198kv Lightning Arresters

Specification for 220 kV Switchyard

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

TECHNICAL SPECIFICATION NO. E0021 FOR 198KV LIGHTNING ARRESTERS

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021 COVER

Specification for 220 kV Switchyard

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

SPECIFICATION FOR 198 KV LIGHTNING ARRESTERS CONTENTS SECTION

DESCRIPTION

PAGE NO.

1.00.00

INTENT OF SPECIFICATION

E0021:1

2.00.00

SCOPE OF WORK

E0021:1

3.00.00

GENERAL REQUIREMENTS

E0021:1

4.00.00

DESIGN CRITERIA

E0021:2

5.00.00

SPECIFIC REQUIREMENTS

E0021:3

6.00.00

TESTS

E0021:4

7.00.00

DRAWINGS, DATA & MANUALS

E0021:5

ATTACHMENTS ANNEXURE-A

RATINGS AND REQUIREMENTS

E0021:7

ANNEXURE-B

FITTINGS AND ACCESSORIES

E0021:10

ANNEXURE-C

MANDATORY SPARES

E0021:11

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021 INDEX

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

SPECIFICATION FOR 198 KV LIGHTNING ARRESTERS

1.00.00

INTENT OF SPECIFICATION

1.01.00

This Specification is intended to cover the design, manufacture, assembly, testing at manufacturer's works, supply & delivery, properly packed for transport F.O.R. site of 198 KV LIGHTNING ARRESTERS complete with all materials and accessories for efficient and trouble-free operation.

1.02.00

In the event of any discrepancy with listed documents, the stipulation of this specification shall govern.

1.03.00

This specification shall be read and construed in conjunction with other sections of the bidding document.

2.00.00

SCOPE OF WORK

2.01.00

Scope of Supply Type and rating of the equipment listed below are further detailed in the annexures. The ratings indicated are minimum values. Bidder shall check the same with respect to insulation coordination.

2.01.01

Each lighting arrester shall be furnished complete with accessories as listed in the annexure.

2.01.02

All relevant drawings, data and manuals sufficient to operate, maintain & repair main equipment and auxiliary system.

2.01.03

Commissioning spares and recommended spare parts for three (3) years operation.

3.00.00

GENERAL REQUIREMENTS

3.01.00

Codes and Standards

3.01.01

All equipment and materials shall be designed, manufactured and tested in accordance with the latest applicable IEC/IS except where modified and/or supplemented by this specification.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 1

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

3.01.02

Equipment and materials conforming to any other standard which ensures equal or better quality may be accepted. In such case, copies of the English version of the standard adopted shall be submitted along with the bid.

3.02.00

Annexures

3.02.01

All annexures appended to this specification shall form part of this specification and supplement the requirements specified herein.

3.02.02

This specification shall be read and construed in conjunction with the annexures to determine the scope of work.

4.00.00

DESIGN CRITERIA

4.01.00

The equipment will be used in 220KV switchyard of DCR TPP at Yamunanagar. The electrical system data are as listed in the annexure.

4.02.00

The equipment will be installed outdoor in a hot, humid and tropical atmosphere with heavy pollution.

4.03.00

All equipment, accessories and wiring shall have tropical protection, involving special treatment of metal and insulation against fungus, insects and corrosion.

4.04.00

The maximum temperature in any part of the equipment at specified rating shall not exceed the permissible limits as stipulated in the relevant standards.

4.05.00

The equipment shall be capable of withstanding the dynamic and thermal stresses of listed short circuit current without any damage or deterioration.

4.06.00

There shall be no radio interference when the equipment is operated at maximum service voltage.

4.07.00

The safety clearances of all live parts of the equipment shall be as per relevant standards.

4.08.00

Arresters shall be designed with sufficient cantilever strength to meet with stress due to wind pressure and short circuit forces arising from rated short time current.

4.09.00

The lightning arrester shall be installed as close to the equipment as possible and also on the line entrance.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 2

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

5.00.00

SPECIFIC REQUIREMENTS

5.01.00

Type and Rating

5.01.01

Lightning arrester shall be station class, heavy duty, metal oxide gapless type with ratings as detailed in the annexure.

5.01.02

The arrester shall have adequate thermal discharge capacity for severe switching surges, long duration surges and multiple strokes.

5.02.00

Constructional Features

5.02.01

The arrester shall be single pole, hermetically sealed with non-linear blocks of sintered metal oxide material so as to obtain a robust construction with excellent electrical, thermal and mechanical characteristics even after repeated operation.

5.02.02

Insulator shall be wet process porcelain, brown glazed and free from imperfections. All metal parts and hardware shall be hot dip galvanised.

5.02.03

Creepage distance shall correspond to heavily polluted atmosphere. Grading ring, if required, shall be provided to maintain voltage gradient within permissible limit.

5.02.04

The arrester shall be provided with pressure relief device to prevent shattering of porcelain in case excessive gas pressure builds up.

5.03.00

Accessories

5.03.01

Lightning arrester shall be furnished complete with insulating base, arrester disconnector, surge counter, leakage current monitor, insulated Cu. cable and anchoring hardware for mounting on steel structure.

5.03.02

The surge counter shall be suitably enclosed for outdoor duty and be mounted at a convenient height for reading. Counter terminals shall be such as to permit connections with minimum possible bends. No auxiliary power supply or battery shall be required for operation of counter.

5.03.03

A leakage current detector shall be furnished with the counter as an integral part. This is for monitoring the leakage to indicate any possible breakdown. Readings of milli-ammeter and counter shall be visible through inspection glass panel.

5.03.04

A suitably sized by-pass shunt along with necessary terminals shall be furnished for bypassing the discharge counter if required.

5.03.05

Grading ring/corona ring as applicable for the particular voltage class of arrester shall be provided.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 3

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

5.04.00

Terminals

5.04.01

All connection terminals shall be of corrosion resistant material and complete connection hardware.

5.04.02

All ground terminals shall have provision of connection to G.I. flat of approved size.

6.00.00

TESTS

6.01.00

Routine Tests

6.01.01

During manufacture and on completion, all equipment shall be subjected to the Routine Tests as laid down in latest revision of IEC/IS.

6.02.00

Acceptance & Type Tests

6.02.01

Acceptance & type tests to be carried out on lightning arresters according to latest revision of IEC/IS. Acceptance tests, whenever possible shall be conducted on the complete arrestor unit. Each metal oxide block of surge arrester shall be tested for the guaranteed specific energy capability in addition to the routine/acceptance test as per IEC/IS.

6.03.00

Special Tests

6.03.01

Special thermal stability tests to be conducted on lightning arresters according to IEC, as an acceptance test.

6.03.02

Temperature cycle test on the porcelain housing of the arrester to be conducted as per IS/IEC.

6.03.03

The artificial pollution test shall be carried out as per applicable standards.

6.03.04

The galvanisation test on metal parts shall be carried out as acceptance test.

6.03.05

The functional (operational) acceptance tests shall be carried out on the surge counter.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 4

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

6.04.00

Test Witness Tests shall be performed in presence of Purchaser's representative if so desired by the Purchaser. The Contractor shall give at least thirty (30) days' advance notice of the date when the tests are to be carried out.

6.05.00

Test Certificates

6.05.01

Certified reports of all the tests carried out at the works shall be furnished in requisite no. of copies for approval of the Purchaser.

6.05.02

The equipment shall be despatched from works only after receipt of Purchaser's written approval of the test reports.

6.05.03

Type test certificate of any associated equipment, if so desired by the Purchaser, shall be furnished. Otherwise, the equipment shall have to be type tested, free of charge, to prove the design.

6.05.04

The test report shall furnish complete identification of the equipment such as serial no., rating, equipment designation and date of test.

7.00.00

DRAWINGS, DATA & MANUALS

7.01.00

Drawings, Data and Manuals shall be submitted with the bid and in quantities and procedures as specified in General Conditions of Contract and/or elsewhere in this specification for approval and subsequent distribution after the issue of Letter of Award.

7.02.00

To be submitted with each copy of the Bid.

7.02.01

Typical general arrangement drawing showing constructional features and disposition of various accessories.

7.02.02

Technical leaflets.

7.02.03

Type test certificate on similar equipment.

7.03.00

To be submitted for Approval and Distribution

7.03.01

Dimensioned general arrangement drawing showing disposition of various accessories and safety clearances.

7.03.02

Transport/Shipping dimensions with weight.

7.03.03

Foundation plan and loading.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 5

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

7.03.04

Assembly drawing for erection at site with part numbers and schedule of materials.

7.03.05

Characteristic curves for insulation coordination.

7.03.06

Any other relevant drawing or data necessary for satisfactory installation, operation and maintenance.

7.03.07

Instruction manuals on the equipment and its various accessories. The manual shall clearly indicate method of installation, check-ups and tests to be carried out before commissioning of the equipment.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 6

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

ANNEXURE-A RATINGS & REQUIREMENTS LIGHTNING ARRESTER 1.0

Reference Standard

:

IEC 99-4 / IS 3070

2.0

Type

:

Station class, Metal oxide gapless

3.0

Service

:

Outdoor, heavily polluted atmosphere.

4.0

System Details

4.1

Voltage (Nom/Max.)... KV

:

220/245

4.2

Nos. of phases

:

3

4.3

Frequency

:

50 Hz ±5%

4.4

System Neutral

:

Effectively earthed

4.5

3-Phase Symmetrical Fault level

:

40 KA for 1 second

a) Transformer

:

±950

b) CB/Isolator

:

±1050

c) Instrument Transformer

:

±1050

d) Across open contacts

:

±1200

:

Transformer/C.B./Isolator/CT/CVT

4.6

Insulation level of the equipment to be protected (lightning)..KVP

5.0

Arrester Duty

5.1

Type of equipment being protected

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

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of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

ANNEXURE-A 6.0

L.A. Rating

6.1

Rated Voltage

:

198 KV

6.2

Nominal discharge current

:

10 KA

6.3

Long duration Discharge class

:

Class 3

6.4

Maximum continuous operating voltage (kV rms)

:

168

7.0

Insulation Level of Arrester housing

7.1

1-minute 50 Hz withstand (dry & wet)

:

380

7.2

Lightning Impulse withstand

:

650

8.0

Maximum Lightning Impulse Residual voltage at 8/20 µs current wave (KV peak)

8.1

At 5KA

:

450

8.2

At 10 KA

:

481

9.0

Switching Impulse Residual Voltage (KVP)

9.1

Maximum at 1 KAp

:

409

10.0

High Current impulse withstand value (4/10 micro sec.impulse)

:

100 KA

.. KA

11.0

Creepage......mm (mimimum)

:

6125

12.0

Mounting

:

Steel Structure

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 8

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

ANNEXURE-A 13.0

Pressure relief current

:

40KA

14.0

Pressure relief class

:

A

15.0

Continuous current

15.1

Resistive component of continuous current (Max) ...microamp

:

1000

15.2

Capacitive component of continuous current (Max) ...microamp

:

1500

16.0

Minimum energy handling capacity

:

4.5KJ/KV

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 9

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

ANNEXURE-B

FITTINGS AND ACCESSORIES

Each Lightning Arrester shall be furnished complete with the accessories as listed below : 1.

Insulating Base with anchoring bolts, nuts etc. for fixing the equipment on to structure.

2.

Surge counter with integral leakage current monitor.

3.

By-pass shunt with connection provision.

4.

Ground terminals.

5.

Clamp type bimetallic terminal connectors to suit Twin Moose

6.

Grading ring, if necessary.

7.

Arrester disconnector.

8.

Other standard accessories, which are not specifically mentioned but are usually provided with Lightning Arrester of such type and rating for efficient and trouble-free operation.

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Page 10

of 11

HPGC : 2 x 300 MW Deenbandhu Chhotu Ram TPP, Yamuna Nagar

Specification for 220 kV Switchyard

ANNEXURE-C

MANDATORY SPARES Bidder shall quote for the mandatory spares indicated below. In case any item is not considered by the bidder, same shall be supplied free of cost, if found applicable during detailed engineering as per approved scheme, equipment requirement, etc

Sl. No. 1.0

Description Complete surge arrester with insulating base, surge monitor and terminal connector

DOCUMENT NO. REL-DCRTP-CEE-201-P-501

E0021

Unit

Qty.

No.

3

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