33kV Outdoor Switchyard Specification
Short Description
33kV Outdoor Switchyard Specification - Complete Version...
Description
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 1.0.0. 1.0.1
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SCOPE: The Specification covers technical requirements of 33 KV switchyard for M/s Company India limited. For their project Company chocolate plant at Place
1.2.0
The scope shall comprise but not limited to the design, engineering., manufacture, testing and inspection at manufacture’s 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 33 kV Air Insulated switchgears (Switchyard) and equipment erection including associated civil and structural works for Switchyard.
1.3.0
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.
1.0.4
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.
1.0.5
The scope of the vendor includes all shop tests, site tests, routine tests etc., fulfillment of complete quality assurance & inspection requirements and related activities for all the equipment & systems covered under the scope of work of vendor as per the stipulations of Technical Specifications
1.0.6
DETAILED SCOPE OF WORK:
1.0.6.1
Design, engineering, supply, erection and commissioning
of all the 33kV Electrical
equipment like Breaker, Isolators, Lightning arrestors, Current Transformers, Voltage Transformers, Tariff meters, and junction & marshaling boxes / cubical with all steel structure for equipment support and Gantries. 1.0.6.2
Erection and commissioning of power transformer.
1.0.6.3
Design, engineering, Supply, erection and commissioning of ACSR Conductor, insulators, Clamps and connectors.
1.0.6.4
Supply, erection and commissioning of ACDB, LDB and associated cables.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 1.0.6.5
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Design, engineering, supply, erection and commissioning of Control and Relay panels for switchyard, and Battery and Battery chargers with DCDB.
1.0.6.6
Supply of 1.1 kV Control cables along with necessary lugs, glands, end termination units, nut bolts, support clamps and all accessories / hardware.
1.0.6.7
Design, laying through trays and commissioning of 11kV Power cables for Neutral Grounding resistance panel and Control cables from Switchyard equipment to Control & Relay Panels, & Neutral Grounding resistance panel and from 11kV Main Panel to Neutral Grounding resistance panel.
1.0.6.8
Design & Erection of Cable trenches inside the Switchyard.
1.0.6.9
Design & Erection of Cable Trays and Tray supports inside trenches in the Switchyard
1.0.6.10
Design, erection and commissioning of Earthing, Lightning protection and Lighting system for switchyard.
1.0.6.11
Providing engineering data, design calculations, GA drawings including loading data, mounting arrangement along with Erection & O&M manuals for review, approval and records.
1.0.6.12
Packing and transportation from the manufacturer’s works to the site including insurance, customs clearance & port clearance, port charges, if any.
1.0.6.13
Receipt, storage, insurance, preservation and conservation of equipment at the site.
1.0.6.14
Complete switchyard structure and miscellaneous structures, switchyard fencing, and complete civil works considering the following.
1.0.6.15
Galvanized steel structure for CB, Main bus, isolators, CT, VT & LA.
1.0.6.16
Fabrication, pre-assembly, erection, testing and putting into satisfactory operation of all the equipment/material including successful commissioning.
1.0.6.17
Satisfactory conclusion of the contract.
1.0.6.18
The Vendor 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.
1.0.6.19
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
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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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. 1.0.6.20
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.
1.0.6.21
Contractor is requested to carefully examine and understand the specifications and seek clarifications, if required, to ensure that they have understood the specifications.
1.0.6.22
Any deviation or variation from the scope requirement and/or intent of this specification shall be clearly mentioned under Deviation Schedule irrespective of the fact that such deviations/variations may be standard practice or a possible interpretation of the specification by the Vendor. Except for the deviations/variations which are accepted before the award of the contract, it will be the responsibility of the vendor to fully meet the intent and the requirements of the specification.
1.0.6.23
The drawings enclosed to this document and forming a part of the specification shall supplement the requirements specified herein. These are preliminary drawings, good for bidding purpose only and are subject to changes that may be necessary keeping the basic parameters as specified.
1.0.6.24
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. Vendor shall be responsible for removing all deficiencies and supplying the equipment that meet the requirement.
1.0.6.25
The scope also includes but not limited to the following services/items described herein and elsewhere in specification: Civil works. Structural works. Erection works. Project management and site supervision.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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Testing and commissioning. Interface coordination. Performance testing. Clearances from statutory authorities.
1.0.7
ERECTION WORKS:
1.0.7.1
The Vendor shall construct, erect and install all equipment and material of switchyard covered under the contract.
1.0.7.2
Vendor shall erect and commission of power transformer, 33kV Control Panels, Neutral grounding resistance panel.
1.0.7.3
Vendor shall erect and commission lighting, lightning protection and earthing system for 33kV Switchyard.
1.0.7.4
Vendor shall be responsible for provision of all labour, tools and plant, and supervisory staff for safe, reliable, proper and correct erection of the components.
1.0.7.5
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.
1.0.7.6
The vendor shall ensure periodic cleaning of work sites and removal of all waste material, packing material, surplus earth and left-over’s and their proper disposal.
1.0.8
BATTERY LIMITS OF 33kV VENDOR :
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
SR. NO
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DETAILS
33kV SWITCHYARD VENDOR
1
Supply of 33kV Equipment; 33kV Control Panels, 11kV ,100A neutral grounding
YES
resistor panel. 2
Erection and commissioning of 33kV Equipment; 33kV/11kV, 5 MVA
YES
Transformer, 33kV Control Panels and 11kV,100A neutral grounding resistor panel. 3
Supply, Erection, Termination and Commissioning of 11kV Power Cables of
YES
Neutral Grounding resistance panel in trays inside trenches . 4
Supply, Erection, Termination and Commissioning of 1.1kV Control Cables
YES
from Switchyard to 33kV Control Panels and TR Neutral Grounding resistance panel in trays inside trenches. 5
Supply, Erection, Termination and Commissioning of Earthing system for Switchyard , 33kV /11kV Transformer, 33kV Control panel, TR Neutral Grounding resistance panel.
6
Supply, Erection, and Commissioning of
YES
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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Lighting system for 33kV Switchyard. 7
YES
Supply, Erection, and Commissioning of Lightning Protection system for 33kV
YES
Switchyard 8
Civil, Structural and Architectural design, Erection and Construction of 33kV
YES
equipment foundation and cable trenches/ conduits inside switchyard
2.0.0 2.0.1.
CODES AND STANDARDS: Unless they are in variance with the clause of this specification the 33kV Switchyard and its components shall comply with the latest edition of the applicable standards listed below. For imported electrical equipment corresponding local codes and standards shall apply.
S.NO.
DESCRIPTION
1
Current
IS/ IEEE/ IEC CODE IS: 2705-1981, 1992
Transformers 2
Bushings for
IS: 2099-1986
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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alternating voltages above 1000 Volts 3
Guide for selection
IS: 13134 - 1992
of insulators in Respect of pollution conditions 4
Aluminum
IS: 398 (Part-3 1976)
conductors aluminized Steel reinforced 5
High voltage ac
IEC: 62271
circuit breakers 6
Common clauses for
IEC-694-1980
high voltage Switchgear and control gear standards 7
Hollow insulators for
IS: 5621 1980
use in electrical Equipment 9
Classification of
IS: 12063-1987
degrees of protection Provided by enclosures of electrical Equipment 10
LV switchgear and
IS: 13947-1993
control gear 11
Electric power connectors
IS: 5561-1970
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
12
Indian Electricity
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1956
Rules 13
Indian Electricity Act
14
Isolators and
2003 IS: 9921(Part-I) -1981
Earthing switches 15
Porcelain IS:731-1971; Insulators
16
Voltage
IS:544-1973; IS: 5350-1969/70/73 IS: 3156 (Part - 1) - 1992
Transformers/Gener al Requirements 17
IEEE Guide for
IEEE: 80-1986
Safety in A.C. Substation Grounding 18
Code of Practice for
IS: 3043-1987
Earthing 20
Industrial luminaries
IS: 1777-1978
with metal reflectors 21
Protection of
IS: 2309-1989
buildings and allied structures Against lightning 22
Power Transformer
IEC 60076
23
Electrical relays for
IS: 3231-1965
power system protection
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 24
Specification for
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IS 3070
Lightning Arrestors(Part-III) For alternating current system 25
Non-linear resistor
IEC: 60099
type gapped surge arresters for AC systems 26
New insulating oils
IS 335
27
Measuring relays
IEC 60255
and protective equipment 28 30
Low voltage
IEC 60947
switchgear and control gear 30
2.0.2.
-
CBIP manual
The equipment shall also confirm to the provisions of Indian Electricity rules and other statutory requirements currently in force. In case of any contradiction between the standards listed above and this specification, the requirement laid down in this specification shall prevail.
3.0.0
SERVICE AND OPERATING CONDITIONS: a.
Maximum Ambient Temperature
:
50° C
b.
Minimum Ambient Temperature
:
22° C
c.
Ambient temperature for Equipment Design
:
50° C
d.
Relative Humidity
:
min -20% & max -80%
e.
Seismic Zone
:
Zone II (As per IS 1893)
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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f.
Wind Velocity
:
As per IS: 875 (Part 3)
g.
Highest System voltage
:
36kV, 3ph, 50Hz
h.
Nominal Operating Voltage
:
33kV, 3Ph, 50 Hz
i.
Primary Distribution Voltage
:
11kV, 3PH, 50Hz
j.
Nominal Low voltage
:
415V, 3 Phase, 4-Wire
k.
Voltage variation
:
±10%
l.
Fault level
m.
Operating Frequency
:
50 Hz
n.
Frequency variation
:
±5%
o.
Control voltage
:
110V DC
p.
Auxiliary voltage
:
415/230V, 50 Hz
:
26 kA for 1 Sec
4.0.0
SPECIFIC REQUIRMENTS:
4.0.1
MANDATORY STATUTORY APPROVAL AND LICENSING:
4.0.1.1
Contractor shall carry out all Statutory approval and licensing work on behalf of owner with Government agencies like APTRANCO, Office of The Chief Electrical Inspector Organization, Andhra Pradesh, Chief Inspector of Factories and APPCB, Contractor requires preparing Drawings, Sizing Calculations as per prescribed format given by agencies.
4.0.1.2
Contractor needs to take authorization letter from owner and shall submit required drawings and sizing calculations to agencies in hardcopies in role of authorized contractor putting his / her signature and stamp.
4.0.1.3
Contractor need to interact with agencies and get the final approval on all schemes, drawings and sizing calculations.
4.0.1.4
Contractor shall prepare as build document and submit to Office of The Chief Electrical Inspector Organization and Factory inspector office to final approval for plant operation.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 4.0.1.5
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Contractor shall furnished all document / format that need to maintain during plant operation for submission to government agencies.
4.0.2
CIVIL & STRUCTURAL WORKS:
4.0.2.1
The scope of civil works shall include design & construction of all civil works & Structural for Switch Yard works including supply of all materials complete for all equipment of
the
Switchyard package. 4.0.2.2
Vendor shall design, construct, fabricate, supply, erect and commission foundation, main structure and support structure for 33kV equipment including 33kV Transformer, fencing, CT, CB, LA, Isolators and Towers.
4.0.2.3
The work shall generally involve earthwork in excavation and filling in all types of soils, dressing to the required profile, dewatering till the structures are constructed /erected up to required level, shoring, backfilling around completed structures and plinth filling, disposal of surplus earth, concreting including reinforcement and formwork, fabrication, galvanizing, Proto-assembly & erection of Gantry Structure & Equipment supporting structure, fabrication and erection of all structural steel and miscellaneous steel ( i.e., cable tray supports, galvanized foundation bolts etc.), breaking of concrete/ brickwork/ roads and removal of sheet piling, precast covers, RCC cable trenches, cable ducts/duct banks, soil sterilization/anti weed treatment, drainage, fencing, gravel filling, final grading and site clearance before handing over and other auxiliary items of work etc.
4.0.2.4
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.
4.0.2.5
The Vendor shall provide all structures / facilities required for the effective functioning of switchyard. The scope of vendor for Civil & Structural works shall include but not limited to the following : a.
Detailed design criteria including basis of design shall be prepared by the vendor based on various requirements specified elsewhere in the specifications. All the above documents shall be finalized after Owner’s approval and the same shall form the basis of Detailed Engineering Work.
b.
Civil & structural works associated with switchyard structure etc.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD c.
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Civil & structural works associated with switchyard equipment supporting structure as required.
d.
Civil and structural works associated with Cable trenches from individual bays.
e.
Site Preparation, soil sterilization/ant weed treatment including gravel filling but excluding major leveling.
4.0.3 4.0.3.1
f.
Complete fencing along with gates for the switchyard.
g.
All protection measures to prevent any damage to the adjoining structures / facilities.
PRE-COMMISSIONING AND COMMISSIONING ACTIVITIES: The vendor's scope shall include all pre-commissioning and commissioning activities, materials and services as of Technical Specifications (Erection Conditions of Contract) including supply of all consumables, temporary equipment and piping, instruments, labor/skilled manpower etc.
4.0.4
CONSUMABLES
4.0.4.1
All the first fill and One year's topping requirements of consumable such as oil, silica gel, and essential chemicals etc. which will be required to put the equipment covered under the scope of specifications, into successful commissioning/ initial operation and to establish completion of facilities shall be furnished by the contractor.
4.0.5
SPARES:
4.0.5.1
The scope of work includes supply of mandatory spares, commissioning spares, consumable spares and others as specified under conditions of contract. Spare shall be considered for two years successful operation.
4.0.5.2
Each spare part shall be clearly marked or labeled on the outside of the packing with its description. When more than one spare part is packed in a single case, a general description of the contents shall be shown on the outside of such case; and a detailed list enclosed. All cases, containers and packages shall be suitably marked and numbered for identification.
4.0.6
SPECIAL TOOLS & TACKELES :
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 4.0.6.1
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One set of all special tools and tackles including testing, calibrating and measuring instruments required for erection, assembly, disassembly and maintenance of all equipment/ systems covered under the scope shall be supplied by the vendor.
4.0.6.2
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 owner.
4.0.6.3
4.0.7 4.0.7.1
A list of all such special tools and tackles shall be submitted along with the offer.
PROJECT MANAGEMENT AND SITE SUPERVISION: The vendor 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.
4.0.7.2
The vendor shall be responsible for adequate training of owner’s operation and maintenance personnel as to be able to operate & maintain the equipment and its components properly, safely and efficiently over long period of time.
4.0.7.3
The vendor’s supervisory personnel shall provide operation and maintenance assistance during the warranty period.
4.0.7.4
A project execution schedule called in the form of PERT chart and based on `Work break down structure’ shall be prepared by the vendor for approval. The schedule shall identify milestones of key events for each work/component in the areas of engineering, procurement, manufacture, dispatch, erection and commissioning.
4.0.8
INTERFACE COORDINATION :
4.0.8.1
The vendor shall identify all interface issues and shall be responsible for such interfacing, coordination and exchange of all necessary information.
4.0.8.2
The vendor shall submit to the owner all drawings for review.
4.0.8.3
He shall list the detailed requirements of interface between Contractor’s work and the material and services to be supplied by owner and other vendor.
4.0.9
ARRANGEMENT BY THE VENDOR:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 4.0.9.1
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Vendor shall make his own necessary arrangements for the following and for those not listed anywhere else: a) Distribution/extension of the construction power supply at all works areas. b) Further distribution of construction water. c) Construction office and store (open & covered). d) Construction workshop and material/field testing laboratory. e) Boarding & lodging arrangement for their personnel. I.e. contractor’s personnel. f)
Fire protection and security arrangements during construction stage.
g) Suitable and adequate land/space & power supply for office, storage area, pre assembly and fabrication areas, labour and staff colony area, toilets etc.
4.0.10
DOCUMENT TO BE SUBMITTED ALONG WITH OFFER: a)
Datasheet.
b) Specifications. c) Catalogue. d) GA drawings. e)
QAP.
f) Wiring Diagram. g) Test Certificates.
4.0.11
DOCUMENT TO BE SUBMITTED AFTER AWARD OF CONTRACT FOR APPROVAL: a)
Design Calculations for ACSR conductors, Circuit Breakers, Isolators, LA, CT, PT, Lightning Protection, Cable tray, Steel Structures, and Switchyard Earthing.
b)
Layout drawings for Switchyard Equipment, Cable routing, Lighting, Lightning Protection and Earthing.
c) Equipment Installation and foundation drawings.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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d) Steel structure Assembly and Fabrication drawings. e) Schedule –Control Cable with Junction & Marshaling boxes interconnection schedule.
4.0.12
TEST : TYPE TEST: a. All equipment to be supplied shall be of type tested quality. The vendor shall submit for 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. b. 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 owner. c. In case the vendor is not able to submit report of the type test(s) conducted within last five years from the date of supply opening or in case the type test report(s) are not found to be meeting the specification requirements, the vendor shall conduct all such tests under this contract free of cost to the Employer and submit the reports for approval.
ROUTINE TEST: a) All equipment to be supplied shall be of Tested for routine test as listed as per
relevant standard. b) All tests shall be carried out in presence of Owner or owner representative. Schedule of
testing shall be submitted by vendor to owner before 2 week of
actual date of test. c) Equipment shall be complete in all respect like wiring, switchgears, control logics operational requirements, auxiliary system, consumables shall be present and installed at respective locations. Any short fall will not be tolerated and equipment shall not be tested.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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d) Copy of test results shall be given person witnessing test at end of test with authority
signatures from Contractor, OEM and Owner / owner representatives.
e) Equipment shall be dispatch to owner site once dispatch certificate is issued by owner on completion of tests.
5.0.0
CIRCUIT BREAKER:
5.0.1
INTENT :
5.0.1.1
The intent of this Section is to provide the information for the 33KV Circuit Breaker. The design, manufacture, testing and performance of Breaker shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
5.0.2
SCOPE :
5.0.2.1
The following is the scope of Supply, of the following:
5.0.2.2
a.
33kV ,Vacuum Circuit Breaker including mounting Structures:
b.
Clamps and, Connectors
1 Nos.
: 1 Lot
The work shall be carried out in accordance with drawings, specifications and data sheets enclosed with this document.
5.0.3
GENERAL :
5.0.3.1
The design, manufacture, testing and performance of all equipment shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
5.0.3.2
The circuit breaker shall be outdoor type Vaccum circuit breaker .
5.0.3.3
One number separate 415V, 3 phase, 50Hz AC supply feeder shall be provided for local control cabinet for feeding spring charging motor and 230V, 1 phase, 50Hz AC supply for
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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space heaters and etc. 5.0.3.4
Breaker shall be suitable for operation from local, Relay and Control (R & C) panel .
5.0.3.5
The local controls shall include emergency hand trip devices, local/remote selector switch, local control switch and various indicating lamps etc.
5.0.3.6
All secondary and auxiliary wiring terminals shall be finger touch proof shrouded design.
5.0.3.7
The terminals of the circuit breakers shall be suitable for horizontal take off of ACSR Conductor.
5.0.3.8
Double compression type glands of suitable size shall be supplied along with marshaling box of Circuit Breaker.
5.0.3.9
The Marshaling Boxes for equipment shall be of outdoor type with IP55 protection. The door of the cabinet shall have facility for pad locking. Provision shall be available inside the cabinet for taking single phase supply through 32A industrial metal clad power socket controlled by one 32A, MCB. The control cabinet shall be provided with suitable earthing studs of tin plated brass of suitable size for connecting to the earth grid. The control cabinet shall be provided with thermostat control space heater through MCB feeder of suitable rating.
5.0.3.10
The entire power & control network have been designed as fuse less system. Hence, no fuses shall be used in control circuits of equipment. MCBs of suitable rating and type shall be used in the control circuits (AC/DC).
5.0.3.11
The indicating lamps shall be cluster LED type. The color of lamp shall be – RED- ON, GREEN – OFF, AMBER – TRIP, BLUE – SPRING CHARGE, ORANGE / WHITE – TRIP CIRCUIT HEALTHY.
5.0.3.12
All control cabling shall be of minimum size 2.5 Sq. mm flexible multi-stranded copper, FRPVC insulated cables.
5.0.3.13
Contact multiplication for the auxiliary contacts to be achieved only through VAJC type or static auxiliary relay and not by means of air break contactors.
5.0.3.14
CB Control switch shall be 3 position spring returns to neutral switch with 2 contacts in each of the Trip and Close positions.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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5.0.4
CONSTRUCTION:
5.0.4.1
The circuit breakers shall comprise one three-phase unit or single units linked together, either mechanically or electrically. Type of execution, whether single phase or three phases shall be as specified in Data Sheet.
5.0.4.2
Circuit breakers shall be supplied with a common base and factory installed inter-phase wiring.
5.0.4.3
All similar parts, particularly removable ones, shall be interchangeable with one another.
5.0.4.4
The circuit breaker shall withstand the seismic acceleration specified.
5.0.4.5
A pole discrepancy protective scheme shall be incorporated in the circuit breaker control circuit to detect discrepancy in the instants of parting/touching of moving and stationary contacts in the three (3) poles and actuate alarm and trip circuits in the event of discrepancy persisting for durations beyond the preset times. The scheme shall be complete with time delay relay adjustable from 0.1 to 2 second, contactors etc.
5.0.5 5.0.5.1
OPERATING MECHANISM : Circuit breakers shall be power operated by a motor charged spring operated mechanism. Main poles of the breaker shall be such that the design shall ensure a close pole spread with a maximum of 4 ms opening and 6 ms closing. The operating mechanism shall include all auxiliary devices and accessories for the type of mechanisms offered.
5.0.5.2
Operating mechanism shall utilize 415 V AC supply for closing & Tripping coils.
5.0.5.3
Circuit breakers shall feature high repeatability of absolute closing time over a wide range of parameters (ambient temperature, pneumatic pressure, control voltages, etc.). Operating mechanism shall be non-pumping electrically and either mechanically under every method of closing (except during manual closing of a breaker for maintenance). Electrical antipumping feature shall be obtained by means of an auxiliary relay and use of a contactor to achieve this feature shall not be acceptable.
5.0.5.4
Operating mechanism shall be suitable for high speed reclosing. It shall be non-pumping electrically and either mechanically under every method of closing (except during manual closing of a breaker for maintenance). A latch checking switch shall be provided on
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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mechanically trip free mechanisms to prevent reclosure before the breaker latches have reset. 5.0.5.5
Main poles shall operate simultaneously. There shall be no objectionable rebound and the mechanism shall not require any critical adjustment. It shall be strong, rigid, positive and fast in operation.
5.0.5.6
Trip coil shall be rated for not less than 200 W continuously and two numbers to be provided.
5.0.5.7
Disagreement circuit shall be provided which shall detect pole position discrepancy in case of three single phase units.
5.0.5.8
The design of the circuit breaker shall be such that contacts will not close automatically upon loss of gas.
5.0.5.9
A mechanical indicator shall be provided inside the operating mechanism box to show open and closed positions where it will be visible through a glass window to a man standing on the ground with the mechanism housing closed. An operation counter shall also be provided.
5.0.5.10
A closing release shall operate correctly at all values of voltage between 85% and 110% of the rated voltage. A shunt trip shall operate correctly under all operating conditions of the circuit breaker up to the rated breaking capacity of the circuit breaker and at all values of supply voltage between 70% and 110% of rated voltage.
5.0.5.11
Working parts of the mechanism shall be of corrosion resisting material. Bearings which require grease shall be equipped with pressure type grease fittings. Bearing pin, bolts, nuts and other parts shall be adequately pinned or locked to prevent loosening or changing adjustment with repeated operation of the breaker.
5.0.5.12
Provision shall be made for attaching an operation analyser to perform speed tests after installation of the breakers at Site.
5.0.6 5.0.6.1
SPRING OPERATED MECHANISM: Spring operated mechanism shall be complete with motor, opening spring, closing spring
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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with limit switch for automatic charging and all necessary accessories to make the mechanism a complete operating unit. 5.0.6.2
As long as power is available to the motor, a continuous sequence of closing and opening operations shall be possible.
5.0.6.3
After failure of power supply to the motor, at least one open-close-open operation of the circuit breaker shall be possible.
5.0.6.4
Breaker operation shall be independent of the motor, which shall be used solely for compressing the closing spring.
5.0.6.5
Motor rating shall be such that it requires only about 30 seconds for fully charging the closing spring. Motors shall conform to Data Sheet.
5.0.6.6
Closing action of the circuit breaker shall compress the opening spring ready for tripping.
5.0.6.7
When closing springs are discharged, after closing a breaker, closing springs shall automatically be charged for the next operation. Facility for manual charging of the closing spring shall be provided.
5.0.6.8
Mechanism shall be such that failure of any auxiliary spring shall not prevent tripping and will not cause tripping or closing operation of the power operated closing devices. When the circuit breaker is already closed, failure of any auxiliary spring shall not cause damage to the circuit breaker or endanger the operator.
5.0.6.9
Mechanical indicators to indicate charged and discharged condition of spring shall be provided. Means shall be provided to slowly open and close the breaker manually for maintenance purpose when the operating power is not available.
5.0.7 5.0.7.1
OPERATING MECHANISM CONTROL: All accessories shall be enclosed in a weather-proof mechanism cabinet of hot dip galvanized sheet steel construction, the thickness of which shall not be less than 2 mm.
5.0.7.2
Hinged doors giving access to the mechanism at the front and sides shall be provided. Suitable gaskets shall be provided to make the mechanism housing water-proof and dustproof.
5.0.7.3
A conveniently located manual tripping switch shall also be provided for local tripping of
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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the breaker. A local manual closing device which can easily be operated by one man standing on the ground shall also be provided for maintenance purposes. Direction of motion of handle shall be clearly marked. 5.0.7.4
Common marshaling box with cables shall be provided. Cables from Relay and control panel will be termination in the Marshaling box.
5.0.8
BUSHINGS/ INSULATORS:
5.0.8.1
Porcelain used for the manufacture of bushing/ insulator and it shall be homogeneous, free from laminations, cavities and other flaws or imperfections that might affect the mechanical or dielectric quality and shall be thoroughly vitrified, tough and impervious to moisture.
5.0.8.2
Glazing of the porcelain shall be of uniform brown colour free from blisters, burns and similar other defects. Bushings/ insulator shall be designed to have ample mechanical strength and rigidity for the conditions under which they will be used. All bushings of identical ratings shall be interchangeable.
5.0.8.3
Puncture strength of bushings/ insulator shall be greater than the dry flashover value. When operating at normal rated voltage, there shall be no electric discharge between the conductors and bushing which would cause corrosion or injury to conductors, insulators or supports by the formation of substances produced by chemical action. No radio interference shall be caused by the bushings when operating at the normal rated voltage.
5.0.8.4
All iron parts shall be hot dip galvanized and all joints shall be airtight. Surface of the joints shall be trued-up; porcelain parts by grinding and metal parts by machining. Bushing design shall be to ensure a uniform compressive pressure on the joints.
5.0.8.5
All current carrying contact surfaces shall be silver faced. Silver facing shall not be less than one mil in thickness.
5.0.8.6
Bushings/ insulator shall satisfactorily withstand the specified insulation level.
5.0.9
BREAKER CONTACTS:
5.0.9.1
Main contacts shall have ample area and contact pressure for carrying the rated current and the short time rated current of the breaker without excessive temperature rise, which may
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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cause pitting, or welding. 5.0.9.2
Contacts shall be adjustable to allow for wear, easily replaceable and shall have a minimum of movable parts and adjustments to accomplish these results. Main contacts shall be the first to open and the last to close so that the contact burning and wear shall be least.
5.0.9.3
Arcing contacts, if provided, shall be the first to close and the last to open and shall be easily accessible for inspection and replacement. Tips of arcing and main contacts shall be silver faced or have tungsten alloy tipping.
5.0.9.4
Positive mechanical interconnection shall be provided between interrupting contacts, blast valve mechanism, if any, to ensure maximum operating reliability and retention timing.
5.0.9.5
If multi-break interrupters are used, they shall be so designed and augmented that a fairly uniform voltage distribution is developed across them.
5.0.10 5.0.10.1
EARTHING : Two clamp type earthing terminals each suitable for the clamping Owner’s earthing conductor shall be provided on each circuit breaker. Vendor shall specify min / max conductor that can be terminated.
5.0.11 5.0.11.1
STRUCTURES : Vendor shall design, fabricate and supply the support strcture require to erect the circuit breaker.
5.0.11.2
The scope of work includes supply, fabrication, galvanizing, marking/ punching part numbers of all steel structures required for the Mounting of Equipment.
5.0.11.3
5.0.12 5.0.12.1
Preparation of fabrication drawings shall be Vendor’s scope.
NAME PLATE : Each breaker shall be provided a name plate in English, with the following data indelibly marked on it. a. Manufacturer’s name or trade mark. b. Serial number and type designation. c. Rated voltage
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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d. Rated current e. Rated insulation level f.
Rated frequency
g. Rated breaking capacities (symmetrical and asymmetrical). h. Weight (for circuit breakers) including oil/gas i.
5.0.13 5.0.13.1
Rated short time (for duration as specified in Data Sheet) current.
PAINTING: The external finish paint shade for the Circuit Breaker, mounting structure, mechanism box and its accessories shall be Shade 631 of IS 5.
5.0.13.2
The type of paint shall be synthetic enamel air-dried.
5.0.13.3
The interior of the Control Panel / Marshaling box shall be painted with glossy white enamel paint.
5.0.13.4
All metallic parts shall have rust protection.
5.0.13.5
All steel surfaces shall be thoroughly cleaned by sand blasting or chemical agents as required, to produce a smooth surface free of scales, grease and rust.
5.0.13.6
The external surfaces, after cleaning, shall be given a coat of high quality red oxide or yellow chromate primer followed by filler coats.
5.0.13.7
Sufficient quantity of touch up paint shall be furnished for application after installation at site.
5.0.13.8
All supporting structures and hardware shall be hot dip galvanized.
5.0.14 5.0.14.1
FITTINGS & ACCESSORIES: A list of some of the major fittings and the accessories to be furnished by the VENDOR as an integral part of the equipment. Operating mechanism housing complete with: a.
Padlocks and duplicate keys
b.
Space heaters equipped with automatic thermostatic control
TECHNICAL SPECIFICATION – 33kV SWITCHYARD c.
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Manually operated tripping push button/lever (mechanical) conveniently located to trip all three phases simultaneously.
d.
Operation counter
e.
Terminal boards with minimum 6 spare terminals
f.
Control switches to cut off control power supplies
g.
MCB’s as required
h.
Two earthing terminals
i.
Auxiliary relays required for satisfactory operation
j.
Motor contactor with thermal release for spring charging motor
k.
Breaker local control switch
l.
3 pin 15A socket outlet and cubicle lamp
m. Steel frames for frame mounted breakers
5.0.15 5.0.15.1
n.
Manually operated device for breaker closing under failure of normal power
o.
Maintenance closing device
p.
Foundation templates
q.
Foundation bolts
r.
Galvanized Steel bracket for mounting current transformers
s.
Gas filling and filtering valve.
t.
Clamps and connectors
SPARE PARTS : Mandatory Spare for healthy operation of equipment and two years maintenance spare parts shall be included in offer as optional item. The item listed under (but restricted to) shall consider by vendor. In addition to following item, vendor can recommend necessary spare parts required for 2yrs of operation. a. One complete pole of the breaker with the control
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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b. Main interrupter units c. Grading capacitor units d. Closing coils e. Tripping coils f.
Accelerating and damping springs
g. Spring charging motor h. Cross head and lift rods i.
Pressure switches
j.
Set of gaskets
k. Pressure gauges l.
Local/remote changeover switch
m. Bushings / Insulators (all types) n. Fixed contact assemblies o. Moving contact assemblies p. Arcing contact assemblies q. Quenching chambers r.
Vacuum bottle.
s. Pressure pipe insulator t.
Arcing chamber insulator
u. Silica gel charge
5.0.16
DOCUMENTATION :
5.0.16.1 Bidder shall submit the following documents for equipment’s in THREE (3) SETS with the offer. a. Data Sheet. b. GA Diagrams.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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c. Catalogues. d. Wiring Diagram. e. Test Certificates.
5.0.16.2
f.
Deviation List
g.
Bill of material with type, ratings and makes of all components.
Vendor
shall submit the following documents for all equipment after award of job for
approvals: i. Datasheet ii. Overall general arrangement drawings giving plan, section, foundation loading data (both static and dynamic), side view, etc. in cad drawings iii. Control and schematic diagrams with ferrule and terminal numbers. iv. Catalogue of the Equipment v. General outline drawings showing dimensions, net and shipping weights, quantity of SF6 / air receiver capacity, etc. vi. Internal component layout drawings. vii. Sectional views showing the general constructional features of the circuit breaker including operating mechanism, arcing chambers, contacts, Vacuum bottle, with bushing lifting dimensions. viii. General arrangement of the foundations or structure mountings in CAD. ix. Instruction and Training Manual x. Packing drawings and Packing list xi. Equipment Storage xii. QAP
5.0.17
TEST :
5.0.17.1 ROUTINE TEST
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All routine tests as per applicable standard shall be carried out on each circuit Breaker without any extra charges.
a. Insulation resistance test b. Millivolt drop test c. Connections test d. Overload tripping test e. Mechanical operation f.
Measurement of opening and closing time
g. Tightness test h. Electrical operation i.
Physical dimension check
j.
Primary and secondary injection test
5.0.17.2 TYPE TEST a. Impulse test b. Power frequency withstand test c. Heat run d. Making capacity and breaking capacity test e. Short circuit test f.
Mechanical endurance
g. Electrical endurance h. Ingress protection 5.0.17.3
Vendor shall submit report for type test list above. The test shall be conducted on same make, model and configuration of equipment offered. The reports shall not older than 5 years from date of supply. If report do not comply the above requirement, vendor need to perform the test on one equipment without any cost or time implication.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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6.0.0
33 kV ISOLATORS :
6.0.1
INTENT :
6.0.1.1
The intent of this specification is to provide the information for the 33 kV Isolator. The design, manufacture, testing and performance of isolator & its equipment shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
6.0.2 6.0.2.1
SCOPE OF SUPPLY : The following is the scope of Supply, of the following : a)
33kV Isolator with one earth switches including mounting Structures
b)
33kV Isolator without earth switches including mounting Structures
c)
2 Nos. 1 Nos
Aluminium alloy connectors for 33kV Isolator pad to ACSR Conductor
6.0.2.2
The work shall be carried out in accordance with drawings, specifications and data sheets enclosed with this document.
6.0.3
CONSTRUCTIONAL FEATURES:
6.0.3.1
The isolator/earthing switch shall be complete with all parts that are necessary or essential for efficient operation.
Such parts shall be deemed to be within the scope of supply,
whether specifically mentioned or not. 6.0.3.2
All similar parts shall be interchangeable.
6.0.3.3
Base channels and other structural steel members such as operating pipes, phase coupling rods etc. operating mechanism boxes, bolts, pins etc., shall be dip galvanized or metallized. All castings except current carrying parts shall be made of galvanized steel.
6.0.3.4
Live metal parts shall be of non-rusting and non-corroding metal. Current carrying parts shall be of non-ferrous materials such as aluminum or copper, but copper silicon alloy shall be avoided. Bolts, screws and pins shall be provided with lock washers, keys or equivalent locking facilities.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 6.0.3.5
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The isolator design shall be such that it is free from visible corona discharge in both closed and open positions at the visible discharge test voltages as per applicable standards. Necessary stress relieving rings or shields shall be provided to meet this requirement.
6.0.3.6
Isolators and earthing switches including their operating mechanism shall be such that they cannot be dislodged from their open or closed positions by gravity, wind pressure, vibrations, shocks or accidental touching or seismic forces or breaking or the connecting rods or the operating mechanism.
6.0.3.7
The design shall be such that no lubrication of any part is required except at very infrequent intervals.
6.0.3.8
During the course of normal operation, it is likely that the isolator/earth switch may be left in the Open/Closed position for long periods of time.
They shall be designed to operate
satisfactorily even after being kept in one position for long periods. 6.0.3.9
The isolator or earthing switch shall be provided with high current carrying contacts on the hinge and jaw faced copper.
6.0.3.10 The isolators and earth switches shall be designed to withstand stresses corresponding to specified short circuit duties. 6.0.3.11 The insulators shall withstand the seismic force level given.
6.0.4
ACCESSORIES : a) Position Indicator: A mechanical position indicating device shall be provided for each isolator/earthing switch, irrespective of whether the isolating distance is visible or not.
b) Earthing Pads: Each pole of the isolator shall be provided with earthing pads of non-corrodible material, brazed to the channel base.
Flexible copper earth connectors shall be provided for
connecting operating handles of isolators and earthing system.
c) Counter Balance Springs
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These shall be provided for counter balancing the isolators to prevent impact at the end of travel both on opening and closing of the isolator/earthing switch. The springs shall be non-rusting alloy.
6.0.5 6.0.5.1
NAME PLATES : A weatherproof and corrosion-proof nameplate shall be provided on isolators, earthing switches and operating devices. The nameplate shall conform to applicable standards.
6.0.5.2
Adequately rated, renewable type arcing tips shall be provided on the isolators to make and break the magnetizing or line/bus charging currents.
6.0.6
EARTHING SWITCH:
6.0.6.1
Earthing switch shall form an integral part of each pole of the isolator. Two independent earthing pads each with flexible copper braids and suitable connection for the specified size of earth conductor lead shall be provided at the hinge end of the switch.
6.0.7
INTERLOCKS:
6.0.7.1
Isolators and earthing switches shall be provided with padlocking facility to lock them in fully open or fully closed positions. Padlocks shall be supplied with the isolators.
6.0.7.2
Isolator and earthing switches shall be mechanically interlocked such that it will not be possible to close the earthing switch when the isolator is closed and vice-versa.
6.0.7.3
Isolator shall be provided with electrical interlocking feature. This shall be in the form of bolt interlock comprising an interlock coil of latch-in type to lock the isolator-driving shaft and hence prevent isolator operation in the latch in condition.
It shall be possible to
release the latch by energizing the interlock coil when certain pre-set conditions of interlocking scheme are fulfilled. For this purpose the VENDOR shall provide facilities for wiring external
interlocking contacts both in isolator opening and closing circuits. Further, a separate bypass switch shall be provided on the local control cabinet to facilitate emergency manual operation of isolator. 6.0.7.4
Electrical interlocking arrangement shall be fail less safe type.
6.0.7.5
Isolator shall be provided electrical interlocking facility with upstream breaker.
6.0.7.6
The isolator shall have min following interlock but not limited to –
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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i.
Isolator shall not able to close when breaker is closed.
ii.
Isolator shall not able to open when breaker is closed.
iii.
Isolator shall able to close or open only when breaker is open and earthing switch is Closed.
iv.
6.0.8 6.0.8.1
Earthing switch shall not able to close when Isolator is closed.
INSULATORS : Porcelain used for the manufacture of insulators and it shall be homogeneous, free from flaws or imperfections that might affect the mechanical or dielectric quality. They shall be thoroughly vitrified, tough and impervious to moisture. The glazing of the porcelain shall be of uniform brown colour, free from blisters, burns and other similar defects. Insulators of the same rating and type shall be interchangeable.
6.0.8.2
The porcelain and metal parts shall be assembled in such a manner that any thermal expansion differential between the metal and the porcelain parts throughout the range of temperature variation shall not loosen the part or create undue internal stresses which may affect the electrical mechanical strength and rigidity. Each cap and base shall be of high-grade cast steel or malleable steel casting and they shall be machine faced and smoothly galvanized. The cap and base of the insulators shall be interchangeable with each other.
6.0.9
OPERATING MECHANISM AND CONTROLS:
6.0.9.1
The operating mechanism shall provide quick, simple and effective operation. Time of operation shall not exceed 12 seconds. One man shall be able to operate the isolator/earthing switch (when manually operated) without undue effort.
6.0.9.2
The ganging mechanism shall be provided with sufficient adjustment to allow for Final alignment of the isolator blades for simultaneous operation. Adjustable stops shall be provided to prevent over travel in either direction.
6.0.9.3
The isolator shall be provided with positive continuous control throughout the entire cycle of operation. The operating pipes and rods shall be sufficiently rigid to maintain positive control under most adverse conditions and when operated in tension or compression for
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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isolator closing. They shall also be capable of withstanding all torsional and bending stresses due to operation of the isolator. 6.0.9.4
It shall not be possible, after final adjustment has been made, for any part of the Mechanism to be displaced at any point in the travel sufficiently to allow improper functioning of the isolator when the isolator is opened or closed at any speed. All holes in cranks, linkages etc., having pins shall be drilled to accurate fit so as to maintain the minimum amount of slack and lost motion in the entire mechanism.
6.0.9.5
The manual operating handles shall be mounted on the base of supporting structure. Guide bearings shall be provided if necessary at a height of 750mm above grade level. All brackets, angles, guides, guide bearings or other members necessary for attaching the operating mechanism and operating handles supporting structure and foundations shall be supplied as an integral part of the isolator. Rustproof pins and bearings of the bronze bushing, ball and roller type, shall be furnished. All bearings shall be weather protected by means of covers and grease retainers. Bearing pressures shall be kept low to ensure long life and ease of operation.
6.0.9.6
The operating mechanism design shall be such that during the operation of the isolator (especially manual operation) the moving blades once they reach the sparking distance, springs shall take over to give a quick, snap action enclosing so that the isolator closing is independent of manual efforts.
Similarly, the springs must assist during the opening
operation to give quick breaking feature.
6.0.10 6.0.10.1
6.0.11 6.0.11.1
INSULATION LEVELS : The rated insulation levels shall be in accordance with the applicable standards.
TEMPERATURE RISE : The temperature rises of any part of the isolator and associated equipment shall not exceed the maximum permissible temperature rise values as stipulated in the applicable standard, corresponding specified design ambient temperature.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 6.0.12 6.0.12.1
6.0.13 6.0.13.1
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CLAMPS AND CONNECTORS: Clamps and connectors shall be supplied as a part of the isolator.
SHORT CIRCUIT REQUIREMENTS : The rated peak short-circuit current or the rated short time current carried by an isolator or earthing switch for the rated maximum duration of short circuit shall not cause: a.
Mechanical damage to any part of the isolator or earthing switch.
b. Separation of the contacts or contact welding; and c. 6.0.13.2
A temperature rise likely to damage insulation.
After the passage of these currents, the isolator shall be able to carry its rated current under specified conditions and the operation of the operating device shall not be impaired.
6.0.13.3
The rated peak short circuit current and the rated short time current, of the earthing switch shall be at least equal to those specified for the isolator. The earthing switch shall be capable of making on a dead short circuit without damage of endangering the operator.
6.0.14
SUPPORTING STRUCTURES:
6.0.14.1
Supporting structures for isolator and earthing switches are included in the VENDOR’S scope of supply.
The VENDOR shall furnish detailed dimensioned drawings indicating
weights and all fixing details and relative locations of chassis, operating mechanism box and operating handles. Final responsibility for ensuring that mounting and supporting arrangements of isolator are proper and that there is no interference of any part of the isolator with supporting structures rests with the VENDOR. 6.0.14.2
The mounting heights indicated in Data Sheet/ Layout are only tentative and are likely to vary within +25%. This will be confirmed at the time of the drawing approval.
6.0.15
DOCUMENTATION:
6.0.15.1
Vendor shall submit the following documents for all equipment along with offer a)
Data Sheet.
b)
Tentative GA Diagrams.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
6.0.15.2
Vendor
c)
Catalogues.
d)
Wiring diagram.
e)
Test certificates.
f)
Deviation List.
Doc. No.: Version: Effective Date: Supersede: Page:
shall submit the following documents for all equipment after award of job for
approvals:
6.0.16
a)
GA Drawing with Termination details
b)
Filled datasheets
c)
Quality plan.
d)
Foundation layout drawing.
e)
Erection drawings.
f)
Control Schematic
g)
Wiring Diagrams
h)
Shipping drawing showing the dimensions and weights
i)
Packing list
j)
O&M manual of the transformer
k)
Catalogues.
TEST :
6.0.16.1
All routine tests specified in relevant IS and IEC standards need to perform on each isolator.
6.0.16.2
All routine tests shall be performed in presence of Owner engineer or their representative.
6.0.16.3
The equipment offered shall be furnished with all type test report as per relevant IS and IEC standards. The certificates shall not be older than 5 years from date of supply. Any absence of certificate or certificate older than 5 year will ask to perform the test on equipment. All such test shall perform without any extra cost and time. All tests shall be made on completely assembled isolators, earthing, switches, their operating devices and auxiliary equipment.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
7.0.0
BUSBAR:
7.0.1
INTENT:
7.0.1.1
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The intent of this Section is for the ALUMINIUM CONDUCTOR STEEL REINFORCED (ACSR) Conductor. The design, manufacture, testing and performance of ACSR Conductor shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
7.0.1.2
The exact quantity shall be decided by vendor based on actual site condition and handling.
7.0.2
SPECIFIC REQUIREMENTS:
7.0.2.1 WIRE SIZE a.
Nominal Size The aluminium and galvanised steel wires for the stranded conductor covered by this standard shall have Suitable diameters. The diameter of the galvanized steel wires shall be measured over the zinc coating.
b.
Tolerance on Normal Size i. Aluminium Wires: No negative tolerance shall be permitted on the nominal diameter of Al wires. However, the diameter as per IS: 398 (part-2) amended up to date. ii. Galvanised Steel Wires: A tolerance of +/- 2 % is permitted on the nominal
diameter.
7.0.3 7.0.3.1
FREEDOM FROM DEFECTS: The wires shall be smooth and free from all imperfections such as spills, splits, slag inclusion, die marks, scratches, fittings, blow-holes, projections, looseness, overlapping of strands, chipping of aluminium layers etc. and all such other defects which may hamper the mechanical and electrical properties of the conductor. Special care should be taken to keep away dirt, grit etc. during stranding.
7.0.4 7.0.4.1
JOINTS IN WIRES: Aluminium Wires: No joints shall be permitted in the Aluminium wires in the outermost layer
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of the ACSR conductor. Joints in the inner layers are permitted, in addition to those made in the base rod or wire before final drawing, but no two such joints shall be less than 15 metre apart in the complete stranded conductor. Such joints shall be made by cold pressure buttwelding. 7.0.4.2
Joints are not permitted in the outermost layer of the conductor in order to ensure a smooth conductor finish.
7.0.4.3
Galvanized Steel Wires: There shall be no joints except those in the base rod or wire before final drawing, in steel wires forming the core of the steel re-inforced Aluminium conductor.
7.0.4.4
Joints are not permitted in the steel wires after final drawing in order to avoid reduction in the breaking strength of the conductor that may occur as a result of failure of the joints.
7.0.5 7.0.5.1
STRANDING: The wires used in the construction of galvanized steel reinforced Aluminium conductor shall before stranding, satisfy all the relevant requirements of this specification.
7.0.5.2
While stranding, pre forming and post forming method should be used for stranded steel core. In order to relieve the residual tension in core wire to avoid flaring of conductor.
7.0.5.3
In all constructions, the successive layers shall have opposite directions of lay, the outermost layer being right-handed. The wires in each layer shall be evenly and closely stranded.
7.0.5.4
In conductors having multiple layers of Aluminium wires, the lay-ratio of any Aluminium layer shall not be greater than the lay-ratio of Aluminium layer immediately beneath it.
7.0.6 7.0.6.1
CONDUCTOR DRUM : The conductor shall be supplied in non-returnable strong wooden drums provided with lagging of adequate strength and displacement during transit, storage and subsequent handling and stringing operation in the field. The drums shall generally conform to IS: 1778.
7.0.6.2
Each drum shall stenciled on in indelible ink for Name and address of consignee, Manufacturer’s name and address, Drum Number, Size of Conductor, Length of Conductor in meters, Gross weight of drum with Conductor, and Arrow marking for unwinding.
7.0.6.3
Before reeling, card board or double corrugated or thick bituminized waterproof bamboo
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paper shall be secured to the drum barrel and inside of flanges or the drum by means of a suitable commercial adhesive material. The paper should be dried before use. Medium grade craft paper shall be used in between the layers of the conductor. 7.0.6.4
After reeling the conductor, the exposed surface of the outer layer conductor shall be wrapped with thin polythene sheet across the flanges to preserve the conductor from dirt, grit and damage during transportation and handling and also to prevent ingress of rain water during storage/transport.
7.0.6.5
The conductor ends shall be properly sealed and secured with the help of nails or bolts on one side of the flanges to avoid loosening of conductor layers in transit and handling.
7.0.7.1
DOCUMENTATION:
7.0.8.1
Vendor shall submit the following documents for all equipment along with offer:
7.0.8.2
Vendor
i.
Data Sheet.
ii.
Typical cross-sectional details
iii.
Catalogues.
iv.
Wiring diagram.
v.
Test certificates.
vi.
Deviation List
shall submit the following documents for all equipment after award of job for
approvals: i. Filled datasheets ii. Quality plan. iii. Shipping drawing showing the dimensions and weights. iv. Termination details, Bending Details v. Catalogues vi. O&M manual
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 7.0.7
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TEST : ROUTINE TESTS: All routine tests as per applicable standard shall be carried out in presence of engineer form owner or their representative without any extra charges. a.
Check to ensure that the joints are as per specification.
b.
Check that there are no cuts etc. on the strands.
c.
Check that drums are as per specification.
d.
All acceptance tests mentioned as above shall be carried out on each coil and the record of the same shall be kept by the supplier and same shall be produced at the time of inspection.
e.
Resistance Test
TYPE TESTS: The following Type Tests shall be conducted a.
Test for surface condition
b.
Test for ultimate breaking load on stranded conductor.
If
vendor can furnished the Type Test certificate for test conducted not 5 years before date of supply, the type test can be waived off. Any failure of submission of certificate or certificates older than 5 yrs., vendor need to perform the test without extra cost and time.
8.0.0
LIGHTNING ARRESTOR:
8.0.1
INTENT:
8.0.1.1
The intent of this Section is to provide the information for the 30 kV Lightning Arrester .The design, manufacture, testing and performance of all equipment shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
8.0.2 8.0.2.1
SCOPE: The following is the scope of Supply, of the following : a.
30 kV Lightning Arrestors including mounting Structures
06 Nos.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD b. 8.0.2.2
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Clamps, and Connectors
1 Lot.
The work shall be carried out in accordance with drawings, specifications and data sheets enclosed with this document.
8.0.3
GENERAL REQUIREMENTS :
8.0.3.1
The LA's shall be supplied with insulating base to monitor the discharge currents.
8.0.3.2
Each LA shall be supplied with one discharge counter and leakage current indicator.
8.0.3.3
The discharge counter shall be provided with M12 tin plated brass studs with two nuts, brass washers & spring washer for connections to Purchaser’s earth grid. Suitably rated bypass shunt for bypassing the discharge counter shall also be provided.
8.0.3.4 8.0.3.5
The discharge counter shall be suitable for outdoor installation with IP55 protection. The insulated flexible connector required for connecting LA to the discharge counter is in the scope of the bidder.
8.0.3.6
The flexible connectors shall be of adequate length with margin.
8.0.3.7
The LA will be connected to ACSR conductor. The terminals shall be suitable for vertical takeoff and clamps and connectors shall be indicated in Data sheet.
8.0.3.8
The materials and components not specifically stated in this specification but which are necessary for satisfactory operation of the equipment are deemed to be included in the scope of supply unless specifically excluded.
8.0.4
CONSTRUCTIONAL FEATURES:
8.0.4.1
Lightning arrestors shall be of the hermetically sealed type of self-supporting Construction, suitable for mounting on the steel structures.
8.0.4.2
They shall have adequate thermal discharge capacity for severe switching surges, long duration surges and multiple strokes. The lightning arrestors when provided with pressure relief devices shall be capable of withstanding the internal pressures developed during the above discharges without operation of the pressure relief devices..
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 8.0.4.3
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Spacers for gaps and valve elements or valve blocks shall be of ceramic material. These shall be provided in such a way as to obtain robust construction, with excellent mechanical and electrical properties.
8.0.4.4
Outer insulators shall be of porcelain having adequate mechanical strength and rigidity, for satisfactory operation under climatic conditions obtaining at Site. Porcelain shall be finely glazed and shall be free from imperfections.
8.0.4.5
Arrestors shall be designed to withstand seismic acceleration and wind pressure as specified.
8.0.4.6
Arrestors
shall
incorporate
anti-contamination
feature
to
prevent
arrestor
failure,
consequent to uneven voltage gradient across the stack in the event of contamination of the arrestor porcelain. These features shall be described in detail when submitting the Bid. 8.0.4.7
Arrestors shall be suitable for hot line washing.
8.0.4.8
All metal parts shall be of non-rusting and non-corroding metal. Bolts, screws and shall be provided with lock washers, keys or equivalent locking facilities. All
pins
similar parts,
particularly removable ones, shall be interchangeable. 8.0.4.9
8.0.4.10
Arrestors shall be capable of spark over on frequent switching surges.
Arrestors shall be capable of discharging over-voltages occurring during switching of unloaded transformers, capacitor banks and long lines.
8.0.5
ACCESSORIES :
8.0.5.1
SUPPORTING ARRANGEMENT:
8.0.5.1.1
Arrestors shall be complete with insulating boxes having provision for bolting to flat surface of supporting structure. Steel Supporting structure is part of the scope of supply of the VENDOR. The VENDOR shall furnish detailed dimensional drawings indicating all fixing details and electrical clearance diagram for installation.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
8.0.6 8.0.6.1
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DISCHARGE COUNTER: Self-contained discharge counter, suitably enclosed for outdoor use and requiring no auxiliary or battery supply shall be provided for each single pole unit.
8.0.6.2
The discharge counter shall be visible through an inspection window.
8.0.6.3
The counter terminals shall be robust and shall be so located that incoming and outgoing connections are made with minimum possible bends.
8.0.6.4
Suitably sized bypass shunts of copper to facilitate bypassing the discharge counter shall be furnished. The design of the terminal connectors shall permit the connection of these shunts.
8.0.6.5
The connecting conductor from lightning arrestor earth terminal to the discharge counter incoming terminal shall be insulated for a minimum of 4 kV and this insulated conductor shall be supplied along with the arrestor by the VENDOR. This insulating conductor shall be of the type which does not require sealing ends or plumbed joints at its either end for terminations.
8.0.6.6
A leakage current detector as an integral part of the discharge counter shall be supplied. The counter along with the detector shall be so arranged that it will be possible to read the leakage current values from ground level. The value of leakage current beyond which the operation is abnormal shall be clearly marked in red colour on the detector.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
8.0.7 8.0.7.1
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GRADING RINGS : Grading rings shall be provided on each complete arrestor unit for proper stress distribution as dictated by the voltage class of the arrestor.
8.0.8 8.0.8.1
TERMINALS : Arrestor shall be complete with line and earth terminals. The terminal clamps/connectors on the earth terminal of the arrestors and the discharge counter incoming and outgoing terminals shall be within the scope of the VENDOR.
8.0.9 8.0.9.1
NAME PLATES : Each lightning arrestor shall be provided with non-rusting and non-corroding name plate bearing Arrestor Identification as per applicable standards.
8.0.10
PAINTING:
8.0.10.1.1 The external finish paint shade for the LA, mounting structure, mechanism box and its accessories if any shall be Shade 631 of IS 5. 8.0.10.2
The type of paint shall be synthetic enamel air-dried.
8.0.10.3
The interior of the Control Panel / Marshaling box shall be painted with glossy white enamel paint.
8.0.10.4
All metallic parts shall have rust protection.
8.0.10.5
All steel surfaces shall be thoroughly cleaned by sand blasting or chemical agents as required, to produce a smooth surface free of scales, grease and rust.
8.0.10.6
The external surfaces, after cleaning, shall be given a coat of high quality red oxide or yellow chromate primer followed by filler coats.
8.0.10.7
Sufficient quantity of touch up paint shall be furnished for application after installation at site.
8.0.10.8
All supporting structures and hardware shall be hot dip galvanized.
8.0.11
DOCUMENTATION:
8.0.11.1
Bidder shall submit the following documents for equipment with the offer.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
8.0.11.2
Doc. No.: Version: Effective Date: Supersede: Page:
a.
Datasheet
b.
Specifications
c.
Catalogue
d.
GA drawings & Installation Drawings
e.
QAP
f.
Test Certificates
g.
Support Structure drawing
h.
Discharge counter details drawing
i.
Packing list
j.
Deviation list
Vendor
shall submit the following documents for all equipment after award of job for
approvals: a.
Datasheet
b.
Overall general arrangement drawings giving plan, section, foundation loading
data (both static and dynamic), side view, etc in cad drawings c.
Control and schematic diagrams with ferrule and terminal numbers.
d.
Catalogue of the Equipment
e.
General outline drawings showing dimensions, net and shipping weights, quantity
etc. f.
Internal component layout drawings.
g.
Sectional views showing the general constructional features of the circuit breaker
including operating mechanism, arcing chambers, contacts, Vacuum bottle, with bushing lifting dimensions. h. General arrangement of the foundations or structure mountings in CAD. i.
Instruction and Training Manual
j.
Packing drawings and Packing list
k. Equipment Storage l.
8.0.12
TESTs :
QAP
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
Doc. No.: Version: Effective Date: Supersede: Page:
ROUTINE TEST: a. Measurement of reference voltage b. Residual voltage test c.
Leakage check
d. Current distribution test for multi column arrester e. Physical Inspection for Dimension verifications f. Operational test on Leakage Detector and surge Counter.
All the routine test certificates as per relevant IS of LA’s and the insulators shall be submitted at the time of inspection.
TYPE TESTS: The equipment offered should be type tested. a. Power frequency residual voltage test b. Switching impulse residual voltage test c. Repeated energy withstand test d. Energy withstand and power frequency voltage stability tests e. Pressure relief test
If Type test report not less than 5 year old, conducted on equivalent and similar equipment, listed type tests need not to perform again. Any failure of submission.
9.0.0
CURRENT TRANSFORMER & POTENTIAL TRANSFORMER:
9.0.1
INTENT:
9.0.1.1
The intent of this Section is to provide the information for the 33 kV CT and 33kV PT. The design, manufacture, testing and performance of all equipment shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
9.0.2
SCOPE OF SUPPLY:
9.0.2.1 The following is the scope of Supply, of the following: a.
33kV Current Transformers including mounting Structures
6 Nos ( 2 sets)
TECHNICAL SPECIFICATION – 33kV SWITCHYARD b. 9.0.2.2
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33kV Potential Transformers including mounting Structures
6 Nos (2 sets)
The work shall be carried out in accordance with drawings, specifications and data sheets enclosed with this document.
9.0.3 9.0.3.1
SPECIFIC REQUIREMENTS: The design, manufacture, testing and performance of all equipment shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
9.0.3.2
CTs & PTs shall be hermetically sealed type and their corresponding terminal boxes shall have a degree of protection of IP 65.
9.0.3.3
The terminals for CT secondary shall be shorting type and suitable for conductor size up to 6 sq.mm. Minimum of 6 spare terminal connectors shall be available in CT junction boxes for Purchaser’s use.
9.0.3.4
Double compression type glands of suitable size shall be supplied along with CT & PT terminal boxes.
9.0.3.5
CT & PT terminals shall be suitable for horizontal take off of ACSR Conductor and clamps and connectors shall be as indicated in Data Sheet.
9.0.3.6
Instrument transformers shall be complete with accessories like terminal connectors, grounding lugs, filling and draining plugs, oil sight glass, weather proof terminal box etc.
9.0.4 9.0.4.1
CONSTRUCTIONAL FEATURES OF CT : Current Transformers shall be in appropriate voltage class oil filled shaded porcelain bushings, suitable for outdoor service and upright mounting on steel structures.
9.0.4.2
Design and construction of CTs shall be sufficient to withstand the thermal and mechanical stresses resulting from the specified short circuit current.
9.0.4.3
The core laminations shall be of cold rolled grain oriented silicon steel or other equivalent alloy. The exciting current shall be as low as possible and the current transformer shall be capable of maintaining its rated accuracy for burdens and saturation limits specified.
9.0.4.4
Current Transformers shall be suitable for outdoor use. Current Transformers shall have high accuracy commensurate with the faster protection schemes employed in the system.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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The cores to be used for protection shall, therefore, besides being of low reactance type, produce undistorted secondary currents under transient condition on all the ratios. 9.0.4.5
CT secondary terminals shall be brought out in a weather proof terminal box.
9.0.4.6
The terminal box shall be provided with five glands suitable for 1100 V grade, PVC insulated, PVC sheathed, 6 sq.mm copper conductor cables.
9.0.4.7
Polarity marks shall be indelibly marked on each current transformer and at the lead terminations in the associated terminal block.
9.0.4.8
Facility shall be provided for short circuiting and grounding the CT secondary at the terminal blocks.
9.0.4.9
CT shall be provided with name plate showing the particulars and diagram of the current transformer in line with the relevant IEC.
9.0.4.10
CTs shall be hermetically sealed to eliminate breathing, prevent air and moisture from entering the tank. These shall be provided with oil level gauge and pressure relieving device capable of releasing abnormal pressure.
9.0.4.11
Continuous current rating of secondary winding of core should be as per requirement specified. The secondary terminal should be brought out in a compartment on one side of CT for easy access.
9.0.4.12
CT secondary terminals should be provided with short circuiting arrangement. The secondary leads should be adequately reinforced to withstand normal handling without damage.
9.0.4.13
The sealing arrangement of secondary terminals should also be provided in a compartment of two sides of CT terminal box. CT secondary terminal box should be partitioned so as to house the metering terminals separately with the provision of sealing and locking of the metering terminals.
9.0.4.14
CT cores used for protective relaying purpose should be of accuracy class specified. Magnetization curves should be furnished for metering and protection cores.
9.0.4.15
The secondary terminal box and junction box should be partitioned in two compartments comprising two hinged doors so as to house the metering & protection terminals separately with locking and sealing arrangement.
9.0.4.16
“METERING” & “PROTECTION” should be clearly indicated on each compartment door respectively by engraving or by providing the metallic plate.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
Doc. No.: Version: Effective Date: Supersede: Page:
9.0.5
CONSTRUCTIONAL FEATURES OF PT :
9.0.5.1
The core of PTs should be of high grade, non-aging, electrical silicon laminated steel of low hysteresis loss and high permeability to ensure high accuracy at both normal voltage and over voltage.
9.0.5.2
The potential transformers shall be hermetically sealed to eliminate breathing and prevent air and moisture from entering into the tank. If necessary these shall be provided with oil level gauge and shall be provided with pressure relieving device capable of releasing abnormal internal pressures. The details of hermetic sealing should be given in the offer.
9.0.5.3
The potential transformers will consist of a top tank to accommodate primary terminal assembly, oil level gauge, pressure relief device etc. and a bottom tank to accommodate secondary cores, terminal boxes etc.
9.0.5.4
All potential transformers shall be paper insulated oil filled type. The potential transformers unit after providing paper insulation shall be housed in the tank containing oil. Please note that epoxy casting in primary & secondary core is not acceptable.
9.0.6
MAIN TANK :
9.0.6.1
Material for main tank which should be minimum 3 mm thick mild steel / stainless steel / Aluminium alloy.
9.0.6.2
The practice of providing inserts of non-magnetic material in the body of the tank with suitable welding to reduce eddy current shall not be acceptable. This problem should be avoided by selection of tank of suitable material.
9.0.6.3
Welded joints have to be minimized to avoid possibility of oil leakage. In any case welding in horizontal plane shall be avoided.
9.0.6.4
Cutting of slot or hole in the bottom tank should be done smoothly to avoid any sharp edges within the tank. All welded surfaces need to be smoothening and shall be covered with pressboard or other insulating material of good mechanical properties.
9.0.6.5
The bottom tank should not have any dents and pitting to ensure proper tightening of gasket and to avoid any oil leakage. Fabrication of bottom tank shall be done by utilizing fresh sheet steel only.
9.0.6.6
The top & bottom tanks should be painted with two coats of zinc chromate primer both inside and outside after proper cleaning and pickling. Finally the inside of tanks should be
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
Doc. No.: Version: Effective Date: Supersede: Page:
painted with two coats of white enameled paint or any other paint which is non-reactive to oil.
9.0.7 9.0.7.1
BUSHINGS: Bushings shall be made of homogeneous, vitreous porcelain of high mechanical and dielectric strength. Glazing of porcelain shall be of uniform brown or dark brown colour with a smooth surface arranged to shed away rain water.
9.0.7.2
Bushings conforming to IS-2099 & 3347 shall be hollow porcelain type hermetically sealed to prevent ingress of moisture and with suitable facility to indicate oil level.
9.0.7.3
Cast metal end caps for the bushings shall be of high strength, hot dip galvanized malleable iron. They shall have smooth surface to prevent discharge taking place between the metal parts and porcelain as a result of ionization.
9.0.7.4
All instruments transformers shall be provided with terminal connectors suitable to receive ACSR conductor in case of 33 KV CTs
9.0.7.5
Two grounding terminals shall be provided on the tank of each transformer on opposite sides with separate earthing terminal for bolted connection to station earthing system.. The grounding conductor shall be of GI flat of size 50x6 sq. mm.
9.0.8
MATERIAL:
9.0.8.1
For non-current carrying parts, the bolts, nuts, washer and check nuts up to 10mm size should be of stainless steel and 12 mm size or above should be hot dip galvanized marked with ISI certification mark.
9.0.8.2
Nuts, washers, bolt for current carrying parts should be tinned copper. These should be manufactured by a reputed concern.
9.0.9
CONNECTORS:
9.0.9.1
The design of the connectors shall be such as to give intimate contact between the conductor and terminal and offer protection to the contact surfaces against effects of electrolytic (between two dissimilar metals) and atmospheric corrosion.
9.0.9.2
The connector shall have sufficient mechanical strength and shall completely enclose the conductor and terminals.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 9.0.9.3
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The connector shall hold the conductor and terminal very tightly so that the connector withstands the mechanical stresses set up by vibration, wind and short circuit current.
9.0.9.4
The conductivity of connectors shall be high to minimize power loss. The connector should be designed with large factor of safety and should comply in all respect of temperature rise; resistance and tensile strength.
9.0.10
INSULATING OIL:
9.0.10.1
A sufficient quantity of oil for the base top and porcelain housing shall be furnished with each CT.
9.0.10.2
PTs shall be supplied completely filled with oil. The oil shall confirm to the requirement o IS: 335.
9.0.11
JUNCTION BOX:
9.0.11.1
One junction box each shall be provided for each set of three nos. single phases 33kV CTs and PT.
9.0.11.2
Each junction box shall be equipped with at least 38 nos. terminals. CT Terminal box shall be provided with shorting links.
9.0.11.3
These terminals shall be suitable to receive at least 6 sq.mm copper conductor cable. These terminals should be suitable to withstand up to 5 kV. Terminal blocks shall be provided with serial no. tags.
9.0.12
STRUCTURES:
9.0.12.1
The scope of work includes supply, fabrication, galvanizing, marking/ punching part numbers of all steel structures required for the mounting for Equipment.
9.0.12.2
Preparation of fabrication drawings shall be in vendor scope.
9.0.13
PAINTING:
9.0.13.1
The finish shade shall be 631 of IS 5.
9.0.13.2
The type of paint shall be synthetic enamel air-dried.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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9.0.13.3
The interior of the terminal box shall be painted with glossy white enamel paint.
9.0.13.4
All metal parts coming in contact with oil shall be painted with oil resistant paint.
9.0.13.5
All steel surfaces shall be thoroughly cleaned by sand blasting or chemical agents as required, to produce a smooth surface free of scales, grease and rust.
9.0.13.6
All supporting structures and hardware shall be hot dip galvanized.
9.0.14 DOCUMENTATION: 9.0.14.1 Vendor shall submit the following documents for equipment with the offer. a. Datasheet b. Specifications c. Catalogue d. GA drawings & Installation Drawings e. QAP f. Test Certificates g .Support Structure drawing h. Discharge counter details drawing i. Packing list j .Deviation list 9.0.14.2
Vendor shall submit the following documents for all equipment after award of job for approvals: k.
Datasheet
l.
Overall general arrangement drawings giving plan, section, foundation loading data (both static and dynamic), side view, etc in cad drawings
m.
Schematic diagrams with ferrule and terminal numbers.
n.
Catalogue of the Equipment
o.
General outline drawings showing dimensions, net and shipping weights, quantity etc.
p.
Internal component layout drawings.
q.
Sectional views showing the general constructional features including bushing lifting dimensions, mounting arrangement and support structure details.
r.
General arrangement of the foundations or structure mountings in CAD file.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
9.0.15
Doc. No.: Version: Effective Date: Supersede: Page:
s.
Instruction and Training Manual
t.
Packing drawings and Packing list
u.
Equipment Storage
v.
QAP
TEST :
9.0.15.1 ROUTINE TEST ON CT AND PT : i.
Verification of terminal markings and polarity.
ii.
Ratio Test
iii.
High voltage power frequency tests on primary windings.
iv.
High voltage power frequency tests on secondary windings.
v.
Determination of errors according to the requirements of the appropriate accuracy class.
vi.
Polarity Test
vii.
High Voltage test on Junction Box.
9.0.15.2 ROUTINE TEST ON BUSHING:
9.0.15.3
9.0.15.4
i.
Visual examination.
ii.
One minute dry withstand test.
iii.
Oil tightness test.
TYPE TEST ON CT AND PT : i.
Temperature rise.
ii.
Impulse withstand test
iii.
Partial Discharge Test
iv.
Capacitance and Tan Delta measurement
v.
Magnetization current measurement.
TYPE TEST ON BUSHINGS: i.
Partial Discharge Test in dusty, wet and dry conditions.
ii.
Capacitance and Tan Delta measurement
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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10.0.0 CONTROL AND RELAY PANEL: 10.0.1 INTENT: 10.0.1.1 The intent of this specification is to provide the information for the Control and Relay panel. The design, manufacture, testing and performance of all equipment shall comply in all respects with the requirements of the latest edition of the applicable standards and codes.
10.0.2
SCOPE OF SUPPLY:
10.0.2.1
Vendor shall design and supply control and relay panel outdoor type required .
10.0.2.2
No. of panels and their configuration shall be optimum housing minimum of number of verticals. Control and Relay panel
10.0.2.3
:
1 no.
The relays and control, metering and indication equipment’s, cubicles etc. shall be sourced from a well-known and proven manufacturer who is adept in the manufacture of these items.
10.0.3
CONSTRUCTIONAL FEATURES :
10.0.3.2
The Control and Relay Board shall be of panels of control desk type at upcoming 33KV Substation. It is the responsibility of the vendor to ensure that the equipment specified and equipment required for completeness of the Protection/Control Schemes be properly accommodated in the panels without congestion.
10.0.3.3
The panels shall be completely metal enclosed to ensure a dust, moisture and vermin proof atmosphere. The enclosure shall provide a degree of protection not less than IP 31.
10.0.3.4
Panels shall be rigid free standing and floor mounting type and comprise of structural frames enclosed completely with specially selected texture finished, cold rolled sheet steel of thickness not less than 3 mm for weight bearing members of the panels such as base frame, front sheet and door frames and not less than 2.0 mm for sides, door top and bottom portions. There shall be sufficient reinforcement to provide level surfaces, resistance to vibration and rigidity during transportation and installation.
10.0.3.5
All joints shall be made flush and all edges shall be bent at right angles and rounded. All
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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structural members shall be bolted or welded together. Necessary arrangement shall be provided for bolting together the adjacent panels as well as for fastening them to the floor. 10.0.3.6
The opening required for mounting the Equipment shall be punched or cut and filed smooth. All doors, removable covers and panels shall be gasketed all around with synthetic rubber gaskets Neoprene/EPDM generally conforming to provision of IS. Ventilating louvers, if provided shall have screens and filters. The screens shall be made of either brass or GI wire mesh. Frame shall be designed and supplied by vendor.
10.0.3.7
All control cables shall be laid in control room via cable trench in ground floor. The cable then raised to first floor through cable trays. Hence cable entries to the panels shall be from the bottom. The bottom plates of the panels shall be fitted with removable gland plates for fixing the cable glands, the size of which shall suit the owner's external cables to the panels.
10.0.3.8
Cable gland plates shall be fitted without glands. Cable gland plate fitted in the bottom of the panel and it shall be connected to the earthing of panel/station through a flexible braided copper conductor rigidly.
10.0.3.9
Necessary foundation drawings showing cables entry positions and foundation belt locations shall be supplied by the Vendor. All necessary arrangements shall be made inside the control panel to hold the cables so that no load comes on terminals due to the weight of hanging cable. Owner's external cable connections will be terminated on the terminal blocks to be provided by the Vendor.
10.0.3.10
Design, material selection and workmanship shall be such as to result in neat appearance, inside and outside with no welds, rivets or bolt head apparent from outside with all exterior surfaces tune and smooth.
10.0.3.11
Relay panels of modern, modular construction of standard 19" 483 mm width in accordance with IEC 60297 shall also be acceptable.
10.0.4
MOUNTING:
10.0.4.2
All equipment on and in panels shall be mounted and completely wired to the terminals blocks ready for external connection. The equipment on front of panel shall be mounted flush.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 10.0.4.3
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Equipment shall be mounted such that removal and replacement can be accomplished individually without interruption of service to adjacent devices and are readily accessible without use of special tools. Terminal marking shall be clearly visible.
10.0.4.4
Cutouts if any, provided for future mounting of equipment shall be properly blanked off with blanking plate.
10.0.4.5
The Centre lines of switches, push buttons and indicating lamps shall be not less than 750 mm from the bottom of the panel. The Centre lines of relays, meters and recorders shall be not less than 450 mm from the bottom of the panel.
10.0.4.6
The Centre lines of switches, push buttons and indicating lamps shall be matched to give a neat and uniform appearance. Likewise the top lines of all meters, relays and recorders etc. shall be matched. No equipment shall be mounted on the doors.
10.0.4.7
All the equipment connections and cabling shall be designed and arranged to minimize the risk of fire and damage which may be caused by fire.
10.0.5 10.0.5.2
PANEL INTERNAL WIRING AND OTHER ACCESSORY EQUIPMENT: Panels shall be supplied complete with interconnecting wiring provided between all electrical devices mounted and wired in the panels and between the devices and terminal blocks for the devices to be connected to equipment outside the panels.
10.0.5.3
When panels are arranged to be located adjacent to each other all inter panel wiring and connections between the panels shall be furnished and the wiring shall be carried out internally. These adjacent inter panel wiring shall be clearly indicated in the drawing furnished by the Vendor.
10.0.5.4
All wiring shall be carried out with 1100V grade, single core, stranded copper conductor wires with PVC insulation and shall be low smoke flame retardant grade which shall have oxygen index not less than 29 and temperature index not less than 250 deg. C. The minimum size of the stranded copper conductor used for internal wiring shall be 2.5 mm sq. Copper.
10.0.5.5
All internal wiring shall be securely supported, neatly arranged, readily accessible and connected to equipment terminals and terminal blocks. Wiring gutters & troughs shall be used for this purpose.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 10.0.5.6
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Auxiliary bus wiring for AC and DC supplies, voltage transformer circuits, annunciation circuits and other common services shall be provided near the top of the panels running throughout the entire length of the panels. These buses shall have a nominal cross section equivalent to a copper diameter of 6 mm and shall be suitably insulated all along their run. D.C. buses shall be divided into two sections to permit two independent supply points.
10.0.5.7
Wire termination shall be made with solder less crimping type and tinned copper lugs which firmly grip the conductor and insulation. Insulated sleeves shall be provided on all the wire terminations. Engraved core identification plastic ferrules marked to correspond with panel wiring diagram shall be fitted at both ends of each wire. Ferrules shall fit tightly on the wire and shall not fall off when the wire is disconnected from terminal blocks. All wires directly connected to device shall be distinguished by the addition of red colored unlettered ferrule. Numbers 6 and 9 shall be underlined for correct position in ferule. The wire numbers shown in the wiring diagram shall be as per IS 305.
10.0.5.8
Longitudinal troughs extending throughout the full length of the panel shall be preferred for inter panel wiring. Inter-connections to adjacent panel shall be brought out to a separate set of terminal blocks located near the slots of holes meant for taking the inter-connecting wires. Arrangements shall permit easy inter-connections to adjacent panels at site and wires for this purposes provided by Vendor shall be looped and bunched properly inside the panel.
10.0.5.9
Vendor shall be solely responsible for the completeness and correctness of the internal wiring and for the proper functioning of the connected equipment.
10.0.6 10.0.6.2
TERMINAL BLOCKS: All internal wiring to be connected to the external equipment shall terminate on terminal blocks, preferably vertically mounted on the side of each panel. Terminal blocks shall be 1100 V grade and have 10 amps continuous rating, moulded piece, complete with insulated barriers, stud type terminals, washers, nuts and lock nuts. Terminal block design shall include a white fiber markings strip with clear plastic, slip-on/clip-on terminal covers. Markings on the terminal strips shall correspond to wire number and terminal numbers on the wiring diagrams.
10.0.6.3
Not more than 2 wires shall be connected to any terminal. Suitable supports shall be
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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provided for the incoming cables. The terminal blocks shall be arranged to provide maximum accessibility to all conductor terminations. The terminal blocks shall be fully enclosed with easily removable covers and made of molded, non-inflammable plastic material with bases and barriers moulded integrally. 10.0.6.4
Terminal blocks for current transformer and voltage transformer secondary leads shall be provided with test links and isolating facilities. Also current transformer secondary leads shall be provided with short circuiting and earthing facilities.
10.0.6.5
At least 20% spare terminals shall be provided on each panel and these spare terminals shall be uniformly distributed on all terminal blocks.
10.0.6.6
Unless otherwise specified, terminal blocks shall be suitable for connecting the following conductors of owner's cables:
10.0.6.7
a.
All circuits expect CT circuits one 2.5 Sqmm. copper
b.
All CT minimum of two of 6 mm sq. copper.
c.
PT circuits’ incoming terminal 2.5 sqmm copper and other 2.5 sqmm copper
d.
AC/DC power supply circuits one of 6 mm sq. aluminum.
There shall be a minimum clearance of 250 mm between the first row of terminal blocks and the associated cable gland plate or panel side wall as per the terminal block mounting arrangement adopted. Also, the clearance between two rows of terminal blocks shall be a minimum of 150 mm.
10.0.6.8
Arrangement of the terminal block assemblies and the wiring channel within the enclosure shall be such that a row of terminal blocks is run parallel and in close proximity along each side of the wiring duct to provide for convenient attachment of internal panel wiring. The side of the terminal block opposite the wiring duct shall be reserved for the owner's external cable connection. An adjacent terminal block shall also share this field wiring corridor. A steel strip shall be connected between wiring shall be provided with adequate support inside the panels to hold them firmly and to enable free and flexible termination without causing strain to terminals.
10.0.6.9
All number and sizes of the owner's multicore incoming cable will be furnished to the Vendor after placement of the order. All necessary cable terminating accessories such as gland
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plates, packing glands, crimp type tinned copper lugs supporting clamps and brackets, wiring troughs and gutters etc. for owner's cable shall be included in the Vendor's scope of supply.
10.0.7
METERS
10.0.7.2
All instrument & meters shall be enclosed in dust proof, moisture resistant, black finished cases and shall be suitable for tropical use.
10.0.7.3
All accessories including the test switches and test plugs, where applicable shall be furnished. Their elements shall be shock resistant and shielded from external magnetic fields.
10.0.8
INDICATING INSTRUMENTS:
10.0.8.2
Unless otherwise specified all electrical indicating instruments shall have circular 240 deg. scale and with a dial of 96 mm x 96 mm. They shall be suitable for flush mounting with only flanges projecting on vertical panel and back connected.
10.0.8.3
Instrument covers shall be of shadow proof design, utilizing all available light. The indicating instruments shall have red marks on the dial corresponding to rated values of the associated primary equipment.
10.0.8.4
Ammeters and current coils of Wattmeter and VAR meters shall continuously withstand 120% of rated current and 10 times the rated current for 0.5 sec. without loss of accuracy.
10.0.8.5
Voltmeters and potential coils of Wattmeter and VAR meters shall withstand 120% of rated voltage for 0.5 seconds without loss of accuracy.
10.0.8.6
Digital meter shall have digital display of five (5) and four (4) digits respectively with display size not less than 25 mm (height).
10.0.9 10.0.9.2
UTILITY TRIVECTOR METERS: Energy meters shall be static type conforming to IEC: 62053 and suitable for inter utility EHV bi-directional power flow and for CT/PT connection.
10.0.9.3
The static meter shall carryout measurement of active energy (import) and reactive energy (import) by 3-phase four wire principles suitable for balanced/unbalanced 3-phase load. The accuracy of energy measurement shall be 0.2 for active energy and 1 for reactive energy. The active and reactive energy shall be directly computed in CT & VT primary ratings and
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stored in four different registers of the memory of the meter as MWH (E), MVAH (E), MWH (I) and MVARH(I). Further the meter shall continuously integrate the energy readings of each register up to that time. 10.0.9.4
All these readings shall be displayed on demand. Cumulative reading of each register shall be stored in non-volatile memory at the end of each hour of the day starting from 0100 hrs. These readings shall be stored for a period of 40 days before being erased.
10.0.9.5
The static meter shall have a built-in clock and calendar having an accuracy of at least 1 minute per month or better. Date/time shall be displayed on demand. The clock shall be synchronized by GPS time synchronizing equipment being provided or other time signals.
10.0.9.6
Each meter shall have a unique identification code provided and shall be marked permanently on the front and also on the non-volatile memory. The voltage monitoring of all the three voltages shall be provided.
10.0.9.7
The meter shall normally operate with power drawn from VT supplies. The power supply to the meter shall be healthy even with a single phase VT supply. An automatic backup shall be provided by a builtin life time battery and shall not need replacement for at least ten years with a continuous VT interruption of at least two years. Date and time of VT interruption and restoration shall be automatically stored in non-volatile memory.
10.0.9.8
The static meter shall have an optical port at the front of the meter for data collection by a hand held device.
10.0.10
RELAYS:
10.0.13.1
PROTECTION RELAYS: a. All Protection relays shall be numerical type and confirm IEC 60870-5-103. b. Each relay shall have 1 no Ethernet Port and 1no RS 485 Port for Remote SCADA / BUMS connection. c. Relays shall be suitable for flush or semi-flush mounting on the front with connections from the rear.
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d. All AC relays shall be suitable for operation of 50hz AC voltage fed from PT at 110V/ Sqrt 3 and CT secondary at 1 A . e. The relays shall be designed to operate successfully for DC voltage of 85% to 110% of rated 110V DC. f. The relays shall behave communication port of Ethernet IP. g. The protection relay shall have sufficient binary inputs and outputs. The relay shall have min 4 line of LCD display with Alpha numeric key pad. h. The relay shall be have inbuilt Event / disturbance/ fault recorder with date and time stamping. i.
Relay shall be selectable / programmable all operational characteristics as per IEC and ANSI.
10.0.13.2
AUXILIARY RELAYS: a. Auxiliary relays can be either static/ comb flex type. If electromechanical relays are offered, same shall be considered only after approval. Any disapproval of same, vendor shall supply equivalent static / combiflex relays without any extra cost or time. b. All tripping relays shall be flag relay with manual reset type. c. Auxiliary relays for condition monitoring like transformer WTI, OTI, Buchholz shall have communication port of Ethernet IP. d. Self-reset auxiliary/monitoring voltages relays for specified D.C. Voltage shall be provided for use in the interlocking schemes for multiplication of contacts, and for monitoring of control supplied and circuit. e. Monitoring relays for lockout relay circuit shall be connected in series with lockout relay coils. f. The supply and circuit monitoring relay shall be connected to initiate an alarm upon failure of respective supply circuit. They shall preferably have reverse flags, which drop when the relay is de-energized.
10.0.13.3 TRIP CIRCUIT SUPERVISION RELAYS:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD a.
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The trip circuit shall be supervised by means of relays. The scheme shall continuously monitor the trip circuit both before closing and after closing of the breaker.
b.
The scheme shall detect
i.
Failure of trip supply to trip coil of each phase
ii.
Open circuit of trip circuit wiring and
iii.
Failure of mechanism to complete the tripping operation.
c.
The relay shall have time delay on drop off of not less than 200 milli-seconds and be provided with operation indications for each phase.
d.
Necessary external resistors for trip circuit supervision relays shall be supplied.
10.0.13.4 D.C. SUPPLY SUPERVISION RELAY: a. The relay shall be capable of monitoring the failure of DC supply to which it is connected. b. It shall have adequate potential free contacts to meet the scheme requirement. c. The relay shall have a 'time delay on drop-off' of not less than 100 milliseconds and be provided with operation indicator/flag.
10.0.13.5 HIGH SPEED TRIPPING RELAY : a.
It shall be instantaneous operating (operating time not to exceed 10 milli seconds).
b.
It shall have adequate hand resetting type contacts to meet the requirement of scheme.
c.
It shall have necessary supervisory relays
10.0.11
MISCELLANEOUS ACCESSORIES:
10.0.11.2
240 Volts, Single Phase, 50 Hz AC socket with switch suitable to accept 5 amps and 15 amps pin round standard plug, shall be provided.
10.0.11.3
Lighting fixture rated for 240 Volts, single phase, 50Hz supply for the interior illumination of the
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panel during maintenance shall be provided. The fittings shall be complete with switch-fuse unit and switching of the lighting shall be controlled by the respective panel door switch. 10.0.11.4
Each panel shall be provided with necessary arrangements for receiving, distributing &isolating the DC and AC supplies for various control, signaling, and lighting and space heater circuits.
10.0.11.5
The incoming and sub-circuits shall be separately provided with miniature circuit breakers (MCB). Selection of the main and sub-circuit MCB ratings shall be such as to ensure selective clearance of sub-circuit faults. Each MCB shall be provided with one potential free contact and the same shall be wired for annunciation purpose.
10.0.11.6
Tubular space heaters of adequate capacity and suitable for connection to single phase, 240V, 50Hz supply shall be provided inside each panel and controlled by a thermostat.
10.0.11.7
Switchboard type, back connected semi flush mounting type test blocks with contacts suitably rated shall be provided with links or other devices to enable insertion of a series device into the circuit without causing open circuit in the CT. secondary or to enable short circuiting of the CT. Secondary.
10.0.11.8
Test block covers shall be removable from the front of the panels and shall be provided with suitable sealing arrangement to prevent unauthorized access to the test studs. If any test plugs are to be used with the test studs, 6 Nos. of each type of such test plugs shall be supplied free with the main equipment.
10.0.11.9
Test link, special terminal boards and other accessories normally required for testing operation and maintenance of all relays and meters shall be furnished by the Vendor.
10.0.12
EARTHING:
10.0.12.2
All panels shall be equipped with an earth bus securely fixed. Location of earth bus shall ensure no radiation interference for earth systems under various switching conditions of isolators and breakers. The material and the sizes of the bus bar shall be at least 50 x 6 mm GI flat or equivalent copper unless specified otherwise. When several panels are mounted adjoining each other, the earth bus shall be made continuous and necessary connectors and clamps for this purpose shall be included in the scope of supply of Vendor. Provision shall be made for extending the earth bus bars to future adjoining panels on either side.
10.0.12.3
Provision shall be made on each earth bus bars of the end panels for connecting Owner's
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earthing grid. Necessary terminal clamps and connectors for the purpose shall be included in the scope of supply of Vendor. The size of Owner's earthing grid connections will be furnished later to the Vendor. The earth wire or screens should be clearly bonded and earthed at the gland plate. The earthing scheme shall be got approved 10.0.12.4
All metallic cases of relays, instruments and other panel mounted equipment shall be connected to the earth bus by independent copper wires of size not less than 2.5 sq.mm. The colour code of earthing wires shall be green. Earthing wire shall be connected on terminals with suitable clamp connectors and soldering shall not be permitted.
10.0.12.5
Looping of earth connections which would result in loss of earth connection to other devices when the loop is broken shall not be permitted. However, looping of earth connections between equipment to provide alternative paths to earth bus shall be provided.
10.0.12.6
VT and CT secondary neutral or common lead shall be earthed at one place only at the terminal blocks where they enter the panel. Such earthing shall be made through links so that earthing may be removed from one group without disturbing continuity of earthing system for other groups.
10.0.12.7
The detailed earthing scheme shall be submitted for approval.
10.0.13
NAME PLATES:
10.0.13.2
All equipment mounted on front and rear side as well as equipment mounted inside the panels shall be provided with individual name plates with equipment designation engraved. Also on the top of each panel on front as well as rear side large and bold name plates shall be provided for circuit/feeder designation. These circuit labels shall be larger than the other name plates.
10.0.13.3
All front mounted equipment shall also be provided at the rear with individual name plates engraved with tag numbers corresponding to the one shown in the panel internal wiring to facilitate easy tracing of the wiring. The name plates shall be mounted directly by the side of the respective equipment and shall not be hidden by the equipment wiring.
10.0.13.4
Name plates shall be made of non-rusting metal or 3 ply lamicoid. Name plates shall be black with white engraving lettering. The name plate inscription and size of name plates and letters shall be submitted to the Owner for approval.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 10.0.13.5
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Each instrument and meter shall be prominently marked with the quantity measured (e.g. kV, A, MW etc.). All relays and other devices shall be clearly marked with manufacturer's name and type, serial numbers and electrical rating data.
10.0.13.6
Each switch shall bear clear inscription identifying its function. Similar inscription shall also be provided on each device whose function is not otherwise identified. If any switch device does not bear this inscription separate name plate giving its function shall be provided for it. Switch shall also have clear inscription for each position indication .
10.0.13.7
All relays and other devices shall be clearly marked with manufacturer's name, manufacturer's type, serial number and electrical rating data.
10.0.14
PAINTING:
10.0.14.2
The color shall be RAL 7032 for the enclosure
10.0.14.3
All metallic parts shall have rust protection.
10.0.14.4
All steel surfaces shall be thoroughly cleaned by sand blasting or chemical agents as required, to produce a smooth surface free of scales, grease and rust.
10.0.14.5
The external surfaces, after cleaning, shall be given a coat of high quality red oxide or yellow chromate primer followed by filler coats.
10.0.14.6
Sufficient quantity of touch up paint shall be furnished for application after installation at site.
10.0.14.7
All supporting structures and hardware shall be hot dip galvanized.
10.0.15
DOCUMENTATION:
10.0.15.2
Vendor shall submit the following documents for all equipment along with offer: a. Data sheet (Separate for CRP and Relays) b. Tentative GA Drawings. c. Catalogues d .Wiring diagram e. Test certificates. f. Deviation List
10.0.15.3
Vendor
shall submit the following documents for all equipment after award of job for
approvals:
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a.Datasheets (Separate for CRP and Relays)
b. Tentative GA Diagrams c. Quality plan. d. Shipping drawing showing the dimensions and weights. e. Erection drawings. f. Rating plate drawing g. Valid Type test Reports – 2 sets h. O&M manual of relays
10.0.16 TEST : 10.0.23.1 ROUTING TEST: Control & Relay Panel shall also be subjected to following tests: a. Mechanical operation Test. b. Verification of degree of protection as per IS: 2147. c. High voltage test/Insulator Resistance Test. d. Electrical control, interlock & sequential operation test. e. Verification of wiring as per approved schematic.
10.0.23.2 TYPE TEST : Test certificates not older than 5 year from date of supply for All relays and instruments of following test a. Insulation tests b. High frequency disturbance test c. Impulse test d. Fast transient test e. Relay characteristics, performance and accuracy test as per IEC 60255 f.
Tests for thermal and mechanical requirements
g. Contact performance test
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11.0.0
EARTH MAT:
11.0.1
INTENT:
11.0.1.1
The intent of this section is to provide information for the Earthing Mat to be provided in the 33 kV switchyard area.
11.0.1.2
Earthing mat of the 33 kV switchyard shall be bonded to the following: a. the neutral points of transformer & other equipment through their own independent earthing electrodes. b. Equipment framework and other non-current carrying parts in the switchyard and transformer yard. c. the earthing points of lightning arresters, through their permanent independent earthing electrodes. d. All extraneous metallic frameworks not associated with equipment. e. Switchyard fence.
11.0.1.3
Provisions of all the earthing electrodes required for the various systems, lightning arresters, voltage transformers, and the material for their and equipment framework connections to the earthing mat shall also be in the Contractor’s scope.
11.0.1.4
Vendor shall Design, erection and commissioning of 75X10 mm copper flat & 2 numbers of copper plate earth pits for power transformer neutral earthing.
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11.0.2
DESIGN AND CONSTRUCTION REQUIREMENTS:
11.0.2.1
Earthing mat comprising a mesh made of MS rods with cross-sectional area not less than about 500 sq.mm for welded runs and about 620 sq.mm for risers to be bolted to the earthing pads on equipment’s, structures etc. The design of the earthing mat shall be based on the following: a.
Average soil resistivity (ohm meter)
: To be determined by the Contractor
b.
Magnitude of design fault current (kA)
:31.5KA
c.
Duration of fault (second)
: One (1)
d.
Duration of shock (second)
: Half (0.5)
e.
Material of earthing mat conductor
: Mild Steel
f.
Type of joints: Permanent
: Welded
Suitable for testing operations
: Bolted
g.
Value of design ambient temperature
: 50°C
h.
Type of surface layer
: Crushed rock of size 15-20mm
i.
Average resistivity of surface layer
: 3000 (ohm meter)
j.
Minimum diameter and type of earthing Mat conductor:
11.02.2
Size
: Not less 65X10mm
Type
: GI flat
k.
Allowance for corrosiveness of soil
: Fifteen (15) percent
l.
Minimum depth of burial of earthing mat
: minimum 0.6 metre
The design of the earthing mat shall be such that the safe values of touch, step and transferred potentials are not exceeded under any condition. Earthing electrodes shall be provided as required and connected to earthing mat to achieve the desired value, if considered appropriate.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 11.02.3
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If the transferred potential exceeds the permissible value, the Contractor shall take necessary proven measures to protect the affected systems from the effects of transferred potential to the satisfaction of the Owner.
11.02.4
The design of earthing mat shall provide for welded joints between the earthing mat conductors, except where the mat may have to be isolated from equipment, cable sheath etc for testing. The joints intended to be isolated for testing shall be bolted.
11.0.2.5
The welds shall be treated with Barium Chromate to protect them from rusting. The exposed steel conductors/risers shall be protected with bituminous paint. The Barium Chromate treated surfaces shall thereafter be painted with red lead and aluminum paint and coated with bituminous paint.
11.0.2.6
Connections from mat to the switchyard equipment, frame work and other earthing points shall be made with two connecting strips each of adequate cross-sectional areas as per IS:3043 or 50 mm x 10 mm whichever is greater.
11.0.2.7
If the earthing mat terminates more than 1.5 meters inside the fenced area and electrical isolation between the fencing and earthing mat can be ensured, the climbable fencing shall be kept electrically isolated from the earthing mat and the fence shall be independently and effectively earthed by running an earthing conductor under the boundary and connecting it to the fencing at frequent intervals.
11.0.2.8
Connections from mat to the power transformer neutrals shall be made with 75x10mm copper flat and neutral shall be connected to the earth mat through copper plate earth electrodes.
11.0.2.9
If the earthing mat extends right up to fencing or where electrical isolation between the earthing mat and fencing cannot be ensured, but the design calculations reveal that the values of touch potentials both from within and outside the fenced-in area are within safe limits, fencing shall be connected with the earthing mat at frequent intervals.
11.0.2.10 If the earthing mat extends right up to the fencing, but the calculations reveal that touch potential at the fence is beyond tolerable limits, the earthing mat shall be terminated about 1.5 meter within the boundary line of the fence and the fence shall be electrically isolated and independently earthed by running earthing conductor underneath the fence and bonded with the fence at frequent intervals or by means of adequate number of earthing electrodes.
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11.0.2.11 Earthing terminal accessories wherever not supplied with the various equipment shall be provided by the Contractor without any additional cost to the Owner.
11.0.3
DOCUMENTATION:
11.0.3.1
Vendor shall submit the following documents for all equipment along with offer: (i) Design procedure along with the various equations and values of constants proposed to be adopted for the earthing mat design. (ii) Typical general arrangement drawings of the proposed connections with equipment frame-work, earthing electrodes, lightning arresters, and voltage transformers, details of welded and bolted joints, earthing electrodes; details of protecting welded joints from corrosion etc. (iii) Description of the proposed measures for limiting the transferred potential in the systems under influence.
11.0.3.2
Vendor
shall submit the following documents for all equipment after award of job for
approvals: (i) Soil resistivity measurement report based on the measurement carried out. (ii) Detailed calculations for determining the resistance of the earthing mat, values of estimated step, touch and transferred potentials, ground potential rise etc. (iii) Dimensional drawing of switchyard area showing the disposition of earthing mat conductors and extension of risers to the various equipment’s, structures, drawings & locations of earthing electrodes and their connections to all the related equipment’s, fence etc. (iv) Bill of materials giving estimated quantities of main earthing mat conductor, risers, and electrodes separately. (v) Results of measurements of actual resistance of earthing mat, touch, step and transferred potentials.
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12.0.0
DIRECT STROKE LIGHTNING PROTECTION SYSTEM:
12.0.1
SCOPE:
12.0.1.1
The type and requirements of the system for protection of the 33 kV bus bars, switchyard to transformer yard connections and transformer yard equipment from direct strokes of lightning are specified in this sub-section.
12.0.2
DESIGN REQUIREMENTS:
12.0.2.1
The design of the direct stroke lightning protection system shall be based on adequate number of lightning masts of appropriate height installed in the switchyard in such a manner that they provide adequate shielding cover to all the 33 kV bus bars, their connections to the bay equipment and the equipment from the direct lightning strokes. The equipment in the transformer yard and the connections of the same to the switchyard gantry shall be shielded with lightning masts.
12.02.2
The lightning masts shall consist of switchyard lattice steel structures (these can be the towers for the busbar supports) on the top of which pipes of adequate heights and dimensions shall be rigidly fixed suitably.
12.02.3
The thickness of zinc coating on the galvanized elements shall be commensurate with the very high level of pollution in the area.
12.02.4
Assumptions, if any, on which design of the direct stroke lightning protection offered is based shall be clearly stated in the bid.
12.03.0 12.0.3.1
DOCUMENTATION: Vendor shall submit the following documents for all equipment along with offer: (i)
Drawings of the transformer yard and switchyard showing the locations of lightning masts etc.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD (ii)
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Typical general arrangement drawings of pipe masts, proposed arrangements for fixing the pipe masts, shielding wire termination, grounding etc.
12.0.3.2
Vendor
shall submit the following documents for all equipment after award of job for
approvals: (i)
Calculations for determining the heights of lightning masts, zones of protection etc.
(ii)
Dimensional drawings of the switchyard in plan and sections showing the mast in positions and their zones of protection.
(iii)
Dimensional drawings giving details of masts, fixing arrangements of pipes on the switchyard structures, shield wires etc.
(iv)
Dimensional drawing of earthing electrodes and connections of the same to the direct-stroke lightning protection system.
13.0.0
(v)
Bill of materials.
(vi)
Other relevant data, information etc.
NEUTRAL GRONDING RESISTOR:
13.0.1
SCOPE:
13.0.1.1
This section covers Technical requirements of Neutral grounding resistor for 33/11Kv, 5 MVA Transformer.
13.0.1.2
Scope includes Design, manufacture, assemble, inspection, supply, Delivery at site, Installation, testing and commissioning (SAT) & final handover for operation with documentation.
13.0.2
SYSTEM PARTICULARS:
13.0.2.1
Power Supply (Primary side)
:
33 kV± 10%, 50 Hz ± 5%, 3Ph, 3 wire AC supply.
13.0.2.2
Fault Level
:
31.5kA for 3 Sec at 11 kV
13.0.2.3
Space heater supply
:
230 V ± 10%, 50 Hz ± 1%, 1
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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Phase, AC supply 13.0.2.4
Grounding Primary side
:
Not applicable
13.0.2.5
Grounding (11kV system)
:
Resistance grounding through NGR designed for 250 amps for 10 Sec
13.0.3.1
GENERAL REQUIREMENTS:
13.0.3.1
The NGR equipment shall be brand new with state of art technology and proven field track record.
13.0.3.2
Vendor shall ensure availability of spare parts and maintenance support services for the offered equipment at least for 15 years from the date of supply.
13.0.3.3
Vendor shall give a notice of at least one year to the end user of equipment before phasing out the product / spares to enable the end user for placement of order for spares and services.
13.0.4 13.0.4.1
SITE CONDITIONS: The Neutral Grounding Resistor shall be suitable for outdoor installation (without a shed) and for satisfactory operation under conditions of restricted natural air ventilation . The NGR shall be designed to operate under site conditions as specified in the data sheet. If not specifically mentioned therein, a design ambient temperature of 50C and an altitude not exceeding 1000m above mean sea level shall be considered.
13.0.5 13.0.5.1
13.0.5.1.1
NEUTRAL GROUNDING RESISTOR UNIT: RESISTOR:
The resistor elements shall be made of unbreakable, corrosion proof, joint-less stainless steel grids conforming to ASTM standard A240-304. The grids shall be in punched form.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 13.0.5.1.2
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Resistors shall be able to carry rated current specified in the data sheet for 10 seconds with maximum temperature limited to 790° for stainless steel elements, while limiting the temperature of Aluminium conductor /busbar to 350°.
13.0.5.1.3
If specified in the data sheets, the resistor shall also be sized to carry 10% of the rated current continuously with the maximum operating temperature of resistor elements limited to 415C. Further, the temperature rise of the resistor elements when they carry 10% of the rated current followed by the specified rated current for 10 seconds shall not exceed the temperature limits specified in clause 5.1.2 above. Under the steady state conditions when the NGR carries 10% of the rated current, the surface temperature of the enclosure, excluding the roof but including the separate canopy, shall be limited to maximum 70C.
13.0.5.1.4
Grids shall be mounted on steel rods insulated by special heat-resistant insulating materials, suitable for the above temperatures. Ceramic/ porcelain insulators shall be used to insulate the resistor elements from the enclosure. The insulators and terminal bushings shall have adequate minimum Creepage values (total and protected) for the required voltage grade.
13.0.5.1.4
Resistor banks shall be provided in series and parallel combinations to achieve the overall resistance value. Minimum two banks in parallel shall be provided in the system unless specified otherwise.
13.0.5.2
ENCLOSURE:
13.0.5.2.1 The resistor elements shall be housed in a naturally ventilated Galvanized sheet steel enclosure with minimum IP-31 degree of ingress protection and suitable for outdoor installation.
13.0.5.2.2 The enclosure thickness shall not be less than 3mm. The NGR shall have a suitable arrangement for fixing it on concrete foundations/ grouting in floor.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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13.0.5.2.3 The terminals for neutral and earthing connections shall be housed in a separate verminproof, weatherproof terminal box with minimum IP-55 degree of ingress protection. The terminal box shall be provided with a separate bolted removable undrilled gland plate of non-magnetic material. This shall be drilled at site to suit the cable entry. A nickel plated brass double compression cable gland of suitable size shall be provided along with the terminal box.
13.0.5.2.4 A separate canopy shall be provided above the enclosure roof with a suitable air gap between them. It shall also cover the terminal compartment. Hooks or handle shall be provided to lift the canopy.
13.0.5.2.5
It shall be possible to periodically clean the resistor elements and enclosure after removing the bolted side covers.
13.0.5.2.6
Facility shall be provided to earth the enclosure at two points. For this purpose, suitably sized studs shall be provided on the sides of the enclosure to accommodate the connection of copper /GI strip.
13.0.5.2.7
The bottom of the enclosure shall be suitably sloped and provided with a drain plug to remove water that may get collected in the enclosures.
13.0.5.3
TERMINALS:
13.0.5.3.1 The two ends of the resistor shall be brought to suitable porcelain bushing type terminals of adequate rating for the neutral and earth connections. The terminals shall be suitable for terminating the specified size of cables / earthing strip and shall be supplied complete with tinned-copper lugs. Bolted type link shall be provided for isolating the resistor at the neutral end. 13.0.5.3.2
Suitable washers shall be provided between the grid element ends and the terminals to maintain good electrical contact.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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13.0.5.3.3 The connection between the transformer neutral and the NGR shall be carried out by means of single core cable of size and type as specified in the data sheet.
13.0.5.3.4 The connection between the NGR and the earth pits shall be carried out using Copper /GI Earthing strip as specified in the data sheet.
13.0.5.4
SPACE HEATER:
13.0.5.4.1 A suitable anti-condensation space heater shall be provided inside the NGR enclosure to prevent condensation of moisture. This shall be rated to operate from a 240V, 50Hz single phase supply. The terminals of the space heater shall be brought out to a separate verminproof weatherproof terminal box. The terminal box shall have a minimum IP-55 degree of ingress protection and shall be complete with tinned copper lugs and nickel plated brass, double compression cable glands.
13.0.5.4.2
The space heater shall be controlled using a double pole switch, HRC fuse, neutral link and thermostat provided in the terminal box. The switch shall be operatable from the front of enclosure without opening the terminal box cover.
13.0.5.5
CURRENT TRANSFORMER:
13.0.5.5.1
The current transformer, if specified, shall be of cast resin type suitable for the applicable voltage grade and temperature conditions. The secondary connections of the current transformer shall be brought out to suitable terminals provided with a shorting link.
13.0.5.5.2
The CT shall be housed in a separate compartment and avoid locating in resistance box.
13.0.5.5.3
The CT terminals shall be wired in the terminal block with suitable gland plate for terminating the control cable.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 13.0.5.6 13.0.5.6.1
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COOLING: The Neutral Grounding resistor shall be air cooled. Forced cooling shall not be used. If required louvers can be provided in the enclosure provided they are completely guarded on the inside with a fine wire mesh.
13.0.5.7
13.0.5.7.1
NAMEPLATE MARKING:
The equipment shall be provided with a stainless steel nameplate located prominently indicating particulars such as make, tag number of the equipment, rating and other relevant details.
13.0.6 13.0.6.1
INSPECTION AND TESTING: The offered NGR shall have been suitably type tested and manufacturer shall furnish test certificates in this regard.
13.0.6.2
During fabrication, the equipment shall be subjected to inspection by owner or by an agency authorized by the owner. Manufacturer shall furnish all necessary information concerning the Equipment / owner’s inspector. Tests shall be carried out at manufacturer’s works.
13.0.6.3
The following tests shall be conducted:
a. Measurement of resistance value at prevailing ambient temperature by Kelvin Double Bridge. b.One-minute power frequency high voltage withstand test. c. Insulation resistance measurement, both before and after the power frequency high voltage test.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 13.0.7
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DOCUMENTATION:
13.0.7.1 Vendor shall submit the following documents for all equipment along with offer: a. Filled Technical Data Sheet b. Deviation List (if any) c. Proposed GA Drawing d. Type Test Certificate e. Tender Offers without the above information or with incomplete information are liable for rejection. 13.0.7.2 Vendor
shall submit the following documents for all equipment after award of job for
approvals: a. GA Drawing for Equipment. b. Installation detail. c. Calculation. d. Schematic Drawings. e. As Built Drawings. f. Single line diagrams. g. Operation & Maintenance Manual. h. Bill of material. i. Inter panel wiring diagram. j. Name plate diagram. k. All other handover documents as per QA/QC Document. .
14.0.0
BATTERY, BATTERY CHARGER & DCDB:
14.0.1
SCOPE:
14.0.1.1
This section covers Technical requirements of Battery, Battery charger & DCDB for 33kV switchyard.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.1.2
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Scope includes Design, manufacture, assemble, inspection (FAT), supply, Delivery at site, Installation, testing and commissioning (SAT) & final handover for operation with documentation.
14.0.2
SYSTEM PARTICULARS:
14.0.2.1
Power Supply (Primary side)
:
415V± 10%, 50 Hz ± 5%, 3Ph, 3 wire AC supply.
14.0.2.2
Fault Level
:
50 kA for 1 Sec at 415 V.
14.0.2.3
Space heater supply
:
230 V ± 10%, 50 Hz ± 1%, 1 Phase, AC supply.
14.0.3
14.0.3.1
SYSTEM CONCEPT:
Float Cum boost charger will have a ‘FLOAT/BOOST’ selector switch for selection of battery charging mode and an ‘AUTO/MANUAL’ selector switch for selection of battery charging mode.
14.0.3.2
Under normal conditions, the ‘AUTO//MANUAL’ selector switch shall be in ‘AUTO’ position. And the batteries in Float charging, the charging current of the battery shall be supplied by the charger which is continuously monitored. In case this current exceeds a certain value, the charger shall automatically switch over to ‘BOOST’ mode for charging at a higher rate. When the battery is fully charged, the charger shall automatically revert to ‘FLOAT’ mode.
14.0.3.3
In case the ‘AUTO/MANUAL’ selector switch is in ‘Manual’ mode, the battery float or boost charging shall be done manually depending on the requirement.
14.0.3.4
Battery Chargers will be suitable for continuous operation at AC voltage variation of +10%, frequency variation of+5% and combined voltage and frequency variation of +10%.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.3.5
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The 110V, DC battery bank shall be suitably sized considering load cycle requirements, Ageing factor of 1.2 and temperature correction factor for minimum ambient temperature of 22 degC will be taken into account.
14.0.3.6
The voltage at load terminal will not exceed the limits of +10% and –15% of nominal system voltage for 110V.
14.0.3.7
110V DC system shall be unearthed and relays shall be provided for sensitive earth fault detection and annunciation.
14.0.4
BATTERY CHARGER :
14.0.4.1
The battery charger shall be designed for charging the battery in float as well as boost modes and simultaneously supplying the load as per the requirement of the DC load. The charger shall consist of input switchgear, transformer, rectifier, regulator, output switchgear, metering and protective devices.
14.0.4.2
Float cum Boost charger circuit shall have IGBT as semiconductor devices.
14.0.4.3
The charger shall be provided with auto-changeover circuitry from float to boost and viceversa. The float circuit shall be designed for continuous load of 30A and the boost circuit shall be suitable for delivering charging current suitable for 110V, 100AH.
14.0.4.4
DC distribution board shall be of integral part of battery charger and incomer and outgoing feeders shall be provided as per SLD.
14.0.4.5
The charger shall be fabricated out of sheet steel and shall be free standing, floor mounting type painted in shade 631 of IS-5 Enclosure protection shall be IP42.
14.0.4.6
Semiconductors shall be liberally sized for forward current, minimum momentary overload and voltage spikes. Blocking diodes shall be fully rated and redundant so that failure of a single diode shall not incapacitate the system in any way.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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14.0.4.7
Converter unit shall be provided with surge protection and fast acting Semiconductor fuses.
14.0.4.8
Charger shall be self-protecting against all AC & DC transients and steady state abnormal currents and voltages.
14.0.4.9
Charger AC input and DC output shall be electrically isolated from each other and also from panel ground. The harmonics transferred to D.C. side or A.C. side should not exceed 1% (rms).
14.0.4.10
The rectifier transformer shall be dry type double wound with impregnated naturally air cooled, single / three phase transformer with taps in primary winding.
14.0.4.11
The charger shall be provided with automatic voltage regulation current limiting circuitry & soft start feature. Voltage control shall be step less smooth & continuous.
14.0.4.12
A reverse polarity protection is required to trip the main A.C. supply in the event of reverse connection of Batteries or D.C. Bus.
14.0.4.13
All control logic card components shall be selected for continuous operation at ambient temperature of 50°C. The control logic shall be mounted on plug in printed circuit board. All test points and LED's shall be mounted at the front of the board for easy fault identification. Printed circuit boards shall be so designed that wrong cards cannot be inserted in a module.
14.0.4.14
Mimic diagram with LED's shall be provided for ease of fault identification. Alternatively, annunciation with fault description shall be provided.
14.0.4.15
The electronic current limit circuitry shall be provided to give protection against overload currents by inhibiting the trigger pulses. It shall be designed such that under no circumstances the current will exceed a set limiting value. A maximum set limiting value must be maintained that the highest allowable virtual junction temperature never exceed the design temperature.
14.0.4.16
The Boost cum float charger shall be provided with annunciations like AC under Voltage, AC over Voltage, DC under Voltage and DC over Voltage characteristics
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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with audible and visual alarms. The following indicating meters shall be provided with AC input voltage and Current, DC output Voltage and current. Battery current with center zero ammeter.
14.0.5
EQUIPMENT CONSTRUCTION:
14.0.5.1
GENERAL:
14.0.5.1.1
The battery charger shall be suitable for indoor use. The enclosure shall be made out of sheet steel, free standing totally enclosed dust, damp & vermin proof with minimum degree of protection as specified in the Data sheet. Neoprene gaskets where required shall be used. Louvers if provided shall be backed by copper mesh. Lifting hooks (4 Nos.) shall be provided.
14.0.5.1.2
Painting shall be as per Manufacturer’s standard.
14.0.5.1.3
Panel shall be provided with panel lighting, space heater with controlling thermostat & receptacles.
14.0.5.1.4
All equipment and circuits shall be arranged so as to facilitate ease of operation and maintenance and at the same time ensure necessary degree of safety.
14.0.5.1.5
Switches shall be air break type suitable for load break duty with quick make and break action. It shall be two pole type and all contacts shall be silver plated. Key lockable arrangement shall be provided in 'OFF' position.
14.0.5.1.6
Fuses & fuse fittings shall be HRC type links & phenolic moulded base with visual indication for fuse failure & external trip alarm.
14.0.5.1.7
MCB shall be quick make - quick break trip free current limiting type with thermal & magnetic releases. It shall have minimum rupturing capacity of 9 kA.
14.0.5.1.8
The magnetic contactors shall be IEC rated. 1 NO + 1 NC contacts shall be wired to terminal for purchaser’s use.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.5.1.9
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Indicating lamps shall be of low power consumption type with translucent Lamp louvers. Lamps shall be supplied complete with necessary current limiting resistor.
14.0.5.1.10
Selector switches shall be panel mounting type with maintained contact of 10A, 220V rating.
14.0.5.1.11
Power wiring from battery charger to battery shall be by means of single core copper conductor, PVC insulated cable of 1100 V grade.
14.0.5.1.12
Colour coding shall be followed for power cables / control cables, Red for positive, Black for negative, grey for control cables.
14.0.5.1.13 Terminal blocks shall be of 1100 V grade and bolted type/ clamped type. All live potential wires, terminals etc. shall be protected by insulating barriers. The terminals shall be suitable for solder less, crimp type, tinned copper lugs. The terminals shall be adequately rated to carry the current of associated circuit. Terminal blocks shall be numbered with identification strips. 20% spare terminals shall be provided. 14.0.5.1.14 Ground bus shall be provided throughout the panel length with nut bolts & washers for external connections. Permanent grounding of frames, doors and other metal parts of switchgear should be provided by two independent connections with the ground busbar by min. 2.5 sq. mm copper conductor wire PVC insulated and of green colour. 14.0.1.15
Name plate shall be made out of non-corrosive material with black letters on white background and fixed with screws. This shall include the name of the board, item number and rating. All the indicating lamps, meters, switches shall have labels.
14.0.1.16
Caution name plate, labels stating live terminals / bus bars shall be provided for incoming supply and on busbar chambers.
14.0.6
PROTECTION, ALARMS & ANNUNCIATION:
14.0.6.1
Battery charger Equipment shall be fully protected from downstream faults.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.6.2
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All faults shall be alarmed. The status of the alarm and protection functions shall be visually verifiable by clear and unambiguous indicators and be provided with two voltage-free changeover contacts wired to a terminal strip for remote monitoring.
14.0.6.3
Alarms associated with trip functions shall be hand reset only.
14.0.6.4
As a minimum the Battery charger Equipment shall be furnished with the following protection functions. a) Earth fault protection. b) Over current protection. c) Under voltage. d) Over Voltage.
14.0.6.5
All the alarm contacts shall also be wired to the Spare terminal box for taking to remote as an individual alarm or as a group alarm.
14.0.6.6
Visual annunciation shall be provided to indicate the abnormal operating conditions of the charger by the means of facia windows arranged on the top of the charger panels. The following lamp fascia indication shall be provided in the float and boost charger panels: i)
DC system earth fault
ii)
Rectifier fuse blown
iii)
DC output fuse down
iv)
Charger over loaded
v)
AC supply unhealthy
vi)
DC system under voltage & over voltage
vii)
Battery on boost mode
viii)
Battery fuse blown
14.0.8
BATTERY:
14.0.8.1
GENERAL:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.8.1.1
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Battery cells forming part of the Battery Charger Equipment shall be of Lead acidVRLA batteries in accordance with IEEE 485.
14.0.8.1.2
The battery Ampere hour shall be such as to fulfill the load input power requirements when the Battery Charger Equipment is delivering its rated AH output.
14.0.8.1.3
The nominal ampere-hour capacity of the battery supplied with the Battery Charger Equipment shall include the necessary allowance for ageing and temperature effects, which result in a progressive loss of capacity (non-recoverable losses). New battery capacity shall not be less than 120% of the nominal ampere-hour capacity and end of life capacity of the batteries shall not be less than 95% of the nominal amperehour capacity required to fulfill the performance criteria specified.
14.0.8.1.4
In addition the Vendor shall ensure the battery bank is capable of performing a complete repeat duty at rated load immediately.
14.0.8.1.5
The Vendor shall provide calculations to support battery sizing.
14.0.8.1.6
The batteries shall be located on free-standing support racks. The shall be made of MS frame and it shall be coated with anti-corrosive paints
14.0.8.1.7
Vertical separation between layers shall be sufficient to permit free and safe access for cell measurements and/or replacement.
14.0.8.2
CONSTRUCTION:
14.0.8.2.1
Each cell shall be assembled in heat resistant, shock absorbing, robust hard rubber / plastic container complete with all accessories.
14.0.8.2.2
Tin plated copper connectors shall be used. The connector covers shall be of hard PVC to prevent external short circuiting.
14.0.8.2.3
Separator used for the cells shall be porous alkali resistant and high insulating capacity to avoid shorting on leakage of the current between the plates of opposite polarity.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.8.2.4
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There shall be provision for automatically disconnecting the battery bank from load whenever the battery bank voltage reaches the permissible low voltage level. It shall be independent of battery charging circuit with an alarm contact.
14.0.8.3
BATTERY MONITORING&TESTING:
14.0.8.3.1
Battery Charger Equipment shall be provided with an online battery monitoring facility capable of assessing overall battery condition under normal operating conditions and providing an alarm when this falls outside prescribed limits.
14.0.8.3.2
The monitoring facility shall also measure voltage levels of blocks of VRLA cells within a battery and shall alarm at a pre-set voltage level (high and low) to indicate under performance of a particular block of cells.
14.0.9
D.C. DISTRIBUTION BOARD:
14.0.9.1
D.C. Distribution boards shall be integral part of battery charger assembly.
14.0.9.2
All incoming feeders are of fixed type MCCB’s and outgoing are MCBs as shown in the attached SLD.
14.0.10
INSPECTION & TESTING:
14.0.10.1
Equipment shall be tested and Inspected at manufacturer’s works before dispatch to ensure compliance with relevant specifications, drawings, codes & standards.
14.0.10.2
All routine tests as specified by the applicable standard codes shall be conducted. Type test certificates from recognized organization shall be furnished with the bid.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 14.0.10.3
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All acceptance and routine tests as stipulated in the relevant standards shall be carried out in presence of Client or their representatives.
14.0.10.3.1 Client or their representatives may visit the works during manufacture of various equipment to access progress of work as well as to ascertain the Quality of raw materials used.
14.0.11
DOCUMENTATION:
14.0.11.1
Vendor shall submit the following documents for all equipment along with offer: a. Technical Data Sheet b. Deviation List (if any) c. Proposed GA Drawing d. Type Test Certificate
14.0.11.2 Vendor
shall submit the following documents for all equipment after award of job for
approvals: a. Manufacturer catalogue in English language. b. GA Drawing for Equipment. c. Installation detail. d. Calculations. e .Schematic Drawings. f. As Built Drawings. g. Single line diagrams. h. Operation & Maintenance Manual. i. Bill of material. j. Inter panel wiring diagram. k. Name plate diagram.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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15.0.0
MARSHALLING BOXES:
15.0.1
SCOPE:
15.0.1.1
The types and ratings of the outdoor type marshaling boxes for auxiliary and control supplies connections of the various equipment to the secondary terminals of PT’s and CT’s to be provided are specified in this sub-section.
15.0.2
CONSTRUCTION DETAILS:
15.0.2.1
The marshaling boxes shall be outdoor type, suitable for installation and operation in humid,
dusty and tropical atmosphere with seasonal spells of dry and dusty or humid
and raining conditions. 15.0.2.2
Each Ac/dc MB for aux. power and dc control supply distribution shall have three distinctly separate compartments for the following applications. a. For receiving 110 V dc supply and its distribution to the various equipment’s in the switchyard. b. For receiving 415 V ac supply and its distribution to the various equipment’s in the switchyard. c. For housing terminal blocks in vertical formation required for connections in the control circuits for interlocking operation of various equipment’s in the 33 kV switchyard.
15.0.2.3
The terminals shall be stud type with two nuts per stud and suitable for 650 volt service and for taking 2.5 to 10 sq.mm. Copper conductors or equivalent Aluminium conductors. The terminals shall be so arranged that connections of external cables to any terminal block are possible without disturbing any of the other connections and shielding the identification markings. The terminal blocks arrangements which permit max. Access to all conductor terminations and do not obstruct access to the other terminals shall only be accepted.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 15.0.2.4
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The terminal blocks shall be made of non-inflammable, molded resin bases with integrally molded barriers and brass inserts and shall be provided fully enclosed with removable transparent covers. A white marking strip shall be provided on each block for circuit identification. All terminals shall be clearly marked with identification numbers or letters to facilitate making connections correctly.
15.0.2.5
The terminal blocks shall have provision for visible isolation. The terminals in the terminal blocks shall have provision for insertion of banana contacts for testing purposes.
15.0.2.6
All wires to the terminal blocks shall be terminated with terminal lugs. Such washers/ lugs shall be supplied 20% extra over the actual requirements.
15.0.2.7
The design of MB shall be such that it is possible to safely connect or disconnect terminals on live circuits and replace fuse links even
15.0.2.8
when the box is live.
Cable glands for all incoming and outgoing cables shall be provided at the bottom of box and rigidly fixed to box frame work.
15.0.2.9
The switches with HRC fuses/MCB's of appropriate ratings shall be provided for control and protection.
15.0.2.10
Adequate space heaters and lamps shall be provided in the MBs.
15.0.2.11 The terminal blocks in the MBs for instrument transformers shall have facility for easy earthing, shorting, isolating and testing of secondary circuits. Secondary terminals of the three phases of each set of instrument transformers shall be connected to adjacent terminals in the respective MBs.
15.0.3
ENCLOSURE:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 15.0.3.1
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Each MB shall have an enclosure conforming to the provisions of the latest version of IS: 5039 and be provided with two (2) lifting lugs.
15.0.3.2
Each MB shall have a set of double hinged doors with suitable locking arrangements.
15.0.3.3
The MB shall be well-ventilated, vermin proof and weather proof. It shall have a domed or sloping roof.
15.0.3.4
MBs shall be provided with aprons which shall extend from the lower edge of the doors to the level of mounting feet.
15.0.3.5
Each MB shall be self-supporting and provided with appropriate number of foundation bolts for fixing on it.
15.0.3.6
If the equipment within the MB is not easily accessible from ground level, the foundations of MBs shall be so designed that a person can stand on the foundation for operating the equipment.
15.0.4
CORROSION PROOFFING:
15.0.4.1
All parts subject to corrosion shall preferably be hot double-dip galvanized after a rigorous surface treatment to remove all rust, scales, foreign adhering matter, grease etc.
15.0.4.2
The parts which cannot be hot-dip galvanized shall be painted with epoxy based paint suitable for use in corrosive environments. The paint inside the cabinet shall be of anti-condensation type. All paints shall be carefully selected to withstand the heat and extremes of weather. The paint shall not scale off or crinkle or get removed by abrasion due to normal handling.
15.0.5
DOCUMENTATION:
15.0.5.1
Vendor shall submit the following documents for all equipment along with offer: a.
Guaranteed technical particulars of all types of marshaling boxes.
b.
Typical general arrangement drawings of proposed marshaling boxes showing their interior and exterior views.
c. 15.0.5.2
Vendor
approvals :
Type test certificates.
shall submit the following documents for all equipment after award of job for
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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a.
Final data sheets.
b.
Dimensional general arrangement drawings of each type of marshaling box.
c.
supporting structure drawings.
d.
Foundation plans and load data relevant to civil foundation design.
e.
Circuit diagrams.
f.
Site erection drawings.
g.
Bill of material.
h.
Other relevant data, information etc.
16.0.0
POWER & CONTROL CABLES:
16.0.1
SCOPE:
16.0.1.1
The types, ratings and approximate quantities of the various Control Cables to be provided are specified in this sub-section.
16.0.2
CABLES:
16.0.2.1
The control cables shall be 1100 V grade, multi-core, having tinned, annealed, stranded copper conductor, PVC insulated, colour coded, PVC sheathed, galvanized single round steel wire/strip armored, extruded LSOH type.
16.0.2.2
The control cables shall have 3, 5, 10, 19 cores with conductors having cross sectional area of 2.5 and 4 core for 6 sq.mm.
16.0.2.3
Screened control cables shall be used wherever required.
16.0.2.4
The exact lengths and number of terminations of the different sizes of cables in various types shall be worked out by the Contractor for payments as per actuals.
16.0.2.5
The cables shall be tested at the works and at site after installation as per the applicable specifications/standards.
16.0.3
INSTALLATION OF CABLES:
16.0.3.1
The Contractor shall prepare cable schedules for all the cable circuits associated with the equipment in 33 kV switchyard showing length, size and routing of each cable which shall be given suitable code numbers and submit the same for the purchaser's/Engineer's
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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approval. Cable and Conduit laying shall be done strictly in accordance with the approved cable schedules.
16.0.3.2
The control cables in the outdoor area shall be laid in conduits, concrete pipes, ducts, trays or cable trenches unless indicated otherwise. Cables shall be cleated to the cable tray after properly dressing the angle supports.
16.0.3.3
Ducts shall be provided wherever cable trenches cross roads and railway tracks.
16.0.3.4
All civil works, viz, excavations, sand cover, providing brick cover on directly laid cables, construction of foundations, trenches with cable tray supports, cable ducts under roads, back filling, finishing associated with cabling work shall be included.
16.0.3.5
The Contractor shall supply and install all the surface mounted/ embedded, rigid and flexible conduits, their connections, and associated clamps, bushings, lock-nuts, caps etc required in the cabling work.
16.0.3.6
All conduits shall be made of PVC pipe with threads as per BIS Specifications. The internal bore of all pipes shall be smooth and suitable for pulling PVC sheathed cables without damage. All conduit accessories shall be galvanized.
16.0.3.7
The Contractor shall supply all fittings including inspection and ordinary tees and elbows, check nuts, male and female fittings, pull boxes, junction boxes, conduit outlets, outlet boxes, splice boxes, terminal boxes, gaskets and box covers, saddles and all supporting steel work and all such arrangements which are required to complete the conduit installations.
16.0.3.8
Contractor shall supply and install cable, cable trays and accessories, supporting brackets, hangers and all other miscellaneous materials required to make a complete cable tray installation in the cable space below the control, relay and metering panels, in the control room. The arrangement of the cables and their supports in the control room cable space shall be subject to approval of the Purchaser/Engineer.
. 16.0.3.9
All the apparatus, connections and cable work shall be designed and arranged to eliminate the risk of fire and minimize damage which might be caused in the event of fire. Wherever
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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cables pass through floor or wall openings or other partitions, suitable bushes of approved type shall be supplied and put in position by the Contractor.
16.0.3.10
Standard cable grips, reels and rollers shall be utilized for cable pulling.
16.0.3.11
Each cable shall be provided with a metallic or plastic tag of an approved type, bearing cable reference number indicated in the cable schedule prepared by the Contractor, at every 10 metre run and at both ends of the cable, adjacent to the terminations as well as where cables enter or leave ducts. Cable routing shall be so done that cables are accessible for identification and maintenance easily, and are arranged neatly.
16.0.3.12
In no case the cables shall be bent sharply or kinked with the radius of bending falling below 10D where D is the overall diameter of the cable.
16.0.3.13
wherever cables cross roads, water, oil, sewage or gas-lines, special care shall be taken while designing the trenches/ducts for protection of the cables.
16.0.3.14
In each cable run, some extra length shall be provided at a suitable location to enable making of one or two straight-through joints for carrying out repairs if the cable develops fault at a later date.
16.0.3.15
Cable splices shall not be permitted except where called for as per the construction drawings, or where permitted by the Engineer. Straight-through joints in the run of cables wherever unavoidable shall be through joint-boxes.
16.0.3.16
The termination of cables at the various equipment shall be carefully made in accordance with the manufacturer's instructions and detailed connection diagrams.
16.0.3.17
Termination materials for all cables shall match with the type of cable insulation and have thermal and electrical ratings and chemical properties similar to those of the associated cable.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 16.0.3.18
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All terminating materials except for those already supplied with the electrical equipment shall be provided by the Contractor.
.
16.0.3.19
Control cable terminations shall be made in accordance with the colour code marked wiring diagrams of control circuits. Multi-conductor control cable jackets shall be removed as required to terminate the conductors. The cable jacket shall be left on the cable, to the extent possible. The insulated conductors from which the jacket is removed shall be neatly trained in bundles and terminated. The bundles shall be firmly, but not tightly, tied utilizing plastic or nylon ties or specially treated fungus-proof cord.
16.0.3.20
Jointing of cables shall be made in accordance with the applicable Bureau of Indian Standards Code of practice and manufacturer's special instructions. The materials and tools required for cable jointing work shall be in the Contractor's scope.
16.0.3.21
The design of joint boxes shall be such that it ensures higher actual insulation strength between phases and to earth than that obtaining in associated cable and eliminates any possibility of moisture entering the joint.
16.0.3.22
The supply of joint boxes shall include all hardware fittings, compounds, tapes and other materials required for making the joints.
16.0.3.23
Special tools, clips and saddles, glands, seals, PVC sealing compound, locknut, etc, required for connection and termination of cables shall be in the Contractor's scope.
16.0.3.24
All cables shall be megger-tested before jointing. After jointing is completed all L.V cables shall be megger-tested. Cable cores shall be tested for: a. Continuity b. Absence of cross-phasing c. Insulation resistance to earth d. Insulation resistance between conductors
16.0.4
CABLE TRAYS, ACCESSORIES AND TRAY SUPPORTS
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 16.0.4.1
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Cable trays shall be run either in concrete cable trench or overhead supported from building steel, floor slab, etc.
16.0.4.2
Cables shall be clamped to the cable trays in the horizontal runs with 18 gauge GI wires.
16.0.4.3
All cable trays including perforated sheet trays, weld mesh trays, Shall be hot-dip galvanized.
16.0.5
CONDUIT, PIPES AND DUCTS
16.0.5.1
The Contractor shall supply and install conduits pipes and ducts where necessary.
16.0.5.2
The conductors carrying ac and dc supplies shall not be bunched together in a conduit.
16.0.5.3
Flexible metallic conduits shall be used for termination of connections to equipment such as motors or other apparatus to be disconnected at periodic intervals and also for termination of connections to level switches, limit switches, pressure switches etc.
16.0.5.4
In order to minimize condensation or sweating inside the conduit, all outlets of the conduit system shall be properly drained and ventilated so to prevent entry of insects and water as far as possible.
16.0.5.5
The conduits or pipes shall be run along walls, floor and ceilings, on steel supports, embedded in soil, floor, wall or foundation, in accordance with the relevant layout drawings, approved by the Purchaser.
16.0.5.6
The conduits shall be lead into terminal boxes through the entry points provided by the equipment manufacturers unless otherwise shown in the drawings or unless otherwise directed by the Engineer.
16.0.5.7
Exposed conduit shall be adequately supported by racks and clamps or straps or by other approved means.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
16.0.5.8
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Where conduits are stubbed out of masonry for future extension outside the structure, they shall be specially protected against corrosion and shall be boxed in against possible physical damage.
16.0.5.9
Each conduit run shall be marked with its designation as indicated on the drawings - 'Identification'.
16.0.5.10
Where conduit and boxes in locations of severe exposure require, painting of galvanized surfaces with alkyd resin zinc dust paint following by a finish coat of aluminium paint, shall be performed by the Contractor in a good and approved manner.
16.0.5.11
The Contractor shall be responsible for bonding of metal pipes or conduits in which cables have been installed to the main earthing system.
16.0.5.12
The conduits and accessories shall be adequately protected against mechanical damage as well
as corrosion.
17.0.0
SWITCHYARD ILLUMINATION SYSTEM:
17.0.1
SCOPE:
17.0.1.1
The illumination system complete in all respects to be provided in the 33 kV switchyard is specified in this sub-section.
17.0.2 17.0.2.1
ILLUMINATION LEVEL AND OTHER DESIGN REQUIREMENTS: The average illumination levels shall be as specified below.
i.
Switchyard
:
30 LUX
ii.
Roads within switchyard
:
30 LUX
iii.
Fencing around the switchyard
:
30 LUX
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
17.0.2.2
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The illumination level of specific spots like operating mechanisms of circuit breakers, isolators, and oil level and temperature gauges, gas pressure & density meter etc. shall be about 30 Lux.
17.0.2.3
The tenderer shall include in his offer light fittings of standard makes like Philips/Crompton/Bajaj or equivalent. Light fittings to be supplied by the Contractor shall be subject to approval by the Purchaser/Consulting Engineer.
17.0.2.4
Complete design calculation sheets for arriving at the number and type of luminaries required for the normal and emergency requirements shall be furnished by the Contractor. Design calculation sheets for the selection of cables, MCB, HRC fuses, bus bars, etc. are also required to be furnished for purchaser's approval.
17.0.2.5
The illumination system load in the switchyard area shall be supplied from 415/240 volt LDBs to be provided in the switchyard control room. Requisite numbers of 3-phase, 4-wire, cable circuits for illumination system shall be extended from the above board. The laying of cables from the Board to the illumination system and their installation are included in the scope of this section.
17.0.2.6
Each outgoing cable circuit for illumination loads from the 415 volt switchboard shall terminate in the respective junction boxes located in the switchyard.
17.0.2.7
Complete manufacturer's literature/catalogues, performance curves, illumination distribution curves, G.A. drawings, specification sheets, etc. as relevant in respect of all materials/equipment to be supplied shall be submitted by the tenderer to enable the purchaser to make an assessment of the quality and technical suitability of the offered materials/equipment.
17.0.2.8
After completion of installation of the illumination system in the switchyard, the actual illumination level at different locations shall be measured by the Contractor in the presence of purchaser's authorized representative.
17.0.3
JUNCTION BOXES FOR NORMAL ILLUMINATION SYSTEM:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 17.0.3.1
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Distribution junction boxes of adequate dimensions shall be constructed from sheet steel having a Thickness not less than 2 mm. The JB shall be totally enclosed weather proof, dustproof, vermin proof, having hinged doors with locking arrangement and shall be capable of being mounted in the Switchyard. The JB suitable for cable entry at the bottom shall be designed for easy access of Connections to terminals and inspection of equipment mounted therein. The JB to be supplied shall be Subject to approval by Company.
17.0.4 17.0.4.1
CABLES: The cables shall be 1.1 kV grade with stranded Aluminium conductors, PVC insulated and
PVC sheathed, galvanized steel strip armoured or unarmoured conforming to the relevant Indian Standard specifications. 17.0.4.2
Sub-circuit cables shall comprise PVC insulated stranded Aluminium conductors.
17.0.4.3
The sizes of the cables supplied by the Contractor shall be adequate for the various applications from the considerations of voltage regulation and current carrying capacity and shall be subject to approval by the Purchaser.
17.0.4.4
The following factors shall be kept in view while designing the electricity distribution networks for i.
illumination system:
System voltage and type of system
ii. Conditions of installation iii. Maximum continuous current expected iv. Voltage regulation permissible as per I.E. Rules v. Expected short circuit level of the lighting system
17.0.5
LUMINAIRES: Luminaries for use in normal illumination systems in the new switchyard shall be Philips MWF 330,250W, CL 1 XHPI T 250 W.
17.0.6
MOUNTING ARRANGEMENT:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 17.0.6.1
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The flood light luminaries in the switchyard shall be fixed at suitable height on the switchyard structures, so as to provide the specified average illumination in the switchyard area without causing any glare to the operational/ maintenance staff working in the 33 kV switchyard. While fixing the luminaries it shall be ensured that the stipulated electrical clearances in the specification are not violated. The Contractor shall supply and install suitable type of pole structures, required for installing the fittings for illuminating the roads, fence etc.
17.0.6.2
Switchyard lighting circuits in the switchyard shall be divided into two or three sections and provided with time switches of suitable ratings.
17.0.6.3
Lighting pole shall be earthed with 20 mm dia, 3 meter long G.I pipe.
17.0.7
DOCUMENTATION:
17.0.7.1
Vendor shall submit the following documents for all equipment along with offer: a.
Guaranteed Technical Particulars of all the items constituting the switchyard illumination system offered.
b.
General Arrangement drawing showing locations of luminaries, conduit and cable routes, illumination pillars, welding socket outlets, distribution board etc.
c.
Single line diagram showing power supply network for normal illumination system in the switchyard.
17.0.7.2
Vendor
d.
Type-test certificates for all the types of fittings, pillars, panels etc offered.
e.
Catalogues, performance curves, illumination distribution curves, etc.
shall submit the following documents for all equipment after award of job for
approvals : a.
Final data sheets.
b.
Calculations showing availability of the specified illumination levels in the
various areas of switchyard from the proposed lighting system. c.
Dimensional drawings showing the final locations of luminaries, cable routes, pillar/board locations etc.
d.
Calculations showing adequacy of the proposed cable sizes.
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e.
Cable schedule.
f.
Other relevant information/data, instruction books for pre-commissioning,
testing operation, maintenance etc.
18.0.0
SCADA:
18.0.1
SCOPE:
18.0.1.1
The SCADA system completes in all respects to be provided in the 33 kV switchyard is specified in this sub-section.
18.0.2 18.0.2.1
SCADA CONTROL: A supervisory control and data acquisition (SCADA) shall be provided for implementing
a. control, monitoring & interlocks for 33KV switchyard. b. SCADA will also help with built in function of sequence of event recording. c. mimic diagram complete with status equipment and analogue value like voltage, current, MW, MVAR, frequency etc. 18.0.2.2
SCADA system together with One (1) no CRT/Keyboard operator terminal along with remote terminal unit (RTU) shall be located in 33 KV switchyard control room room. Field inputs from different equipment located in switchyard area are received in I/O processing unit (RTU). Signal from RTU are transmitted to high speed data highway through redundant communication controller and received at the HMI unit of SCADA for further monitoring and control. Consoles at the operator stations and engineer’s station are provided with CPU, colour VDU with keyboard, track ball / mouse, printers and interface for control, alarm and data acquisition of the equipment / system in switchyard. Monitoring and control of feeders will be from human machine interface (HMI) of SCADA system.
In addition to SCADA control, a hardwired control panel is also envisaged as
detailed elsewhere in this document..
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 18.0.2.3
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Fiber optic cable shall be used for ensuring connectivity between plant controlroom and switchyard control room.
18.0.2.4
Protective relay shall be multifunctional numerical communicable type.
18.0.2.5
Numerical relays shall be finally connected to network along with communicable meters to electrical SCADA system. All conventional power cable shall be armored LSOHtype.
18.0.2.6
The distribution recorder which is in built in numerical relays shall be finally connected to the SCADA system for archiving and historical storage.
18.0.2.7
The SCADA system will also function as a data acquisition system for all the feeders. The SCADA will also store and log information. The information useful for maintenance planning will be compiled by SCADA system. This will include for example equipment outage time, number of routine outages, number of tripping etc. SCADA system will assist the operator by ensuring proper interlocking and by promoting for the next step in a sequence of steps.
19.0.0 19.1.0 19.1.1
SWITCHYARD CIVIL WORKS : INTENT: The intent of this specification is to provide the information for the 33 kV switchyard civil works viz leveling, civil foundation for power transformer, Fire protection walls, fencing, &cable trench .
19.2.0 19.2.1
DETAILED SCOPE OF WORK: Foundations for switchyard structures, Switchyard equipment supporting structures & their control cubicles, bus post insulator, and lightning mast etc.
19.2.2
Foundation for
power transformers including soak pit underneath transformers & their
cooling banks, R.C.C central oil collecting pit and oil & rain / emulsifier, drainage arrangement from transformer soak pits to central oil collecting pit including laying of all necessary R.C.C pipes of class NP-2 and construction of manholes, as required &
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approved by the purchaser. The scope shall also include the construction of R.C.C baffle/fire protection walls between transformers as per statutory requirements.
19.2.3
R.C.C cable trenches of various sizes with removable type of R.C.C pre-cast covers including edge protection angles in cable trenches, inserts plate for cable tray supports etc. The scope shall also include designing and providing suitable arrangements for cable duct bank at the crossing of roads.
19.2.4
Suitable water drainage arrangement from cable trenches shall be provided by providing slope along the length of cable trenches and by providing sumps of suitable capacities at required locations for collecting water from cable trenches.
19.2.6
The final grading & metal spreading of the switchyard including anti-weed treatment. This work shall be carried out after all foundations and underground works like cable trenches, drains etc. have been completed. The final grading shall include spreading of metal layer after giving anti-weed treatment to the soil underneath these layers.
19.2.7
The complete storm water drainage for the switchyard including all siphons, R.C.C pipe culverts, R.C.C box culverts etc. required for drainage at cable/pipe trench crossings. The scope shall also include the connection of the switchyard drainage with the natural drainage.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
19.3.0
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EXCAVATION AND FOUNDATIONS FOR STRUCTURES: The sub-station structures shall be hot dip MS structures. The foundations of main structures are stub type and other structures are foundation bolt type.
19.3.1
EXCAVATION:
19.3.1.1
Specification shall cover excavation for structures, foundations, trenches, drain channels, and underground facilities and Fire protection walls as shown in the approved drawings and as specified. Earth excavation has to be done in all types of soils which can be excavated with pick axe & crow bars in all conditions such as dry, wet, slushy etc., and in hard rock
Requiring blasting including shoring, shuttering and dewatering wherever necessary covering initial lead and one extra lift.
19.3.2
FOUNDATION CONCRETE:
19.3.2.1
GENERAL REQUIREMENTS: All materials, tests, mixing, placing, formwork, reinforcing and workmanship shall conform to IS: 456-2000 “Code of practice for Plain and Reinforced Concrete for general building construction” and other relevant Indian Standard codes.
19.3.2.2 NOMINAL MIX AND DESIGN MIX: Nominal Mix. Of M20 (Design Mix) and above shall be provided for RCC works. The mix proportions for all grades of concrete shall be designed to obtain strengths for respective grades of concrete.
Preliminary tests as specified in the IS: 456 and required by the purchaser, shall be carried out sufficiently ahead of the actual commencement of the work with different grades of concrete made from representative samples of aggregates and cement expected to be used on the job
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to ascertain the ratios by weight of cement to total quantities of fine and coarse aggregate and the water cement ratio required to produce a concrete of specified strength and desired workability.
Concrete shall be either ordinary or controlled and in grades designated M-10 and M-20 as specified in IS: 456 (latest edition). In addition, The nominal size of stone aggregate for RCC shall be 20mm or downgraded unless otherwise specified. However the nominal size of stone aggregate for PCC shall be 60mm downgraded.
19.3.2.3 ORDINARY CONCRETE: Ordinary concrete is recommended only when accurate control is impracticable and not necessary. However, ordinary concrete shall be used only in the lean concrete wherever allowed.
If ordinary concrete made in accordance with the proportions given in IS: 456 for a particular grade does not yield the specified strength and fails to satisfy the requirements of 'Acceptance Criteria' as specified in IS: 456, the cement content shall be increased as directed by the purchaser to obtain a specified strength at no extra cost. This shall not however be classified as a higher grade on the ground that the test strengths were found higher than the minimum specified.
19.3.2.4 CONTROLLED CONCRETE: Controlled concrete shall be used on all concrete works, except where specified otherwise. Controlled concrete for use in plain and reinforced concrete structures shall be in grade M20.
19.3.2.5 MIXES DESIGN CRITERIA:
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TECHNICAL SPECIFICATION – 33kV SWITCHYARD
Concrete mixes will be designed keeping the following considerations in view. •
Consistent with the various other requirements of the mix, the quantity of water should be kept at the lowest possible level.
•
The nominal maximum size of coarse aggregate shall be as large as possible within the limits specified.
•
The various fractions of coarse and fine aggregates should be mixed in such a proportion as to produce the best possible combined internal grading giving the densest and most workable mix.
•
The finished concrete should have adequate durability in all condition, to withstand satisfactorily the weather and other destruction agencies that it is expected to be subjected to in actual service.
•
Concrete shall be thoroughly mixed to a uniform consistency in the mixing machines of approved types.
Mixing shall continue until the cement is thoroughly
distributed throughout the mass, and shall last at least two minutes or for 80 turns of the mixer after the whole of the water has been added. Any concrete
showing signs
of initial setting before being deposited shall not be used in the works and shall be removed from the site. •
The concrete shall be discharged from the mixer on to a level watertight platform or floor or into a water tight receptacle. Normally hand mixing of concrete will not be allowed but where the total quantity of concrete is considerably small, the mixing may be done by hand subject to the approval and entirely at the discretion and satisfaction of the Engineer.
19.3.2.6
REINFORCEMENT:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 19.3.2.6.1
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Cold twisted and deformed bars as high yield strength deformed steel confirming to IS: 1786(Latest), plain hard drawn steel wire fabric etc. will be used as reinforcement.
19.3.2.7
CONVEYANCE OF CONCRETE:
19.3.2.7.1
The concrete shall be conveyed from the mixer to its place in the works as rapidly as possible and in such a manner that there shall be no separation or loss of the ingredients. In no circumstances shall more than half an hour lapse between the time when water is added to the mix and the time when the concrete is finally consolidated in position. Concrete distributing chutes shall not have inclination of more than 45degrees from the horizontal. In no case shall concrete be dropped from barrows or otherwise from a height of more than one and half meters.
19.3.2.8
DEPOSITING CONCRETE:
19.3.2.8.1
Before any concrete is put in, any filling of pockets or trimming the sides where found necessary to suit the level and line of the concrete to be laid shall be carried out. Unless otherwise approved, concrete shall be placed in one operation to the full thickness of members.
19.3.2.9
CONSOLIDATING CONCRETE:
19.3.2.9.1
After concrete has been placed, it shall be spread, if necessary and thoroughly compacted by approved mechanical vibration to maximum subsidence without segregation and thoroughly worked around shape. To secure maximum density and eliminate formation of air pockets, the concrete shall be thoroughly vibrated and worked around all reinforcement, embedded facilities and into corners or forms during and immediately after placing. Mechanical vibrators conforming to IS: 2505, IS: 2506, IS: 2514 and IS: 4656 (all latest edition) shall be used for this purpose. The extent of vibration shall be through the entire depth and width of each new layer. Duration of vibration shall be sufficient to accomplish thorough compaction and complete embedment of reinforcement. Excess cement paste thus formed at the top of each layer
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shall be removed before the succeeding layer is deposited. Vibrators shall not be used for pushing concrete into adjoining areas. In thin members with heavy congestion of reinforcement or other embedment, where effective use of internal vibrator is, doubtful, in addition to immersion vibrators, form vibrators conforming to IS: 4656 may be used. For slabs and other similar structures, screed vibrator as per IS: 2506 shall be used. Hand tamping may be allowed in rare cases, subject to the approval of the Engineer. Care must be taken to ensure that the inserts, fixtures, reinforcement and formwork are not displaced or distorted during placing and consolidation of concrete.
19.3.2.9.2
Immersion type vibration shall be provided at the rate of at least one 65 mm unit per cu.m. Per hour together with at least one stand by vibrator of the appropriate size. Vibrators shall be inserted in the concrete at a sufficient number of places so that their fields of influence overlap and shall not be used to work the concrete along with forms or screeds. Where electrically operated vibrators are used, diesel or petrol driven stand by vibrators shall be available for carrying on uninterrupted vibration in case of a power failure.
19.3.2.9.3
Concrete to be vibrated shall be placed in level layers of suitable thickness not greater than the effective length of the vibrator needle. The internal vibrator shall not be used to spread the concrete for filling.
It is advisable to deposit concrete well in
advance of
the point of vibration. When the concrete is being continuously deposited to a uniform depth along a member, vibrator shall not be operated too near to the free end of the advancing concrete, usually not within 1.20 meters of it. Every effort shall be made to keep the surface of the previously placed layer of concrete alive so that the succeeding layer can be amalgamated with it by vibration process.
Following points
shall be kept in mind while vibrating concrete.
•
The concrete shall be placed in shallow layers consistent with the method being used
to place and vibrate the concrete.
Usually concrete shall be placed in
thickness not more than 300 mm and on initial placing in thickness not more than 150 mm.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD •
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The vibrator head shall be dipped through filling which is to be consolidated to further depth of 10 to 20 mm in the lowest layer which has already been consolidated.
• Vibration shall be carefully controlled, the internal vibrator being systematically inserted at points minimum 450 mm and maintained in position for a fixed time. Immersion for periods of 5 to 15 seconds should normally be sufficient.
The limit of
action is judged by surface appearance. The surface shall neither be honey combed nor shall it contain excess mortar.
• The vibrator shall be inserted vertically. With inclined or haphazard insertion it will be impossible to regulate the degree of compaction in all portions of the concrete. Care shall be taken to prevent contact of immersion vibrators with form work, reinforcement steel and finished surfaces. Immersion
vibrators
shall not come in contact with
reinforcement steel if initial set of concrete around it has started.
• The vibrator shall be allowed to penetrate on its own accord and should be withdrawn quite slowly, at the rate of about 75 mm per second, whilst
still
running, so
as
to
allow the redistribution of the concrete in its wake.
19.3.2.9.4 The rate of placement of concrete shall be such that no cold joint is formed and fresh concrete is placed always against green concrete that is still plastic and workable. Sufficient tarpaulins or other similar protective arrangement for completely covering the still green concrete from rain may be kept at the site of placement. If there has been any sign of washing of cement and sand, the entire affected concrete shall be removed immediately. Suitable precautions shall be taken in advance to guard against rains before leaving the fresh concrete unattended. No accumulation of water shall be permitted on or around freshly laid concrete.
19.3.2.9.5 Beams and similar members shall be poured in one operation. In special circumstances with the approval of the Engineer-in charge, these can be poured in horizontal layers not
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exceeding fifty (50) cm. in depth. When poured in layers, it must be ensured that the under layer, is not already hardened. Bleeding of under layer if any, shall be effectively removed. Moulding, throating, drip course, etc. shall be poured as shown on the drawings or as directed by the Engineer. Holes shall be provided, and bolts,
sleeves, anchors,
fastenings or other fixtures shall be embedded in concrete as shown on the drawings or as directed by the Engineer.
19.3.2.9.6 In case the forms or supports get displaced during or immediately after the placement and bring the concrete surface out of alignment beyond tolerance limits, the Engineer may direct to remove the portion and reconstruct or repair the same at the Contractor's expense.
19.3.2.9.7 The Engineer shall decide upon the time interval between two placements of concrete of different ages coming in contact with each other, taking in consideration the degree of maturity of the older concrete, shrinkage, heat dissipation and the ability of the older concrete to withstand the load imposed upon it by the fresh placement.
19.3.2.9.8 Concrete shall not ordinarily be placed under water. In unavoidable cases, such concreting shall be done only with the specific approval of procedure and application by the Engineerin-charge. The concrete shall contain at least 10 percent more cement than that required for the same mix placed in the dry, the quality of extra cement varying with condition of placing. The relevant clauses of IS: 456 (latest edition) should be adhered to 11.12(D) (w). Retamping of concrete or mortar which has partially hardened shall not be permitted.
19.3.2.9.9 All excavations prepared for concrete construction shall be maintained free of water until such concrete work is completed. Water used for flushing concrete placing equipment shall be discharged clear of the concrete and forms.
19.3.2.9.10 Contractor shall keep an accurate record of the date on which the concrete is cast for each part of work and date on which the forms are removed.
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19.3.2.10 CURING: 19.3.2.10.1 Curing shall be as per IS: 456. Unless otherwise specified all concrete shall be moist cured by keeping all exposed surfaces, edges and corners continuously moist for at least twenty one days after being placed, by spraying, ponding or covering with waterproof paper or moisture retaining fabric.
19.3.2.10.2 Newly placed concrete shall be protected by approved means from rain, sun and wind. Concrete placed below the ground level shall be protected against contamination from falling earth during and after placing. Concrete placed in ground containing deleterious substances, shall be protected from contact with such ground, or with water draining from such ground, during placing of concrete and for a period of at least three days. The ground water around newly poured concrete shall be kept to an approved level by pumping out or other adequate means of drainage to prevent floatation or flooding.
19.3.2.10.3 As soon as the concrete has hardened sufficiently, it shall be covered either with sand, Hessian, canvas burlap or similar materials which will hold moisture for long period and prevent loss of moisture from concrete and kept continuously wet for at least 18 (eighteen) days after final setting. Curing by continuous sprinkling of water will be allowed if the Engineer is satisfied with the adequacy of the arrangements made by the Contractor.
19.3.2.10.4 Curing of concrete shall start after 8 hours of placement and in hot weather within 4 hours of placement of exposed faces. During the first 24 hours, the concrete shall be cured by use of wet burlap or such other means to cover the concrete surfaces. In very hot weather, precaution shall be taken to see that the temperature of wet concrete does not exceed 38 deg. C while placing.
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19.3.2.10.5 Concrete slabs and floors shall be cured by flooding with water of minimum 25 mm depth for the period mentioned above. Approved curing compounds may be used in lieu of moist curing with the permission of the Engineer-in-charge. Such compounds shall be applied to all exposed surfaces of the concrete as soon as possible after the concrete has set.
19.3.2.10.6 Wash water: Wash water shall be removed in a manner to prevent running down and staining of concrete surfaces which will be exposed at the completion of the work. Should unsightly wash water streak develop on the exposed surfaces, they shall be removed and water has to be lead to a suitable place as directed by Engineer- in charge.
19.3.2.11 GROUTING: 19.3.2.11.1 The block outs and bolt holes which have to be grouted shall be cleaned thoroughly by use of compressed air immediately before taking up the grouting operations. Cement sand mix in 1:1 proportion and aluminum powder or anti-shrinkage admixture of approved quality shall be first blended thoroughly in the required proportion as per manufacturer's specification. Grout shall then be prepared by mixing this admixture with water in the proportion of 2 parts by weight of cement to one part by weight of water. The quantity of aluminum powder shall usually be of the order of 0.005% by weight of cement. Any grout which has been mixed for a period longer than half an hour shall not be used on the work.
19.3.2.11.2 Concrete surfaces receiving the grout shall be properly roughened removing laitance and exposing good concrete. The steel surfaces coming in contact with the grout should be cleaned of rust, mill scales, paints, oil or grease and be wet before setting into place for grouting.
19.3.2.11.3 Immediately after preparation, the grout shall be poured into the block outs, pockets and bolts holes either from the sides or through the holes provided for this purpose in the base plate by using special equipment for pressure grouting. It shall be ensured by poking with
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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rod and by tapping of bolts, that the block out is completely filled without leaving any voids. The pouring shall stop as soon as each hole is filled and any excess grout found on the surface on the concrete foundation shall be completely removed and the surface dried.
19.3.2.11.4 Under-Pinning/Grouting: It shall be resorted to for filling the space between the underside of base plate and the top of foundation concrete. After grouting has been completed, space between the top surface of the foundation concrete and the underside of the base plate shall be filled with mortar or concrete depending upon thickness to be filled as follows:-
Less than 40 mm
Over 40 mm
dry packed mortar
Dry packed fine concrete
19.3.2.11.5 Use of dry pack concrete: The widely used method of obtaining satisfactory grout is based on principle of using lowest water cement ratio reducing the shrinkage to a minimum. Pozzolana cement having less shrinkage than ordinary Portland cement is preferred for this grouting. Only enough water shall be added to produce a grout. The proper amount of mixing water and proper consistency are those which will produce a grout which is at the point of becoming rubbery when the material is solidly packed. Any mortar which has been mixed for a period longer than an hour shall not be used.
Use of special admixtures: To reduce the shrinkage, anti-shrinkage materials as specified earlier to be added.
19.4.0
CABLE TRENCH:
19.4.1
Cable trenches shall be of reinforced concrete type with removable type reinforcement cement concrete covers. These trenches shall not be used as storm water drains. The
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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bed of the cable trenches along their length shall be provided a slope of 1:600 to 1:750 to drain any rain/seepage water that may enter them. The overall depth of various type of cable trenches shall be so decided as to take care of above provision of longitudinal slope along their length without compromising the clearance required between bottoms most tray of cable trench and bed of the cable trench.
19.4.2
Suitable expansion joints shall be provided in cable trenches as per IS specification with PVC water stoppers, bitumen impregnated filler boards, bitumen sealing compound as per specifications or as directed by the purchaser. The water proofing cement additive shall be used for the construction of cable trenches to ensure water tight construction.
19.4.3
The water from cable trenches shall be collected in suitably located sump pits . The sump pits shall be of R.C.C construction covered at top with provision of manhole, rungs .
19.4.4
All cable trenches shall be provided with edge protection angles of size not less than 50x50x6 mm and suitable length as decided at the time of engineering. Suitable lugs of reinforcement steel (10 mm dia minimum) shall be welded to edge protection angles for ensuring their rigidity in the concrete. The weight of a single pre-cast R.C.C cover shall not be more than 75 Kg. Suitable lifting hooks of size 10mm MS rod minimum shall be provided for easy handling of these covers.
19.4.5
The covers of cable trenches shall be of such designs that do not allow any rainwater to enter into them. Necessary embedded steel plates shall be provided for supporting the cable trays.
19.4.6
The top of cable trenches shall be kept 150 mm above finished ground level. The backfilling shall be with excavated soils.
19.4.7
In cable trenches, construction joints shall be provided between the base slab and sidewall with PVC water stoppers.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 19.6.0 19.6.1
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TRANSFORMER FOUNDATION: It shall consist of a R.C.C. soak pit having pedestal for supporting the transformer/reactor and its cooling bank etc. The size of the soak pit shall be 1.0 M bigger all round than the plan size of transformer. The depth of soak pit shall be adequate to accommodate the full quantity of oil contained in the transformer plus 50% of emulsifier water in voids of metal filling inside the soak pit.
19.6.2
The metal size to be filled in the soak pit shall be of 60 mm to 40 mm nominal size and it shall be ensured that 40% of voids are available in the metal filling after its packing in soak pit. The top of the metal filling inside the soak pit shall be 200 mm below the top of the rail.
19.6.3
CENTRAL OIL COLLECTING PIT:
A common R.C.C central oil-collecting pit shall be
provided for all the transformers. This pit shall be closed type and waterproof construction with necessary manholes and rungs etc. for maintenance purposes. The soak pits of transformers shall be connected to this central oil-collecting pit through underground R.C.C pipes and manholes. The size of the oil collecting pit shall be adequate to accommodate the full quantity of oil contained in the largest transformer including rain water and emulsifier water required for the biggest transformer and to ensure that no oil/emulsifier water remains in the transformer soak pit/drain pipes and the level of soak pit shall be accordingly decided. The size of R.C.C pipes to be used for connecting the soak pit of the transformers to the central oil collecting pit shall not be less than 300 mm diameter and shall be of class NP4 conforming to IS: 458(latest) as per recommendations of tariff Advisory Committee. The central oil collecting pit shall have provision for installing 2 Nos. of 100% capacity sump pumps with all accessories like suction and discharge pipes for transferring discharge to oil-water separator such that each pump can pump oil/rain water/emulsifier discharge of auto-transformer of biggest transformer in the switchyard. The suitable size oil-water separator shall be designed and provided by the contractor in a manner that oil would be separated from water and same shall be retained in oil water separator while water shall be disposed off to the nearest storm water drain. The oil water separator shall also be of R.C.C construction. Design of transformer foundations shall be
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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carried out based on the relevant drawings, loading data etc. to be furnished by the purchaser.
19.10.0 SPREADING OF HBG METAL: 19.10.1 40 mm HBG metal of 150 mm thickness shall be spread in switch yard. Kerb stones of size 200 x200 mm shall be provided in the switchyard to retain the metal all along the periphery of the metal spreading where ever it is required. The Kerb stones shall be buried in the ground up to 100mm deep. The joints between the Kerb stones shall be done in CM (1:6) and plastering the Kerb stones shall be done in CM (1:2). 19.10.2 Before spreading the HBG metal care shall be taken to remove all the vegetation and roots of the plant. The trimming of the earth surface for perfect level ground should be carried out and the surface should be watered and rammed for consolidation with suitable means and the earth surface should be given chemical treatment for anti-vegetation growth. The crushed metal dust or quarry dust should not be used. The HBG metal shall be brought from the approved Quarry as directed by engineer.
19.11.0
19.11.1
GATES:
Supply & Errection Of Gates : Main gates shall be supported on RCC pillars. These shall include necessary anchors, rollers, guides etc. in complete shape. Main gate pillars shall be constructed as per the approved drawing. No. Wicket gate shall be grouted into pillars constructed in brick masonry. After erection of gates they shall be painted with two coats of superior quality enamel paint over a coat of primer.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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19.12.0
WATER FOR CONCRETE:
19.12.1
Clean fresh water shall be used for mixing concrete grout and mortar and curing. The water used for mixing and curing shall be free from deleterious matter and acids and alkaline substances in a solution or suspension. Potable water shall generally be used for mixing and curing concrete.
19.12.2
In respect of drinking water, filtration and chlorination by approved means shall be installed as necessary to obtain the required standard. Storage and distribution of potable water shall be such as to prevent contamination.
19.13.0 PROCUREMENT OF STEEL, FABRICATION & GALVANISATION: 19.13.1
Steel such as MS angles, plates, Channels and M.S Rounds required for fabrication of structures shall be procured by the contractor. The structures shall be fabricated as per the structural drawings and galvanized. Proto type structure shall be fabricated and shop drawings for all the structures, stub setting templates etc. shall be furnished. Mass fabrication of the structures shall be done after their approval.
19.14.0 ANTI-WEED TREATMENT: 19.14.1 For safeguarding the switch yard against the growth of weeds, weedicides (such as Biodex-C, Grammaxene, Fernoxene or equivalent products) should be mixed with water in accordance with the manufacturer's instruction (3 liters of weedicide mixed with 200 liters of water is a standard practice) and this solution should be spread over the earth with a chemical spraying pump on the ground.
19.14.2 The anti-weed treatment should be given only after moisture content of the soil is brought below 29%. After completion of spraying of the anti-weed chemicals and before taking up the next activity, a period of 24 hours should be allowed for penetration of the chemical in to the soil.
19.15.0 ANTI-TERMITE TREATMENT:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
19.15.1
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Required to set up a chemical barrier against attack by subterranean termites in the areas like cable trenches etc. This work shall in general, be executed as specified in IS: 6313 part -II and as per approved specification of the agency having special know-how for the job. All necessary work to ensure uniform distribution and proper penetration of treating solution shall be done. Soil treatment shall not be done when it is raining or when the soil is wet with rain or sub soil water. Once formed, the treated soil barrier shall not be distributed.
19.15.2 CHEMICALS AND RATE OF APPLICATION: Any of the following chemicals (conforming to relevant Indian standards) in water emulsion shall be applied by pressure pumps uniformly over the area treated.
Chemicals
Concentration / weight percent
Dieldrin
(IS: 1052-1962)
0.5
Aldrin
(IS: 1306-1958)
0.5
Chlordane
(IS: 2863-1964)
1.0
Heptachlor
0.5
19.15.3 TREATMENT OF CABLE TRENCHES:
Cable trenches may be fully enveloped by the chemical barrier by treating with chemicals at the rate of 15 liters /sqm. on vertical surfaces of excavated trench walls and bottom surfaces at the rate of 5 liters /sqm. Chemical treatment shall be done in stages following the compaction of earth in layers. The treatment shall be carried out after the ramming operation is done by padding the earth at 150mm.Centres close to the wall surface and spraying the chemicals in the specified dose.
PVC PIPES:
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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PVC Pipes where called for shall be either unplasticised PVC pipes or high density polyethylene pipes supplied with appropriate fittings.
PIPES AND FITTINGS: The pipes and fittings shall be of 10 kgs per Sq.m. pressure class. The plastic pipes are to be handled with care and stored in a place protected from sun. Plastic pipes and fittings shall confirm to ISI: 4984.
SETTING OUT: Setting out shall be carried out from the main grid lines of the proposed structures. Immediately before installation of the pile, the pile position shall be marked with suitable identification of pins or markers. POSITION: For a pile head cut off, at or above ground level, the maximum permitted deviation of the pile head cut off center from the center point, shown on the setting out drawing, shall be 50 mm in any direction. For a pile head cut off below ground level an additional tolerance will be permitted on the assumption that the pile head has been within tolerance, if the cut off had been at ground level.
19.17.0
SAFETY REQUIREMENTS :
19.17.1
Safety shall form an integral part of work processes to ensure safety for employees including employees of contractors and sub-contractors as well as visitors.
19.17.2
PROVISIONS RELATING TO COMPANY:-
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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A sound and scientific safety management system should be set up which shall include: a)
Formulation of a written statement of policy in respect of safety and health of employees.
b)
Defining and documenting responsibilities for all levels of functionaries to carry out safety related activities including responsibilities of the contractors.
c)
Preparing detailed Safety Manual complying with statutory requirements, manufacturers’ Recommendations, BIS and any other relevant standards and codes.
d)
Establishing procedures to identify hazards that could give rise to the potential of injury health impairment or death and measures to control impact of such hazards.
e)
Providing adequate human, physical and financial resources to implement the safety management system.
f)
Providing safe working environment and evolving framework for occupational safety and health.
g)
Providing and maintaining medical facilities.
h)
Providing adequate training to all employees to make them aware of safety related issues.
h)
Establishing system for accident reporting, analysis, investigation and implementation of recommendations.
i)
Establishing system for proper communication, documentation and record management in relation to occupational safety and health.
k)
Filing periodic and other returns to the statutory bodies as required under various Acts and Rules within stipulated time.
l)
Formulating emergency management plan for quickly and effectively dealing with probable emergencies that may arise on site as well as off-site.
m)
Establishing methodology for internal and external audit of safety management system.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
n)
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Establishing system for periodic monitoring and review of safety system by Management. Overseeing the safety performance of the contractors.
19.17.7 SAFETY TRAINING AND AWARENESS: 19.17.7.1 Regular training programmes should be conducted for all employees
covering general
safety awareness, first-aid, emergency procedures including shock treatment , use of personal protective equipment, safety pre-cautions while handling electro-mechanical equipment, use of different types of firefighting equipment, response in the event of emergencies including fire, floods, landslides, earthquakes etc., site specific hazards and relevant safety acts, rules and regulations. 19.17.7.3 Project implementing officer shall ensure that adequate safety training is provided by the contractor to his personnel.
20.0.0
PACKING AND DISPATCH:
20.1.0
33kV switchyard equipment’s shall be dispatched to The equipment shall be properly packed for transportation by ship/ rail or trailer and shall be wrapped in polythene sheets before being placed in crates/ cases to prevent damage to finish. The crates/ cases shall have skid bottom for handling. Special notations such as ‘Fragile’, ‘This end up’, ‘Center of gravity’, ‘Weight’, ‘Owner’s particulars’, ‘PO nos.’ etc., shall be clearly marked on the packages together with other details as per purchase order.
20.2.0 The equipment may be stored outdoors for long periods before installation. The packing shall be completely suitable for outdoor storage in areas with heavy rains/ high ambient temperature unless otherwise agreed.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD 21.0.2 21.0.2.1
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MANUFACTURERS DOCUMENTS: The manufacturer shall supply project specific documents, these shall include but not be limited to the following: a) Protection current transformer magnetisation curves. b) Earthing calculation c) DSLP calculation. d) Lighting Calculation e) Busbar Sizing calculation. f)
Battery Sizing calculation.
g) CT/VT sizing calculation. h) Relay characteristics and connection requirements. i)
Recommended spare parts list.
j)
Test reports.
k) O&M manuals shall incorporate the installation, commissioning, operating and maintenance instructions and fault finding procedures.
22.0.0
DRAWINGS / DOCUMENTS: The reference (Typical) drawings, which form a part of the specification, are given at tender document. The Vendor shall maintain the overall dimensions of the layout of substation , but may alter the locations of equipment to obtain the statutory electrical clearances required for the substation. The drawings enclosed give the basic conceptual scheme. in case of any discrepancy between the drawings and text of specification, the requirements of text shall prevail in general. The successful Vendor shall furnish all the drawings for approval of owner. The furnishing of engineering data by the Vendor shall be in accordance with the Schedule for each set of equipment as specified in the Technical Specifications.
TECHNICAL SPECIFICATION – 33kV SWITCHYARD
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The review of these data by the Owner 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 panel room layout. This review by the Owner 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 Owner shall not be considered by the Vendor, as limiting any of his responsibilities and liabilities for mistakes and deviations from the requirements, specified under these specifications and documents. Following are the minimum documents to be provided by the successful Contractor till handover of the project. ( 1 Set CD & 6 paper set)
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