Tech Spec Switchyard Ntpc

TAPOVAN VISHNUGAD HYDRO ELECTRICPOWER PROJECT (4X130 MW)

400 KV SWITCHYARD PACKAGE

TECHNICAL SPECIFICATION

SECTION - VI

(PART- A, B, C, D & F)

BIDDING DOCUMENT NO. CS-5505-500-2

CONSULTANT :Central Electricity AuthoritySewa Bhawan,R.K. Puram, New Delhi-110066 AUGUST - 2007

NTPC Limited(A Government of India Enterprise)

CONTENTS

TAPOVAN VISHNUGAD HYDRO ELECTRIC POWER PROJECT (4 X 130 MW)

400 KV SWITCHYARD PACKAGE BID DOC NO.: CS-5505-500-2

TECHNICAL SPECIFICATION SECTION-VI

CONTENTS

PAGE 1 OF 2


SECTION-VI

------------------------------------------------------------------------------------------------------------------------------------ SUB-SECTION DESCRIPTION ------------------------------------------------------------------------------------------------------------------------------------ PART - A

SUB-SECTION-I INTENT OF SPECIFICATION SUB-SECTION-II PROJECT INFORMATION SUB-SECTION-III SCOPE OF SUPPLY AND SERVICES SUB-SECTION-IV TERMINAL POINTS & EXCLUSIONS SUB-SECTION-V SPARES SUB-SECTION-VI SUB QR PART-B CHAPTER-E:0 SWITCHYARD ELECTRICAL GENERAL CHAPTER-E:1 GAS INSULATED SWITCHGEAR CHAPTER-E:2 ISOLATORS (AIS) CHAPTER-E:3 INSTRUMENT TRANSFORMERS (AIS) CHAPTER-E:4 SURGE ARRESTORS (AIS) CHAPTER-E:5 POST INSULATOR (AIS) CHAPTER-E:6 WAVE TRAP (AIS) CHAPTER-E:7 LIGHTING (COMMON) CHAPTER-E:8 LT SWITCHGEAR & DBs (COMMON) CHAPTER-E:9 LT POWER AND CONTROL CABLES (COMMON) CHAPTER-E:10 SUBSTATION AUTOMATION SYSTEM (COMMON)

CONTENTS




CONTENTS

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------------------------------------------------------------------------------------------------------------------------------------ SUB-SECTION DESCRIPTION ------------------------------------------------------------------------------------------------------------------------------------ CHAPTER-E:11 DC BATTERY AND BATTERY CHARGER (COMMON) CHAPTER-E:12 REQUIREMENTS OF AUXILIARY ITEMS (AIS) CHAPTER-E:13 INSTALLATION (COMMON) CHAPTER-E:14 SITE TESTING AND COMMISSIONING (COMMON) CHAPTER-C:0 TECHNICAL SPECIFICATION CIVIL WORKS PART C GENERAL TECHNICAL REQUIREMENTS (GTR) PART D ERECTION CONDITIONS OF CONTRACT PART F MANDATORY SPARES




PART-A

CONTENTS




PART-A

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PART-A

------------------------------------------------------------------------------------------------------------------------------------ SUB-SECTION DESCRIPTION ------------------------------------------------------------------------------------------------------------------------------------

SUB-SECTION-I INTENT OF SPECIFICATION SUB-SECTION-II PROJECT INFORMATION SUB-SECTION-III SCOPE OF SUPPLY AND SERVICES SUB-SECTION-IV TERMINAL POINTS & EXCLUSIONS SUB-SECTION-V SPARES SUB-SECTION-VI SUB QR




PART-A

SUB-SECTION-I

INTENT OF SPECIFICATION

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PART-A SUB-SECTION-I

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1.00.00 INTENT OF SPECIFICATION

1.01.00 Scope of the proposal

This specification intends to cover the following activities, services and works in respect of 400 KV Switchyard consisting of Gas insulated switchgear, Air Insulated Switchgear (Pothead switchyard) of Tapovan Vishnugad HEPP, Detailed scope of work under this package is listed in Sub section-III of Part-A. Complete design and engineering of all the systems, sub-systems,

equipment, materials and services.

Providing engineering data, design calculations ,drawings and Erection & O&M manuals for Employers review, approval and records.

Packing and transportation from the manufacturers works to the site including insurance, customs clearance & port clearance, port charges, if any.

Receipt, storage, insurance, preservation and conservation of equipment at the site.

All civil works of pothead yard as required. Fabrication, pre-assembly (if any), erection, testing and putting into

satisfactory operation of all the equipment/material including successful commissioning.

Furnishing of spares on FOR site basis. Reconciliation with customs authorities, in case of foreign supplies. Satisfactory conclusion of the contract.

1.02.00 The requirements, conditions, appendices etc. given in Technical Specifications

(Section-VI, Parts A, B, C, D, E and F) shall apply to and shall be considered as a part of this volume as completely as if bound herewith.

1.03.00 The Contractor shall be responsible for providing all material, equipment and

services specified or otherwise which are required to fulfill the intent of ensuring operability, maintainability and the reliability of the complete work covered under this specification.

1.04.00 It is not the intent to specify all aspects of design and construction of equipment

mentioned herein. The systems, sub-systems and equipment shall conform in all respect to high standards of engineering, design and workmanship, and shall be capable of performing in continuous commercial operation in a manner acceptable to the Employer, who will interpret the meaning of the specification and drawings and shall have a right to reject or accept any work or material which, in his assessment, is not complete to meet the requirements of this specification and/or applicable to Indian/ International standards mentioned elsewhere in this specification.

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1.05.00 Whenever a material or article is specified or described by the name of a particular brand, manufacturer or trade mark, the specific item shall be understood as establishing type, function and quality desired. Products of other manufacturers may also be considered, provided sufficient information is furnished so as to enable the Employer to determine that the products are equivalent to those named.

1.06.00 Contractor is requested to carefully examine and understand the specifications and

seek clarifications, if required, to ensure that they have understood the specifications. Such clarifications should be sought within the time period as stipulated in section ITB. Bidders offer should not carry any sections like clarifications, interpretations and/or assumptions. The bid should not include any sections like clarifications, interpretations and/or assumptions. If the Contractor feels that, in his opinion, certain features brought out in his offer are superior to what has been specified, these may be highlighted separately.

1.07.00 The Contractor may also make alternative offers provided such offers are superior in

his opinion, in which case adequate technical information, operational feed back, etc., shall be submitted with the offer to enable the Employer to assess the superiority and reliability of the alternative offered. For each alternative offer, its implications on the performance, auxiliary power consumption, etc. shall be clearly brought out in the bid for the Employer to make an overall assessment. In any case, the base offer shall necessarily be in line with specifications. Under no circumstances the specified equipment etc., shall be brought out as an alternative.

1.08.00 Any deviation or variation from the scope requirement and/or intent of this

specification shall be clearly mentioned under Deviation Schedule of the Bid Proposal Sheets irrespective of the fact that such deviations/variations may be standard practice or a possible interpretation of the specification by the Contractor. Except for the deviations/variations which are accepted by the Employer before the award of the contract, it will be the responsibility of the Contractor to fully meet the intent and the requirements of the specification within the quoted price. No other departure from the specification except for the declared deviation indicated by the Contractor in his proposal shall be considered. The interpretation of the Employer in respect of the scope, details and services to be performed by the Contractor shall be binding, unless specifically clarified otherwise by the Employer in writing before the award of contract.

1.09.00 The drawings enclosed as per list at Part-E to this section and forming a part of the

specification shall supplement the requirements specified herein. The scope and terminal points for the equipment to be furnished under this contract are also identified in these drawings and are to be read in conjunction with the text of the specifications. These are preliminary drawings for bidding purpose only and are subject to changes that may be necessary during detailed engineering after award keeping the basic parameters as specified.

1.10.00 Failure of any equipment to meet the specified requirement of test carried out at

works or at site shall be sufficient cause for rejection of the equipment. Rejection of any equipment will not be held as a valid reason for delay in the completion of the works as per schedule. Contractor shall be responsible for removing all deficiencies and supplying the equipment that meet the requirement.

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1.11.00 LIST OF TENDER DRAWINGS The list of drawings enclosed with these specifications as Part - E is detailed below:

Sl No

NTPC Drawing no. Title

1. 5505-500-PEH-A-001 General Project layout

2. 5505-500-PEH-A-002 Project Location Map and Accessibility

3. 5505-500-PEH-A-003 General Layout plan of Power House

4. 5505-500-PEH-A-004 Power House Cross - Section.

5. 5505-500-PEH-A-005 Power House Layout Plan at EL1289.0m.

6. 5505-500-PEH-A-006 Single Line Diagram of 400 KV GIS/AIS Switchyard.

7. 5505-500-PEH-A-007 400KV Switchyard Protection SLD Line bay

8. 5505-500-PEH-A-008 400KV Switchyard Protection SLD Bus Coupler Bay

9. 5505-500-PEH-A-009 400KV Switchyard Protection SLD GT bay

10. 5505-500-PEH-A-010 400KV Switchyard Relay & protection room layout

11. 5505-500-PEH-A-011 Protection Single line Diagram for Hydro Generator, GT, SAT and UAT

12. 5505-500-PEH-A-012 GIS Layout Plan at EL 1300.00m.

13. 5505-500-PEH-A-013 Pothead Yard Layout Plan & Sections




PART-A

SUB-SECTION-II

PROJECT INFORMATION

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PART-A SUB-SECTION-II

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1.00.00 GENERAL FEATURES OF THE PROJECT 1.01.00 General

Tapovan Vishnugad HE Power Project is a run of the river scheme on Dhauliganga river in Chamoli district of Uttaranchal state. The project envisages utilizing a design head of 483 M. The scheme involves construction of barrage across the river Dhauliganga, located near Tapovan and Bhangual Village at the suspension bridge leading to Bhangual village, HRT of 5.60 M in diameter and 11.710 KM long , Tail Race Tunnel of 513M long and an underground power house. The installed capacity of the project is 520MW (4x130MW) with annual generation at 90% dependability 2418.21 GWh.

1.02.00 Hydraulic and Civil features

The Tapovan Vishnugad Hydro Electric Power Project is located on Dhauliganga river is developed as a run of river scheme by constructing a barrage with 11.710 km long head race tunnel of horse shoe type having a diameter of 5.60 m to carry out a design discharge/velocity of 122.18 cumecs/4.93 m/sec , restricted orifice type surge tank having 13.5M dia with a height of 148.2 M, 2 nos of 3.6 m dia pressure shaft each with a length of about 586.14 m , each of which is near the power house bifurcates into 4 penstocks, each having a diameter of 2.6m and lengths of 46.768 m, 28.172 m, 38.596 m and 46.768 m to feed each unit of 130MW capacity operating at a design head of 483 M, The general layout of the scheme is indicated in the enclosed drawing number 5505-500-PEH-A-001 Project Layout and Project location shown in the drawing number 5505-500-PEH-A-002 Titled Project location Map and Accessibility

2.00.00 SYSTEM DETAILS 2.01.00 The synchronous generators are proposed to be connected with isolated phase bus

ducts to Single phase Generator Transformer with Voltage ratio of 13.8 KV /420/3 KV located down stream of power house in a separate cavern. The HV terminals of Generator Transformers shall be connected with the 400KV GIS located on a separate floor above the transformer bay. The connection between 400KV GIS and 400KV pothead yard shall be through 400KV XLPE cables. The outgoing feeders from the pot-head yard shall be further connected to 400KV substation at Kuwari pass substation and power will be transmitted to Muzaffarnagar.

2.02.00 The power supply for unit auxiliaries is proposed to be obtained from dry type

transformer with HV side voltage of 13.8 KV/0.415KV, 3 phase, 630 KVA unit auxiliary transformer. The arrangement of black start of the generating units & emergency supply to feed the unit auxiliaries and station auxiliaries is shown in the enclosed drawing Drg.No.5505-500-PEH-A-006 Single line diagram of the project.

3.00.00 CLIMATIC CONDITIONS The barrage of the project is situated at an altitude of about 1803.5 M. The Power

House service bay floor is located at EL 1289.00 m & the tail water level is fixed at EL 1268.00m. The climatic conditions are given below:

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i) Maximum temperature of air in summer : 27o C

ii) Maximum temperature of air in winter : 20C iii) Minimum temperature of air in winter : Sub zero iv) Maximum Relative humidity : >70 % v) Minimum Relative humidity : IX (MSK-64 scale), respectively (IS 1893,2002).

5.00.00 HIGH ALTITUDE CORRECTION FACTOR All equipment shall be suitably designed and treated for normal life & satisfactory

operation under high altitude conditions prevalent at the site. All electrical auxiliary equipment shall be specially treated with High altitude correction factor and the materials and method for this treatment shall be got approved in advance. The equipment and each part of it shall be strong enough and sufficiently well connected to resist total operating stresses, including any stresses resulting from an earthquake in any horizontal direction. Electrical clearances adopted due to high attitude need to be justified with supporting calculations and got approved from the Employer.

6.00.00 TRANSPORTATION 6.01.00 Location and Access Tapovan Vishnugad H.E. Project is located on Dhauliganga river in the Chamoli

District of Uttaranchal State. The nearest Railway head of the project is Rishikesh. which is around 280 KM away. The nearest Airport is at Dehradun and the approach/access road to project is on National Highway 58/58A. The main project components can be accessed from the right bank through the National highway serving through a road of 12km away from Joshimath from the highway serving Chamoli-Joshimath-Tapovan.

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6.02.00 Transport Limitations The weights and dimension of the packages for transportation to site shall be limited

to the following:-

a) Max. Weight of the package not to exceed 70 M.Tonnes b) Max. Size of the package not to exceed Length = 8500 mm,

Width= 3000 mm, and Height= 3000 mm.

The above information is tentative and it is the contractors responsibility to verify the actual transport limitation.

7.00.00 BIDDER TO INFORM HIMSELF The Bidder shall make independent/their own investigations about the conditions

and circumstances affecting his tender estimates and about the possibility of executing the works as described. During the evaluation of tenders, it shall be presumed that the Bidder have inspected and examined the site and its surroundings and to have satisfied themselves about the form and nature of the site, the quantities and materials necessary for the completion of the work and the means of transport and access to site, the requirements of accommodation, general labor position at the site and have quoted their prices after taking into account, the risks, contingencies and other circumstances which may influence or affect the execution of the Contract.

Access to the site shall be allowed, to the prospective bidder(s) by prior appointment

with the Employer.




PART-A

SUB-SECTION-III

SCOPE OF SUPPLY AND SERVICES

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PART-A SUB-SECTION-III

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1.00.00 SCOPE OF SUPPLY AND SERVICES

1.01.00 The scope of work for 400 KV switchyard at Tapovan Vishnugad HEPP shall comprise but not limited to the design, engineering., manufacture, testing and inspection at manufactures works, packing., supply, transportation, insurance, delivery to site, unloading and handling at site, storage and preservation at site store, transportation to place of installations, complete work of site assembly, erection, testing at site and commissioning of 420 KV SF6 Gas Insulated Switchgears (GIS), Air Insulated switchgears (Pothead Switchyard) and equipment erection including associated civil works of pothead yard and structural works. Further it shall include the cabling, lighting, lightning protection, earthing, association of subvendors in the erection, supervision, site testing, inspection and commissioning of 400 KV switchyard.

Any other equipment not explicitly mentioned herein or in the Technical specifications and drawings but are necessary for completeness of works specified shall also deemed to be included in the scope. The equipment shall be suitable for climatic conditions as indicated elsewhere in specifications. The supplier shall provide all the materials, labour, supervisory staff, plant, equipment & machinery and services necessary for accomplishing the work.

1.02.00 Scope of supply of the Bidder includes mandatory spares, start-up and commissioning spares and recommended spares. The general requirements of the mandatory spares are detailed in Part - F of Section-VI.

1.03.00 The scope of the bidder includes all shop tests, site tests, routine tests etc., fulfilment of complete quality assurance & inspection requirements and related activities for all the equipment & systems covered under the scope of work of bidder as per the stipulations of Technical Specifications.

1.04.00 Bay Details are as follows:

Gas Insulated Switchgear

Generator Transformer bays : 4 nos Line bays : 2 no Bus Coupler bay : 1 no Air Insulated Switchgear

Line bays : 2 nos 1.05.00 The equipment and materials to be supplied by the Contractor shall form a complete

400 KV switchyard including GIS & AIS. The equipment and services as detailed in all sections of the bidding documents and as shown on the tender drawings shall be within the scope of supply of the Contractor.

Any items though not specifically mentioned but which are required to make the switchyard complete in all respects for its safe, efficient, reliable and trouble free

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operation shall also be deemed to be included and the same shall be supplied and erected by the Contractor, unless they are specifically excluded in the text of exclusions given in sub section IV of Part-A.

- 400KV GIS equipments: 3 - single phase (isolated), SF6 gas insulated, metal-enclosed busbars, Circuit Breakers, disconnectors, safety Ground Switches, High Speed fault making ground switches, Current transformers, Voltage transformers, surge arresters, Local bay control cabinet, SF6 gas monitoring equipments, maintenance equipments etc.

- 400KV AIS equipments: Disconnectors with earth switches, Current transformers, capacitor voltage transformers, surge arresters, Post insulators and wave traps.

- Flexible Conductors (Quad moose ACSR conductor with 450mm spacing to be used for pothead switchyard for all connections)

- 10.98 dia G.S. Earthwire

- Insulators and hardware

- Clamps, connectors and spacers

- 48V DC Battery & battery charger (40A float cum boost battery chargers. Minimum rating 400AH for Plante type or 200AH for Ni Cd battery type)

- Bay Marshalling kiosks

- LT Switchgears

- Lighting Panels

- Contractor shall make earth resistivity measurements at pothead yard & GIS site (based on four electrode method) and design the earthing grid as per IEEE: 80 (Latest edition) and connect the earthing grid with power house earthing grid. The earthing mat for the switchyard shall be individually designed before connection with PH earthing grid.

- Earthing of all equipments (inclusive of supply of 40mm dia MS rod and GI flat).

- Complete Direct Stroke Lightning Protection .

- Power & Control cables, cabling (including interpole and interpanel), cable supports, cable trays and accessories etc. necessary for cable erection such as glands, lugs, clamps for cables, ferrules, cable ties, GI pipes etc. Cable route markers for buried cable trench are also included in the scope.

- AC supply - auxiliary power for GIS, AIS and Protection system. The cables from Station Service Boards in the power house to AC distribution boards are also included in the scope of switchyard Contractor.

- Power & Control cable schedules & termination schedules shall be prepared by the Contractor and approved by Employer.

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- Substation Automation System, Generator Relay Protection and metering system including disturbance recorders, fault locators, event loggers and GPS Time Synchronisation Equipment.

- Phase markers, Danger Plates, Bay identification plates

- The termination of the outgoing lines in pothead yard area on to the takeoff gantry including supply of insulators, strings and hardware on line side shall be done by line contractor. The connection to the line side equipments including supplying clamps, insulator string, connectors are under the scope of the switchyard contractor.

- Civil works for the pothead switchyard

- Inserts, embedments etc. as required for the system

1.06.00 SERVICES AND ITEMS

The scope also includes but not limited to the following services/items described herein and elsewhere in specification:

- System design and engineering

- Supply of equipment and material

- Civil works

- Structural works

- Erection works

- Project management and site supervision

- Testing and commissioning

- Interface coordination

- Performance testing

- Clearances from statutory authorities.

1.07.00 System Design and Engineering

The Contractor shall be responsible for detailed design and engineering of overall system, sub-systems, elements, system facilities, equipments, auxiliary services, etc. It shall include proper definition and execution of all interfaces with systems, equipment, material and services of Employer for proper and correct design, performance and operation of the system.

- Contractor shall provide complete engineering data, drawings, reports, manuals, etc. for Employers review, approval and records.

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- The scope shall also include the design and engineering as per details elaborated elsewhere in this specification.

- The Contractor shall carry out earth resistivity measurements at the switchyard site (based on four electrode method).

- Relay setting calculations shall be submitted by the Contractor and approved by Employer.

- For all civil works of pothead yard and structural works, the Contractor shall carry out design calculations, prepare all the detailed construction and fabrication drawings.

- The details of 400 KV XLPE cable and Generator Transformer shall be intimated to the successful bidder for consideration with GIS/AIS termination during detail Engineering.

1.08.00 Civil & Structural Works ( for pothead yard)

The scope of civil works shall include design & construction of all Civil works of pothead yard & Structural works including supply of all materials, complete for all equipment and Gantry Structures for the Switchyard package.

The nature of work generally involves detailed Geotechnical investigation for various facilities, earthwork in excavation and filling in all types of soils, dressing to the required profile, dewatering till the structures are constructed/erected upto required level or as directed by the engineer, shoring, backfilling around completed structures and plinth filling, disposal of surplus earth, concreting including reinforcement and formwork, fabrication, galvanising, Proto-assembly & erection of Gantry Structure & Equipment supporting structure, fabrication and erection of all structural steel and miscellaneous steel ( i.e., cable tray supports, galvanised foundation bolts etc.), breaking of concrete/ brickwork/ roads and removal of sheet piling, precast covers, RCC cable trenches, cable ducts/duct banks, soil sterlisation/anti - weed treatment, drainage, fencing, gravel filling, final grading and site clearance before handing over and other auxiliary items of work etc. All material including cement, reinforcement steel, structural steel required for completion of the work covered in the Technical specification shall be within the scope of the Contractor.

The scope of work described below is general in nature. The Contractor shall provide all structures / facilities required for the effective functioning of switchyard of the power plant, whether or not they are specifically mentioned. The scope of Contractor for Civil & Structural works shall include but not limited to the following :

a) Detailed Geotechnical investigation of soil as required, classification of soil, measurement of soil resistivity for various facilities.

b) Detailed design criteria including basis of design shall be prepared by the Contractor based on various requirements specified elsewhere in the specifications. All the above documents shall be finalised after Employers approval and the same shall form the basis of Detailed Engineering Work.

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c) Civil & structural works associated with switchyard gantry structure etc

d) Civil & structural works associated with switchyard equipment supporting structure as required.

e) Civil and structural works associated with Cable trenches from individual bays and to Employers terminal point including cable trench for power & control cables upto cable and ventilation tunnel.

f) Site Preparation, soil sterilisation/antiweed treatment including gravel filling but excluding major levelling.

g) Complete fencing along with gates for the switchyard.

h) Any other facility/structure that would be required as per system requirements.

i) All protection measures to prevent any damage to the adjoining structures / facilities.

j) Scope of the Contractor shall also include supply and laying of 40mm dia MS Rods alongwith other earthing materials as required to complete the earthing system.

1.09.00 Erection Works

The Contractor shall construct, erect and install all equipment and material of switchyard covered under the contract. He shall be responsible for provision of all labour, tools and plant, and supervisory staff for safe, reliable, proper and correct erection of the components.

The tools and plant shall include, but not limited to, special hoisting equipment, cranes, stringing equipment, slings, consumables and all other articles and supplies as required.

The Contractor shall ensure periodic cleaning of work sites and removal of all waste material, packing material, surplus earth and left-overs and their proper disposal.

1.10.00 Project Management and Site Supervision

The Contractor shall be responsible for the overall management and supervision of works. He shall provide experienced, skilled, knowledgeable and competent personnel for all phases of the contract, so as to provide the Employer with a high quality system.

The Contractor shall be responsible for adequate training of Employers operation and maintenance personnel as to be able to operate & maintain the equipments and its components properly, safely and efficiently over long period of time.

The Contractors supervisory personnel shall provide operation and maintenance assistance during the warranty period.

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A project execution schedule called Master Network (MNW) in the form of PERT chart/network and based on `Work break down structure shall be prepared by the Contractor for Employers approval. The MNW shall identify milestones of key events for each work/component in the areas of engineering, procurement, manufacture, despatch, erection and commissioning.

1.11.00 Interface Coordination

The Contractor shall identify all interface issues with Employer and other agencies, and shall be responsible for such interfacing, coordination and exchange of all necessary information.

The Contractor shall submit to the Employer all drawings for review. He shall list the detailed requirements of interface between Contractors work and the material and services to be supplied by Employer.

1.12.00 Facilities to be provided by the Employer and the Contractor

Please refer clause no 14.00.00 and 15.00.00 of Part-D, Erection Conditions of Contract

1.13.00 ARRANGEMENT BY THE CONTRACTOR

Contractor shall make his own necessary arrangements for the following and for those not listed anywhere else:

Distribution/extension of the construction power supply at all work areas Further distribution of construction water. Construction office and store (open & covered) Construction workshop and material/field testing laboratory Boarding & lodging arrangement for their personnel. i.e contractors

personnel

Fire protection and security arrangements during construction stage Suitable and adequate land/space & power supply for office, storage area,

pre-assembly and fabrication areas, labour and staff colony area, toilets etc.

1.14.00 TYPE TESTS

1.14.01 For AIS 1.14.01.01 All equipments to be supplied shall be of type tested quality. The contractor shall

submit for Employers approval the reports of all the type tests as listed as per relevant standard and carried out within last five years from the date of bid opening. These reports should be for the test conducted on the equipment similar to those proposed to be supplied under this contract and the test(s) should have been either conducted at an independent laboratory or should have been witnessed by a Client.

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1.14.01.02 In case the contractor is not able to submit report of the type test(s) conducted

within last five years from the date of bid opening or in case the type test report(s) are not found to be meeting the specification requirements, the contractor shall conduct all such tests under this contract free of cost to the Employer and submit the reports for approval.

1.14.02 For GIS

1.14.02.01 The Contractor shall carry out the type tests as listed in this specification on the equipment to be supplied under this contract. The Bidder shall indicate the charges for each of these type tests separately in the relevant schedule of BPS and the same shall be considered for the evaluation of bids. The type test charges shall be paid only for the test(s) actually conducted successfully under the contract and upon certification by the Employer's engineer.

1.14.02.02 The type tests shall be carried out in the presence of the Employer's representative, for which minimum 30 days notice shall be given by the Contractor. The Contractor shall obtain the Employer's approval for the type test procedure before conducting the type test. The type test procedure shall clearly specify the test set up, instrument to be used, procedure, acceptance norms, recording of various parameters, interval of recording, precautions to be taken etc. for the type test(s) to be carried out.

1.14.02.03 In case the Contractor has conducted such specified type test(s) according to the relevant standard and/or specification within last five years as on date of bid opening, he may submit the type test reports to the Employer for waival of conductance of such type test(s). These reports should be for the test conducted on the equipment similar to those proposed to be supplied under this contract and the test(s) should have been either conducted at an independent laboratory or should have been witnessed by a Client. The Employer reserves the right to waive conducting of any or all the specified type tests(s) under this contract. In case the type tests are waived, the type test charges shall not be payable to the Contractor.

1.14.03 Common requirements

1.14.03.01 The Employer will have the right of getting any test of reasonable nature carried out on any component or completely assembled equipment at Contractors premises or at site or in any other place in addition to the aforesaid type and routine tests, to satisfy that the materials/equipment comply with the specification.

1.14.03.02 Failure of any equipment to meet the specified requirements of tests carried out at works or at site shall be sufficient cause for rejection of the equipment. Rejection of any equipment will not be held as a valid reason for delay in the completion of the works as per schedule. Contractor shall be responsible for removing all deficiencies, and supplying the equipment that meet the requirement

1.14.03.03 All acceptance and routine tests as per the specification and relevant standards shall be carried out. Charges for these shall be deemed to be included in the equipment price.

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1.15.00 Pre-commissioning and Commissioning Activities

The bidder's scope shall include all pre-commissioning and commissioning activities, materials and services as detailed in clause no. 21.00.00 of Part-D of Technical Specifications (Erection Conditions of Contract) including supply of all consumables, temporary equipments and pipings, instruments, labour/skilled manpower etc. The scope includes complete requirement of flushing oils including fresh oil refilling during the pre-commissioning & commissioning activities and subsequent initial operation.

1.16.00 First Fill of Consumables, SF6 / Oils & Lubricants

All the first fill and One year's topping requirements of consumable such as SF6 gas, greases, oil, lubricants, servo fluids and essential chemicals etc. which will be required to put the equipments covered under the scope of specifications, into successful commissioning/ initial operation and to establish completion of facilities shall be furnished by the bidder, unless specifically excluded under the Exclusions in these specifications and documents.

1.17.00 Spares

The scope of work includes supply of mandatory spares, commissioning spares, consumable spares and others as specified under conditions of contract. The list of mandatory spares is brought out at Part-F, Section-VI.

1.18.00 Special Tools & Tackles and Test/ Measuring Equipments

One set of all special tools and tackles including testing, calibrating and measuring instruments required for erection, assembly, disassembly and maintenance of all equipments/ systems covered under the scope of the bidder shall be supplied by the bidder as specified elsewhere in Part-A/Part-B of Technical Specifications. These shall not be used for erection/ commissioning purposes and shall be in an unused and new condition, when they are handed over to the Employer. A list of all such special tools and tackles shall be submitted alongwith the offer.

1.19.00 The scope of the bidder includes complete design and engineering, technical co-ordination (including participation and arranging technical co-ordination meetings), finalization of drawings/ documents, submission of engineering drawing / documents and processing of their approvals by the Employer.

1.20.00 Further, the scope shall also include submission, in proper shape & format, of all types of manuals, handbooks & documents in requisite numbers to the Employer at different phases of the project as per the requirement of Employer.

1.21.00 Bidder shall furnish all relevant data required by the Employer, at interface points within 45 days of notification of award.

CLAUSE NO.



BID DOC NO.: CS-5505-500-2



PAGE 9 OF 9

1.22.00 Noise Level

The noise level to be maintained by all the equipment and systems, supplied & erected by the bidder, shall be as specified elsewhere in the Technical specification.

1.23.00 Bidder shall provide all necessary training to Employers personnel as specified in Part-C, Section-VI and as specified elsewhere in technical specification.

1.24.00 The Project construction works involve works to be carried out by other contractors in addition to the works in the scope of 400 KV switchyard package Contractor. The Contractor shall, through co-ordination with the other Contractors, ensure the continuity and the coherence between his supply and that of the other Contractors.




PART-A

SUB-SECTION-IV

TERMINAL POINTS & EXCLUSIONS

Clause No. TERMINAL POINTS & EXCLUSIONS


BID DOC NO.: CS-5505-500-2


PART-A SUB-SECTION IV

PAGE 1 OF 1

1.00.00 TERMINAL POINTS

1.01.00 SF6 gas to Oil bushing of Generator Transformer 1.02.00 SF6 gas to XLPE cable sealing end terminal (GIS hall) 1.03.00 XLPE cable sealing end to outdoor ACSR conductor (in pothead switchyard) 1.04.00 Termination at the switchyard line take off gantry for 400KV lines 1.05.00 Termination of earthing connection upto power house groundmat riser in GIS hall

2.00.00 EXCLUSIONS 2.01.00 Illumination, Ventilation, Fire protection and EOT crane in GIS hall 2.02.00 XLPE cables & cable terminations between GIS and pothead yard 2.03.00 Civil works associated with GIS installation. However foundation bolts, anchor,

support embedments if any etc. are in the scope of the bidder. (Details of foundation alongwith design basis to be given by the contractor)

2.04.00 Levelling of pothead yard area including approach road. 2.05.00 Civil works for Construction of Relay room in GIS hall 2.06.00 PLCC 2.07.00 220V DC Battery and Battery charger. 2.08.00 All equipments for the future bay




PART-A

SUB-SECTION-V

SPARES

CLAUSE NO.

SPARES


BID DOC NO.: CS-5505-500-2


PART-A SUB-SECTION-V

PAGE 1 OF 3

SPARES

1.00.00 All spares supplied under this contract shall be strictly interchangeable with the parts for which they are intended for replacement. The spares shall be treated and packed for long term storage in the climatic conditions prevailing at the site. Small items shall be packed in sealed transparent plastic covers with desiccant bags as necessary.

1.01.00 Each spare part shall be clearly marked and labeled on the outside of the packing together with the description when more than one spare part is packed in single case. A general description of the contents shall be shown on outside of the case and detailed list enclosed. All cases, containers and other packages must be suitably marked and numbered for the purpose of identification.

1.02.00 Commissioning spares: The Contractor shall include in his scope of supply all commissioning spares. List of such spares along with the quantities shall be indicated in the bid

1.03.00 The Contractor shall supply spares which he expects to consume during installation testing and commissioning of system. The quantity of these spares shall be decided based on his previous experience, such that site works shall not be hampered due to non-availability of these spares. Contractor shall submit a complete list of such spares along with the bid, the cost of which shall be deemed to have been included in the lumsum proposal price of the package. The unused commissioning spares may be left at the site for use by the Employer, if so agreed at a cost to be negotiated.

1.04.00 No mandatory or recommended spares will be used during the commissioning of the equipment/plant before take over by the Employer.

1.05.00 Mandatory spares and Maintenance Equipment

a) The list of mandatory spares considered essential by the Employer is indicated in Section-VI, Part-F. The contractor shall indicate the prices for each and every item (except for items not applicable to the contractors design) in the Schedule of Mandatory Spares whether or not he considers it necessary for the Employer to have such spares. If the contractor fails to comply with the above or fails to quote the price of any spare item, the cost of such spares shall be deemed to be included in the contract price. The contractor shall furnish the population per unit of each item in the Bid Forms & Price Schedules. Whenever the quantity is mentioned in sets the contractor has to give the item details and prices of each item.

b) Whenever the quantity is indicated as a percentage, it shall mean percentage of total population of that item in the station (project), unless specified otherwise, and the fraction will be rounded off to the next higher whole number. Wherever the requirement has been specified as a set it will include the total requirement of the item for a unit, module or the station as

CLAUSE NO.

SPARES


BID DOC NO.: CS-5505-500-2



PAGE 2 OF 3

specified. Where it is not specified, a set would mean the requirement for the single equipment / system as the case may be. Also one set for the particular equipment. e.g. set of bearings for a pump would include the total number of bearings in a pump. Also the set would include all components required to replace the item; for example, a set of bearings shall include all hardware normally required while replacing the bearings.

c) The Employer reserves the right to buy any or all the mandatory spare parts

d) The prices of mandatory spares indicated by the Contractor in the Bid Proposal sheets shall be used for bid evaluation purposes

e) All mandatory spares shall be delivered at site at least two months before scheduled date of initial operation of the first unit. However, spares shall not be dispatched before dispatch of corresponding main equipments

f) Wherever quantity is specified both as a percentage and a value, the Contractor has to supply the higher quantity until & unless specified otherwise.

1.06.00 Recommended spares

a) In addition to the mandatory spares, the Contractor shall also provide a list of recommended spares giving unit prices and total prices for 3 years of normal operation of equipment in list and total prices in relevant schedule of the Bid Forms & Price Schedules. This list shall take into consideration the specified mandatory spares and should be a separate list. The Employer reserves the right to buy any or all the recommended spares. The recommended spares parts shall be delivered at the site. The list of recommended spares to be furnished by the Contractor should also contain the following:

Population of each item installed along with reference drawing number.

Service life expectancy of each item. Offer validity period

b) Price of recommended spares will not be used for evaluation of bids. The prices of these spares will remain valid for a period of not less than 120 days after the date on which the validity of main bid expires. Whenever recommended spares are the same as mandatory spares, then the prices of the mandatory spares and such common recommended spares shall be the same. Further, the prices of any recommended spares, which are not common with mandatory spares listed in the volume, shall be subject to review by the Employer and shall be finalised after mutual discussions.

CLAUSE NO.

SPARES


BID DOC NO.: CS-5505-500-2



PAGE 3 OF 3

1.07.00 Tools & tackles

The Contractor shall also supply at site one set of all special tool & tackles, etc. which are required by the Employers maintenance staff to maintain the works successfully at no extra cost. The list of such tools and tackles shall be enclosed with the offer.




PART-A

SUB-SECTION-VI

SUB QR

CLAUSE NO.



BID DOC NO.: CS-5505-500-2


PART-A SUB-SECTION-VI

PAGE 1 OF 2

1.00.00 ALL THE MAJOR EQUIPMENTS/ SYSTEMS TO BE SUPPLIED/ ERECTED

FOR THE PROJECT SHALL MEET THE FOLLOWING REQUIREMENTS:

1.01.00 400 KV INSTRUMENT TRANSFORMERS The 400 KV Instrument Transformers being offered should be from manufacturer

who have manufactured and supplied minimum fifteen (15) nos. of single phase Current Transformers and fifteen (15) nos. of single phase Capacitor Voltage Transformer suitable for Air Insulated Substation/Switchyard of 400 KV or above class which must have been in successful operation for a minimum period of two(2) years as on the date of bid opening.

1.02.00 400KV DISCONNECTORS AND SURGE ARRESTORS The 400KV Disconnectors and Surge Arrestors being offered should be from

manufacturer(s) who have manufactured and supplied atleast five (5) nos. of three phase Disconnectors and atleast fifteen (15) nos. of single phase Surge Arrestors suitable for Air Insulated Substation/Switchyard of 400KV or above class which must have been in successful operation for a minimum period of two (2) years as on the date of bid opening.

1.03.00 SCADA SYSTEM & PROTECTIVE RELAYS The SCADA (Supervisory Control And Data Acquisition) System offered with

distributed architecture (excluding the requirement of communication protocol IEC-61850) should have been in successful operation in atleast one(1) Substation/Switchyard of not less than 220 KV class for a minimum period of one(1) year as on date of bid opening.

The Generator Protection Relays, the Bay Protection Units including the Busbar

protection and the energy metering System offered should be from manufacturer(s) who have manufactured and supplied respective equipment (excluding the requirement of IEC-61850), which must have been in successful operation in a 100 MW or above unit/ 220 KV class or above Substation/Switchyard for a minimum period of one (1) year as on the date of bid opening.

1.04.00 SITE SUPERVISION OF EQUIPMENTS Bidder shall furnish undertaking (as per the enclosed format) from respective

equipment manufacturers for the equipments indicated above that erection, testing and commissioning shall be carried out under their supervision.

1.05.00 For other items of supply the Bidder shall supply equipment/accessories from the

manufacturer who has designed, manufactured, type tested and supplied similar items and these should have been in successful operation.

1.06.00 The Bidder must enclose the type test reports for the substation equipment and

accessories, main protective relays distance to fault locator, disturbance recorder, event logger, time synchronizing equipment and tariff meters along with the offer.

CLAUSE NO.



BID DOC NO.: CS-5505-500-2


PART-A SUB-SECTION-VI

PAGE 2 OF 2

1.07.00 The Bidder shall clearly and unambiguously identify and name the proposed sub-Vendors for various equipment and enclose detailed documents for each proposed sub-vendor with the bid to establish that such sub-vendors meet the above stipulated requirements. Any vague statements like .make or equivalent shall not be accepted.

Any Bidder who fails to comply with the above clause Nos. 1.01.00 to 1.07.00 is

liable to be disqualified and his bid is liable to be rejected.




PART-B

CONTENTS




PART - B

PAGE 1 OF 1


PART - B

------------------------------------------------------------------------------------------------------------------------------------ SUB-SECTION DESCRIPTION ------------------------------------------------------------------------------------------------------------------------------------ CHAPTER-E0 SWITCHYARD ELECTRICAL GENERAL CHAPTER-E1 GAS INSULATED SWITCHGEAR CHAPTER-E2 ISOLATORS (AIS) CHAPTER-E3 INSTRUMENT TRANSFORMERS (AIS) CHAPTER-E4 SURGE ARRESTORS (AIS) CHAPTER-E5 POST INSULATOR (AIS) CHAPTER-E6 WAVE TRAPS (AIS) CHAPTER-E7 LIGHTING (COMMON) CHAPTER-E8 LT SWITCHGEAR & DBs (COMMON) CHAPTER-E9 LT POWER AND CONTROL CABLES (COMMON) CHAPTER-E10 SUBSTATION AUTOMATION SYSTEM (COMMON) CHAPTER-E11 DC BATTERY AND BATTERY CHARGER (COMMON) CHAPTER-E12 REQUIREMENTS OF AUXILIARY ITEMS (AIS) CHAPTER-E13 INSTALLATION (COMMON) CHAPTER-E14 SITE TESTING AND COMMISSIONING (COMMON) CHAPTER-C0 TECHNICAL SPECIFICATION CIVIL WORKS




PART-B

SUB-SECTION-E0

SWITCHYARD ELECTRICAL GENERAL

CLAUSE NO.

SWITCHYARD ELECTRICAL GENERAL (E0)


BID DOC NO.: CS-5505-500-2


PART-B CHAPTER-E0

PAGE 1 OF 5

1.00.00 SCOPE AND GENERAL INFORMATION

1.01.00 In addition to the detailed scope and other requirements specified in Part-A, the intent of the specifications for various electrical equipments shall also cover the following scope:

1.02.00 Contractor shall be responsible for design and engineering of overall system/station,

and all elements, systems, sub-systems, facilities, equipments, material, etc.. The Contractor shall submit design calculations, drawings, codes, codes of practices, construction drawings, etc. for Employers approval.

The basic design shall include, but not limited to, the following:

a) Development of general arrangement. b) Development of detailed layout (plan & section/elevation) drawings. c) Development of single line diagram with parameters of equipment and details

of protection. d) Protection and control philosophy and selection of protection, control and

annunciation schemes. e) Development of interlocking schemes. f) Development of switchyard structure loading details. g) Development of earthing system. h) Development of direct stroke lightning protection system. i) Insulation coordination of the EHV equipment. j) Calculation of static and dynamic force load and selection of spacer spans

and equipment terminal loading, (for outdoor switchyard) k) Development of clearance diagrams. l) Lighting design, Lux level calculations and conduit wiring diagram (for out

door switchyard). m) Development of power & control cable laying and termination schedules. n) Relay setting calculations. o) Development of erection key diagram with bill of material. p) Foundation design and construction drawings. q) Development of cable trench layout and sections, and construction drawings.

CLAUSE NO.



BID DOC NO.: CS-5505-500-2


PART-B CHAPTER-E0

PAGE 2 OF 5

1.03.00 Contractor shall furnish detailed drawings for the various equipments covered in their scope for Employers approval. The equipment shall conform to type tests as per specification and applicable standards and reports of the same shall be furnished for approval.

1.04.00 Contractor shall furnish design calculations and construction drawings for all civil

works showing details of pockets to be left in foundations and embedments to be provided in cable trenches.

1.05.00 Contractor shall furnish the schematics, general arrangement drawings, cable

schedules, interconnection schedules, panel wiring diagrams etc. for various control and relay panels for Employers approval. Contractor shall also furnish the recommended relay settings to be adopted.

1.06.00 The Contractor shall note that the list of standards specified elsewhere in this

specification is not complete. Whenever necessary the list of standards shall be considered in conjunction with specification, IS & IEC. In case governing standards for the equipment is different from IS or IEC, the salient points shall be clearly brought out alongwith English language version of the same.

1.07.00 Exposed live parts shall be placed high enough above ground to meet the

requirements of Indian Electricity Rules and other statutory codes. All responsibilities regarding co-ordination with Electrical Inspection Agencies and obtaining clearance certificate from them rests with the Contractor.

1.08.00 All equipment shall be supplied with suitable terminal connectors. The terminal

connector shall be well coordinated with the type/size of conductor and equipment to be connected. The conductor terminations for equipment shall be either rigid or expansion type suitable for tube or horizontal or vertical take off suitable for quad moose The spacing for quad moose ACSR conductor shall be 450 mm as required. The exact requirement to terminal clamps would be finalised by the Contractor in consultation with Employer based on layout requirement. The terminal pads shall preferably be capable of taking the required conductor span under normal, short circuit and meteorological conditions, without affecting the performance of the equipment.

1.09.00 All equipment shall be supplied with necessary interpole cabling and its cost shall be

included in the cost of equipment. 1.10.00 The minimum temperature is expected to reach upto -10 degree Celcius under

extreme condition. The equipments shall be designed to withstand such conditions satisfactorily.

1.11.00 All equipment (outdoor) shall be suitable for hot line washing. 1.12.00 The Contractor shall cooperate in all respects and exchange the necessary technical

data/ drawings with other agencies and Employers other Contractors under intimation to Employer to ensure proper coordination and completion of work in time.

CLAUSE NO.



BID DOC NO.: CS-5505-500-2


PART-B CHAPTER-E0

PAGE 3 OF 5

1.13.00 Insulation Co-ordination and Selection of Surge Arrestor 1.13.01 The contractor shall be fully responsible for complete insulation co-ordination of

switchyard including GIS. Contractor shall carry out detailed studies and design calculations to evolve the required parameters locations, energy capability etc. of surge arrestors such that adequate protective margin is available between peak impulse, surge and power frequency discharge voltages and BIL of the protected requirement. The locations of surge arrestors shown in single line diagram is indicative only. If the contractors feels that surge arrestors at some more locations are required to be provided, the cost for the same should also be included in the offer.

1.13.02 The contractor shall perform all necessary studies for surge arrestors. The report

shall detail the limits of all equipment parameters which could affect the insulation co-ordination. The report shall also detail the characteristics of the surge arrestor and shall demonstrate arrestors protective and withstand levels, discharge and coordinating currents and arrestor ratings and comply with the requirement of this specification.

1.13.03 The contractor shall also consider in the studies, the open circuit breaker condition,

fast transients generated by slow operation of disconnecting switches and high speed earthswitches etc. The study report and design calculations shall be submitted for Employers approval.

2.00.00 LT SWITCHGEAR

AC Feeders: The LT AC switchgear shall be designed to cater for all the loads required for bay marshalling kiosks, auxiliary power requirement. For reliability, each equipment and bay marshalling kiosk shall be connected with two independent sources of power supplies. The LT switchgear shall be suitable for power supplies to all Marshalling kiosks, maximum four (4) bay marshalling kiosks can be looped by forming a ring main. The LT switchgear panels shall be equipped with 20% spare feeders. Two feeders of AC supply at 415V shall be available at Station Service Boards for connection to the (two) nos of 415V, 3 phase AC distribution boards with required no. of MCCB modules including 20% spare modules for switchyard requirement. Additional 2 (two) feeders shall also be available from 415V Switchboard installed in pothead switchyard for catering power supply to outdoor switchyard.

DC Feeders: The Contractor shall provide suitable DC distribution boards with busbars and all other equipments. For reliability, dual supplies for all loads shall be considered. 20% spare feeders shall be provided. 4 (four) feeders of DC supply shall be available in unitized unit DC distribution boards of the power house for further connection to DC distribution boards for distribution.

CLAUSE NO.



BID DOC NO.: CS-5505-500-2


PART-B CHAPTER-E0

PAGE 4 OF 5

3.00.00 CLEARANCES

The minimum clearances for 400 KV Outdoor Switchyard shall be as given below: 400KV

Phase to earth clearance 3500 mm Phase to phase clearance 4000 mm Section clearance 6500 mm Ground clearance 8000 mm

The above clearances are valid upto altitude 1000M only. Bidder shall provide adequate clearances considering the altitude of the site. The Contractor shall supply the structures suitable to meet the clearances.

4.00.00 SERVICES TO BE PERFORMED BY THE EQUIPMENT BEING SUPPLIED

The 400 KV system is being designed to limit the power frequency over voltage of 1.5 p.u. and the switching surge over voltage to 2.5 p.u. In 400 KV system the initial value of temporary over voltage could be 2.0 p.u. for 1-2 cycles. All the equipment/materials covered in this specification shall perform all its functions satisfactorily without undue strain, restrike etc. under such over voltage conditions.

5.00.00 SYSTEM PARAMETERS

The system parameters shall be as under: GIS AIS

a) Highest system voltage 420 KV rms 420 KV rms

b) System Frequency 50Hz 50Hz

c) Lightning Impulse Voltage

Phase to earth & between phases 1425 KV 1425 KV

Across isolating distance 1425(+240) KV

d) Switching Impulse Voltage

Phase to earth 1050KV 1050 KV

Across isolating distance 900(+345) KV

Between phases 1575KV

e) Power frequency withstand for 1 min (rms)

Phase to earth & between phases 650KV 520 KV

CLAUSE NO.



BID DOC NO.: CS-5505-500-2


PART-B CHAPTER-E0

PAGE 5 OF 5

Across isolating distances 815KV 610 KV

f) PD level of GIS conductor Less than 5 Pico coulomb

Less than 10 Pico coulomb

g) Corona Extinction voltage 320 KV (rms)

h) Short Circuit current 40 kA for 1 sec.

40 kA for 1 sec.

The values of insulation level given above are applicable to altitude of 1000 M. Bidder shall appropriately correct the values as per the site altitude.




PART-B

SUB-SECTION-E1

GAS INSULATED SWITCHGEAR

CLAUSE NO.

GAS INSULATED SWITCHGEAR (E1)




PART-B CHAPTER E1

PAGE 1 OF 69

1.00.00 420 KV GAS INSULATED SWITCHGEAR (GIS) EQUIPMENTS

1.01.00 CODES & STANDARDS

The switchgear specified herein shall operate satisfactorily in the climatic conditions as specified. The performance, testing and rating of the switchgear shall conform to the latest edition of the following IEC / IS publications:

IEC -62271-100 : High Voltage Alternating Current circuit breaker

IEC- 60376 : Technical grade Sulphur Hexaflouride(SF6) for use in Electrical equipment

IEC- 68 Part III : Environmental Testing

IEC -71 : Insulation coordination.

IEC-60099-1/4 : Non linear resistor type gapped surge arresters for AC systems.

IEC -62271-102 : AC disconnectors and earthing switches

IEC- 60137 : Insulated Bushings for alternating voltages above 1000 V.

IEC 60044-1 : Current transformers

IEC 60044-2 : Inductive Voltage transformers

IEC 267 : Guide to testing of circuit breakers

IEC 60270 : High voltage test techniques-Partial discharge measurements.

IEC- 60480 : Guidelines for the checking and treatment of SF6 taken from electrical equipment and specification for its re use

IEC- 506 : Switching impulse test on HV insulators.

IEC-62271-203 : Gas Insulated metal enclosed switchgear for rated voltage above 52 KV

IEC-60694 /62271-1 : Common specification for HV switchgear and control gear standards.

IEC- 60859 : Cable connections for gas insulated metal enclosed switchgear.

IEC 61128 : Alternating current disconnectors: Bus transfer current switching by disconnector

IEC -61129 : AC earthing switches: Induced current switching.

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PART-B CHAPTER E1

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IEC-1259 : Requirement for switching of bus charging current by disconnectors.

IS 2705 : Current transformers

IS- 3156 : Voltage transformers

IEC- 60439 : Low Voltage Switchgear and Control Gear assemblies

IEEE-80 (2000) : IEEE- Guide for safety in AC substation grounding

CIGRE-44 : Earthing of GIS an application guide( Elecra no: 151, Dec93)

IEC-62271-306 : Cable connection between power transformer & gas insulated metal enclosed switchgear for rated voltages above 52KV

IEC-62271-305 : Cable connection for gas insulated metal enclosed switchgear for rated voltages above 52KV

1.02.00 The proposed switchgear may conform to the standards of the country of manufacture, provided these standards are based on or equivalent or better to the above referred standards. The contractor proposing any other standards than the above referred standards must specifically indicate the standards to which the switchgear conforms. The deviations, if any, from the above codes & standards that affect performance and rating are required to be clearly indicated by the contractor alongwith the offer. The contractor is required to furnish the English version copy of all the standards alongwith the bid.

1.03.00 Compliance with the provisions of the specifications does not absolve the switchgear contractor from the responsibility of furnishing switchgear and accessories of proper design, electrically and mechanically suited to meet the operating guarantees at the specified service conditions.

1.04.00 If there are, in the opinion of the contractor, any contradictions between the above standards and these specifications, such contradictions shall be brought to the attention of the Employer.

2.00.00 RATINGS

2.01.00 The ratings and general characteristics of the GIS shall be as follows:

(The ratings applicable to specific items of equipment are indicated in the applicable sections dealing with the equipment).

a) Type of Switchgear 420 KV Single phase, metal enclosed, SF6 gas

insulated switchgear b) Location Indoor

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PART-B CHAPTER E1

PAGE 3 OF 69

c) Frequency 50 + 3% -5% Hz d) Rated voltage 420 class, KV rms e) Highest System voltage, KV rms 420 f) Number of phases Three g) Rated lightning impulse withstand voltage (KV peak) i) Phase to earth 1425

ii) Across open contacts 1665

h) Rated Switching impulse withstand voltage (KV peak)

- Phase to earth 1050 - Phase to phase 1575 - Across open contacts 1245 i) Rated one minute power frequency with stand voltage (KV rms)

i) Phase to earth 650 ii) Across open contacts 815

j) System earthing Effectively grounded k) Rated normal current (Amps.)

i) Generator transformer feeder circuits 2500A

ii) Out going feeder circuits 2500A

iii) Bus coupler circuits 2500A

l) Rated short circuit withstand current Not less than at rated maximum voltage for one sec. 40 KA rms (symmetrical) m) Rated breaking capacity of 40 KA rms circuit breaker

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PART-B CHAPTER E1

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n) Rated making capacity 100 KA peak o) Prospective transient recovery As per IEC62271-100 Voltage appearing across the Circuit breaker terminals p) Radio interference voltage at Less then 1000 micro volts 266 KV(rms) q) Partial discharge level 5 pico coulombs or less at 1.1 Un/ 3 r) Material of enclosure Alluminium alloy s) Material of bus bar Aluminium alloy

t) Insulation medium SF6 gas

2.02.00 All current carrying components of the equipment specified shall be capable of continuous operation at the specified rated current without exceeding the maximum temperature rise specified in the relevant IEC standards.

2.03.00 Thermal calculations shall be based on the climatic conditions indicated in. Project Features. These calculations shall be submitted for review of the Employer.

3.00.00 GENERAL DESIGN AND SAFETY REQUIREMENT

3.01.00 The GIS assembly shall be of double busbar arrangement and consist of separate modular compartments e.g. Circuit Breaker compartment, Bus bar compartment filled SF6 gas and separated gas tight partitions so as to minimize risk to human life, allow ease of maintenance and limit the effects of gas leaks failures & internal arcs etc. These compartments shall be such that maintenance on one feeder may be performed without de-energising the adjacent feeders. These compartments shall be designed to minimize the risk of damage to adjacent sections and protection of personnel in the event of a failure occurring within the compartments. Stainless steel carbon impregnated or nickel plate rupture diaphragms with suitable deflectors shall be provided to prevent uncontrolled bursting pressures developing within the enclosures under worst operating conditions. The compartments of GIS assemblies shall be supplied filled with SF6 gas at a positive pressure and hermetically sealed to protect the dielectric system during transportation.

3.02.00 The workmanship shall be of the highest quality and shall conform to the latest modern practices for the manufacture of high technology machinery and electrical switchgear.

3.03.00 The switchgear, which shall be of modular design, shall have complete phase isolation. The conductors and the live parts shall be mounted on high graded epoxy resin insulators. These insulators shall be designed to have high structural strength and electrical dielectric properties and shall be shaped so as to provide uniform field distribution and to minimize the effects of particle deposition either from migration of

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PART-B CHAPTER E1

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foreign particles within the enclosures or from the by-products of SF6 breakdown under arcing conditions.

3.04.00 Gas barrier insulators and support insulators shall have the same basis of design. The support insulators shall have holes on both sides for proper flow of gas.

3.05.00 Gas barrier insulators shall be provided so as to divide the GIS into separate compartments. They shall be suitably located in order to minimize disturbance in case of leakage or dismantling. They shall be designed to withstand 1.5 times full rated pressure on one side while vacuum is exerted on the other side. They shall be designed to withstand any internal fault thereby keeping an internal arc inside the faulty compartment. Due to safety requirement for working on the pressurised equipment, whenever the pressure of the adjacent gas compartment is reduced, it should be ensured by the contractor that adjacent compartment would remain in service with reduced pressure. The gas tight barriers shall be clearly marked on the outside of the enclosures.

3.06.00 The material and thickness of the enclosures shall be such as to withstand an internal flash over without burn through for a period of 500ms till the backup relay protection clears the fault. The material shall be such that it has no effect of environment as well as from the by-products of SF6 breakdown under arcing condition.

3.07.00 Sufficient inspection windows/access openings shall be provided at the switchgear to ensure that each switchgear component can be inspected / monitored during installation and future maintenance. Each section shall have plug-in or easily removable connection pieces to allow for easy replacement of any component with the minimum of disturbance to the remainder of the equipment.

3.08.00 The material used for manufacturing the switchgear equipment shall be of the type, composition and have physical properties best suited to their particular purposes and in accordance with the latest engineering practices. All the conductors shall be fabricated of aluminum tubes of cross sectional area suitable to meet the normal and short circuit current rating requirements. The finish of the conductors shall be smooth so as to prevent any electrical discharge. The conductor ends shall be silver plated and fitted into finger contacts or tulip contacts. The contacts shall be of sliding type to allow the conductors to expand or contract axially due to temperature variation without imposing any mechanical stress on supporting insulators.

3.09.00 Each pressure filled enclosure shall be designed and fabricated to comply with the requirements of the applicable pressure vessel codes and based on the design temperature and design pressures as defined in IEC -62271-203 .

3.10.00 The contractor shall guarantee that the pressure loss within each individual gas-filled compartment shall not be more than half percent ( 0.5%) per year.

3.11.00 Each gas-filled compartment shall be equipped with static filters, density switches, filling valve and safety diaphragm. The filters shall be capable of absorbing any water vapour which may penetrate into the enclosures as well as the by-products of SF6 during interruption. Each gas compartment shall be fitted with separate non-

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PART-B CHAPTER E1

PAGE 6 OF 69

return valve connectors for evacuating & filling the gas and checking the gas pressure etc.

3.12.00 The switchgear line-up when installed and operating under the ambient conditions shall perform satisfactorily and safely under all normal and fault conditions. Even repeated operations upto the permissible servicing intervals under 100% rated & fault conditions shall not diminish the performance or significantly shorten the useful life of the switchgear. Any fault caused by external reasons shall be positively confined to the originating compartment and shall not spread to other parts of the switchgear. Routine maintenance to any of its external components including the protective relays and instrument transformers shall not be required in less than five years intervals. The internal components shall be maintenance free for at least 10 years. Routine replacement of insulating gas shall not be required in intervals of less than ten years.

3.13.00 Bracings shall be provided for all mechanical components against the effects of short circuit currents. The arc faults shall be positively confined to the originating compartment and shall not spread to the other parts of switchgear.

3.14.00 The thermal rating of all current carrying parts shall be minimum for one sec. for the rated symmetrical short-circuits current.

3.15.00 The Switchgear shall be of the free standing, self-supporting with easy accessibility to all the parts during installation & maintenance, dead front design with all high-voltage equipment installed inside gas-insulated metallic and earthed enclosures, suitably sub-divided into individual arc and gas-proof compartments at least for:

a) Busbars

b) Intermediate compartment

c) Circuit breakers

d) Bus / Line disconnections

e) Gas insulated bus duct section between Generator-Transformer and GIS.

f) Current Transformers

g) Voltage Transformers

h) Surge Arrestors

i) Gas Insulated bus duct section between GIS and XLPE cable

GIS shall be of isolated phase type and each phase/pole shall be housed in a separate enclosure. The bus enclosure should be sectionalized in a manner that maintenance work on any bus disconnector ( when bus and bus disconnector are enclosed in a single enclosure) can be carried out by isolating and evacuating the small effected section and not the entire bus.

3.16.00 The arrangement of the individual switchgear bays shall be such so as to achieve optimum space-saving, neat and logical arrangement and adequate accessibility to all external components.

CLAUSE NO.





PART-B CHAPTER E1

PAGE 7 OF 69

3.17.00 It is required that the three phases of each switchgear bay be arranged side by side. Segregated phase blocks of equipment in which one phase of each switchgear bay is mounted in a separate block are not acceptable. The arrangement of the equipment offered must provide adequate access for operation, testing and maintenance.

3.18.00 The arrangement of gas section or compartments shall be such as to facilitate extension of any make on either end without any drilling, cutting or welding on existing equipments. The GIS shall be designed such that a future bay can be extended with-out any necessity to move or dislocate the existing switchgear bays. It shall be kept in view that very little shutdown time is needed for adding future bay.

3.19.00 The bay control unit shall be placed in the relay room on the downstream side of GIS Hall as shown in drawing no: 5505-500-PEH-A-012 GIS Layout Plan at 1300.0M

3.20.00 All the elements shall be accessible without removing support structures for routine inspections and possible repairs. The removal of individual enclosure part or entire breaker bays shall be possible without disturbing the enclosures of neighboring bays.

3.21.00 It should be impossible to unwillingly touch live parts of the switchgear or to perform operations that lead to arcing faults without the use of tools or brute force.

3.22.00 All interlocks that prevent potentially dangerous mal-operations, shall be constructed such that they can not be operated easily, i.e. the operator must use tools or brute force to over-ride them.

3.23.00 The actual position of circuit breakers, disconnections and grounding switches must be positively displayed by mechanical indicators visible from the operating position.

3.24.00 In general the contours of energized metal parts of the GIS and any other accessory shall be such, so as to eliminate areas or points of high electrostatic flux concentrations. The surfaces shall be smooth with no projection or irregularities which may cause visible corona. No corona shall be visible in complete darkness when the equipment is subjected to specified test voltage. There shall be no radio interference from the energized switchgear at rated voltage.

3.25.00 The enclosure shall be of continuous design and shall meet the requirement as specified in clause no: 10 (special consideration for GIS) of IEEE -80 year 2000.

The enclosure shall be sized for carrying induced current equal to the rated current of the bus. The conductor and the enclosure shall form the concentric pair with effective shielding of the field internal to the enclosure.

3.26.00 The fabricated metal enclosures shall be of Aluminum alloy and have high resistance to corrosion, low electrical losses and negligible magnetic losses. All .jointed surfaces shall be machined and all castings shall be spot faced for all bolt heads or nuts and washers. All screws, bolts, studs and nuts shall conform to metric system.

CLAUSE NO.





PART-B CHAPTER E1

PAGE 8 OF 69

3.27.00 The breaker enclosure shall have provision for easy withdrawal of the interrupter assemblies. The removed interrupter assembly must be easily and safely accessible for inspection and possible repairs.

3.28.00 The enclosures of the same phase shall be electrically interconnected and at proper points they shall be connected to the other phases thus entailing a return current almost equal to the current circulating in the conductors.

3.29.00 The enclosure shall be designed to practically eliminate the external electromagnetic field and thereby electrodynamics stresses even under short circuit conditions.

3.30.00 The elbows, bends, cross and T-sections of interconnections shall include the insulators bearing the conductor when the direction changes take place in order to ensure that live parts remain perfectly centered and the electrical field is not increased at such points.

3.31.00 The Contractor shall furnish the following information regarding the loosely distributed metallic particles within the GIS encapsulation.

a) Calculations of critical field strength for specific particles of defined mass and geometry.

b) The methodology and the equipments required for electrical partial discharge (PD) detection and/or acoustic detection method.

The switchgear shall have provision for connection with ground mat risers to be provided by the Employer. This provision shall consist of grounding pads to be connected to the ground mat riser in the vicinity of the equipment. The connection between the grounding pads of switchgear and ground mat risers shall be provided by the contractor. The contractor shall furnish the details & drawings for ground mat requirement for GIS.

3.32.00 The ladders and walkways shall be provided wherever necessary for access to the equipment. The suitability of using a portable ladder with adjustable height may be examined by the contractor and if found suitable shall be offered.

3.33.00 Wherever required, the heaters shall be provided for the equipment in order to ensure the proper functioning of the switchgear at specified ambient temperatures. The heaters shall be rated for 240V AC supply and shall be complete with thermostat, control switches and fuses, connected as balanced 3-phase, 4-wire loa

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Tech Spec Switchyard Ntpc