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COEGA DEVELOPMENT CORPORATION (Pty) Ltd

CONTRACT NO. CDC/619/19

ENGINEERING 3.2 ENGINEERING.............................................................................................................1

3.2.1 SUBSTATION SPECIFICATION...........................................................................1

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3.2 ENGINEERING

3.2.1 SUBSTATION SPECIFICATION This specification covers the manufacture, factory testing, supply, delivery, off-loading, installation, after-installation testing and commissioning for all Substation works to be completed as part of CDC/619/19 – Construction of BAIC Bulk Electrical Overhead Lines and Substation.The Contractor shall be responsible for the complete substation or extension, including incorporation into the Municipality’s SCADA system, to the point where it could be safely energised.

Drawings: The contract also covers the preparation and supply of all shop drawings required for the effective and complete manufacture, operation and maintenance of the new works by the Employer’s staff. The drawings shall, inter alia, include foundation and support structure drawings, earth mat layout, yard layout, exact position of all installed cables (power and other) and all schematic and control drawings.

IEC61850 substation bus and SCADA : Electrical equipment (indoor and outdoor) shall be fitted for remote indication and control purposes (SCADA). The successful tenderer shall provide and install an IEC61850 substation bus. All equipment required to serve information to this bus or subscribed to information on the bus, shall be connected to the bus by the Contractor. The Contractor shall supply and install all hardware, firmware and software required to enable this.

3.2.1.1 CLIMATIC CONDITIONSThe new plant shall be sufficiently rated for the following environmental conditions in the table below.

Table 3.2.1-1 : Service ConditionsTemperature

Maximum 40 °C

Minimum -5 °C

Daily Average Temperature 35 °C

Altitude

MSL 1400 m

Humidity

Maximum 90 %

Minimum 10 %

Wind Speed

Regional Basic Wind Speed 40 m/s

Lightning

Isokeraunic level 0,7 / km2/ year

Pollution

Level Extreme

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3.2.1.2 Network RequirementsThe new plant shall be sufficiently rated for the following network requirements as in the table below.

Table 3.2.1-2 : Network RequirementsNormal Operating Range (kV) 132 22 11

System Highest Voltage (kV) 145 36 24

Normal Operation Range (kV) ±10 % ±10 % ±10 %

Power Frequency Withstand Voltage (kV) 275 50 28

Lightning Surge Impulse Withstand Voltage (kVpeak) 650 150 95

Substation one second short time current rating (kA) 31,5 25 25

Specific Creepage Distance (SCD) (mm/kV) 31 31 31

3.2.1.3 Electrical and safety clearancesThe new plant shall comply with the minimum safety clearances as in the table below.

Table 3.2.1-3 : Electrical & Working Clearance

System Nominal

Voltage (kV)

Minimum Phase-to-Earth Electrical Clearance (mm)

Minimum Phase-to-Phase Electrical

Clearance (mm)

Vertical Working

Clearance (m)

Horizontal Working

Clearance (m)

11 200 270 2.7 1.3

22 320 430 2.8 1.4

132 1200 1650 3.7 2.3

3.2.1.4 STANDARDS

3.2.1.4.1 The works covered in this contract shall be to engineer, manufacture, build, test and commission, in accordance with the Acts, Rules, Laws and Regulations of South Africa / relevant IEC or SANS or NRS and PEE Code of Practises and Standards.

3.2.1.4.2 Bidders/Contractor may please note that all offered materials shall be manufactured, tested and supplied with all guaranteed technical particulars generally conforming to meet the requirement of technical specification as brought out in various clauses and latest revisions of relevant standards of IEC or SANS or NRS and PEE Code of Practise with latest amendments of relevant standards rules and codes. The lists of standards are specified in relevant Sections of bid document.

3.2.1.4.3 The Contractor shall also note that list of standards presented in this specification is not complete. Wherever necessary the list of standards shall be considered in conjunction with specific IEC/SANS/NRS/PEE Code of Practise.

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3.2.1.4.4 When the specific requirements stipulated in the specifications exceed or differ than those required by the applicable standards, the stipulation of the specification shall take precedence.

3.2.1.5 ENGINEERING DATA AND DRAWINGS

3.2.1.5.1 The list of drawings/documents which are to be submitted to the Bidder/Contractor shall be discussed and finalised by the Employer/Consultant at the time of award.

3.2.1.5.2 The Contractor shall submit 4 (four) sets of drawings / documents / data and 1 (one) set of test reports for the approval of the Employer/Consultant. The contractor shall also submit the softcopy of the above documents in addition to hardcopy.

3.2.1.5.3 All drawings submitted by the Contractor shall be in sufficient detail to indicate the type, size, arrangement, material description, Bill of Materials, weight of each component, break-up for packing and shipment, dimensions, internal & the external connections, fixing arrangement required and any other information specifically requested in the specifications.

3.2.1.5.4 Drawings submitted by the Contractor shall be clearly marked with the name of the Purchaser, the unit designation, the specifications title, the specification number and the name of the Project. Employer/Consultant has standardized few drawings/documents of various make including type test reports which can be used for all projects having similar requirements and in such cases no project specific approval (except for list of applicable drawings along with type test reports) is required. However, distribution copies of standard drawings/documents shall be submitted as per provision of the contract. All titles, noting, markings and writings on the drawing shall be in English. All the dimensions should be in SI units.

3.2.1.5.5 The review of these data by the Employer/Consultant will cover only general conformance of the data to the specifications and documents interfaces with the equipment provided under the specifications, external connections and of the dimensions which might affect layout. This review by the Employer/Consultant may not indicate a thorough review of all dimensions, quantities and details of the equipment, materials, any devices or items indicated or the accuracy of the information submitted. This review and/or approval by the Employer/Consultant shall not be considered by the Contractor, as limiting any of his responsibilities and liabilities for mistakes and deviations from the requirements, specified under these specifications and documents.

3.2.1.5.6 All manufacturing and fabrication work in connection with the equipment prior to the approval of the drawings shall be at the Contractor’s risk. The Contractor may make any changes in the design which are necessary to make the equipment conform to the provisions and intent of the Contract and such changes will again be subject to approval by the Employer/Consultant. Approval of Contractor’s drawing or work by the Employer/Consultant shall not relieve the contractor of any of his responsibilities and liabilities under the Contract.

3.2.1.5.7 All engineering data submitted by the Contractor after final process including review and approval by the Employer/Consultant shall form part of the Contract Document and the entire works performed under these specifications shall be performed in strict

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conformity, unless otherwise expressly requested by the Employer/Consultant in Writing.

3.2.1.6 APPROVAL PROCEDURE

3.2.1.6.1 The scheduled dates for the submission of the drawings as well as for, any data/information to be furnished by the Employer/Consultant would be discussed and finalised at the time of award. The following schedule shall be followed generally for approval and for providing final documentation.

I. Approval/Comments by Employer As per agreed schedule

II. Resubmission 3 Weeks from date of comments.III. Approval/Comments by Employer 3 Weeks from of receiving

resubmissionIV. Distribution Copies (5 hard copies)

(Substation & Test Reports)2 Weeks from the date of approval

V. As Built Documentation As per agreed schedule

3.2.1.6.2 The contractor should note that all resubmissions must incorporate all comments given in the earlier submission by the Employer/Consultant or adequate justification for not incorporating the same must be submitted failing which the submission of documents is likely to be returned.

3.2.1.6.3 Hard copies of design drawings and soft copies of design drawings shall be submitted in AutoCAD/Microstation format. This is only applicable where the contractor is required to design a certain portion of the works as well as for the As-Built drawings and manufacturing drawings.

3.2.1.6.4 The Hard and soft copies of instruction Manuals shall contain full details of drawings of all equipment being supplied under this contract, their diagrams with complete instructions for storage, handling, erection, commissioning, testing, operation, trouble shooting, servicing and overhauling procedures.The Contractor shall furnish to the Purchaser catalogues of spare parts.

3.2.1.6.5 All Hard and soft copies of As-built drawings/documents shall be certified by site indicating the changes before final submission.

3.2.1.7 MATERIAL/ WORKMANSHIP3.2.1.7.1 Where the specification does not contain references to workmanship, equipment,

materials and components of the covered equipment, it is essential that the same must be new, of highest grade of the best quality of their kind, conforming to best engineering practice and suitable for the purpose for which they are intended.

3.2.1.7.2 In case where the equipment, materials or components are indicated in the specification as “similar” to any special standard, the Employer/Consultant shall decide upon the question of similarity. Where required by the specification or when required by the Employer/Consultant the Contractor shall submit, for approval, all the information concerning the materials or components to be used in manufacture. Machinery, equipment, materials and components supplied, installed or used without such approval shall run the risk of subsequent rejection, it being understood that the cost as well as the time delay associated with the rejection shall be borne by the Contractor.

3.2.1.7.3 Whenever possible, all similar part of the Works shall be made to gauge and shall also be made interchangeable with similar parts. All spare parts shall also be

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interchangeable and shall be made of the same materials and workmanship as the corresponding parts of the Equipment supplied under the Specification. Where feasible, common component units shall be employed in different pieces of equipment in order to minimize spare parts stocking requirements. All equipment of the same type and rating shall be physically and electrically interchangeable.

3.2.1.7.4 All materials and equipment shall be installed in strict accordance with the manufacturer’s recommendation(s). Only high standard work in accordance with the best modern practices will be accepted. Installation shall be considered as being the erection of equipment at its permanent location. This, unless otherwise specified, shall include unpacking, cleaning and lifting into position, grouting, levelling, aligning, coupling of or bolting down to previously installed equipment bases/foundations, performing the alignment check and final adjustment prior to initial operation, testing and commissioning in accordance with the manufacturer’s tolerances, instructions and the Specification. All factory assembled rotating machinery shall be checked for alignment and adjustments made as necessary to re-establish the manufacturer’s limits suitable guards shall be provided for the protection of personnel on all exposed rotating and / or moving machine parts and shall be designed for easy installation and removal for maintenance purposes. The spare equipment(s) shall be installed at designated locations and tested for healthiness.

3.2.1.7.5 The Contractor shall apply oil and grease of the proper specification to suit the machinery, as is necessary for the installation of the equipment. Lubricants used for installation purposes shall be drained out and the system flushed through where necessary for applying the lubricant required for operation. The Contractor shall apply all operational lubricants to the equipment installed by him.

3.2.1.7.6 The Contractor shall apply oil and grease of the proper specification to suit the machinery, as is necessary for the installation of the equipment. Lubricants used for installation purposes shall be drained out and the system flushed through where necessary for applying the lubricant required for operation. The Contractor shall apply all operational lubricants to the equipment installed by him.

3.2.1.7.7 Outdoor and Indoor equipment supplied under the specification shall be suitable for service and storage under specified climatic conditions

3.2.1.7.8 One or more adequately rated thermostatically connected heaters shall be supplied to prevent condensation in any compartment. The space heaters shall be suitable for continuous operation at 230V as supply voltage. On- off switch and fuse shall be provided.

3.2.1.7.9 The enclosures of the Control Cabinets, Junction boxes and Marshalling Boxes, panels etc. to be installed shall provide minimum degree of protection according to IEC-60529 as below:

I. Installed outdoor: IP- 55 II. Installed indoor in air-conditioned area: IP-31

III. Installed in covered area: IP-52 IV. AC & DC distribution Boards: IP-52 V. Rating Plates, Name Plates and Labels

3.2.1.7.10 Each main and auxiliary item is to have permanently attached to it in a conspicuous position a rating plate of non-corrosive material upon which is to be engraved manufacturer’s name, year of manufacture, equipment name, type or serial number together with details of the loading conditions under which the item in question has been designed to operate, and such diagram plates as may be required by the Employer/Consultant. The rating plate of each equipment shall be according to IEC requirement.

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3.2.1.7.11 All the consumables required under the scope of the specifications for first fill, successful Operation, shall be furnished by the Contractor unless specifically excluded under the exclusions in these specifications and documents.

3.2.1.8 DESIGN IMPROVEMENTS 3.2.1.8.1 The Bidder/Contractor shall note that the equipment offered in the bid, shall be

accepted for supply. However, the Employer/Consultant or the Contractor may propose changes in the specification of the equipment or quality thereof and if the Employer/Consultant & contractor agree upon any such changes, the specification shall be modified accordingly.

3.2.1.8.2 If any such agreed upon change is such that it affects the price and schedule of completion, the parties shall agree in writing as to the extent of any change in the price and/or schedule of completion before the Contractor proceeds with the change. Following such agreement, the provision thereof, shall be deemed to have been amended accordingly.

3.2.1.8.3 The Contractor shall be responsible for the selection and design of appropriate equipment’s to provide the best co-ordinated performance of the entire system. The basic design requirements are detailed out in this Specification. The design of various components, sub-assemblies and assemblies shall be so done that it facilitates easy field assembly and maintenance.

3.2.1.9 QUALITY ASSURANCE 3.2.1.9.1 The Contractor shall submit a detailed quality assurance programme cover the

following:a) Contractor organisation structure for the management and implementation of the

proposed quality assurance programme.

b) Documentation control system.

c) Qualification data for Contractor/Bidder’s key personnel.

d) The procedure for purchases of materials, parts components and selection of sub-Contractor’s services including vendor analysis, source inspection, incoming raw material inspection, verification of material purchases etc.

e) System for shop manufacturing and site erection controls including process controls and fabrication and assembly control.

f) Control of non-conforming items and system for corrective actions.

g) Inspection and test procedure both for manufacture and field activities.

h) Control of calibration and testing of measuring instruments and field activities.

i) System for indication and appraisal of inspection status.

j) System for quality audits;

k) System for authorising release of manufactured product.

l) System for handling storage and delivery; and

m) A quality plan detailing out the specific quality control measures and procedures adopted for controlling the quality characteristics relevant to each item of equipment furnished and/or services rendered.

3.2.1.9.2 The Employer/Consultant or his duly authorised representative reserves the right to carry out quality audit and quality surveillance of the system and procedure of the Contractor/his vendor’s quality management and control activities. The contractor

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would be required to submit all the Quality Assurance Documents as stipulated in the Quality Plan at the time of purchaser’s inspection of equipment/material.

3.2.1.10 TESTING & INSPECTION CERTIFICATE 3.2.1.10.1 All equipment being supplied shall conform to type tests as per technical specification

and shall be subject to routine tests in accordance with requirements of relevant standards.

3.2.1.10.2 The reports for all type tests as per technical specification shall be furnished by the Contractor along with equipment / material drawings. The type tests conducted earlier should have either been conducted in accredited laboratory (accredited based on ISO / IEC Guide 25 / 17025 or EN 45001 by the national accreditation body of the country where laboratory is located) or witnessed by Employer/Consultant.

3.2.1.10.3 The test reports submitted shall be of the tests conducted within last 5 (ten) years prior to the originally Scheduled date of bid opening. In case the test reports are of the test conducted earlier than 5 (ten) years prior to the originally Scheduled date of bid opening, the contractor shall repeat these test(s) at no extra cost to the Employer.

3.2.1.10.4 In the event of any discrepancy in the test reports i.e. any test report not acceptable due to any design/manufacturing changes (including substitution of components) or due to non-compliance with the requirement stipulated in the Technical Specification or any/all type tests not carried out, same shall be carried out without any additional cost implication to the Employer.

3.2.1.10.5 The Contractor shall intimate the Purchaser the detailed program about the tests at least two (2) weeks in advance in case of domestic supplies & six (8) weeks in advance in case of foreign supplies. All costs and expenses for three Employer/Consultant representatives to witness the tests shall be borne by the contractor.

3.2.1.10.6 When the factory tests have been completed, the Employer/Consultant shall issue a certificate to this effect within fifteen (15) days after completion of tests but if the tests are not witnessed by the Employer/Consultant, the certificate shall be issued within fifteen (15) days of receipt of the Contractor’s Test certificate by the Employer/Consultant. Failure of the Employer/Consultant to issue such a certificate shall not prevent the Contractor from proceeding with the Works. The completion of these tests or the issue of the certificate shall not bind the Employer/Consultant to accept the equipment should, it, on further tests after erection, is found not to comply with the Contract.

3.2.1.10.7 In all cases where the Contract provides for tests whether at the premises or at the works of the Contractor or of any Sub-Contractor, the Contractor except where otherwise specified shall provide free of charge such items as labour, materials, electricity, fuel, water, stores, apparatus and instruments as may be reasonably demanded by the Employer/Consultant or his authorised representative to carry out effectively such tests of the equipment in accordance with the Contract.

3.2.1.10.8 The Employer will have the right of having at his own expenses any other test(s) of reasonable nature carried out at Contractor’s premises or at site or in any other place in addition of aforesaid type and routine tests, to satisfy that the material complies with the specification.

3.2.1.10.9 The Purchaser reserves the right for getting any field tests not specified in technical specification conducted on the completely assembled equipment at site. The testing equipment’s for these tests shall be provided by the Bidder/Contractor.

3.2.1.10.10The inspection by Employer/Consultant and issue of Inspection Certificate thereon shall in no way limit the liabilities and responsibilities of the Contractor in respect of the agreed quality assurance programme forming a part of the Contract.

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3.2.1.10.11Pre-commissioning Tests: On completion of erection of each equipment, each item of the equipment shall be thoroughly cleaned and then inspected jointly by the Employer/Consultant and the Contractor for correctness and completeness of installation, pre-commissioning tests and Commissioning Tests for acceptance site. The list of pre-commissioning tests to be performed shall be included in the Contractor’s quality assurance programme.

3.2.1.11 PACKAGING 3.2.1.11.1 All the equipment shall be suitably protected, coated, covered or boxed and crated to

prevent damage or deterioration during transit, handling and storage at Site until erected. On request of the Employer/Consultant, the Contractor shall also submit packing details/associated drawing for any equipment/material under his scope of supply. The Contractor shall be responsible for any loss or damage during transportation, handling and storage.

3.2.1.12 FINISHING OF METAL SURFACES 3.2.1.12.1 All metal surfaces shall be subjected to treatment for anti-corrosion protection. All

ferrous surfaces for external use unless otherwise stated elsewhere inthe specification or specifically agreed, shall be hot-dip galvanized after fabrication. High tensile steel nuts & bolts and spring washers shall be electro galvanized to service condition. All supporting steelwork provided under this contract, including insulator hardware, mounting brackets, connectors, isolator blades, etc., shall be hot dip galvanised in accordance with the requirements of SANS 121 but the weights of zinc coatings measured with an approved thickness gauge shall be as in table below.

3.2.1.12.2 High tensile steel holding down bolts shall only be galvanised for the top 150mm thereof to ensure sufficient adhesion between concrete and steel. All split pins shall be grade 316 stainless steel and not galvanised. After installation all structural steelwork and mounting brackets including nuts, bolts and washers shall be painted with two coats of approved zinc rich paint. No drilling, cutting, etc. of galvanised materials will be allowed on site without prior approval from the Engineer who shall specify such measures as he may deem necessary to protect the exposed metal surfaces.

Table 3.2.1-4 : GALVANISING REQUIREMENTS

Materials Minimum Mass of ZincCoating - g/m2

Structural Steel and Mounting Brackets

763

Nuts, Bolts, Washers & Transmission Line Hardware 534

3.2.1.13 PAINTING 3.2.1.13.1 All non-galvanised outdoor steel equipment shall be treated and finished as follows:3.2.1.13.2 Steelwork shall be degreased and rinsed before being treated with zinc phosphate.

After rinsing a 30 µm coat of epoxy red oxide / zinc chromate primer shall be applied. The undercoat shall consist of a 25 µm layer of polyamide cured epoxy. The final coat shall consist of a 25 µm layer of twin pack polyurethane enamel.

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3.2.1.13.3 Indoor equipment shall be powder coated after pre-treatment as above, i.e. degreasing, de-rusting and zinc phosphate. The powder coat of minimum 50 µm shall be an electrostatic process to the manufacturer’s proprietary procedure.

3.2.1.13.4 Switchgear and control panels shall be light grey (Colour No. G29, to SANS 1091). The interior compartments of switchgear shall be painted white.

3.2.1.14 SPECIFICATION FOR COMPACT SWITCHGEAR This standard provides requirement for the design, manufacture, supply, test and installation of outdoor SF6 Compact Switchgear modules to be used network voltages 132kV.

3.2.1.14.1 Normative ReferencesParties using this document shall apply the most recent edition and applicable amendments of the documents listed. Where any of the listed documents are out-dated or superseded, replacement document of the original document shall take precedence.

[1] IEC 9001 Quality management systems – Requirements

[2] IEC 62271-1 High voltage switchgear and control gear: Common specification

[3] IEC 62271-205 High voltage switchgear and control gear: Compact switchgear for rated voltages above 52 kV

[4] IEC 62271-301 High voltage switchgear and control gear: Dimensional standardisation of high-voltage terminal

[5] IEC 62271-301 High voltage switchgear and control gear: Alternating current circuit-breakers with intentionally non-simultaneous pole operation.

[6] ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories

[7] IEC 60071 Insulation co-ordination – Part 1: Definitions, principles and rules

[8] IEC 60815 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions

[9] IEC 61462 Composite hollow insulators

[10] ISO 1461 Hot dip galvanized coatings on fabricated iron and steel articles -- Specifications and test methods

[11] IEC 60865 Short Circuit Current – calculation of effects

[12] IEC 61850 Communication network and systems in substations

[13] IEC 62271-110 High voltage switchgear and control gear: Inductive load switching.

3.2.1.14.2 Terms and definitionsFor the purposes of this standard, the following terms, definitions and abbreviations apply.

Abbreviations:

IEC International Electrotechnical Commission

ISO International Standards Organisation

SANS South African National Standard

A Ampere

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kA Kilo Ampere

V Volt

kV Kilo Volt

3.2.1.14.3 General The tendered shall supply Compact Switchgear, identical to those stipulated in Technical Schedule A and shall complete technical Schedule B of the enquiry document.

3.2.1.14.4 Service conditionsCompact Switchgear shall be suitable for operation at the following normal service conditions in Table 3.2.1-5 and shall comply to the IEC 60076-1 clause 2.

Table 3.2.1-5 : Service condition

Altitude above sea level: 1400 m

Installation: Outdoor

Ambient Temperature:

Maximum 50 ºC

Minimum 15 ºC

Monthly average 40 ºC

Yearly average 30 ºC

Average humidity 30% to 90%

Seismic conditions 0.3g

Pollution level Very Heavy

Solar radiation 2500kWh/m2

3.2.1.14.5 Rated VoltageUnless otherwise specified differently in the technical schedule A, the rated voltage of the Compact Switchgear shall confirm to Table 3.2.1-6.

3.2.1.14.6 Rated Frequency Unless otherwise specified differently the Compact Switchgear shall be designed for operating at a frequency of 50Hz.The Compact Switchgear shall be designed for a rated frequency of 50Hz +/- 2.5Hz.

3.2.1.14.7 Rated Insulation Level Unless otherwise specified differently in the technical schedule A, the rated insulation shall confirm to Table 3.2.1-6.

3.2.1.14.8 Rated Normal Current Unless otherwise specified differently in the technical schedule A, the rated normal current shall confirm to Table 3.2.1-6.

3.2.1.14.9 Rated Short Time Withstand Current

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Unless otherwise specified differently in the technical schedule A, the rated short time withstand current shall confirm to Table 3.2.1-6.

3.2.1.14.10Rated Peak Withstand Current Unless otherwise specified differently in the technical schedule A, the rated peak withstand current is equal to 2,5 time the rated short time withstand current and shall confirm to IEC 62271-1 clause 4.6.

3.2.1.14.11Rated Duration Short Circuit Unless otherwise specified differently in the technical schedule A, the rated duration short circuit is 3 seconds.

3.2.1.14.12Rated Supply VoltageThe supply voltage of closing and opening devices and auxiliary and control circuits shall conform to technical schedule A and shall conform to IEC 62271-1 clause 4.8.

3.2.1.14.13Rated Transient Recovery Voltage Unless otherwise specified differently in the technical schedule A, the transient recovery voltage shall conform to IEC 62271-100 clause 4.102.

3.2.1.14.14Rated Short Circuit Making Current Unless otherwise specified differently in the technical schedule A, the transient recovery voltage shall conform to IEC 62271-100 clause 4.102.

Table 3.2.1-6: Minimum requirements

Rated Voltage

(kV)

Rated Power-Frequency Withstand Voltage U d (kV )

Rated lightning impulse withstand voltage U p(kV )

Rated switching impulse withstand voltage U s(kV )

Rated Normal Current

I r(A)

Rated Short time withstand Current

I sc(kA)

132 275 650 - 2500 31.5

3.2.1.14.15 Rated Operating Sequence Unless otherwise specified differently in the technical schedule A, the transient recovery voltage shall conform to IEC 62271-100 clause 4.104.

3.2.1.14.16 Rated Supply VoltageThe supply voltage of closing and opening devices and auxiliary and control circuits shall conform to technical schedule A and shall conform to IEC 62271-1 clause 4.8.

3.2.1.14.17 Ratios Current TransformersCurrent transformers shall have ratios as specified in Technical schedule A.

3.2.1.14.18 Interlocking Systems

3.2.1.14.18.1 Circuit breaker (CB):

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a) The remote operation of the CB of the module is always possible when the disconnector is closed or opened. Local operation of the CB of the module is always possible.

b) The CB operations are possible only if the pole gas pressure is higher than the threshold block. In general interlocking system and logic can be adapted and customized on request. The CB can be operated also in case of the gas pressure drop down to the atmospheric value. In this case, the power frequency withstand voltage (1 min) must be guaranteed.

3.2.1.14.18.2 Disconnector/Earth Switch:a) The disconnector/earthing switch operation (both motor and manually operated) is

possible only when the CB is opened (the interlocking device shall be electromagnetic). It is understood that all the manufacturers have their own design for the Disconnector and Earth-switch. All the interlocking shall be in accordance to the relevant IEC standard in order to allow the operations in fully safety conditions for the operators.

3.2.1.14.19 Control and Protection Interfacea) The module shall be supplied with a local control cabinet, fully prefabricated, pre-wired

and pre-tested as interface between the multifunctional module and the control and protection system at the substation.

b) In order to minimize wiring and cabling at the site, modules shall have the plug-in connectors from the local control cabinet to the drive mechanisms of the circuit breaker and to the drive mechanism of the disconnector and earth switch.

3.2.1.14.20 Rating plate Unless otherwise specified differently in the technical schedule A, the rating plate shall comply with the requirements of IEC 62271-100 clause 5.10. The rating shall be of stainless steel not less than 1.2 mm in thickness. The required information shall be engraved on the plate and the engraving filled with a glossy black.

3.2.1.14.21 Components and materialsAll components and materials used in the construction of the transformer shall comply with the requirements of the relevant IEC standards where they exist unless otherwise agreed or specified.

3.2.1.14.22TerminalsThe Compact switchgear shall be supplied complete with palm type terminals for the primary conductor connections.

3.2.1.14.23 Sulphur hexafluoride (SF6) gasa) SF6 gas complying with IEC 60376 shall be used as the insulation and/or extinguishing

medium for the circuit breaker. The maximum SF6 gas leakage rate for the complete equipment shall be 0,5 % per year.

b) Access to gas filling / evacuation points shall be at a maximum height of 2,400 mm above ground level allowing easy access to the filling / evacuation point without leaving the ground level.

c) The gas filling / evacuation point and the gas pressure gauge shall be separated, i.e. it shall not be necessary to remove the pressure gauge in order to access the filling / evacuation points.

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d) All compact switchgear units shall be fitted with DILO DN8 gas filling points.

3.2.1.14.24 FinishAll ferrous, non-current carrying components exposed to atmosphere shall be hot-dip galvanised and shall conform to ISO 1461.

3.2.1.14.25 Quality planThe plant shall be manufactured in accordance with an approved quality plan compiled in accordance with the principles of ISO 9001. The quality surveillance, inspection and testing requirements that are applied shall be in accordance with the agreed inspection and test plan.

3.2.1.14.26 Tests

3.2.1.14.26.1 Test CertificatesSingle copies of type test certificates shall be submitted with the tender. If all the required type test certificates are not submitted, the tender will be incomplete and therefore will not be considered.

3.2.1.14.26.2 Type Testsa) Test certificates and reports shall be provided to prove that the Compact Switchgear

comply fully with the provisions of IEC 62271-1 and IEC 62271-205 as well as for any further requirements as stipulated in Technical Schedule A of this standard. Where satisfactory test evidence in the form of test certificates is available, this may be accepted in lieu of a project specific set of type tests. Type tests reports from in-house testing laboratories will be accepted based on the following conditions:

b) Proof of the in-service long-term performance of the product range must be provided or the product range must have an acceptable in-service history on a SADC utility network.

c) Employer/Consultant reserves the right to demand test reports from an accredited testing laboratory, should any problems arise that question the validity of the in-house test reports. An accredited testing laboratory is defined as a laboratory that holds valid certification issued by ILAC (International Laboratory Accreditation) or one of its members.

3.2.1.14.26.3 Routine TestsRoutine tests shall be carried out by the manufacturer in accordance with IEC 62271-100 and IEC 62271-205

3.2.1.14.26.4 Installation testsThe installation of the circuit breaker shall be completed by the OEM (manufacturer) or OEM approved person.

3.2.1.14.26.5 Witnessing of TestsEmployer/Consultant reserves the right to appoint a representative to inspect at any stage of manufacture and to witness and sanction any tests. If inspection or witnessing of tests is required, Employer/Consultant will advise the tender/contractor who shall then give at least 14 days’ notice of the date on which impending inspection or testing will take place.

3.2.1.14.26.6 Supporting Data

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Supporting data in the form of marketing brochures or catalogues stating the characteristics and construction details of Compact Switchgear on offer shall be included with the tender. Any deviations between the published data and the completed B-schedules shall be pointed out and clarified.

3.2.1.14.26.7 Design ChangesAny design changes shall be verified by tests wherever applicable and shall be subject to Employer/Consultant approval.

3.2.1.14.26.8 Drawings

3.2.1.14.26.9 Contractual Three copies of drawings shall be submitted as part of the original tender showing the following information as minimum:

a. Overall dimensions, including mounting details

b. Details of main terminals and conductor clamping arrangements

c. Mass, minimum electrical clearances and creepage distances

A drawing indicating the position of the identification rating plate and the detail that will be provided on the rating plate.

3.2.1.14.26.10 TenderSingle copies of drawings shall be submitted as part of the original tender showing the following details as minimum:

a) Overall dimensions, including mounting details

b) Details of main terminals and conductor clamping arrangements

c) Mass, minimum electrical clearances and creepage distances

d) A drawing indicating the position of the identification rating plate and the detail that will be provided on the rating plate.

3.2.1.14.26.11 Packaging The Compact Switchgear shall be packaged in crates and shall be such as to protect the Compact Switchgear and its components against corrosion and damage during normal handling, un-crating, transportation and outdoor storage for a period up to two years. The crate must be able to be lifted using forklifts and/or slings. Lifting positions must be marked. Crates must be designed such that inspections of the contents can be undertaken without opening or damaging the crate. Where Compact Switchgear are supplied with grading rings, the Compact Switchgear, its corresponding grading ring and associated fittings must be housed in a single package or alternatively in uniquely numbered packages identifying each Compact Switchgear, its corresponding grading ring and associated fittings. It is not acceptable to have multiple Compact Switchgear, grading rings and or fittings in one package. The method of packaging and numbering must be submitted for approval.

3.2.1.14.26.12 Data book and documentationA data book or manual shall be provided for the compact switchgear before the start of commissioning. Any modifications made during commissioning shall be marked up in the data

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book, and a revised data book or manual provided as soon as practicably possible. The data book or manual shall contain clear instructions for routine inspections, maintenance, fault-finding, repair and disposal over the life of the compact switchgear. Reference values of all relevant tests shall be included as the basis for trend analysis during the life of the circuit breaker. The data book shall contain clear instructions for the storage of spare parts, and comprehensive information about the shelf-life of spare parts and any tests which should be conducted on spare parts before utilisation. In addition n to hard copies, soft copies of the data book and documentation for the power transformer shall be supplied.

3.2.1.14.26.13 Spare parts and special toolsI. The Bidder/Contractor shall supply following spares free of cost as minimum:

a. 1 set of SF6 gas leak detector

b. 1 set of Electrolytic hygrometer with accessories

c. 1 set of Portable Gas filling and evacuating plant suitable for supplied equipment with accessories.

d. 10% extra gas for each module.

II. Any special tools, tackles & spanner required during operation and maintenance.

III. Viewing mechanism (if required) from accessible point on ground.

IV. Any other agreed spare parts and special tools shall be supplied before the start of commissioning.

V. Any spare parts consumed during commissioning shall be replaced as soon as practicably possible.

3.2.1.15 SPECIFICATION FOR EARTH SWITCH This standard provides requirement for the design, manufacture, supply, test and installation of outdoor earth switches to be used on network voltages 132kV.

3.2.1.15.1 Normative References

Parties using this document shall apply the most recent edition and applicable amendments of the documents listed. Where any of the listed documents are out-dated or superseded, the replacement document of the original document shall take precedence.

[1] IEC 9001 Quality management systems – Requirements

[2] IEC 62271-1 High voltage switchgear and control gear: Common specification

[3] IEC 62271-102 High voltage switchgear and control gear: Alternating current circuit breaker

[4] ISO 1461 Hot dip galvanized coatings on fabricated iron and steel articles: Specifications and test methods



[7] IEC 62271-301 High voltage switchgear and control gear: Dimensional standardisation of high-voltage terminal

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[10] IEC 60815 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions

[11] IEC 61462 Composite hollow insulators

[12] ISO 1461 Hot dip galvanized coatings on fabricated iron and steel articles -- Specifications and test methods

[13] IEC 60865 Short Circuit Current – calculation of effects

[14] IEC 61850 Communication network and systems in substations

3.2.1.15.2 Terms and DefinitionsFor the purposes of this standard, the following terms, definitions and abbreviations apply.

Abbreviations:

IEC International Electrotechnical CommissionISO International Standards OrganisationSANS South African National StandardA AmperekA Kilo AmpereV VoltkV Kilo Volt

3.2.1.15.3 General The tenderer shall supply disconnectors and earth switches identical to those stipulated in Technical schedule A, and shall complete Technical schedule B of the enquiry document.

3.2.1.15.4 Service conditionsEarth switches complying with this standard shall be suitable for operation under the following expected service conditions in Table 3.2.1-7.





Maximum 50 ºC

Minimum 15 ºC






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3.2.1.15.5 Rated VoltageUnless otherwise specified in Technical schedule A, the rated voltage of Earth switches shall comply with rated supply voltage.

3.2.1.15.6 Rated frequency Unless otherwise specified, the Earth switches shall be designed for operating at a frequency of 50 Hz. The Earth switches shall be designed for continuous operation in the frequency range of 50 Hz ± 2.5 Hz.

3.2.1.15.7 Rated insulation level Unless otherwise specified in Technical schedule A, the rated insulation of Earth switches shall comply with Table 3.2.1-8.

The supply voltage of closing and opening devices and auxiliary and control circuits shall comply with Technical schedule A and IEC 62271-1 clause 4.8.

3.2.1.15.8 Rated normal current Unless otherwise specified in Technical schedule A, the rated normal current of Earth switches shall comply with Table 3.2.1-8.

3.2.1.15.9 Rated short time withstand current Unless otherwise specified in Technical schedule A, the rated short time withstand current of Earth switches shall comply with Table 3.2.1-8.

3.2.1.15.10 Rated peak withstand current Unless otherwise specified in Technical schedule A, the rated peak withstand current of Earth switches is equal to 2.5 times the rated short time withstand current and shall comply with IEC 62271-1 clause 4.6.

3.2.1.15.11Rated duration short circuit Unless otherwise specified in Technical schedule A, the rated short circuit duration of Earth switches shall be 3 seconds.

3.2.1.15.12Rated supply voltageThe supply voltage of closing and opening devices and auxiliary and control circuits shall comply with technical schedule A and IEC 62271-1 clause 4.8.

Table 3.2.1-8: Minimum requirements

Rated Voltage

(kV)

Rated Power-Frequency Withstand Voltage U d (kV )



Rated Normal Current

I r(A)

Rated Short time withstand Current

I sc(kA)

132 275 650 - 2500 31.5

3.2.1.15.13 Rated short circuit making current

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Unless otherwise specified in Technical schedule A, the rated short circuit making current shall comply with IEC 62271-102 clause 4.101.

3.2.1.15.14 Rated contact zone Unless otherwise specified in Technical schedule A, the rated contact zone shall comply with IEC 62271-102 clause 4.102.

3.2.1.15.15 Rated mechanical terminal loadUnless otherwise specified in Technical schedule A, the rated mechanical terminal load shall comply with IEC 62271-102 clause 4.103.

3.2.1.15.16Rated values of the induced current switching capability of earthing switchesUnless otherwise specified in Technical schedule A, rated values of the induced current switching capability of earthing switches shall comply with IEC 62271-102 clause 4.105.

3.2.1.15.17 Rated values of electrical endurance for earthing switchesUnless otherwise specified in Technical schedule A, the rated contact zone shall comply with IEC 62271-102 clause 4.107.

3.2.1.15.18 Nameplate Unless otherwise specified in Technical schedule A, the rating plate shall comply with IEC 62271-102 clause 5.10. The rating plate shall be of stainless steel not less than 1.2 mm in thickness. The required information shall be engraved on the plate and the engraving filled glossy black.

3.2.1.15.19 Components and materialsAll components and materials used in the construction of the Earth switches shall comply with the requirements of the relevant IEC standards where they exist unless otherwise agreed or specified.

3.2.1.15.20 FinishAll ferrous, non-current carrying components exposed to atmosphere shall be hot-dip galvanised and shall comply with ISO 1461.

3.2.1.15.21 Operating mechanism Earth switches operating mechanisms, local control facilities and all parts requiring lubrication shall be protected by weatherproof enclosures complying with IEC 60529. Operating mechanism enclosure enclosures containing exposed bearings, auxiliary switches, motors and other electrical devices shall be IP 55 rated. All open areas in the Earth switches common base frame as well as externally mounted indicating devices where there is a high probability of birds nesting, shall be IP 2X rated. Other enclosures within the Earth switches shall be IP 54 rated.

The enclosure, handles and fixings of the Earth switches operating mechanism shall be manufactured from 3CR12 stainless steel with corrosion protection. The mechanism enclosures of the exposed aluminium shall not be acceptable.

Hinged access door, designed for operation from the front of the Earth switches shall be used for the operating mechanism. The operating mechanism enclosure shall be capable of being padlocked to prevent unauthorized access. The locking facility shall accommodate padlocks that have a shackle diameter of 6 mm

A manual operation facility provided shall be crank handle type with clear indication of direction to operate towards both open and closed conditions. The operation of swing type handles takes

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place in the horizontal plane. The operation of crank type handles takes place in a vertical plane. The height for the operating handle is between 1,000 mm and 1,200 mm above ground level.

Earth switches operating mechanisms enclosure shall be provided with suitably rated permanently connected electric heaters to prevent internal condensation.

3.2.1.15.22 Primary terminalThe Earth Switch shall be supplied complete with IEC 8 hole palm type terminals for the primary conductor connections.

3.2.1.15.23 Secondary terminal Auxiliary switches, internal wiring and other equipment requiring connection to external apparatus shall be wired terminal strips in the Earth switch mechanism box.

DIN rail-mounted spring-loaded type terminals shall be provided for terminating control cables. Each terminal strip shall be provided with not less than 10% spare terminals.

The arrangement of the terminal strips (vertical orientation) in the equipment shall facilitate the entry of the incoming control cables in the bottom entry configuration. Terminal size shall be wide enough to accept multi-stranded (at least 20 strands) copper conductor having a minimum equivalent area of 2.5 mm2 and insulated.

3.2.1.15.24 Quality planEarth switches shall be manufactured in accordance with an approved quality plan compiled in accordance with the principles of ISO 9001. The quality surveillance, inspection and testing requirements that are applied shall be in accordance with the agreed inspection and test plan.

3.2.1.15.25 Tests

3.2.1.15.25.1 Test certificatesSingle copies of type test certificates shall be submitted with the tender. If all the required type test certificates are not submitted, the tender will be viewed as incomplete.

3.2.1.15.25.2 Type testsa. Test certificates and reports shall be provided to prove that the disconnectors and earth

switches comply fully with the provisions of IEC 62271-102 as well as for any further requirements as stipulated in Technical schedule A of this standard. Where satisfactory test evidence in the form of test certificates is available, this may be accepted in lieu of a project specific set of type tests.

b. Type tests reports from in-house testing laboratories will be accepted, based on the following conditions:

c. Proof of the in-service long-term performance of the product range must be provided or the product range must have an acceptable in-service history on a SADC utility network.

d. EMPLOYER/CONSULTANT reserves the right to demand test reports from an accredited testing laboratory, should any problems arise that question the validity of the in-house test reports. An accredited testing laboratory is defined as a laboratory that holds valid certification issued by ILAC (International Laboratory Accreditation) or one of its members.

3.2.1.15.25.2.1 Routine testsRoutine tests shall be carried out by the manufacturer in accordance with IEC 62271-102.

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3.2.1.15.25.2.2 Installation testsThe installation of the circuit breaker shall be completed by the OEM (manufacturer) or OEM approved person. As part of installation of the equipment on site, the following tests shall be completed:

a) Visual checks

b) Insulation resistance test

c) Contact resistance test

d) Contact timing test

e) Motor current measurement

f) Contact travel, end position and alignment

g) Complete operational check, including auxiliary switch function

h) Isolator closing and opening time

i) Operating force measurement for manual type drives

j) Operating forces measurements for motor drives

3.2.1.15.25.2.3 Witnessing of testsEmployer/Consultant reserves the right to appoint a representative to inspect the disconnectors and earth switches at any stage of manufacture and to witness and sanction any tests. If inspection or witnessing of tests is required, Employer/Consultant will advise the tender / contractor who shall then give at least 14 days’ notice of the date on which impending inspection or testing will take place.

3.2.1.15.25.3 Supporting dataSupporting data in the form of marketing brochures or catalogues stating the characteristics and construction details of earth switches on offer shall be included with the tender. Any deviations between the published data and the completed B-schedules shall be pointed out and clarified.

3.2.1.15.25.4 Design changesAny design changes shall be verified by tests wherever applicable and shall be subject to Employer/Consultant approval.

3.2.1.15.26 Drawings




c. Mass, minimum electrical clearances and creepage distances

A drawing indicating the position of the identification rating plate and the detail that will be provided on the rating plate

3.2.1.15.26.2 Tender

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Single copies of drawings shall be submitted as part of the original tender showing the following details as minimum:

a) Overall dimensions, including mounting details

b) Details of main terminals and conductor clamping arrangements

c) Mass, minimum electrical clearances and creepage distances

A drawing indicating the position of the identification rating plate and the detail that will be provided on the rating plate

3.2.1.15.27 Packaging Earth switches shall be packaged in crates and shall be such as to protect each disconnector and earth switch and its components against corrosion and damage during normal handling, un-crating, transportation and outdoor storage for a period up to two years. Crates must be able to be lifted using forklifts and/or slings. Lifting positions must be clearly marked. Crates must be designed such that inspections of the contents can be undertaken without opening or damaging the crate. Where disconnectors and earth switches are supplied with grading rings, each disconnector and earth switch, its corresponding grading ring and associated fittings must be housed in a single package or alternatively in uniquely numbered packages identifying each disconnector and earth switch, it’s corresponding grading ring and associated fittings. It is not acceptable to have multiple disconnectors and earth switches, grading rings and or fittings in one package. The method of packaging and numbering must be submitted for approval.

3.2.1.15.28 Data book and documentationa. A data book or manual shall be provided for each disconnector and earth switch before

start of commissioning. Any modifications made during commissioning shall be marked up in the data book, and a revised data book or manual provided as soon as practicably possible.

b. The data book or manual shall contain clear instructions for routine inspections, maintenance, fault-finding, repair and disposal over the life of each disconnector and earth switch. Reference values of all relevant tests shall be included as the basis for trend analysis during the life of each isolator and earth switch.

c. The data book shall contain clear instructions for the storage of spare parts, and comprehensive information about the shelf-life of spare parts and any tests which should be conducted on spare parts before utilisation.

d. In addition to hard copies, soft copies of the data book and documentation for each isolator and earth switch shall be supplied.

3.2.1.15.29 Spare parts and special toolsThe agreed spare parts and special tools shall be supplied before the start of commissioning. Any spare parts consumed during commissioning shall be replaced as soon as practicably possible.

3.2.1.16 SPECIFICATION FOR SURGE ARRESTOR This standard provides requirement for the design, manufacture, supply, test and installation of outdoor station class metal oxide surge arresters without spark gaps for outdoor installation to be used for network voltages of 132 kV.

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3.2.1.16.1 Normative References

Parties using this document shall apply the most recent edition and applicable amendments of the documents listed. Where any of the listed documents are out-dated or superseded, the replacement document of the original document shall take precedence.

[1] IEC 60099-4 Surge arresters, Part 4: Metal-oxide surge arresters without gaps for a.c. system

[2] IEC 60815 Guide for the selection of insulators in respect of polluted conditions

[3] ISO 1461 Hot dip galvanized coatings on fabricated iron and steel articles Specifications and test methods

[4] NRS 039 Guide for the application of gapless metal-oxide surge arresters in distribution systems.

[5] ISO/IEC 17025

General requirements for the competence of testing and calibration laboratories



Abbreviations:


3.2.1.16.3 GeneralThe tenderer shall supply surge arresters identical to those stipulated in Technical schedule A and shall complete Technical schedule B of the enquiry document.

3.2.1.16.4 Service conditionsSurge arresters complying with this standard shall be suitable for operation under the following expected service conditions in Table 3.2.1-7 and shall comply with IEC 60099-4 clause 5.4.




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Maximum 50 ºC

Minimum 15 ºC







3.2.1.16.5 Nominal system voltage

Unless otherwise specified in Technical schedule A, the rated voltage of the surge arresters shall comply with Table 3.2.1-10.

3.2.1.16.6 Maximum system voltage

Unless otherwise specified in Technical schedule A, the rated voltage of the surge arresters shall comply with Table 3.2.1-10.

3.2.1.16.7 Rated frequency

Unless otherwise specified, surge arresters shall be designed for operating at a frequency of 50 Hz. The surge arresters shall be designed for continuous operation in the frequency range of 50 Hz ± 2.5 Hz.

3.2.1.16.8 Rated insulation level

Unless otherwise specified in Technical schedule A, the rated insulation shall comply with Table3.2.1-10.

3.2.1.16.9 Nominal discharge current

Unless otherwise specified in Technical schedule A, the surge arrester discharge current shall comply with Table 3.2.1-10.

3.2.1.16.10Maximum continuous operating voltage

Unless otherwise specified in Technical schedule A, the surge arrester continuous operating voltage shall comply with Table 3.2.1-10.

3.2.1.16.11Rated short time withstand current

Unless otherwise specified in Technical schedule A, the rated short time withstand current shall comply with Table 3.2.1-10.

3.2.1.16.12Long duration classification

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Unless otherwise specified in Technical schedule A, the surge arrester long duration class shall comply with Table 3.2.1-10.

TABLE 3.2.1-10 : Minimum requirements for surge arresters

Nominal system voltage (kV)

Maximum system voltage (kV)

Lightning impulse withstand (kV)

Switching impulse withstand (kV)

Power frequency withstand (kV)

Nominal discharge current (kA)

Continuous operating voltage (kV)

Rated short time withstand current

I sc(kA)

IEC long duration class

132 145 650 540 275 10 92 31.5 2

3.2.1.16.13 Mechanical requirements

3.2.1.16.13.1 SealingInternal components shall be dry at the time of assembly and surge arresters shall be permanently sealed. If elastomer gaskets or seals are used, precautions shall be taken to ensure adequate compression and that such gaskets or seals do not deteriorate in service as a result of exposure to the environment or electrical stresses. An approved routine test of seal integrity shall be carried out on every assembled surge arrester or arrester unit. Technical details of the sealing arrangements and the routine seal test shall be submitted.

3.2.1.16.13.2 TerminalsAll line terminals shall be 38 mm in diameter. Terminals must be constructed out of a solid piece of material. If dissimilar metals are used for the surge arrester terminals and conductor clamping arrangements, proof shall be provided of the galvanic compatibility of these materials. Terminals will be of sufficient strength to withstand forces arising during installation and service. Such forces will not overstress the components of the surge arrester, particularly the sealing system.

3.2.1.16.13.3 MountingSurge arresters will be isolated from the support structure by either an insulated base or support insulators. The surge arrester base plate shall be of 254 PCD.

Support insulators may be constructed of epoxy or porcelain. Once installed, the surge arrester should be able to stand upright without additional support and must not be able to slide off the support / insulated base insulators. Method and details of components supplied for mounting must be submitted with tender returnable for approval by EMPLOYER/CONSULTANT.

3.2.1.16.13.4 FinishAll ferrous, non-current carrying components exposed to atmosphere shall be hot-dip galvanised and conform to ISO 1461.

3.2.1.16.14Tests


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3.2.1.16.14.2 Test conditionsNew and clean surge arresters shall be used for each test unless specified otherwise. The mounting arrangements of the test samples should simulate installation conditions.

3.2.1.16.14.3 Type testsTest certificates and reports shall be provided to prove that the surge arresters fully comply with the provisions of IEC 60099-4 for polymer-housed arresters as well as for any further requirements as stipulated in Technical schedule A of this standard.

The following type tests shall be performed:

a. Insulation withstand test of the arrester housingb. Residual voltage testsc. Test to verify long term stability under continuous operating voltaged. Repetitive charge transfer withstande. Heat dissipation behaviour of test samplef. Operating duty testsg. Power-frequency voltage versus timeh. Arrester disconnector / fault indicator (when fitted)i. Long duration current impulse withstands testsj. Thermal stability testsk. Power frequency voltage versus time testl. Short-circuit testm. Weather ageing testn. Internal partial discharge testo. Moisture ingress testp. Bending moment test

Where satisfactory test evidence in the form of test certificates is available, this may be accepted in lieu of a project specific set of type tests.

Type tests reports from in-house testing laboratories will be accepted, based on the following conditions:

Proof of the in-service long-term performance of the product range must be provided or the product range must have an acceptable in-service history on a SADC utility network.

Employer/Consultant reserves the right to demand test reports from an accredited testing laboratory, should any problems arise that question the validity of the in-house test reports. An accredited testing laboratory is defined as a laboratory that holds valid certification issued by ILAC (International Laboratory Accreditation) or one of its members.

3.2.1.16.14.4 Routine testsThe following are the minimum requirements for routine tests that shall be carried out by the manufacturer. These tests shall be done in accordance with IEC 60099-4:

a) Measure reference voltage (Uref)

b) Residual voltage test on complete arrester

c) Internal partial discharge test

d) Leakage check test (if applicable)

3.2.1.16.14.5 Witnessing of testsEmployer/Consultant reserves the right to appoint a representative to inspect the surge arresters at any stage of manufacture and to witness and sanction any tests. If inspection or witnessing of

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tests is required, Employer/Consultant will advise the tender / contractor who shall then give at least 14 days’ notice of the date on which impending inspection or testing will take place.

3.2.1.16.14.6 Supporting dataSupporting data in the form of marketing brochures or catalogues stating the electrical characteristics of the surge arresters on offer shall be included with the tender. Any deviations between the published data and the completed B-schedules shall be pointed out and clarified.

3.2.1.16.14.7 Design changesAny design changes shall be verified by tests wherever applicable and shall be subject to Employer/Consultant approval.

3.2.1.16.14.8 Surge arrester characteristic dataThe manufacturer of the metal oxide surge arresters shall furnish EMPLOYER/CONSULTANT with the following characteristic data:

a) V-I characteristic curve at temperatures ranging from 20 °C to 200 °C

b) DC and AC voltage-current curves

c) Nominal lightning discharge current

d) Clear unambiguous definitions of rated voltage, reference voltage and protective level

e) Region of thermal stability

f) Temporary over voltage withstand capability curve

g) Front-of-wave discharge voltage curve

h) Manufacturer’s name and trademark

i) Year of manufacture

j) Model and serial number

3.2.1.16.14.9 Drawings

3.2.1.16.14.9.1 Contractual Three copies of drawings shall be submitted as part of the original tender showing the following information as minimum:


b. Details of main and earthing terminals and conductor clamping arrangements

c. Mass of complete surge arrester, and if applicable, individual arrester sections

d. Minimum electrical clearances

e. Creepage distances

f. A drawing indicating the position of the identification rating plate and the detail that will be provided on the rating plate


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a) Overall dimensions, including mounting details with drilling plan

b) Line conductor and earth conductor clamping arrangements

c) Line and earth terminal type details and physical dimensions

d) Minimum electrical clearances

e) Details of special items such as the disconnecting device or overpressure relief device

f) Insulating base type details and physical dimensions (where applicable)

g) Total creepage and SCD

h) Overall dimensions, including mounting details

i) Details of main and earthing terminals and conductor clamping arrangements

j) Mass of complete surge arrester and if applicable, individual arrester sections

3.2.1.16.14.11 Packaging Surge arrester shall be packaged in crates and shall be such as to protect each surge arrester and its components against corrosion and damage during normal handling, uncrating, transportation and outdoor storage for a period up to two years. Crates must be able to be lifted using forklifts and/or slings. Lifting positions must be clearly marked. Crates must be designed such that inspections of the contents can be undertaken without opening or damaging the crate. Where surge arresters are supplied with grading rings, the arrester, it’s corresponding grading ring and associated fittings must be housed in a single package or alternatively in uniquely numbered packages identifying each arrester, its corresponding grading ring and associated fittings. It is not acceptable to have multiple surge arresters, grading rings and or fittings in one package. The method of packaging and numbering must be submitted for approval.

3.2.1.17 SPECIFICATION FOR VOLTAGE TRANSFORMER This standard provides requirement for the design, manufacture, supply, test and installation of inductive voltage transformers to be used for network voltages of 132 kV.

3.2.1.17.1 Normative ReferencesParties using this document shall apply the most recent edition and applicable amendments of the documents listed. Where any of the listed documents are out-dated or superseded, the replacement document of the original document shall take precedence.

[1] IEC 61869 -3 Inductive voltage transformers

[2] IEC 60815 Guide for the selection of insulators in respect of polluted conditions

[3] ISO 1461 Hot dip galvanized coatings on fabricated iron and steel articles Specifications and test methods

[4] NRS 030 Inductive voltage transformers

[5] IEC 60044 -2 Instrument transformers

3.2.1.17.2 Terms and Definitions

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For the purposes of this standard, the following terms, definitions and abbreviations apply.

Abbreviations:


3.2.1.17.3 General The tenderer shall supply inductive voltage transformers identical to those stipulated in Technical schedule A and shall complete Technical schedule B of the enquiry document.

3.2.1.17.4 Service conditionsInductive voltage transformers shall be suitable for operation under the following expected service conditions in Table 3.2.1-11.

3.2.1.17.5 Rated primary voltageUnless otherwise specified in Technical schedule A, the rated voltage of inductive voltage transformers shall comply with Table 3.2.1-12.

TABLE 3.2.1-11 : SERVICE CONDITIONMaximum altitude above sea level:

1,400 m


Ambient temperature:

Maximum: 50 ºC

Minimum: -15 ºC

Monthly average: 40 ºC

Yearly average: 30 ºC

Humidity: 30% to 90%

Seismic conditions: 0.3 g

Pollution level: Very heavy

Solar radiation: 2,500 kWh/m2

3.2.1.17.6 Rated frequency Unless otherwise specified, inductive voltage transformers shall be designed for operating at a frequency of 50 Hz. The inductive voltage transformer shall be designed for continuous operation in the frequency range of 50 Hz +/- 2.5 Hz.

3.2.1.17.7 Rated secondary voltageUnless otherwise specified in Technical schedule A, the rated voltage of inductive voltage transformers shall comply with Table 3.2.1-12.

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3.2.1.17.8 Rated insulation level Unless otherwise specified in Technical schedule A, the rated insulation of inductive voltage transformers shall comply with Table 3.2.1-12.

3.2.1.17.9 Rated short circuit withstand Unless otherwise specified in Technical schedule A, the inductive voltage transformers shall comply with the short circuit current in Table 3.2.1-12 for duration of 1 second.

TABLE 3.2.1-12 - VOLTAGE TRANSFORMER RATING

Rated primary voltage

(kV)

Rated secondary voltage

(V)

Rated power-frequency withstand voltage Ud (kV )



Rated short circuit current

I sc(kA)

145/√ 3 110/√ 3 275 650 540 31.5

3.2.1.17.10Primary terminals

Unless otherwise specified in Technical schedule A, the primary terminal dimension shall comply with Table 3.2.1-13.

TABLE 3.2.1-13 - TERMINAL DIMENSIONSRated voltage (kV) Primary terminal diameter (mm) Primary terminal

length (mm)

132 26 125

3.2.1.17.11Rated voltage factor

Unless otherwise specified in Technical schedule A, the inductive voltage transformers shall comply with the maximum operating voltage in Table 3.2.1-14.

TABLE 3.2.1-14 - RATED VOLTAGE FACTOR

Rated voltage factor FV

Rated time Method of connecting the primary terminal and system earthing conditions

1,2 Continuous Between phase and earth in an effectively earthed neutral system

1,5 30 s

1,2 Continuous Between phase and earth in a non-effectively earthed neutral system with automatic earth-fault tripping

1,2 Continuous Between phase and earth in isolated neutral system without

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Rated voltage factor FV

Rated time Method of connecting the primary terminal and system earthing conditions

automatic earth-fault tripping or in resonant earthed system without automatic earth-fault tripping

1,9 8 h

3.2.1.17.12 Accuracy class

Unless otherwise specified in Technical schedule A, accuracy class of secondary winding shall be in accordance with Table 3.2.1-15.

TABLE 3.2.1-15 - WINDING ACCURACY CLASS

Winding number 1

(rated burden / accuracy class)

Winding number 2

(rated burden / accuracy class)

50 VA 3P / 100 VA 3P 50 VA 0,2

3.2.1.17.13 Nameplate Unless otherwise specified in Technical schedule A, the rating plate shall comply with the requirement in and IEC 61869-3 clause 6.13. The rating plate shall be of stainless steel not less than 1.2 mm in thickness. The required information shall be engraved on the plate and the engraving filled glossy black.

3.2.1.17.14 Components and materialsAll components and materials used in the construction of the inductive voltage transformers shall comply with the requirements of the relevant IEC standards where they exist unless otherwise agreed or specified.


3.2.1.17.16 Quality planThe plant shall be manufactured in accordance with an approved quality plan compiled in accordance with the principles of ISO 9001. The quality surveillance, inspection and testing requirements that are applied shall be in accordance with the agreed inspection and test plan.

3.2.1.17.17 Tests

3.2.1.17.17.1 Test certificates

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Single copies of type test certificates shall be submitted with the tender. If all the required type test certificates are not submitted, the tender will be incomplete and therefore will not be considered.

3.2.1.17.17.2 Type testsTest certificates and reports shall be provided to prove that the inductive voltage transformers comply fully with the provisions of IEC 60044-2 and IEC 61869-3 as well as for any further requirements as stipulated in Technical schedule A of this standard.

The following type tests shall be performed:

a) Short-time current test [5]

b) Temperature rise test [5]

c) Lightning impulse test [5]

d) Switching impulse test [5]

e) Wet test for outdoor type transformers [5]

f) Determination of errors [5]

g) Radio interference voltage measurement (RIV) [5]

Where satisfactory test evidence in the form of test certificates is available, this may be accepted in lieu of a project specific set of type tests.


Proof of the in-service long-term performance of the product range must be provided or the product range must have an acceptable in-service history on a SADC utility network.

EMPLOYER/CONSULTANT reserves the right to demand test reports from an accredited testing laboratory, should any problems arise that question the validity of the in-house test reports. An accredited testing laboratory is defined as a laboratory that holds valid certification issued by ILAC (International Laboratory Accreditation) or one of its members.

3.2.1.17.17.3 Routine testsThe following are the minimum requirements for routine tests that shall be carried out by the manufacturer. These tests shall be done in accordance with of IEC 60044-2, IEC 61869-3 and NRS030.

a) Verification of terminal markings [5]

b) Power-frequency withstand test on primary winding [5]

c) Partial discharge measurement [5]

d) Power-frequency withstand test on secondary winding [5]

e) Power-frequency withstand test, between sections [5]

f) Inter-turn overvoltage test [5]

g) Determination of errors [5]

h) Polarity test [5]

i) Test for effectiveness of sealing [4]

j) Capacitance and dielectric dissipation factor (tangent delta) [1]

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3.2.1.17.17.4 Special testsSpecial tests [1] specified in Technical schedule A shall be performed and may be specified as type tests or routine tests. Where satisfactory test evidence in the form of test certificates is available, this may be accepted in lieu of a project specific set of type tests.

EMPLOYER/CONSULTANT reserves the right to demand test reports from an accredited testing laboratory, should any problems arise that question the validity of the in-house test reports. An accredited testing laboratory is defined as a laboratory that holds valid certification issued by ILAC (International Laboratory Accreditation) or one of its members.

3.2.1.18 SPECIFICATION FOR POST INSULATOR This standard provides requirement for the design, manufacture, supply, test and installation of post insulators to be used for network voltages of 132 kV.

3.2.1.18.1 Normative ReferencesParties using this document shall apply the most recent edition and applicable amendments of the documents listed. Where any of the listed documents are out-dated or superseded, the replacement document of the original document shall take precedence.

1 ISO 9001 Quality Management Systems

2 IEC 60273 Characteristics of indoor and outdoor post insulator for systems with nominal voltages greater than 1000 V

3 IEC 60168 Tests on indoor and outdoor post insulators of ceramic material or glass for systems with nominal voltages greater than 1000 V

4 IEC 60815 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions

5 IEC 60071-1 Insulation co-ordination

6 ISO 1461 Hot dip galvanized coatings on fabricated iron and steel articles -- Specifications and test methods


Abbreviations:


3.2.1.18.3 General The tenderer shall supply post insulators identical to those stipulated in Technical schedule A and shall complete Technical schedule B of the enquiry document.

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3.2.1.18.4 Service conditionsPost insulators complying with this standard shall be suitable for operation under the following expected service conditions in Table 3.2.1-12.

TABLE 3.2.1-16 : SERVICE CONDITIONMaximum altitude above sea level:

1,400 m


Ambient temperature:

Maximum: 50 ºC

Minimum: -15 ºC

Monthly average: 40 ºC

Yearly average: 30 ºC

Humidity: 30% to 90%

Seismic conditions: 0.3 g

Pollution level: Very heavy

Solar radiation: 2,500 kWh/m2

3.2.1.18.5 Rated insulation levelsUnless otherwise specified in Technical schedule A, the post insulators shall comply with the specifications indicated in Table 3.2.1-17.

TABLE 3.2.1-17 : ELECTRICAL CHARACTERISTICS

System voltage (kV) System highest voltage (kV)

Power frequency withstand voltage (kV)

Switching surge impulse withstand voltage (kVrms)

Lightning surge impulse withstand voltage (kVpeak)

132 145 275 540 650

3.2.1.18.6 Mechanical characteristicsUnless otherwise specified in Technical schedule A, the post insulator mechanical characteristics shall comply with IEC 60273 and the values indicated in Table 3.2.1-18.

TABLE 3.2.1-18 - MECHANICAL CHARACTERISTICS

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Post insulator designation Failing load (N)

Bending Torsion

C6-650 6,000 3,000

C8-650 8,000 4,000


3.2.1.18.8 Quality planPost insulators shall be manufactured in accordance with an approved quality plan compiled in accordance with the principles of ISO 9001. The quality surveillance, inspection and testing requirements that are applied shall be in accordance with the agreed inspection and test plan.

3.2.1.18.9 Tests


3.2.1.18.9.2 Test conditionsNew and clean post insulators shall be used for each test unless specified otherwise. The mounting arrangements of the test samples should simulate installation conditions.

3.2.1.18.9.3 Type testsTest certificates and reports shall be provided to prove that the post insulators comply fully with the provisions of IEC 60168 as well as for any further requirements as stipulated in Technical schedule A of this standard.

Type tests shall be performed according to IEC 60168 clause 3.3. Where satisfactory test evidence in the form of test certificates is available, this may be accepted in lieu of a project specific set of type tests.


a. Proof of the in-service long-term performance of the product range must be provided or the product range must have an acceptable in-service history on a SADC utility network.

b. EMPLOYER/CONSULTANT reserves the right to demand test reports from an accredited testing laboratory, should any problems arise that question the validity of the in-house test reports. An accredited testing laboratory is defined as a laboratory that holds valid certification issued by ILAC (International Laboratory Accreditation) or one of its members.

3.2.1.18.9.4 Sample testsSample tests shall be performed according to IEC 60168 clause 3.4.

3.2.1.18.9.5 Routine tests

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Sample tests shall be performed according to IEC 60168 clause 4.10.

3.2.1.18.9.6 Witnessing of testsEMPLOYER/CONSULTANT reserves the right to appoint a representative to inspect the post insulators at any stage of manufacture and to witness and sanction any tests. If inspection or witnessing of tests is required, EMPLOYER/CONSULTANT will advise the tender / contractor who shall then give at least 14 days’ notice of the date on which impending inspection or testing will take place.

3.2.1.18.9.7 Supporting dataSupporting data in the form of marketing brochures or catalogues stating the characteristics of post insulators on offer shall be included with the tender. Any deviations between the published data and the completed B-schedules shall be pointed out and clarified.

3.2.1.18.9.8 Design changesAny design changes shall be verified by tests wherever applicable and shall be subject to EMPLOYER/CONSULTANT approval.

3.2.1.18.9.9 Drawings




c. Mass of complete post insulator and mechanical characteristics






c. Mass of complete post insulator and mechanical characteristics



3.2.1.18.9.12 Packaging Post insulators shall be packaged in crates and shall be such as to protect each post insulator and its components against corrosion and damage during normal handling, uncrating, transportation and outdoor storage for a period up to two years. Crates must be able to be lifted using forklifts and/or slings. Lifting positions must be clearly marked. Crates must be designed such that inspections of the contents can be undertaken without opening or damaging the crate.

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Where post insulators are supplied with grading rings, each post insulator, it’s corresponding grading ring and associated fittings must be housed in a single package or alternatively in uniquely numbered packages identifying each post insulator, its corresponding grading ring and associated fittings. It is not acceptable to have multiple post insulator, grading rings and or fittings in one package. The method of packaging and numbering must be submitted for approval.

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SPECIFICATION FOR CIVIL WORKS

All works shall comply with SANS 1200 C, SANS 1200 AA, SANS 1200 DA, SANS 1200 LB, SANS 1200 LE, SANS 1200 MJ.

3.2.1.18.10 Site clearingI. The Contractor shall clear the site of all trees, vegetation, stumps, roots, boulders and

white ant nests according to the Engineers approval and environmental requirements.

II. Clearing and grubbing shall be done before commencement of the bulk earthworks. Clear vegetation only from the footprints for the actual substation site, borrow pit and road area. Remove and stockpile all material containing vegetative matter, using only methods, tools and equipment permitted by the environmental management plan. Stockpiled soil may only be used for surface rehabilitation after completion, or to create storm water berms on the higher side of the terrace to prevent water from the surrounding areas running onto the terrace.

3.2.1.18.11 Storm Water Drainage System I. The storm water drainage system shall be designed to prevent water from the

surrounding areas to flow onto the terrace and dispose storm water without eroding the area around the substation.

II. The terrace shall be at least 300 mm higher than the surrounding natural ground level, or where cut and fill method is used, suitable drainage ditches must be provided on the higher side of the terrace to channel water away from the terrace.

III. Surface drainage system shall consist of a gently sloping ground surface so that the water drains to the edge of the yard or to shallow channels within the yard. The channels shall discharge through a system of underground pipes and culverts, removing the storm water run-off from the yard surface.

IV. The storm water drainage system will slope towards the lower side of the surrounding land and the natural water course. The storm water system will be designed to ensure that no ponding or flooding of the yard will take place in the 1:50 year flood event.

V. Reinforced concrete (RCP) pipe of 300 mm or larger diameter shall be used for the storm sewer.

VI. Polyvinyl chloride (PVC) pipe (or concrete pipe) of 150 mm to 300 mm diameter shall be used for the sub-grade drainage system.

VII. Slope of pipes for the storm sewer and sub-grade drainage system shall be 0.5% (1:200). The pipe flow velocities of the storm sewer and sub-grade drainage system shall be 1 m/s minimum and 3 m/s maximum.

VIII. The storm sewer and sub-grade drainage system shall provide manholes at a maximum separation distance of 90 m.

3.2.1.18.12 EarthworksI. The terrace shall be ripped, filled and compacted in layers not exceeding 150 mm, to a

density of 95% MOD AASHTO density and must have a minimum bearing pressure of not less than 150 kPa (kN/m2).

II. Fill material shall be of G5 to G7 quality material with a neutral pH value and a low electrical resistivity ≤ 100 Ωm. The use of dump rock from mining activities will not be accepted.

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III. The terrace shall have a slope of between 100:1 and 200:1 along its longer axis (at right angles to the busbars) for water run-off.

IV. The terrace shall be at least 300 mm higher than the surrounding natural ground level, or where cut and fill method is used, suitable drainage ditches shall be provided on the higher side of the terrace in order to channel water away from the terrace.

V. All embankments lower than 1 m shall be protected against erosion by means of seeding the embankment with indigenous grass. These embankments must be watered regularly to ensure that the seeding is successful.

VI. All embankments higher than 1 m shall be protected by means of interlock paving blocks that securely anchored at the base with a concrete lined ditch placed at the top to prevent rain water from filtering in behind the paving.

3.2.1.18.13 RoadsI. The access road and internal substation roads shall be designed for heavy loads such

delivery of heavy equipment (transformers, reactors etc.) and maintenance vehicles (crane trucks, bucket lifts etc.).

II. Any culverts or sewers crossing the roads shall be designed for the anticipated heavy equipment load. The maximum vertical slope of the road shall be 4%.

III. The minimum requirement is 9 m wide single lane road with 500 mm shoulder both sides, minimum centreline radius 20 m, and gates positioned to accommodate 5 m off-tracking. The road shall be cambered at the centre for drainage.

IV. For well-graded sand and gravel road to the substation, the roadbed shall be a 450 mm thick layer of in-situ material ripped and re-compacted in 150 mm layers to a 93% MOD AASHTO density, the subbase layer (acting as a wearing course) will be a 150 mm thick G7 quality material compact to 98% MOD AASHTO density.

V. For high-clay-content soils and loose sand, the road shall be a 450 mm thick layer of in-situ material ripped and re-compacted in 150 mm layers to a 93% MOD AASHTO density, the subbase layer will be a 150 mm thick G7 quality material compact to 95% MOD AASHTO density and the gravel wearing course will be a 150 mm thick G5 quality material compacted to 98% MOD AASHTO density.

VI. The main substation internal road shall be of a 150 mm thick layer of in-situ material ripped and re-compacted to 90% MOD AASHTO density, the lower selected layer will be a 150 mm thick G9 quality material compact to 93% MOD AASHTO density, the upper selected layer will be a 150 mm thick G7 quality material compact to 95% MOD AASHTO density, the subbase layer will be a 150 mm thick C4 quality cemented material compact to 97% MOD AASHTO density and the wearing course will be a 200 mm thick meshed concrete slab to be designed by a structural engineer.

VII. An alternative wearing course may be prescribed for the main internal substation road, if found suitable, in the form of a 80 mm thick interlocking paving block bedded on river sand with a minimum compression strength capable of withstanding the maximum prescribed loads without crushing under the load and locked in with a 150 wide x 150 mm thick concrete edge beam.

3.2.1.18.14 Trench and KerbI. Cable trenches shall be provided for auxiliary and control cables (i.e. from CTs, VTs,

Compact Switchgears, isolators, etc.) into the relay room.

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II. Concrete curbs with the following dimensions shall be used to construct the vertical sides of the cable trench: 1,000 mm (length) X 300 mm (width) X 90 mm, (thickness at the bottom) and 60 mm (thickness at the top). The one side (where thickness is 60mm) is rounded slightly.

III. The overall trench width measuring from the outside of the one curb to the outside of the other curb shall be 750 mm.

IV. The abovementioned curbs shall be installed 150 mm below ground level in its length so that 150 mm still sticks out above ground level in order to cater for a 150 mm thick layer of yard stone.

V. The curbs shall be installed on a dry concrete mixture and the bottom of the trench shall be filled with a 100 mm layer of river sand. (Trenches that carry power cables do not have a sand filling.)

VI. Reinforced concrete covers with the following dimensions shall be used to cover the trenches: 750 mm X 300 mm X 50 mm. One side of the cover shall be finished with an anti-slip finish. The concrete covers shall be reinforced with mesh reinforcing.

3.2.1.18.15 Crushed stone The switchyard perimeters shall be enclosed with concrete kerbing, and covered with a layer of crushed stone, with 25 mm to 32 mm nominal size, in a layer that is a minimum of 150 mm thick in all places. The crushed stone shall be lightly compacted to the required levels and surface smoothness.

3.2.1.18.16 Control building I. Refer to the control building layout drawing provided.

II. The floors shall be constructed with reinforced weld mesh and 25 MPa strength concrete.

III. The floor finish shall be laid on a 25 mm screed, on a 100 mm (minimum) concrete surface bed.

IV. The surface bed shall be laid over Gunplas USB green surface bed membrane or approved alternative (0,25 mm Polyolefin to SABS 952), placed on clean building sand fill, compacted to 100% Mod AAASHTO at OMC in max 150 mm layers.

V. The bricks shall be clay face brick Class ”FBX” to SABS 227 in class II mortar and internal plastered walls shall be clay bricks class “NFP” in class II mortar.

VI. The firewall between the battery room and the relay room shall be a minimum of 230 mm thickness and built up to the underside of the roof tiles and shall be sealed between the brickwork and tiles with suitable foam filler to prevent the escape of hydrogen into the relay room.

VII. Brickwork shall be reinforced with 2.8 mm “ brick force” reinforcement every course for the first five courses above the foundation, and then every fourth course to roof height. Further brick force shall be applied every course for five courses above any window or door. Five butterfly ties per square meter shall be used in all cavity walls.

VIII. Prefabricated reinforced roof trusses shall be supported on wall plates which shall be bedded on a cement grout bed. Every truss shall be secured to the wall plate with 40x2 mm galvanized hoop irons embedded 5 courses of brickwork below the wall plate.

I. Interlocking roof cement tiles shall be laid on Hydro nail type trusses with 38 x 38 mm battens.

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II. Pre-painted aluminium gutters (150 x 150 x 0.8 mm) and downpipes (100 x 100 mm) shall be used.

III. Ceilings shall be constructed with 6.4 mm Gypsum board on 38 x 38 mm brandering at 400 CRS with steel H section cover strips.

3.2.1.18.17 Control room and relay room:I. The walls shall be plastered with steel float finish and painted with one coat of plaster

sealer and two ceilings shall have one undercoat and two coats of eggshell acrylic paint.

II. Floors shall be covered with H.D vinyl tiles and 75 x 22 mm meranti skirting with 19 mm quadrant. The doors shall be treated with Woodcock 30.

III. The doors and window frames shall be painted with C68-White sand gloss enamel to SABS 1091/1976.

IV. Battery room walls and floors shall be painted with an approved acid or alkali resistant paint. Alternatively, battery room floors may be tiled with acid resistant ceramic tiles.

V. The bathroom walls shall be plastered with steel-float finish and shall be painted and one coat of plaster sealer and two coats of eggshell acrylic. Ceilings shall have one undercoat and two coats of eggshell acrylic paint. Floors shall be covered with H.D vinyl tiles and 75 x 22 mm meranti skirting with 19 mm quadrant. The doors shall be treated with Woodcock 30. The doors and window frames shall be painted with C68-White sand gloss enamel to SABS 1091/1976.

VI. The store room walls shall be plastered with steel-float finish and shall be painted with one coat of plaster sealer and two coats of eggshell acrylic. Ceilings shall have one undercoat and two coats of eggshell acrylic paint. Floors shall be painted with a suitable non-slip, durable paint. 75 mm x 22 mm meranti skirting with 19 mm quadrant shall be provided. The doors shall be treated with Woodcock 30. The doors and window frames shall be painted with C68-White sand gloss enamel to SABS 1091/1976.

3.2.1.18.18Foundations, Plinths and Concrete StructuresI. Excavations:

a. All excavations for structural foundations shall be done to degree of accuracy II as per SABS 1200 D-1988 Section 6.1(a). To ensure the safety of workmen and equipment, the sides of excavations shall be laterally supported, and all excavations shall be fenced. Lateral supports shall be strong enough to resist side thrust and prevent slips, blow and damage to adjacent works and property. Excavation shall not be carried out below the foundation level of nearby structures until the required precautions have been taken. Blasting is not permitted for excavation.

b. If water is encountered within an excavation, due to springs, seepage, rain or other causes, it shall be removed by suitable diversions, pumping or bailing, and the excavation shall free of water at all times.

c. Any obstacle encountered during excavation shall be reported immediately to the project site engineer and dealt with according to instructions. Removal of buried piping or cables shall not be done without prior permission and reasonable precautions shall be taken to prevent damage to buried services.

d. If the excavation is carried out to a depth greater than that shown on the drawing, the excess depth shall be filled up to the required level with selected material and compacted to 95% of MOD AASHTO density or with mass concrete of grade 15 Mpa.

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e. The corners of the excavated pits shall be made true and square and all loose debris shall be removed.

f. Just before pouring the foundation concrete, all trench bottoms shall be lightly watered and thoroughly rammed.

II. Formwork:

a. Formwork shall be in accordance with SABS 1200 G-1982 Section 5.2. Materials used for the formwork inclusive of the supports and centring shall be capable of withstanding the working load and remain undistorted throughout the curing period that it’s left in service. Plywood for forms shall generally conform to relevant SABS – specifications for plywood for general purposes and may be supplied with a plastic coating or overlay, or brush treated with a preservative. Plywood form shutters may be strengthened with framework of either timber or metal. In metal forms black mild steel sheets of designed thickness may be backed with framing of angles and other sections. Sawn timber forms may also be lined with mild steel sheets or plywood to give the desired surface of finish. Formwork shall include all material to ensure a good finish of foundation corners with chamfered edges to prevent easy breaking of concrete.

b. Staging, centring and scaffolding may be made from either timber, tubular steel members or rolled steel sections like angles, channels or beams. Design, engineering and construction of staging, centring, formwork and all other temporary works required for construction shall be the responsibility of the Contractor. Include pricing for all formwork in the pricing schedules as part of completed foundations.

3.2.1.18.19Oil drainage I. An oil catchment area shall be provided around each oil filled transformers.

II. The maximum depth of an oil catchment area shall be maximum 500 mm and the volumetric capacity should be 100 percent of the total liquid content of oil-filled equipment within the catchment area.

III. Oil catchment areas shall comprise of liquid-tight bund walls with a fire resistance rating of not less than two hours Bund walls shall be a minimum height of six courses of bricks (approximately 450 mm) above the concrete runway and located at a minimum distance of 0,2 H meters (minimum distance of 1,5 m) from the oil filled equipment. “H” is the height of the highest point where oil is contained, usually the conservator. Bund walls shall extend over concrete runways with vertical joints on either side so that the bund wall can be removed when installing a new transformer or reactor.

IV. Oil trap shall be provided within each transformer bund wall. The oil trap shall have liquid-tight bund walls with a fire resistance rating of not less than two hours consisting of selected clay face brick class “FBS” (semi face brick) built in class 11 mortar.

V. Auxiliary transformers or any other oil-filled equipment presenting a potential fire threat to the main equipment, should be located a minimum distance of 3 m from the main equipment, and accommodated in a separate oil catchment area. Should such auxiliary equipment be located 8 m or more from the main equipment, no oil catchment area will be necessary for the auxiliary equipment.

VI. All oil catchment areas, including catchment areas around auxiliary equipment, shall be provided with an oil drainage system.

VII. The oil catchment drain pipe shall have a positive slope (minimum 1:50) towards the oil holding dam.

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VIII. The oil drainage system from catchment areas shall be separate to the storm water drainage system.

IX. Reinforced concrete (RCP) pipe of 300 mm or larger diameter shall be used for the oil drainage system and at a gradient of not less than 1:200 (depending on site terrain).

X. The oil drainage system should be designed to prevent the conveyance of oil from the fire origin to oil catchment areas of adjacent units of equipment.

XI. An open oil holding dam shall be provided at the termination point of the drainage pipes from oil catchment areas.

XII. The oil containment shall be located away from equipment or buildings to reduce fire hazard.

XIII. Oil dams shall be sized to contain 120% of the volume of oil contained in the largest transformer or shunt reactor in the substation.

XIV. Cable trenches shall be filled with sand to a distance 10 m from bunds and oil holding dams and, if within the bund, such trenches shall be capped with a weak mortar mix.

XV. The minimum separation distance between the oil-filled equipment to adjacent oil filled unit, adjacent buildings and switchgear shall be minimum 23 m.

XVI. Where the distance of 23 m cannot be achieved, a heat radiation barrier (fire wall) shall be provided.

XVII. Heat radiation barriers (fire walls) between units of oil-filled equipment shall be at a minimum height of 0,5 m above the highest point of the equipment and with a width of the oil catchment area.

XVIII. The heat radiation barriers (fire walls) shall be minimum 1,5 m from the oil catchment bund walls.

3.2.1.18.20 Reinforcing steel:a. Reinforcing steel of different grades and sizes shall be stored separately and in a

manner, which will permit easy identification and prevent mixing up of different sizes and grades. All bars shall be properly tagged for easy identification.

b. Reinforcement bars shall be stored at site in such a manner as to prevent corrosion and contamination of the surface by deleterious materials like dirt, oil, grease, paint etc. When placed in the work, all reinforcement shall be free of loose mill scale, rust and any deleterious matter. However, removal of tight adhering mill scale and mild rust is not necessary. Bars displaying excessive rusting will be rejected and removed from the site and replaced with the exact similarly tagged bar for use. Steel reinforcement shall always be protected from damage due to impact and rough handling.

a. Reinforcing bars shall be bent by machine or another approved method that produces a gradual and even bending motion in accordance with SANS 1200 G-1982 Section 8.1.1. Bending schedules shall indicate steel size, bending radii and fixing. No reinforcement shall be bent or straightened, once it has been placed and positioned, whether or not it is partially embedded in concrete. Bars having fracture cracks or split/ends shall be rejected and removed from site.

b. Reinforcing steel shall be fixed in accordance with SABS 1200 G-1982 Section 5.1.2. Whenever plans call for the use of couplers to join bars, such couplers shall have sufficient cross section to transmit the full strength of the bars. The screw thread shall be metric coarse pitch conforming to SABS and relevant to the diameter of bar to be coupled. Field welding of reinforcing bars is not permitted.

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c. Clear concrete cover for reinforcement shall be 50mm in foundations as per SABS 1200 G-1982 Section 5.1.3.

3.2.1.18.21 Concretea. Concrete shall be from an approved supplier and shall have strength of no less than

25MPA. Grades of concrete shall comply to SABS 0100.

b. The cement to be used in the concrete works shall be, OPC or Portland cement complying to SABS ENV 197 CEMI 425 with 25% - 30% fly ash content, conforming to SABS 1491 Part 2 blended by direct mass to mass substitution. Any cement that is to be used at the site shall be tested before use if so directed, if on testing the cement does not comply in full with the specifications, the total consignment from which the sample has been drawn shall be rejected and removed from the site.

c. In accordance with SABS 1200 G-1982 Section 3.5, all concrete shall be designed for normal rates of setting and hardening at normal temperature. Variations in temperature and humidity under different climatic conditions will affect the rate of setting and hardening, which will, in turn, affect the workability and quality of the concrete. Admixtures may be used, when permitted in accordance with SABS to modify the rate of hardening, to improve workability or as an aid to control concrete quality. Calcium chloride or any admixture containing this compound shall not be used under any circumstances.

d. Fine aggregates shall generally conform to SABS 1083. Fine aggregates shall consist of natural sand or manufactured sand or any approved combination thereof. Aggregate smaller than 4.75mm and within the grading limits and other requirements set in SABS 1083 is termed as fine aggregate. In the event of the fine aggregate being contaminated by dirt or other deleterious materials, the aggregate shall be washed with clean fresh water.

e. Coarse aggregate shall generally conform to the requirements of SABS 1083 and shall consist of hard, strong, durable particles of crushed stones and shall be free from elongated soft pieces, vegetable matter and other deleterious matter. It shall have no adherent coating. Flaky and elongated particles shall be avoided. Aggregates of sizes ranging between 4.75 mm and 150mm will be termed as coarse aggregate. Maximum size of coarse aggregate for use in reinforced concrete work shall be limited generally to 19mm. The grading of coarse aggregate shall be selected from the standard grading given in Table 9 of SABS 1083. Normal aggregate shall have a specific gravity not less than 2.6. Amount of deleterious matter determined in accordance with SABS 1083. In the event of the coarse aggregate being contaminated it shall be washed with clean fresh water.

a. Water shall be in accordance with SABS 1200 G-1982 Section 3.3. The pH value of the water shall generally lie between 6 and 8. Water that contains excess of acid, alkali, sugar or salt may not be used.

b. Install all anchor bolts in place before any concrete pouring are done. Take extreme care to ensure bolts align properly with steelwork. No alterations to finalised foundations will be allowed.

3.2.1.18.22 Backfilling:Removal of shuttering and backfilling around plinths, foundations and cable trenches, shall only be done after the concrete in the foundations has fully set and 7 days curing has been completed. All fill shall be suitable material, compacted in accordance with SABS 1200 D-1988 Section 5.2.3.2.

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3.2.1.18.23 Termite protection and Weed KillerTreat the substation terrace with approved weed and termite treatment before installing the crushed stone cover.

3.2.1.18.24 Cable access Provide access for low-voltage power and control cables from each switchgear bay to the substation control building by means of cable trenches. The cable trenches shall have a concrete base, concrete or masonry sides, and reinforced concrete covers. For drainage, the floor(s) of the cable trench(s) shall slope away from buildings towards a sump connected to the drainage system. There shall be sleeves through the trench wall wherever cables enter the trench. Cables from trench to individual items of plant may be installed in smaller cable trenches, or buried directly in the ground with a bedding layer and a covering layer of sifted soil. Wherever cables must cross roads, there shall be ducts or culverts underneath roads, or trenches with reinforced covers designed to withstand the load of any plant delivery vehicles and lifting equipment that may be used during construction and operation of the substation. If ducts are used, the minimum size shall be 150mm diameter or equivalent rectangular size. The cable entries to buildings shall be vermin-proofed, and constructed in a way that prevents water from entering the building.

3.2.1.18.25 Fencing and gates I. Perimeter fencing, switchyard fencing, and all gates shall be done strictly in accordance

with approved drawings and schedules, and locally accepted practices and standards. Conductive fences and gates shall be bonded to the substation earthmat in accordance with Standard specification – Main earthmat and plant bonding.

II. Provide pedestrian gates, double-leaf gates, and removable panels wide enough to allow access for the installation of plant.

III. The substation fence shall be 2.4m high steel palisade fences, with non-lethal electrified fence on top and concrete kerbing underneath the palisade to prevent any furrowing.

3.2.1.19 SPECIFICATION FOR EARTHING

3.2.1.19.1 All works shall comply with System Neutral Earthing Policy / Practice, see PEE Code of Practice Number 10.3 and IEEE 80.

3.2.1.19.2 The four-probe “Wenner method” shall be used for soil resistivity determination. Soil resistivity measurement shall be completed for depth equal to the diagonal distance on the substation.

3.2.1.19.3 The main earth grid shall be designed to limit the Ground potential rise to 5 kV and to achieve safe touch and step potential. (Finite element software CDEGS, should be used for the designs)

3.2.1.19.4 The main earth grid shall be design using 10 mm ∅ annealed copper (unless otherwise indicated) buried at least 1,000 mm below finished ground level extending over the whole area occupied by the substation.

3.2.1.19.5 The crushed stone layer 150 mm thick shall be installed extending over the whole area occupied by the substation having a minimum wet resistivity value exceeding 3,000 Ω.m and be between 25 and 38 mm largest dimension.

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3.2.1.19.6 All metalwork in the substation (e.g. steel structures, gutters, fences, etc.) is then bonded to this earth-mat either with 2 x 10 mm ∅ or 50 x 3 mm flat copper straps so that a direct low-resistance path to earth is provided for short-circuit currents. (Fence should be bonded every 10m)

3.2.1.19.7 Combination of ground electrodes with main grid shall be used for control of unsafe localised potentials gradients.

3.2.1.19.8 The earth grid shall be designed for the minimum single phase to earth design fault current 25 kA and backup protection fault clearing time of 1 second.

3.2.1.19.9 For voltages at 132 kV the fault clearing of 1 second shall be selected based on the backup protection tripping time. (Exceptions to the values in shall be applied on extreme soil conditions were all possibilities such importing soil, applying split factor etc., has been exhausted)

3.2.1.20 SPECIFICATION FOR LIGHTING

3.2.1.20.1 The floodlighting installation shall provide a minimum average illumination level of 10 lux with in the high voltage yard and 20 lux at the transformer bays and reactor bays, with a uniformity ratio of 5 within the high voltage yard being considered.

3.2.1.20.2 The light sources provided shall have a suitable colour index to enable satisfactory differentiation between phase colour plates. The illumination shall be sufficient for personnel to observe obstructions and other hazards while moving within the H.V. yard and to read high voltage apparatus identification labels mounted at a height not exceeding 2 metres above ground level on high voltage apparatus and thus enable personnel to identify any apparatus on which they are required to operate.

3.2.1.20.3 The point of supply shall be provided for at the 400/230 V main AC board which is a standalone panel situated within the control room.

3.2.1.20.4 For operating and maintenance requirements the circuits can be controlled from an independent floodlighting board inside the control room. In addition to that floodlighting kiosk situated outside, having its circuits remotely controlled from a switch box situated within the control room.

3.2.1.20.5 The steel wire armouring should be used as the earth continuity conductor between the point of supply and the point of consumption. The steel wire armouring must be connected to the main substation earth-mat at the point of supply and the floodlighting mast at the point of consumption. The floodlighting mast should further be connected to the main substation earth-mat.

3.2.1.20.6 The cables should be positioned in existing cable trenches where possible. Where the cables are buried other services such as the terrace drainage should be avoided where possible. Where the cables are buried, the required depth should be 500 mm below the finished terrace level. Cable route markers should be positioned on the surface above the cable while cable marker tape shall be buried 200 mm above the cable to indicate its presence when digging. All reticulation cables should have cable number tags attached to both ends.

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3.2.1.20.7 The lighting designs shall be completed using simulation tools such as Relux Desktop or equivalent.

3.2.1.21 NMBM SUBSTATION STANDARDSA list of NMBM standards applicable to substations is shown in Table 3.2.1-21 below.

TABLE 3.2.1-19 – LIST OF NMBM STANDARDSSUBSTATIONSNo Title Revison1 Protection Design Guidelines2 PEE Code of Practice No: 10.1 - Common Rules Draft - 33 PEE Code of Practice No: 9.1 - The Small Wiring of Transmission Equipment and InstallationsDraft - 14 PEE Standard: 003 - MV Switchgear up to 24kV Draft - 85 PEE Standard: 013 - Underground Cables up to 22kV Draft - 46 PEE Standard: 100 - Protection and Auxiliary Relays Draft - 57 PEE Standard: 101 - Scada Interface Requirements Rev - 228 PEE Standard: 102 - Power Transformers Draft - 99 PEE Standard: 105 - Outdoor Type Current Transformers Draft - 210 PEE Standard: 106 - 6.6 and 11kV Oil Cooled Outdoor Neutral Earthing Resistors Rev - 211 PEE Standard: 113 - Indoor Control Panels Draft - 612 PEE Standard: 114 - Outdoor Type Surge Arresters Draft - 113 PEE Standard: 122 - Outdoor Disconnectors 66kV and 132kV Draft - 214 PEE Standard: 123 - Support Structures in HV Outdoor Substation Yards Draft - 115 PEE Standard: 124 - Tubular Aluminium Busbars and Clamps Draft - 216 PEE Standard: 125 - Earthing of Major Substations Draft - 1

17PEE Standard: 126 - Trenching, Backfilling and Foundations for Outdoor Electrical Equipment in Main Substations Draft - 1

18 PEE Standard: 128 - Outdoor Circuit Breakers Draft - 119 PEE Standard: 129 - Outdoor Marshalling Kiosks Draft - 220 PEE Standard: 130 - Lightning Masts and Associated Lighting Draft - 121 PEE Standard: 138 - Construction of HV Substations Draft - 3

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