz from redundant source.

UPS Output Voltage 240V ± 1% AC

Frequency 50 Hz ± 0.5%

Total Harmonic

distortion

Less than 2%

Input Voltage 415 V ± 10%, 50 Hz

The detail UPS specification is furnished in the electrical part of this Technical

Specification.





03.08.01 Distributed Control System (DCS/PLC)

This clause defines the technical requirement to the Distributed Control

System (DCS)/PLC for the Hydel Power Plant. Bidder shall be responsible for

engineering, selection and connection of all components and sub-system to

form a complete system whose performance shall be in accordance with the

functional, hardware, software and other requirements of the specification.

The successful bidder’s activities in compliance with the present specification

shall include design, analysis, issue of drawings / documents, manufacturing,

inspection and testing, packing, shipping, storage and commissioning as well

as furnishing of instruction & maintenance manuals. The main purpose of the

DCS/PLC shall allow the plant to be automatically managed in all the foreseen

operative conditions, while generating the reliability, availability,

maintainability requirements relative to the entire plant.

The system shall be placed in an air-conditioned environment, the

temperature may vary 21 deg. C to 36 deg. C with 55% + 5% relative

humidity. If the air conditioning system breaks down, the DCS/PLC shall be

able to operate, without any problem caused to the functions, with an outside

temperature between 18 deg C to 52 deg C and a non-condensing humidity

between 40% and 80%.

All dedicated systems like EHTC, SRV unit Turbine supervisory system will

also be connected to the DCS/PLC through soft link/Hard wire link, so that all

required parameters are suitably monitored and controlled from the DCS/PLC

based HMI system. All required I/O cards and other processing modules etc.

shall be provided for this purpose.

All panels for DCS/PLC, Turbine supervisory instrumentation system, EHTC, SRV unit etc will be located in the local control rooms for each unit at generator hall (0 Mtr. level). Local control room will be renovated with adequate Air – conditioning, illumination and proper glass partitions.





All controller panels shall have inbuilt LCD display with touch screen to monitor and configure locally with proper security level. DCS/PLCs of all units shall be connected to eathernet switch located in networking panel at centralized control room through FO cable.

03.08.02. DCS (Distributed Control System)/PLC (Programmable logic controller)

for Unit- 1 to 6

DCS/PLC shall be latest State-of-the-Art microprocessor based system which

shall be used to execute all the process and safety shut-down logics of the

plant. Every unit shall have individual independent DCS/PLC. This shall be

an independent unit.

i) 1:1 hot standby Redundancy level shall be envisaged for the following items:

• CPU 32 bit level

• Communication card level

• Critical I/Os

• 24V DC Power Supply .However detailed of rating & Power distribution

shall be done during detailed engineering.

• Communication Bus, Ethernet Switches for Connectivity, redundant

modbus

ii) Switch for connectivity with 8/16 port.

iii) Memory will be non volatile. However , in case volatile memory is provided by

battery backup shall be provided with minimum of 3 months life time to keep

the program safe. Battery drain indication shall be provide before final drain

iv) Watch dog timer will be software device.





v) DI,DO and AI/AO Marshalling cabinet shall be finalised during detailed

engineering.

vi) DCS/PLC panel shall be as per manufacturer standards, however panel

dimension shall be finalised during detail engineering.

vii) Interposing Relay 24V ( 1NO+1NC) with LED indication

viii) 240V AC,50Hz UPS Parallel redundant (Refer Electrical TS)

ix) Inside panel minimum 250mm space shall be left from bottom plate

x) Panel shall be fitted with Proper illumination with 2nos. CFL at Front and rear

and 2nos fans.

xi) Tenderer shall ensure full co-ordination of the colour of various components of

the control room viz. walls, ceiling, floor, control desk & other furniture,

which shall be aesthetically appealing. A comprehensive proposal for the

control room & colour coordination shall be furnished to Client/Consultant

during detailed engineering for approval.

xii) Control desk shall be modular type and composition of MDF board and

Aluminum Composite Panel (ACP).

xiii) Colour Combination : Customized during Detailed engineering

xiv) Light Lux Level : As per International norms &Specification

xv) Control room shall be false flooring or granite floor shall be decided during

detailed engineering or Bidder shall proposed as per site condition.

xvi) Designer False Ceiling –Combination of Gypsum & Ceiling tiles,

xvii) ES & Operator console shall be finalised during detailed engineering





xviii) Multiple window facilities/face plate in all the operating station.

xix) 20% installed spare need to be considered in I/Os over and above basic count

xx) 20% spare I/O channels on each card level equally distributed and

• 20 % I/O channels of actual used shall be provided as spare with wired.

• 10% spare installed I/O modules

• 20 % spare module space shall be provided in all the panels.

• 30% spare TBs space with wiring for future use.

xxi) 40% spare in CPU memory even in worst loading condition

xxii) Soft link Communication from DCS/PLC to switch yard SCADA system (if any)

shall be provided.

xxiii) OPC Interfacing facility shall be provided with unit- 7 & 8 DCS/PLC/SCADA

for MIS and level-2 automation system with all necessary software as well as

hardwires (Like cards, converters fiber optical cables etc.) for effective

communication. Minimum 02 nos. of OPC gateway shall be provided.

xxiv) 32/16 channel for all DI/DO in each card wise

xxv) 8/16 channel for all AI/AO in each card wise (AI/AO in same card is not

acceptable) AI module accepting 4-20mA to avoid ground loop formation and

noise pickup.

xxvi) RTD and Thermocouple card shall be separate.

DCS/PLC engineering and application Licensed Software details to

be handed over to client along with Part no. and with latest

version after commissioning etc.

Watch dog timer shall be software based. The healthiness of processor shall

be continuously monitored by watch dog timer. Any hardware or software

problem in the processor system which shall include CPU, memory, power

supply, communication etc. shall cause the watch dog timer to report the

failure of processor and switch over to the bumpless redundant processor.





xxvii) Report/Long Term/Event data archival package/self documentation/test

function/stand builder function/Alarms shall be provided for all operating

station as well as Engineering Station.

xxviii) Report/Long term data archival package/ Shift report package/self

documentation/ Software Manual/

xxix) On line replacement of any module in the DCS/PLC shall be possible in such

a way that removal and addition of a module shall be possible without de-

energizing the system. Further there should not be any interruption in the

system while replacing a faulty module wherever redundant modules are

provided.

xxx) Online logic can be edited/changed and down load without interruption of

DCS/PLC.

xxxi) For communication Fiber optic cable including laying ,termination and its

convertor etc shall be in tenderer scope.

xxxii) Logic chart control loop display/Trending/Graphics/ electronic documentation

History/Alarms software shall be considered for all operating station as well

as ES cum operating stations

03.08.03. Human Machine Interface (HMI)

1. The Human Machine Interface (HMI) system is the primary interface to the

DCS/PLC functionality. It is critical to the operation of the DCS/PLC/PLC. A

secure, flexible and user friendly HMI shall be provided by which engineers,

supervisors & the operators shall interact with the system. The HMI shall

exploit the best characteristics of 22”TFT, Key boards, Cursor control devices

and character / graphic printers.

2. The System Configuration of the proposed DCS/PLC shall be as per Drawing

enclosed with the tender document. Six nos.(6) of 22”TFT Operator Work





Stations (OWS) with one no. (1) of dot Matrix Printer & three (03) nos. of

colour laser printer (A4), three(03) nos. 22” TFT Engineering work station

(EWS) and one number (1) Large Video Screen LCD type 65” with one no.

(1) of colour laser printer(A3) shall be provided at the Main Central Control

Room.

3. The OWS shall consist of computers with 22”TFT, printer, keyboard & . The

computers shall be of commercial grade IBM compatible based on latest and

industry-proven processors. Sufficient memory capacity as per system

requirement with necessary spare capacity shall be provided. All OWS shall

be fully interchangeable i.e. all operator functions including control, monitoring

and operation of any plant area or drive shall be possible from any of the

OWS at any point of time without the necessity of any action like downloading

of additional files. Each OWS shall be able to access all control / information

related data under all operating conditions including a single processor /

computer failure in the HMI. Further, simultaneous operation from a single

display without calling additional displays for multiple drive operation shall be

possible.

The EWS with plant supervision and management capabilities equal to those

of the OWS shall be provided. The EWS shall be able to access the system

data base and modify the elements. The EWS shall have programming

facilities for Control System as well as for HMI system. The system shall have

in-build safety features which shall protect the system against inadvertent and

unauthorized use of these tools. Necessary hard key-locks & software locks

etc. shall be provided for this. The EWS shall allow for the management of

process variables, of the input and output signal address, of the control loop

and control logic structure, of the modalities in which information is presented

to the operator, of the synoptic graphics, of the printing and archiving

protocols and of all those characteristics which are needed to carry out the





tasks assigned to the control system. The engineer shall be able to manage

the systems memory devices through the EWS in order to save the

configuration files. EWS shall also act as Diagnostic Station for automatic

display and recording of any system disturbance to enhance the system

availability. For these all processors, modules / cards, operator console etc.

shall have on-line self-diagnostic features which shall be displayed at

equipment / module level and inform to the EWS to display the fault with

equipment / module identification in clean text. All types of faults and

disturbances in all modules used in the system shall be automatically

displayed and printed. A graphic system that supports the systems self-

diagnosing system shall be created. These graphic pages shall allow for the

identification of any system component that is not functioning perfectly. The

diagnostic pages of the system shall be arranged according to a hierarchical

structure. This self-diagnosis level in the DCS/PLC shall run continuously and

automatically without requesting any type of action to be taken by the

operator.

1 no. of PC with 22” TFT monitor shall be provided for Inventory management system. Necessary hardware and software shall be provided for the same.

03.08.04. Synchronization System (Master Clock)

The DCS/PLC shall be equipped with a master clock system for the

synchronization of modules through a satellite signal (GPS). The system shall

also foresee an adequate number of interfaces for the connection and

synchronization of the other plant control system if required. Facilities for GPS

system shall be provided.

03.08.05. Sequence of Events Recording System (SOER)





The DCS/PLC shall be able to guarantee the chronological recording of the

events (SOE function) relative to the plant & electrical equipment. The time

resolution for this function must be 1 ms or better. The integral SOER system

shall provide the operators with a time-logged log of all conditions which can

directly trip the Turbine-Generator, its auxiliaries, electrical system and other

electrical equipment as well as other conditions which require better time

resolution than the standard alarm printer offers. The SOE system shall be

sized to accept the inputs (minimum 64 nos. for each unit) with 20% spare

capacity for additional inputs.

04.00.00 GENERAL TECHNICAL RULES

04.01.00 The general engineering and calculations shall be made as per prevailing

Indian/ International standards acceptable to Purchaser. Wherever such

standards are not available, they shall be as per practice in India and abroad.

04.02.00 All measurements shall be in metric units.

04.03.00 Scale range shall be selected so that normal process parameter is

approximately 75 % of full scale. The gauges shall be provided with zero and

over range mechanical and over range protection of 125%.

04.04.00 Maintenance platforms with suitable approach shall be provided for flow

elements, control valves, servo valves, critical switches used for

protection and interlocks, annunciation and other equipment installed at

inaccessible locations.

04.05.00 The field instruments shall be of reliable and rugged in construction and of

proven design, suitable for following conditions:





Temperature : 65 deg. C

Relative humidity : 100 % max.

04.06.00 Instruments installed in the open shall be weather proof, dust tight, shock

proof and splash proof. If such instruments are not available, these shall be

housed in weather proof enclosures having IP 65 protection.

04.07.00 Instrument with following accuracy’s shall be offered:

Flow/ pressure /differential

pressure/ temperature

transmitters

:

± 0.1% of calibrated span or better

Panel mounted indicator/

recorder

: ± 0.5% of full scale or better with

minimum denomination of 1% marking

Digital indicator : ± 0.1% of full scale ± 1 count

Pressure gauges : ± 1% or better

Temperature gauges : ± 1% or better

Pressure switch : Repeatability ± 1% or better.

Temperature switch : ±2% or better

RTD : Response time < 20 secs with

thermowell

Thermocouple

: Response time < 20 secs with

thermowell Limit of error –

‘K’ type thermocouple

±3 deg. C < 400 deg. C

04.08.00 Transmitters shall be positioned as close as possible to the measuring points.





04.09.00 Flow transmitters shall be fitted with 3 valves manifold and pressure

transmitters with 2 valve manifold.

04.10.00. Direct pressure measuring instruments shall be diaphragm, bourdon or

bellows type elements depending upon the service conditions. In general,

diaphragm elements shall be used in the range of 0-1000 mmWC

pressure, bellows type elements for ranges of 0-1kg/sq.cm and bourdon tube

elements for ranges greater than 1 kg/sq. cm.

04.11.00. Primary element material shall be corrosion resistant to process fluid or

diaphragm seal shall be provided for protection.

04.12.00 Pressure gauges shall be provided with SS 3 way gauge cocks, single

coil siphons and shall also be with snubbers, diaphragm seal wherever

applicable.

04.13.00. Pressure switches shall be installed with SS 2 way valves with detachable

handles. Electrical connection from pressure switches shall be properly

glanded and bottom entry.

04.14.00 Directly mounted pressure switch shall have elements either diaphragm,

bellows or bourdon type depending on the service conditions. Material of the

element shall be minimum SS 316 & with 1/2" NPTF connections.

04.15.00 For low pressure application where long elements are used, well supported

protecting tube shall be installed to prevent mechanical damage and erosion

of the elements.

04.16.00. Minimum dial sizes of pressure and receiver gauges shall be 150 mm for local

as well as panel mounted gauges.





04.17.00 All the remote monitoring/controlling instruments shall be located in main

control room, which should be dust proof.

04.18.00. Gauge glasses shall normally be reflex or transparent type depending upon

service, with over all length not exceeding 1500 mm.

04.19.00. For liquid level measurements, float, displacer, or differential pressure type

shall be used depending upon the vessel/tank is closed or open type and

the medium for which it is used. Accuracy of measurement shall be 1% of full

scale or better. Wherever necessary standpipes or float chambers shall be

provided and also make up line for filling up the constant vessel shall be

provided.

04.20.00. All flanged end connections of instruments shall be of minimum 150-300 lbs

ANSI standard.

04.21.00. For measurement of Penstock water flow Winter Keneddy type flow meter shall

be used.

04.22.00. Duplex type Thermocouples/RTD should be complete with compensating

leads, installation fittings. The indicators, controllers shall have broken

sensor protection.

04.23.00. Interconnections to/from thermocouples to temperature transmitters shall be

made via compensating cables having thermoelectric characteristics

compatible with thermocouple to which they connect.

04.24.00. In case of compensating leads that are to be laid on the top of any heated

zone, they shall be covered with suitable insulating materials except asbestos





04.25.00. Compensating cables connected to transmitters shall not be through terminal

blocks but shall be directly connected.

04.26.00. Thermocouple/RTD calibration shall conform to relevant IS/DIN standards of

latest revision.

04.27.00. Thermowell shall be drilled out of bar stock and the length and construction

shall comply with process requirement/relevant standards. Material of

construction of thermowells shall be stainless steel /hastelloy/ inconel suitable

for the application..

04.28.00. Self-actuating controllers may be used wherever appropriate.

04.29.00 The panels shall be upright, floor mounted and dead front type and shall have

ventilation with steel mesh. The outside colour of all instrumentation panels,

control desks, consoles, local panels, marshalling cabinets, system cabinets

etc. shall be finalised during detailed engineering stage. The inside colour of

all these panels shall be brilliant white. This shall hold good for

instrumentation panel of all auxiliary units also.

04.30.00 15mm Anti-vibration mounting and shock absorbers shall be provided for all

panels and Control Desks.

04.31.00 The panel surface shall be thoroughly degreased, smoothed, filled and

painted with rust resistant two coats of primer and three coats of paint to

present a smooth and flat finish.





04.32.00 Front of panels shall be primed and filled as required giving at least two

coats of primer and minimum three coats of final colour above the primer

coating to present a smooth and mat finish.

04.33.00. Legend plates shall be provided on the panel face, desk face and for

instruments behind panel/desk to identify equipment.

04.34.00. Overall dimensions of nameplates shall be decided by the text of legend,

maintaining overall consistency and clarity and avoiding size variations.

04.35.00 On the panels, equipment shall not be mounted below 300mm from the gland

plate level. Alarm bells/hooters etc. shall be mounted on the panel top.

04.36.00 Equipment inside the panel shall be so located that their terminals and

adjustments are readily accessible for inspection and maintenance.

04.37.00 Instrument power supply (see clause 04.10) shall be through circuit breaker

(with adjustable short circuit and over load release facility) and 1:1 isolating

transformer. Miniature circuit breakers with fuse shall be provided on the

secondary side for providing power supply to group of 2 – 3 instruments. All

instruments shall have individual switch fuse units mounted on control

desk/panel. Plug and socket shall be provided for each panel and desk for

portable lamp.

04.38.00 The power supply equipment for instruments shall be installed inside the

instrument panel, with proper heat dissipation facility.

04.39.00 Electrical accessories e.g. circuit breakers, control switches, push buttons,

panel lighting fixtures, light switches, hooters etc. required for the panel shall





be from acceptable reputed make and these shall be supplied with the

panels/desks. These should be suitable for the application and environmental

conditions.

04.40.00 All panel wiring, except power and thermocouple circuits, shall be made with

660 V grade PVC insulated 0.5 to 1.0 sq. mm multi strand copper conductor.

Power supply wiring shall be done with 2.5 sq.mm copper conductor.

04.41.00 All terminal blocks shall be provided with minimum 20% spare terminals.

Terminal blocks shall not have smaller than 4 mm terminal connecting screws.

04.42.00 Wires shall run in suitable plastic wiring sleeves between terminal ends and

tagged.

04.43.00 Wires shall run in suitable flexible metallic conduits under the false floor

between terminal ends.

04.44.00 No instrument contact shall be used directly in any alarm or interlock circuits.

It should be always be through relay contacts.

04.45.00 Wherever screened cables will be used for signal transmission, these shall

be of cross twisted pair, shield type shield shall be earthed one end only

inside the control room.

04.46.00 The various flexible cores, within the cables shall be PVC insulated and

numbered and/or identified by a colour code. All cables shall be in accordance

with applicable standards and codes.





04.47.00 Shield shall have 25% overlap and 100% coverage. Shield thickness shall

be 0.06 mm (min.) and tinned copper drain wire of 0,8 mm dia nominal.

04.48.00 Separate cables shall be used for low and high voltages. All the equipment

fed from electrical system and installations shall meet the statutory

requirements of Indian Electricity Rules.

04.49.00 For cable laying, cable trays shall be made of hot dip galvanised steel plates

of minimum thickness of 5.0 mm. Each tray shall be provided with 20% spare

space.

04.50.00 A minimum clearance of 250mm shall be kept between instrument and

power/signal cables.

04.51.00 Cables shall be properly dressed and clamped with the cable trays as per

standards.

04.52.00 Cables which are not laid in the cable trays shall be laid through protective G I

conduits.

04.53.00 Sharp bends in cables should be avoided. Wherever necessary, junction

and pull boxes with proper gland shall be used. Cables shall be laid neatly

and crossing in trays shall be avoided.

04.54.00 Conduits, junction boxes and pull boxes shall be properly grounded.





04.55.00 All instrument cables shall be glanded and terminated both in field

(instruments, JB etc.) and at control room (marshalling cabinet etc.) using

double compression glands.

04.56.00 All the cores of the cables shall be marked with ferrules. Acrylic tags shall be

provided at both the ends of the cables for identification.

04.57.00 After completion of cable laying work, all cable bushings on panels, desks and

cabinets shall be filled with fire resistant sealing compound against the floor.

The instrumentation earthing system wherever necessary must run to a

common pit as per standard.

04.58.00 Erection fittings shall be rust proof.

04.59.00 Seamless SS tubes of size 1/2" (12 mm) dia (1.5 mm thick) or as per

manufacturer standard shall be used for impulse lines. As far as possible

impulse lines shall be welded. Swage-lock or equivalent compression type

joints shall be provided wherever it necessary to open the lines frequently. For

proper drainage, impulse lines from primary point to transmitter shall be laid

with proper gradient

04.60.00 Instrument shall be of SS, provided with expansion loops, isolating valves,

equalising valves, drain valves at suitable places and shut off valves at

tapping points wherever applicable. Process fluids shall not be piped directly

to instruments in the control room.

04.61.00 Integrated control with other Units





05.00.00 List of Measurements, Controls, Alarms And Interlocks

Following are the indicative list of measurements, controls, alarms and

interlocks for the Unit. These Electrical & process measurements shall be

made available at the control room DCS/PLC and local as detailed below.

However the tenderer shall provide these and other measurements as felt

necessary for their system offered as per their standard proven make

05.01.00 Remote measurement

1. Generator

i) Stator Voltage

ii) Stator Current

iii) Field Current

iv) Field Voltage

v) MW

vi) MVAR

vii) Frequency

viii) Power factor

ix) Temperature in different segment of stator wdg and stator core

x) Rotor temperature

xi) Partial Discharge

xii) speed**

xiii) breaking air pressure

xiv) jacking oil pressure

xv) kWh meter





2. Excitation

i) Excitation current

ii) Excitation voltage

iii) Null detector

iv) Excitator winding temp.

v) Kwh meter

3. Generator Thrust Bearing/Upper Guide Bearing/Lower Guide Bearing

i) Bearing pad metal temp. Thrust pads and guide pads

ii) Bearing lube oil temp.

iii) Oil level in bearing lube oil housing

iv) Lube oil pressure

v) Water in oil detector

4. Generator Air Cooler

i) CW inlet temperature

ii) CW outlet temperature

iii) CW inlet pressure

iv) Hot air temp. of each cooler

v) Cold air temp. of each cooler

5. Turbine

i) Turbine Governing Valve opening in % and in mm

ii) Guide vane opening in % and in degree

iii) Guide vane locking indication

iv) Spiral case inlet pressure

v) Draft tube pressure





vi) Turbine speed ( 2 out of 3)

vii) Head cover water level

viii) Shaft seal CW pressure and flow.

ix) Turbine inlet water flow.

x) Turbine inlet water pressure.

6. Governor Oil Pressure Unit

i) Oil level in sump tank

ii) Flow of water to oil cooler

iii) OPU tank oil level

iv) OPU tank oil temperature

v) Gov. Oil pressure

7. Turbine Guide Bearing (TGB)

i) Lube oil temp.

ii) Guide bearing metal temperature

iii) Vibration**

iv) Oil level

v) Water in oil detector

8. CW system

i) CW pump discharge header pressure, flow and temperature.

ii) Cooling water outlet temperature at Oil coolers outlet.

9. Drainage

i) Sump level





10. Air Compressor

i) Compressor delivery pressure

11. Generator Transformer

i) MW

ii) MWH

iii) A

iv) V

v) oil temp

vi) winding temperature

vii) Transformer oil header pressure

12. Unit Auxiliary Transformer

i. A

ii. V

iii. KWH

13. Station Transformer

i. A

ii. V

iii. KWH

** measurements shall be as per manufacturer standards





05.02.00 Local Measurements

Following local gauges shall be envisaged for each unit as a

`minimum :

i) Inlet pressure of spiral casing.

ii) Draft tube pressure.

iii) Spiral casing winter kennedy differential pressure.

iv) Local turbine speed indicator.

v) Guide vane opening indication.

vi) Guide vane servomotor stroke indication (scale).

vii) Governor oil pressure.

viii) Pressure receiver tank oil pressure.

ix) Oil level in pressure receiver tank (gauge glass).

x) Turbine servomotor oil pressure.

xi) Hydrostatic lube oil pressure.

xii) Differential pressure across oil filter.

xiii) Generator thrust bearing/upper guide bearing/lower guide bearing lube oil

inlet pressure.

xiv) Generator thrust bearing/upper guide bearing/lower guide bearing lube oil

temperature.

xv) Generator thrust bearing/upper guide bearing/lower guide bearing metal

temperature.

xvi) Turbine guide bearing oil and metal temperature.

xvii) Turbine guide bearing lube oil inlet pressure.

xviii) Oil level in bearing lube oil housing.

xix) Jacking oil pressure.

xx) Shaft seal cooling water pressure.

xxi) Cooling water system main inlet pressure at inlet to lube oil coolers and

generator air coolers.





xxii) Cooling water system strainer / filter differential pressure.

xxiii) Cooling water discharge header pressure.

xxiv) Cooling water pump suction and discharge pressure.

xxv) Vacuum pump discharge pressure.

xxvi) Circulating tank level.

xxvii) Drainage and dewatering pump discharge pressure.

xxviii) Air compressor pressure.

xxix) Braking air pressure.

xxx) Transformer oil cooler inlet flow and pressure.

xxxi) Transformer oil cooler outlet temperature.

05.03.00 List of Alarms

Sl.No. Items Description

1 Generator All electrical Protection operated*

2 Generator All non electrical protection*

operated

3 Generator Brake Air Pressure Low

4 Generator PT fuse failure

5 Generator Rotor earth fault

6 Generator (TB, LGB, UGB) Bearing temperature high

7 Generator Bearing temperature very high*

8 Generator Stator winding temperature high

9 Generator Stator winding temperature very

high*

10 Generator Creeping

11 Generator Overspeed

12 Turbine guide bearing Bearing temperature high






13 Turbine guide bearing Bearing temperature very high*

14 Turbine guide bearing Bearing oil level low

15 Turbine guide bearing Bearing oil level very low*

16 Bearing Oil Contaminated

17 Generator lower guide bearing

cooler

Water flow low

18 Generator upper guide bearing

cooler

Water flow low

19 Generator air cooler Water flow low

20 Shaft Seal Water pressure low

21 Turbine guide bearing cooler Water flow low

22 Governor Oil Level Low

23 Governor Oil Pressure low*

24 Excitation Transformer Temperature high

25 Generator Transformer Oil temperature high

26 Generator Transformer Oil temperature very high

27 Generator Transformer Winding temperature high

28 Generator Transformer Winding temperature very high*

29 Generator Transformer Buchholz Alarm

30 Generator Transformer Buchholz Trip*

31 Station Transformer Oil temperature high

32 Station Transformer Oil temperature very high

33 Station Transformer Winding temperature high

34 Station Transformer Winding temperature very high*

35 Gen. Circuit Breaker Auto Closed

35 Auto Syn. Lock out

36 11 kV Feeder breaker Fault trip






37 415 V feeders Fault trip

38 Auxiliary DC Supply Under Voltage

39 Auxiliary DC Supply Earth fault

40 UPS Fault in System

41 Head Cover Water Level high

42 Air Compressor Low press

43 CO2 bank Released

44 Differential pressure across oil

filter

High

45 Differential pressure across

side stream filter

High

46 CW supply header pressure &

flow

low

47 CW pumps (individual)

discharge pressure.

low

48 Circulating tank level low

49 Brake air pressure low

50 Drainage sump level High and low

NOTES : * Astrick mark points to be used for tripping purpose als

05.04.00 Control & Interlocks

Sl.

No. Description Interlocks

1 Unit start /stop Satndard interlocking arrangement shall be

provided for starting, emergency shut down

and normal shutdown





Sl.


2 Governor opening and

closing

Start / stop provision

3 Governor oil pump Start on Low pressure alarm & stop on high

pressure

4 Turbine Speed Raise / Lower Provision

5 11 kV Breaker closing Syn. Closing with checking of incoming /

running voltage, frequency and phase angle

in auto mode, Manual mode operator will

close manually but check command will be

there from SCADA to avoid wrong closing

6 11 kV Breaker closing Check syn. Closing provision

7 Generator Voltage Raise/ Lower provision

8 11 kV breaker tripping Protection and for manual tripping

9 11 kV transformer

secondary side

breaker tripping

On tripping of 132kV breakers

10 11 kV Circuit breaker

closing/tripping

provision

Provision of tripping / closing

11 Compressor for

governing oil system

Start on low pressure and stop on high

pressure

12 De-watering Pump Start and stop based on sump level

13 Governing oil Control pressure at set value

14 Oil filter Auto change over with respect to the

differential pressure across the filter.

15 CW pump Interlock with circulating tank.

16 CW pump Stan by pump start on low pressure





Sl.


17 Vacuum pump Start on circulating tank for CW pump level

low & stop on circulating tank level high

18 Drainage pump Start on drainage sump level high & stop on

drainage sump level low

The list of alarms, measurements, control & interlocks mentioned above are

minimum to provide and will be finalised during detail engineering stage

06.00.00 Drawings and Documents

Following drawing and documents shall be submitted for instrumentation.

All communication/descriptions in the drawings, documents, technical

literatures and manuals shall be

in English language only.

06.01.00 Along with the Offer

i) Process and instrumentation (P&I) diagrams for each unit with all auxiliaries

indicating all field mounted, local panel mounted, control room panel mounted

instruments using ISA symbols and using suitable tag numbers against each

instrumentation equipment. Also and interlock functions shall also be

indicated in the P&I diagrams.

ii) Specification of each instrumentation equipment indicating make, model no.,

application, , quantity, tag no. accuracy, etc. as per standard

specification sheets along with instrument schedule of complete C&I

package





iii) Detailed technical literature of each instrumentation equipment offered.

iv) System configuration Diagram for proposed DCS/PLC and shall have SCADA

compatible.

v) Technical specification with literatures of all the sub system of DCS/PLC & I/O

sizing considered

vi) Control schemes along with write-up for turbine governing system and

protection/interlock schemes for turbine and its auxiliaries and bill of materials.

vii) Quality and quantity of electric power requirement for

instrumentation and also instrument air requirement.

06.02.00 Drawings/documents to be submitted by the successful tenderer

A. For approval

i) Process and instrumentation (P&I) diagrams for the unit with all auxiliaries

indicating all field and panel mounted instruments using ISA symbols and

using suitable tag numbers against each instrumentation equipment Alarm

and interlock functions shall also be indicated in the P&I diagram.

ii) Specification of each instrumentation equipment indicating make, model no.,

application, scale range, quantity, tag no. (as per P&I diagram), accuracy,

power consumption etc. Data sheets for each instrument as per standard

format shall be submitted with all the required details filled in along with

detailed technical literature. Schedule of instruments/BOM shall be submitted

by the successful tenderer.





iii) Control schemes along with write-up for turbine governing system and

protection/interlock schemes for turbine and its auxiliaries and bill of materials.

• Overall system configuration diagram along with write-up on the system

• I/O list

• Final technical specification of all sub system of DCS/PLC

• OGA & GA of various cabinets/panels consoles with dimensional details of

DCS/PLC

• QAP for DCS/PLC

• FAT procedure for DCS/PLC

iv) Instrument power supply diagram along with bill of quantities (BOQ).

v) Instrument panel general arrangement drawings (both local and remote

panels) along with BOQ.

vi)Disposition of instrument panels, desk, cabinets etc. inside local control

room and unit control board.

viii)The protection and interlocking schemes for all equipment, general

interlocking schemes for turbo-generator protection system.

B. For Procedural Checking and Records

i) Instrument panel wiring diagrams

ii) Hook-up diagrams





iii) Erection/installation diagrams for all primary sensors and field

mounted equipment

iv) Alarm annunciation scheme

v) Sequential & safety interlock scheme

vi) Loop schematic diagrams

• open/close loop list

• DCS/PLC I/O hardware signal list

• SOE input signals

• Logic diagrams

• Graphic display sheets

• Measuring point list

• DCS/PLC cubicle/panel power supply distribution single line

diagram

• logging formats

• Bus loading calculation

vii) Flow sensor sizing calculation sheets

viii) Instrumentation layout drawing showing location of sensors,

transmitters etc. and route of cables from these up to the

instrument panel in the control room.

ix) Cable and pipe schedules with specification, Manufacturer's

test, calibration and guarantee certificates for all the instruments

xi) Operation and maintenance manuals for each instrument

xii) Quality assurance plan for each instrument





The quantity of drawings listed above and to be submitted by the successful

tenderer shall be as per the general conditions of contract (GCC).

List of 2 years spares for operation and maintenance as per manufacturer's

recommendation and list of commissioning spares shall also be submitted.

07.00.00 List of spares

07.01.00 Operation & Maintenance Spares

Recommended list of spares for operation and maintenance for 5 years shall

be provided with unit rate along with the firm offer.

07.02.00 List of Mandatory Spare for Each Unit

A) Measuring Instruments/Field instruments.

i) 5% of total Temperature & Pressure gauges of each type & model

or a minimum of one of each type and model which ever is more.

ii) 10% of total temperature elements with thermowells for RTD/TC or

minimum one of each range & model which ever is more.

B) Distributed Control System (DCS/PLC)

i) 1 no. of colour laser printer

ii) 15 no. of each of black & colour in cartridges for each type of colour

iii) One no. of hard disk Drive unit of each type as offered in the main

Offer.

iv) 1no. of CD drive & CD writer & 10 nos. of CDs.





v) 20% of the total quality of each type & model of electronic modules or

a minimum of 2 nos. of each type & model of electronic modules, which ever is

more.

a) I/O cards/Modules

• Analog input (4-20mA) -2nos.

• Analog input RTD -2nos

• Analog input T/C -2nos.

• Analog out put (AO) -2nos.

• Digital input cards (DI) -2nos

• Digital output cards (DO) -2nos

b) Controller cards -2nos

c) CPU module -2nos

d) Communication card -2nos

e) Interposing relay & Coupling relay 10 nos.

f) 10% of the total quality of each type & model of batteries used for

battery backup of RAMs or a minimum of two (02)nos of each type &

model of battery, which ever is more , as offered in the main offer.

i) 100% of the total quality for each type model & rating of fuse.

j) Cooling fans for Power supplies/Panels 10% of total.

k) Power supply modules 20% or minimum 2 nos. of the total quantity

offered for each type & rating, which ever is more.





C) Electronic smart transmitters

i) 10% of total electronic transmitters of each type range and model or minimum

of one number of each type, range & model which ever is more.

D) Vibration Monitoring System

i) One no. of velocity coil type, accelerometer type and proximity

type vibration transducer

ii) One no. of power supply module.

E) Process Actuated switch devices

• 5% of total pressure switches , limit switches, differential switches,

temperature switches, flow switches of each type & model or minimum

of one number of each type & model which ever is more.

F) Local Instrument

i) 10 % of each type of Push buttons, indicating lamps, colour caps & control

sation for each type.

G) Alarm Annunciator

i) 10% of total electronic cards of each type & model or minimum of 2nos

of each type & model . This shall include all types of cards





07.03.00 Commissioning Spare

Commissioning spares list shall be furnished along with the firm offer . The left

out commissioning spares shall be handed over to client after commissioning.

The offer shall be submitted along with tender offer indicating unit price.

08.00.00 Inspection

For inspection of Instrumentation items procedure shall be governed as given

in chapter inspection & testing in Vol-IV. However C&I DCS/PLC integrated

FAT shall be inspected at manufacturer’s works.

FAT of PLC/DCS and governing control system shall also be conducted by

the bidder at their works and arrangement for witnessing the test for Three

(03) persons of the Employers and consultant are also to be arranged by the

Bidder free of cost i.e without any cost implication to the Employer.

09.00.00 List of Preferred Makes

PLC

• Rockwell Automation Control Logix L73

• GE Fanuc PAC Rx3i

• Siemens S7-400H series

• ABB 800XA

• Schneider(Quantum) or better





DCS

• Yokogawa Centum VP

• ABB Simphony Harmony

• Honeywell Experion Pks

• METSO/BHEL MAX DNA

• Emersion Ovation

TRANSMITTERS (PRESSURE, FLOW & LEVEL) :

YOKOGAWA INDIA LTD., EMERSON., HONEYWELL LTD,

DIGITAL INDICATORS :

YOKOGAWA BLUESTAR LTD., MASIBUS ELECTRONICS, RANUTROL

LTD.

PRESSURE/TEMPERATURE GAUGES :

WAIKA, WAREE ,GIC , A.N. INSTRUMENTS PVT. LTD

RTDs & THERMOCOUPLES :

GENERAL INSTRUMENTS, INDUSTRIAL INSTRUMENTATION,

INSTRUMENTATION LTD, NAGMAN SENSORS, TOSHNIWAL BROTHERS.

TEMPERATURE TRANSMITTER :

YOKOGAWA (I) LTD, EMERSON., HONEYWELL LTD.

DIGITAL SCANNER :

JYOTI, LECTROTEK, PROCON, MASIBUS.

PRESSURE SWITCH :

INDFOSS (INDIA) LTD., SWITZER INSTRUMENTATION PVT LTD.





FLOW TOTALISER :

YOKOGAWA (I) LTD., SIEMENS.

SOLID STATE ALARM ANNUNCIATOR :

APPLIED ELECTRONICS LTD. (APLAB), PROCON INSTRUMENTATION

PVT. LTD., PIRI SYSTEMS PVT LTD., IIC, MINILEC, MASIBUS.

.

POWER CABLES :

CABLE CORPORATION OF INDIA LTD., UNIVERSAL CABLES LTD., FORT

GLOSTER INDUSTRIES LTD., ASIAN CABLES LTD, FINOLEX CABLES

LTD., KEI.

INSTRUMENTATION SCREENED CABLES :

CABLE CORPORATION OF INDIA LTD., FINOLEX CABLES LTD.,

TOSHNIWAL CABLES, DELTON CABLES, KEI,MEM ASIAN CABLES,

UNIVERSAL CABLES.

COMPENSATING CABLES :

TOSHNIWAL CABLES, GENERAL INSTRUMENTS, UDAY RAJ, KEI.

ORIFIC / FLOW NOZZLE

ENGINEERING SPECIALITIES (PVT) LTD., MICRO PRECISSION, GIC

PC

HP, DELL, COMPAQ

ETHERNET SWITCH

CISCO,SIEMENS.

CONTROL VALVE





IL, MIL, Fisher-Xomox

PRESSURE SWITCH

WIKA, SWITZER, WAREE, ORION, INDFOSS

FLOW SWITCH

TRAC, CHEMTROL, D.K.INSTRUMENTATION, LEVCON

Note :

For those equipments/instruments whose make are not indicated in

TS prior approval of Purchaser/Consultant shall be obtained.

OHPC Balimela Volume 4

Documents

Transcript of OHPC Balimela Volume 4