section-4. technical specification for 220kv switchyard

7/27/2019 Section-4. Technical Specification for 220kv Switchyard

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DEIFY INFRASTRUCTURE LIMITED

JAYASWAL NECO INDUSTRIAL LIMITED

2x25 MW CAPTIVE POWER PLANT

TECHNICAL SPECIFICATION FOR

132kV SWITCHYARD AND HARDWARES

DOC. NO : 4 3643 ELCT 001

6 IEC-2331 High Voltage porcelain bushings.

7 IEC - 60 High voltage test techniques

8 IEC 71 Part-I & II Insulation co-ordination, Terms, definitions,

principles and rules

9 CIGRE Working group Switching over-voltages in EHV Report No.13-02-1973 and UHV systems with special reference to

closing and re-closing transmission lines.

10 IEC 270 Partial discharge measurements.

11 Indian Electricity

Rules.

1.3 PRINCIPAL PARAMETERS

1.3.1 The breaker shall conform to the specific technical requirements specified below.

SI.No. Item Requirements

1 Rated voltage of the breaker /

Highest system voltage kV rms

145

2 System frequency 50 HZ

3 System Neutral grounding Effectively earthed

4 Continuous current rating (A) 800

5 Installation (Indoor/Outdoor) Outdoor

6 Type of breaker Live tank SF6

7 Mounting On hot dip galvanised steel support structure

or on the operating mechanism box.

8 Number of Poles 1

Consultant:

Snyder Energo Private Limited Section-4 2 of 140

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9 Type of operation Individual Individually operated single poles

10 Phase to phase spacing in the

switchyard i.e. preferred inter

pole spacing for breaker (in

mm).

3600

11 Required ground clearance

from the lowest live part fromthe top of the concrete plinth

( mm )

4600

i) If both the terminals are

not in the same horizontalplane.

ii) If both the terminals are inthe same horizontal plane.

5200

6200

12 Height of concrete plinth

above ground level (to be

provided by the Purchaser)(mm)

300mm height plinth from FGL

Minimum height of the lowestpart of the support insulator

from ground level (mm).

2750

13 Operating mechanism Spring operated

14 Auto re-closing duty (Only one

breaker out of 6 breakers)

Single phase & Three phase if gang operated

15 Rated operating duty cycle.

O-0.3 seconds-CO-3 minutes-CO

16 "First pole to clear factor 1.5

17 Max.closing time (ms) 60 (3 cycles)

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Bangalore & Chennai


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18 Maximum total break time at

rated breaking capacity.

60 (3 cycles)

19 Lightning impulse level (kVP) 650

20 One minute power frequencywithstands voltage (kV rms.)

275

21 Max.radio interference voltage

at 156 kV (micro volts)

1000

22 Rated breaking current

capacity.

i) Line charging at rated

voltage(A)

125

ii)Single Capacitor Bank(Amp)

400

iii) Small inductive current (A) 0.5 to 10 without switching over voltageexceeding 2.0 pu.

iv) Short Circuit current

a) Rated short circuit breaking

current kA rms

40

b) Short time current carryingcapacity for 3 sec in kA rms

40

c) Percentage D.C.component Corresponding to minimum opening time as

per standard.

23 Rated short circuit making

current capacity (kA peak)

100

24 Permissible limit of As per IEC

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Bangalore & Chennai


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DOC. NO : 4 3643 ELCT 001

temperature rise of various

parts in the equipment.

25 Maximum acceptabledifference in the instants of

closing/opening of contacts:

i) Between poles (ms)

5 ms

26 Minimum creepage distance of

support insulator (mm)

3625

1.4 GENERAL TECHNICAL REQUIREMENTS

1.4.1 Similar parts of the breaker, especially the removable ones, shall be freely interchangeable

without the necessity of any modification at site.

1.4.2 The breakers will be required to break Capacitor currents, small inductive currents and

line charging current without causing excessive over voltage, and charging

current without restrike. The breaker shall also be required to handle evolving faults andmeet the requirements regarding partial discharge, radio interference etc, as specified in

relevant standards.

1.4.3 Breaker contacts

Main contacts shall have ample area and contact pressure for carrying the rated

continuous and short time currents of the breaker without excessive temperature rise

which may cause pitting or welding. Contacts shall be adjustable to allow for wear,shall be easily replaceable and shall have a minimum number of movable parts and

adjustments to accomplish these results. Main contacts shall be the first to open and

the last to close so that there will be little contact burning and wear. Tips of maincontacts shall be silver plated.

Arcing contacts, if provided, shall be the first to close and the last to open and shall beeasily accessible for inspection and replacement. The arcing contacts shall have

tungsten alloy tipping.

If multi-break interrupters are used, they shall be so designed and augmented that a

fairly uniform voltage distribution is developed across them.

The inside operating rod or insulated fibre glass connecting rods wherever used, shall

be sturdy and shall not break during the entire life period of the breaker. Theinsulated rods shall have anti tracking quality towards electrical stresses.

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Bangalore & Chennai


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DOC. NO : 4 3643 ELCT 001

1.4.4 Take off terminal pads

Terminal pads shall be provided with silver plating of at least 25 microns thickness ifthese are made of metal other than aluminium. No such plating shall be required if the

terminal pad is made out of Aluminium. The pads shall be suitably designed to takethe approximate terminal loads, specified below.

The breaker shall be designed to withstand the rated terminal load, wind load/Earth

quake load and short circuit forces. The short circuit forces to be considered for thedesign shall be based on length of bus bars consisting of conductors and phase to

phase spacing shown below.

The current density adopted for the design of the terminal pad shall in no case exceed

1.6A/sq.mm for copper pad and 1.0 A/sq.mm for pad made of other material.

The vertical clearance of lowest live part from ground level (excluding concretefoundation plinth) shall be as given below. In no case the height less than 4600mmwill be accepted:

1.4.5 Porcelain Housing

The porcelain housing for the interrupter shall be of a single piece constructionwithout any joint. It 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 orcondensed water particles (fog).

1.4.6 Support insulator

Breaking units shall be mounted on insulator column of not more than two insulatorsin each column.

1.4.7 Surface Finish

All metal sheet surfaces exposed to atmosphere shall be given two primer coats of zinc

phosphate and two coats of epoxy paint with epoxy base thinner. All metal parts not

accessible for painting shall be made of corrosion resisting material. All machine

finished or bright surfaces shall be coated with a suitable preventive compound andsuitably wrapped or otherwise protected.

All paints shall be carefully selected to withstand tropical heat and extremes ofweather within the limits specified. The paints shall be light grey shade No.631 of IS

5. The paint shall not scale off or wrinkle or be removed by abrasion due to normal

handling.

1.4.8 Supporting structures and Galvanising

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DOC. NO : 4 3643 ELCT 001

All ferrous parts including nuts, bolts, plain and spring washers of size M 10 andabove, support channels, structures, etc. shall be hot dip galvanised to conform to

latest version of IS 2629 or any other equivalent authoritative standard. All other

fixing nuts, bolts, washers of size below M 10 shall be made out of stainless steel.

1.4.9 Earthing

The operating mechanism housing, support structures etc. shall be provided with two

separate earthing terminals for bolted connection to 50 x 8 mm GI flat to station earthmat. The connecting point shall be marked with "earth" symbol No.86 of IEC

publication 117-1 part 1.

The coils of operating devices shall be marked clearly with the catalogue

number/reference number as indicated in control wiring diagram.

1.4.10 Control Circuits

The control circuit shall include the following features:

i) Two electrically independent trip circuits including two trip coils per

pole/CB as the case may be along with 2 bus arrangement for DC system protected

with two separate MCBs.

ii) One local/remote selector switch.

iii) Conveniently located manual emergency trip

iv) Pole discrepancy feature to trip closed poles in the event of polediscrepancy (not applicable for gang operated breaker). While opening and/orclosing, all the three poles shall operate simultaneously.

v) Anti pumping feature

vi) Auxiliary switches as specified else where.

vii) Independence of trip circuit from local/remote selection.

viii) Alarms, indications, monitoring equipments and interlocks as specified

elsewhere.

ix) Trip circuit supervision for pre trip as well as post trip

A separate cabinet shall be provided for housing operating mechanism and control circuitry.

These control cabinets shall meet the standard requirements.

1.4.11 Auxiliary Switches

Each operating mechanism of the circuit breaker shall be provided with Cam/Snap

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DOC. NO : 4 3643 ELCT 001

type auxiliary switches with Ten (10) normally open and Ten (10) normally closedcontacts for EHV CBs & 4NO+4NC for CBs exclusively for the Purchaser's use

with continuous current rating of 10 A D.C. Breaking capacity of the contacts shall

be minimum 2 A with circuit time constant less than 20 milli seconds at the rated

D.C. voltage. Normal position of auxiliary switches refers to contact position whencircuit breaker is open.

1.4.12 Alarms and Indications: (as applicable)

Potential free contacts shall be provided, duly wired up to the operating mechanism

housing/control cabinet for the following alarms and indications to control panel.

Alarms

i) General lockout for SF6 gas/air.

ii) Low pressure of SF6 gas.

iii) Auto reclosing lockout (for low pressure of gas/air).

iv) Pole discrepancy

v) Auxiliary a.c./d.c. supply failure

vi) Spring charging motor overload

Indications

i) Breaker on-off

ii) Spring charged

iii) Breaker Trip

1.4.13 Indications in Operating Mechanism

The operating mechanism housing shall be provided with the following mechanical andElectrical indications/counters:

i) Breaker on-off

ii) Spring Charged

iii) Operation counters to register the number of breaker operations.

1.4.14 Interlocks

The details of the scheme shall be furnished by the successful Tenderer.

The requirement of auxiliary contacts to be provided in breaker operating mechanism

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Bangalore & Chennai


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by the Tenderer for successful operation of the scheme

1.4.15 Mounting

The design and supply of support structure, required for mounting the circuit breakershall be in the Tenderers scope. The Purchaser's scope shall necessary civil works forthe support structures. The support structure shall be lattice type or tubular type and

shall be made out of hot dip galvanised steel. The support structure shall be installed

on a concrete plinth of 300 mm height. The height of the support structure shall meetthe following requirements.

i) Vertical clearance of lowest live part as mentioned in specification.

ii) Minimum height of 2450 mm above the top of concrete plinth (This isa Statutory Regulation)

The Circuit Breaker shall be connected to adjacent equipment in the switch yardthrough Drake conductor.

The support structure shall be designed on the basis of applicable Indian/International

Standards and codes of practice.

1.5 Operating mechanism, control cabinet & Associated equipments

Control cabinets shall preferably be of the free standing floor mounting type for EHV CBs.

Control cabinets shall be sheet steel enclosed and shall be dust, water and vermin proof. Sheet

steel shall be at least 2.6 mm thick when control cabinets are specified for indoor use and 3.0 mmthick when control cabinets are intended for outdoor operation. There shall be sufficientreinforcement to provide level surfaces, resistance to vibrations and rigidity during transportation

and installation. Control cabinets shall be provided with double hinged door and

padlocking arrangement. The door hinges shall be of union joint type to facilitate easy removaland the distance between hinges shall not exceed 350 mm. Door shall be properly braced to

prevent wobbling. Sloping rain-hood shall be provided to cover all sides. 15mm thick neoprene or

better type of gaskets shall be provided to ensure degree of protection of at least IP55 as per IS:

2147.

Equipment and devices shall be suitable for operation on specified auxiliary A.C. supply system.

Motors rated 1 kW and above being controlled from the control cabinet would be suitable for

operation on a 415 V, 3 phase 50Hz system. Fractional kW motors would be suitable foroperation on a 240V, 1Phase, two pole 50 Hz A.C. supply system, with one pole grounded.

Push button shall be rated for not less than 6 Amps, 415 Volts A.C or 2 Amp,220 V D.C and

shall be flush mounted on the cabinet door and provided with appropriate name plates. Red,

green and amber indicating lamps shall be flush mounted and provided with series resistors toeliminate the possibility of short circuiting of control supply in the event of fusing of lamps.

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Bangalore & Chennai


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For motors up to 5 kW, starters shall be direct-on-line with air break, single throw typecontactors suitable for making and breaking the stalled current of the associated motor which

shall be assumed equal to 6.5 times the full load current of the motor at 0.2 p.f. For motors

above 5 kW, automatic star delta type starters shall be provided. 3 pole contactors shall be

furnished for 3 phase motors and 2Pole contactors for single phase motors.Reversing contactors shall be provided with electrical interlocks between forward and reverse

contactors. If possible, mechanical interlocks shall also be provided. Contactors shall be

suitable for uninterrupted duty and shall be of duty category class AC4 as defined in IS 2959.The main contacts of the contactors shall be silver plated and the insulation class for the coils

shall be Class E or better. The dropout voltage of the contactors shall not exceed 70% of the rated

voltage.

Contactor shall be provided with a three element, positive acting ambient temperature

compensated, time lagged, hand reset type thermal over load relay with adjustable setting. Handreset button shall be flush with the front door of the cabinet and suitable for resetting with starter

compartment door closed. Relays shall be either direct connected or CT operated depending onthe rated motor current.

Single phasing protection shall be built in the thermal over load protection.

Mini starters shall be provided with no volt coils when required.

Power cables shall be of 1100 Volt grade stranded aluminum conductor, PVC insulated PVC

sheathed single steel wire armoured and PVC jacketed. All necessary cable terminatingaccessories such as glands, crimp type tinned copper lugs etc., for power as well as control cables

shall be included in Tenderer's scope of supply. Double compression type brass cable glands

shall be provided for cable entry. Cable details for same will be furnished during vendor drawingreview.

Wiring for all control circuits shall be carried out with 1100 Volts grade PVC insulated tinnedcopper stranded conductors of sizes not smaller than 2.5 mm. At least 10% spare terminal blocks

for control wire terminations shall be provided on each panel. The terminal blocks shall be similar

to ELMEX type CAT-44. All terminals shall be provided with ferrules indelibly marked ornumbered and these identifications shall correspond to the designations on the relevant wiring

diagrams. The terminals shall be rated for adequate capacity which shall not be less than

10 Amps.

Control cabinet shall be provided with 240 V, 1-phase 50 Hz, 20W fluorescent lighting fixture

with on /off switch and a suitably rated 240 V, 1 phase, 15 amp, 3 pin socket for hand-lamp/handtools.

Suitable heaters shall be provided inside each cabinet. Heaters shall be controlled by suitable

MCBs.

All a-c control equipment shall be suitable for operation on 240V, 1 Phase two wire 50 Hz

system, with one pole grounded.

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Bangalore & Chennai


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Item inside the cabinet made of organic material shall be coated with a fungus resistant varnish.

For protection of AC/DC aux. circuits, MCBs of suitable capacity & reputed make to be

provided.

The schematic/ wiring diagram plate shall be provided on the door of the mechanism Box.

The circuit breaker shall be designed for electrical local as well as remote control. In addition

there shall be provision for local mechanical control.

The operating mechanism shall be of motor charged spring closing type operated by electricalcontrol under normal operation. The mechanism shall be adequately designed for the specified

tripping and reclosing duty. The entire operating mechanism control circuitry, spring charging

motor etc., as required, shall be housed in an outdoor type, steel enclosure. This enclosure shallconform to the degree of protection IP-55 of IS-2147/IEC 529.

All metal parts in the mechanism shall be of corrosion resistant material. All bearings whichrequire greasing shall be equipped with pressure grease fittings.

The design of the operating mechanism shall be such that it shall be practically maintenance free.

The guaranteed number of years of maintenance free operation, the number of possible full load

and full rated short circuit current breaking operations without requiring any maintenance or

overhauling shall be clearly stated in the tender bid. As far as possible, the need for lubricatingthe operating mechanism shall be kept to the minimum and eliminated altogether, if possible.

The operating mechanism shall be anti-pumping and trip free. There shall be no rebounds in the

mechanism and it shall not require any critical adjustments at site. Operation of the power

operated closing device, when the circuit breaker is already closed, shall not cause damage to thecircuit breaker or endanger the operator. Provision shall be made for attaching an operation

analyser to facilitate testing of breaker at site.

The technical requirement of spring type operating mechanism, and pneumatic mechanism shall

be as below.

1.6 Specification for operating mechanism

1.6.1 Spring operating mechanism

i) The spring operating mechanism shall have adequate energy storedin the operating spring to close and latch the circuit breaker against the rated

making current and also to provide required energy for the tripping mechanismin case the tripping energy is derived from the operating mechanism. The

mechanism shall be capable of performing the rated operating duty cycle of O-0.3

Sec - CO - 3 min - CO. The spring charging motor shall not take more than 30secs for fully charging the closing springs and provision shall be made for

automatic charging of the closing springs as soon as they are discharged in a

closing operation. For this, the mechanism shall be such that the charging of the

springs by the motor does not interfere with the operation of the breaker.Consultant:


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ii) The motor shall be adequately rated to carry out a minimum of 10 closeand open operations continuously. Overload relay shall be provided to protect

the motor against overloads.

iii) In case of failure of power supply to the spring charging motor, themechanism shall be capable of performing one sequence of O - 0.3 Sec - CO.

iv) Mechanical interlocks shall be provided in the operating mechanism to

prevent discharging of the closing springs when the breaker is already in the closed

position. Provision shall also be made to prevent a closing operation to be carriedout with the spring partially charged.

v) Facility shall be provided for manual charging of the closing springs.

The actuating force required for manually charging the spring shall be less than

250N. In support of this requirement the Tenderer shall furnish the test report for

actual requirement of force based on actual measurement.

1.6.2 Operating Mechanism Housing

i) The operating mechanism housing/control cabinet shall conform toadditional requirements specified in Clause 7.16.6.

ii) All the electrical control equipments/switches, the operating pointfor manual spring charging handle etc. shall not be at a height of more than

1500mm from ground level OR from a suitable platform which shall be provided

by Tenderer on the structure at a height not more than 750mm from ground level.The size of the platform shall be such that clear working space on the platform

shall not be less than 300mm from all sides of operating mechanism/control box.

The Tenderer shall specifically confirm that the offered breaker meets thisrequirement and furnish the G.A. Drawing showing the arrangement.

1.6.3 SF6 Gas

The SF6 breakers shall be supplied with first filling of SF6 gas, which shall meet therequirements as below. In addition to this, 20 % of the total gas requirement shall be

supplied in separate cylinders as spare requirement. (Every CB shall be provided with a

separate cylinder).

Specification and acceptance of new Sulphur Hexafluoride Gas (SF6)

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Consultant:


Bangalore & Chennai

SI.No. Technical particulars Requirements

1 Physical properties and non-flammable.

Colourless, odourless, non toxic

2 Density at 20 deg.c and 1 bar 6.08 grams/litre

3 Electric strength that of Nitrogen. Two and one half times

4 Compatibility Up to temperature of about 180 deg. C.its compatibility with material used in

electrical construction shall be similar

to that of Nitrogen.

5 Toxic impurities SF6 gas shall comply with therequirements of the test as per clause 22

of IEC: 487-1971.

Impurity or group: Maximum permitted

concentration of impurities % by mass.

CF 4 - 0.05%

Oxygen + Nitrogen - 0.05%

Water - 15 PPM

Acidity expressed as HF - 0.3 PPM.

Hydrolysable fluorides expressed as HF

1.0 PPM

Oil content - Substantially free from oil.

6 Standard sizes of cylinders 3,5,10,20,40,80,150 and 500 litres

7 Preferred sizes of cylinders 10 and 40 litres.

8 Test pressure of cylinder According to gas cylinder rules 1981

and to comply with IS 7285-1974.

9 Maximum filling ratio for tropicalcountry.

-- do --

10 Tests

Toxicity test As per IEC 60376

Water content and condensation

temperature

-- do --

Carbon tetrafluoride oxygen andnitro en contents.

-- do --


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Special Requirements of SF6 Gas Breaker

i) SF6 breaker shall be so designed that upon loss of pressure the gap

between open contacts shall be adequate to withstand at least the rated voltage at

atmospheric pressure of gas.

ii) Tenderer shall clearly bring out in his offer, the precautions to be taken

in the use of SF6 breaker.

iii) Following features shall be provided for monitoring of SF6 gas in the

breaker:

a. A temperature compensated SF6 gas density monitor with two potential

free contacts of suitable rating. One of these contacts shall be used forannunciation of low density. The other contact shall be used by the

Tenderer to ensure breaker lockout in the event of low SF6 gas density.The successful Tenderer shall furnish a chart showing relation between

pressure and density of SF6 gas, as well as settings for alarm and lockout.

b. Preferably temperature compensated pressure gauges shall be provided forSF6 gas, pneumatic air, as applicable. Gauge dials shall be clearly visible

with naked eye to an observer standing on ground.

c. Adequate number of pressure contacts, shall be provided for monitoring

pressure of SF6 gas/air. The pressure switches shall be provided with

sufficient number of potential free NO & NC contacts for Purchaser's usein control, protection and alarm circuits.

iv) For 132kV CBs independent gas system in each pole with separate

pressure gauge, density monitor, gas filling port etc. should be provided if

applicable.

v) The Tenderer shall furnish along with the tender bid, detailed

Schematic drawings showing all types of control, protection, monitoring schemesto be employed by him. The successful Tenderer shall be required to modify the

schemes, if necessary, after discussions with the Purchaser/Consultant.

vi) Closing coil shall operate correctly at all values of voltage between

85% and 110% at the rated control voltage and trip coil shall operate correctly atall values of voltage between 70% and 110% of the rated control voltage.

1.7 TESTS

The Breaker offered shall have been type tested and validity of the type test reports shallnot be more than five years from the date of offer for the following tests.

1.7.1 List of type tests

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i) Basic short circuit tests.

ii) Short line fault tests.

iii) Out of phase making and breaking tests.

iv) Line charging breaking current tests.

v) Cable charging breaking current tests.

vi) Single Capacitors Bank breaking current tests.

vii) Short time and peak withstand current tests.

viii) Lightning impulse voltage test.

ix) P.F.Voltage withstand test (dry & wet).

x) Temperature rise test.

xi) Mechanical operation test.

xii) Degree of protection (IP55) for all cabinets.

xiii) RIV Test/Visible corona test.

xiv) Single phase short circuit test (for 3 phase mechanically gang operated

breaker).

xv) Seismic test.

The type test shall be carried out at following Laboratories or at any other Laboratories

accredited by National Accreditation Board for Testing & Calibration Laboratories

(NABL).

i) Central Power Research Institute (CPRI).

ii) Electrical Research and Development Association, Vadodara (ERDA).

iii) Indian Institute of Technology (IIT) for Seismic Test.

1.7.2 Acceptance & Routine Tests

All acceptance and routine tests as stipulated in relevant standards, amended up-to-date,

shall be carried out by the Tenderer in the presence of Purchaser's representative without

any extra cost to the Purchaser.

(Note: - All measuring/testing equipments shall be of appropriate class of accuracy and

shall have valid calibration certificates which shall be produced to the Inspecting Officer

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for verification)

After finalisation of the programme of type/acceptance/routine testing, the Tenderer shall

give three weeks advance intimation to the Purchaser, to enable him to depute his

representatives for witnessing the tests.

1.8 INSPECTION

The inspection may be carried out by the Purchaser or his representative at any stage

of manufacture. The successful Tenderer shall grant free access to the Purchaser's

representative/s at a reasonable notice when the work is in progress. Inspection andacceptance of any equipment under this specification by the Purchaser, shall not

relieve the Tenderer of his obligation of furnishing equipment in accordance with the

specification and shall not prevent subsequent rejection if the equipment is found to

be defective.

The Tenderer shall keep the Purchaser informed in advance, about the manufacturing

programme so that arrangement can be made for stage inspection.

The Purchaser reserves the right to insist for witnessing the acceptance/routine testing

of the bought out items. The Tenderer shall keep the Purchaser informed, in advance,

about such testing programme.

1.9 DOCUMENTATION

After award of contract, the bidder shall submit 3 sets of drawings/documents to

Purchaser/Consultant giving details, for scrutiny and approval. Once the drawingshave been approved, no alteration or modification will be carried out without priorapproval of the Purchaser.

The manufacturing of the equipment shall be strictly in accordance with the approved

drawing and no deviation shall be permitted without the written approval of the

purchaser. All manufacturing and fabrication work in connection with the equipment

prior to the approval of the drawing shall be at the BIDDER's risk.

Approval of drawing/work by purchaser shall not relieve the BIDDER of hisresponsibility and liability for ensuring correctness and correct interpretation of

the latest revision of applicable standards, rules and code of practices.

After award of contract, the bidder shall also submit 2 sets of type test reports to C.E.

(Tr. Pl.) for scrutiny and approval, before commencement of supply.

Adequate copies of acceptance and routine test certificates, duly approved by thepurchaser, shall accompany the dispatch consignment.

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2.0 SINGLE BREAK ISOLATOR

2.1 Scope of supply

2.1.1 132kV single break centre pole rotating motorized isolator without earth switch 4 nos.

2.1.2 132kV single break centre pole rotating motorized isolator with one manual earth switch

8 nos.

2.1.3 132kV single break centre pole rotating motorized isolator with two manual earth

switches 1 no.

2.1.4 Engineering, Design, fabrication, manufacture, assembly, shop testing including type test

as specified and inspection at manufacturers works.

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2.1.5 Providing all labours, materials and equipment for testing at site as required.

2.1.6 Unloading and storage at site.

2.1.7 Commissioning of the isolators.

2.1.8 All spare parts required for commissioning of the equipment/system covered under this

specification.

2.1.9 Recommended Spares for two (2) years of trouble free operation.

2.1.10 Special tools and tackles required for operation and maintenance inspection and repair of

the equipment/system offered.

2.2 Standards

SI. No. Standard No. Title

1. IS : 9921 Alternating current isolators (Disconnectors) and

earthing switches

2. IEC : 60129 -- do --

3. IS : 2544 Porcelain post insulators

4. IEC : 168 -- do --

5. IS : 13947 Degree of protection provided by enclosures.

6. IS : 4691 -- do --

7. IS : 325 Three phase induction motors.

8. IS : 4722 Rotating electrical machines.

9. IS : 2629 Recommended practice for hot dip galvanising of iron

and steel.

10. IS : 4759 Hot dip galvanization coating on structural steel.

11. IS : 2633 Method of testing weight thickness and uniformity of coating on fasteners.

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12. IS : 1573 Electro plated coating of zinc on iron and steel.

13. IS : 3033 Separating washers.

14. IS : 2016 Plain washers.

15. NEMA Pub. 107 Radio Interference Voltage Tests.

16. ISRI Pub. 1-

1972

-- do --

17. IS 5561 Power Connectors

18. IS 1554 PVC Cables

19. IS 375 Marking and arrangement for switch gear busbar mainconnectors and auxiliary wirings.

20. IS 3961 Recommended current rating for PVC insulated & PVCsheathed heavy duty cables.

21. IS 1239 Standard for ERW pipes.

22. IS 8263 Method for RIV test on high voltage insulators.

23. IEC 437 Radio Interference voltage test.

2.3 PRINCIPAL TECHNICAL PARAMETERS

SI.No

.

Technical Parameter Requirement

1. Rated system voltage (kV

rms) / Highest system voltage

132/145 kV

2. Rated normal current (Amps) 650

3. Rated Freq. (Hz) 50

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4. System Neutral Earthing Effectively earthed

5. No. of phases (Poles) 3

6. Temperature rise As per relevant IS / IEC Publication

7. Safe duration of overload

a. 150% of rated current

b. 120% of rated current

5 minutes

30 minutes

8. Type of disconnect (Air

Break, AB) Single Break Rotating

9. Short circuit interrupting

current in kA rms40

9.1 Rated short time withstandscurrent (kA rms) of Main

Switch (MS) and Earth Switch

(ES) for 1 second.

40

10. Rated Peak current (kAp) ofMS and EB

100

11. Rated short circuit (kApeak)making current of E.B.

100

12. Special requirements a) Earthing blades shall be capable to

discharge the trapped charge of the line.

b) Isolator Main switch shall be required to

make or break line charging currentwhen no significant change in voltage

occurs across the isolating distance on

account of make or break.

13. Basic insulation level

1) Lightning impulse with

stand voltage: (kVpeak)

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a) To earth

b) Across isolating

distance

2) Rated power frequency

withstand voltage(kVrms)

a) To earth

b) Across isolating

distance

650

1200

270

530

14. Minimum Creepage (mm)

distance

3625

15. Rated Mech. Term load

i) Straight load (kg.)

ii) Across load (kg.)

102

33.65

16. Rated Magnetising (Amp.)

current / capacitive currentmake and break

0.7

17. Phase to phase spacing (mm)

for installation2700

18. Minimum Clearances (mm)

i. Phase to earth

ii. Phase to phase

1300

1300

19. Required ground clearance

from the lowest live part from

the top of the concrete plinth( mm )

4600

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20 Derating factor for specified

site condition1

21 Rain hood HDG MS,20 SWG

22 Cross section Area of movingBlade/contacts

1250Amp >1000 sq. mm

23 Nos of operation the isolatorcan make without

deterioration of contact

1000

24 Insulators base plate HDG MS plate 10 mm thick

25 Contact zone As per IS 9921

2.4 GENERAL TECHNICAL REQUIREMENTS

2.4.1 Type of disconnects

The disconnector, with support structure and without terminal connectors, shall be threephases gang operated horizontal Single break type with turn and twist type moving blades

and vertical break earth blades as per requirement given in scope of supply.

2.4.2 Current carrying parts

Material of earthing blades and contacts shall be the same as those of main switch moving

blades and contacts respectively. Cross sectional area of earthing blades and contacts shall

not be less than 50% of cross sectional area of main blades and contacts. The earthingblades shall have the same short time current rating (thermal and dynamic) as that of main

switch.

2.4.3 Current density:

Current density, to be adopted for all the parts of isolator shall not exceed the followinglimits:

i) Hollow tube sections - Copper - 2.0 A/sq. mm.

ii) Other sections - Copper - 1.6 A/sq. mm.

2.4.4 Insulators:

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cantilever strength of minimum 4 KN.

The insulators shall be provided with a completely galvanized steel base designfor mounting on the support. The base and mounting arrangement shall be such

that the insulator shall be rigid and self supporting and no guying or crossbracings between phases shall be necessary. Three no of insulators per pole to be

provided

The insulator shall be made of homogenous and vitreous porcelain of highmechanical and dielectric strength. It shall have sufficient mechanical strength to

sustain electrical and mechanical loading on account of wind load, short circuit

process etc. Glazing of the porcelain shall be of uniform brown or dark brown

colour with a smooth surface arranged to shade away rain water. The porcelainshall be free from lamination and other flaws or imperfections that might affect

the mechanical or dielectric quality. It shall be thoroughly vitrified, tough and

impervious to moisture. The porcelain and metal parts shall be assembled in sucha manner and with such material that any thermal differential expansion between

the metal and porcelain through the range of temperature specified in this

specification shall not loosen the parts or create undue internal stresses whichmay affect the mechanical or electrical strength or rigidity. The assembly shall

not have excessive concentration of electrical stresses in any section or across

leakage surfaces. The cement used shall not give rise to chemical reaction with

metal fittings. The insulator shall be suitable for water washing by rain orartificial means in service conditions.

Cap to be provided on top of the insulator shall be of high grade cast

iron/malleable steel casting or aluminium alloy. It shall be machine faced and hotdip galvanized. The cap shall have four nos. of tapped holes spaced on a pitchcircle diameter of 127 mm. to accommodate the terminal clamp for supporting the

Customers busbars for 132 kV rating class of insulators. The holes shall be

suitable for bolts with threads having anticorrosive protection. The effectivedepth of threads shall not be less than the nominal diameter of the bolt. The

bottom P.C.D. for the 132 kV rating shall be 200mm.

The casting shall be free from blow holes, cracks and such other defects.

All the ferrous metal parts shall be hot dip galvanized smoothly as IS 3638 (as

amended upto date), IS 2623 or any other equivalent authoritative standard. Thematerial shall be galvanised only after shop operations upon it have beencompleted. The metal parts before galvanization should be thoroughly cleaned of

any paint, grease, rust, scales or alkalies or any foreign deposits which are likely

to come in the way of galvanization process. The metal parts coating shallwithstand minimum four one minute dips in copper sulphate solutions as per IEC-

168.

The insulator unit shall be assembled in a suitable jig to ensure correct

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positioning of the top and bottom metal fittings relative to one another. The facesof the metal fittings shall be parallel and at right angle to the axis of the insulator

and corresponding holes in the top and bottom metal fittings shall be in a vertical

plane containing the axis of the insulator.

It shall be the sole responsibility of the Tenderer to carry out thorough inspection

and quality checks on the insulators at the insulator Tenderer works, beforeoffering the insulators for Customer's inspection.

2.4.5 Operating Mechanism:

Manual operating mechanism individual operated through a crank and reduction gear

shall be provided for switch. In addition, three phase AC Motor, operated mechanism

shall be provided for main switch of motorised isolators.

Manual operated mechanism individual operated through a lever/handle on operating shaftshall be provided for earth switch

2.4.6 Motor

Motor shall be suitable for 3-phase 415V AC supply with variations as specified

in this specification.

Motor shall be squirrel cage induction motor suitable for direct-on-line (DOL)starting and shall generally confirm to IS 325.

Motor shall be total enclosed surface cooled (TESC) type with IP- 67 protectionclass after mounting on actuator.

It shall be possible to separate the motor from the lubricant filled gearing of

actuator allowing easy replacement of motor without loosing any lubricant

regardless of mounting position.

Motor shall be minimum class F insulation with temperature rise restricted to

class B.

The motor shall withstand, without damage, stalled torque for at least three timesthe duration of tripping device.

Motor shall be intermittent duty with following duty rating: open/close dutyactuators 20 starts/hour.

The operating mechanism shall provide quick, simple and effective operation. The

design shall be such that one man shall be able to operate the isolator without undue

effort. The main switch shall close or open with about 20 (TWENTY) revolutions of

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the crank. The earth switch shall close or open by rotation of lever/hand through 90degrees. The operating mechanism shall be suitable to hold the main switch or earth

switch in closed or open position to prevent operation by gravity, wind, short circuit,

seismic acceleration, vibration, shock, accidental touching etc.

2.4.7 Control Cabinet

The control cabinet of each operating mechanism shall be made out of 10 SWG

thick) sheet steel or 10 mm thick aluminum in the form of plate or casting.Control cabinet shall be provided with hinged doors along with pad 10 SWG

thick arrangements. Sloping rain hood shall be provided to cover all sides. 15 mm

thick neoprene or better type of gaskets shall be provided to ensure degree ofprotection of at least IP55 as per IS 2147. The cabinet shall be suitable for fixing

on support structure with adjustment for vertical horizontal and longitudinal

alignment. Details of the arrangement provided for such adjustment as well as for

sealing shall be furnished along with the tender.

The disconnector may be required to operate occasionally, with considerably longidle intervals. Special care shall be taken for selection of material for gear and

lubrication of gears to meet this requirement. The gears shall be made of

aluminum, bronze or any other better material and lubricated for life with

graphite or better quality non draining and non hardening grease. Completedetails of components, material, grade, self lubricating arrangement, grade of

lubricants, details of jig, fixtures and devices used for quality check shall-be

furnished by the tenderer.

2.4.8 Gland plate and glands

A removable gland plate with double compression type brass cable glands shall beprovided with each operating mechanism for terminating all cables.

2.4.9 Auxiliary switch:

The operating mechanism for main switch shall be equipped with eight Nos. eachof NO and NC and operating mechanism for earth switch shall be equipped with

four Nos. of NO and NC separate and reliable auxiliary switches exclusively for

Customer's interlocking and protection scheme. The Customer shall use these

switches either directly or through contact multiplication relays for variousprotection schemes.

The auxiliary switches and auxiliary circuits shall be capable of carrying current

of at least 10 Amps continuously.

Auxiliary switches shall be capable of breaking at least 2 A in a 220 VDC circuit with

a time constant of not less than 20 milliseconds.

The main requirement of the Aux. contacts of the Isolator is that Aux. contacts should

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close before the primary (Main) contact closes and open after the primary contactopens.

The auxiliary switches shall be actuated by a cam or similar arrangement directly

mounted on the isolator shaft without any intermediate levers, linkages etc. toensure fool-proof operation.

2.4.10 Terminal block and wiring

Each operating mechanism shall be provided with 1100V grade stud type

terminal block. All auxiliary switches, interlocks and other terminals shall be

wired upto the terminal block. The terminal block shall have at least 20 percentextra terminals. All wiring shall be carried out with 1100V grade PVC (Poly

Vinyle Chloride) insulated 2.5 sq.mm copper conductor. Maximum conductor

temperature shall be as per I.S.:3961.

2.4.11 Interlocking

Isolator Main switch and earth switch are required to be interlocked with associatedswitchgear and protection schemes through auxiliary contacts. It shall not be possible

to operate the isolator and the earth switch without meeting the interlocking

conditions. Further, mechanical interlocking between main switch and earth switch

shall also be provided. Electrical interlocking shall be suitable for 220V d.c. supply.The device shall ensure locking the disconnector when in de energised condition. It

shall be possible to engage the crank for operation by energising the device through

push button, only when all interlocking contacts are through. Any modifications to

scheme suggested by the Customer on scrutiny of the offer shall be acceptable to thetenderer.

2.4.12 Control Circuits

Control device shall store OPEN and CLOSE command even if the corresponding

switch is momentarily pressed until the command is fully executed and the

components get de-energised after execution. Failure of auxiliary power supply orloose contact shall not cause faulty operation.

2.4.13 Limit Switch

Limit switches to cut off power supply to motor at either end of travel shall beindependent. An auxiliary switch shall not be used as limit switch. Details of

make, rating and type of limit switch shall be furnished in the offer.

2.4.14 Overload and Single Phasing Preventer

Suitable relay/device shall be provided to prevent over-loading of the motor.

Single phase preventer shall be provided to operate on open circuiting of any

phase and shall trip off the motor. Complete details of the devices shall be

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furnished in the offer.

2.4.15 Contactor

The contactor shall be suitable for making and breaking stalled motor current. Thecontactor coil shall be suitable for 220 V D.C. or 415 V A.C. with suitable inter-locking D.C. relay to cut off A.C. supply to the motor in accordance with the

interlocking scheme. Two Nos. of contactors shall be provided for each motor for

OPEN and CLOSE operation respectively. Make, type, rating and details of thecontactor shall be furnished in the offer.

2.4.16 Space heaters

Space heater suitable for 1 phase 240V A.C. supply shall be provided for each motoroperated operating mechanism to prevent condensation. A common switch and

individual, fuse/link shall be provided in one of the operating mechanisms of threepoles.

2.4.17 Interior illumination

A Control cabinet shall be provided with 240 V, 1-phase 50 Hz, 20W fluorescent

lighting fixture with on /off switch.

2.4.18 Power socket

A 1 phase 240V 15A, 3 pin power socket for hand-lamp / hand tools shall be provided

in one of the motor operated mechanisms of three poles.

2.4.19 Control and Auxiliary Supply

A 3 phase switch with HRC fuses for phases and link for neutral shall, beprovided for power supply and a 2 way switch with HRC fuses shall be provided

for control supply in the motor operated mechanisms of three poles.

2.4.20 Accessories

The accessories to be provided on the isolator shall include but not be limited tothe following:

2.4.21 Position Indicator:

A position indicator to show whether the isolator is in ON or OFF position.

2.4.22 Counter Balance Springs:

Counter balance springs, cushions etc. shall be provided to prevent impact at theend of travel both on opening and closing of the isolator. The springs shall be

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2.4.23 Name Plates

i) The disconnector shall be provided with a name plate. The nameplate shall

be weather proof and corrosion-proof. It shall be mounted in such a position

that it shall be visible in the position of normal service and installation. Itshall carry the following information duly punched or engraved on it.

ii) Isolators base

Name of the manufacturer :

A/T No :

Type, Designation :

Serial Number :

Rated voltage :

Rated normal current :

Rated short time current : M.S. E.S.

(kArms and duration in sec.)

Rated short time peak current : M.S. E.S.

(kAp)

Weight :

iii) Operating Device

Name of manufacturer :

A/T No :

Type, Designation :

Reduction gear ratio :

A. C. Motor

Rated auxiliary voltage :

Starting current :

Designation of AC motor as per IS: 4722 :

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Starting torque at 80'% of supply voltage.

Over travel in degrees after cutting off supply :

Total operating time in seconds.

CLOSE operation : electrical Manual

OPEN operation : electrical Manual

Space heater

Rated voltage and power :

Auxiliary contacts

Rated current (Amps) :

Time constant (ms) :

No. of contacts used (NC & NO) :

No. of free contacts (NC & NO) :

Terminal blocks & wiring

Rated current :

Voltage grade and type :

iv) Interlocking device

Type/ Make :

Voltage :

Wattage :

Any other particulars :

2.4.24 Padlocking device

i) The isolator and earthing switch shall be provided with padlock ingdevice to permit locking of the isolator and earthing switch in both fully open

and fully closed positions.

2.4.25 Signaling

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Signaling of the close position shall not take place unless the, movable contact has setin a position in which the rated normal current, the peak withstand current and the

short time withstand currant can be carried satisfactorily.

Signaling of open position shall not take place unless the movable contact hasreached the position such that the clearance between the contacts is at least 80%

of the isolating distance.

2.4.26 Earthing

Flexible copper connections shall be provided between rotating earth blades and theframe which shall have cross section of at least 50 sq.mm and shall be tinned or

suitably treated against corrosion.

The frame of each disconnector and earthing switch shall be provided with two

reliable earthing terminals for connection to the Customers earthing conductor /flat so also clamping screw suitable for carrying specified short time current. Thediameter of clamping screw shall be at least 12 mm. The connecting point shall

be marked with earth symbol.

2.5 Design and construction:

Full particulars of design, manufacture, jig, template and qualify control devices

developed for manufacture of the equipments offered in respect of the following

items shall be furnished with drawings and descriptions along with the tender.

i) Contacts, material, current density etc.

ii) Design of contact pressure

iii) Contact support and fixing arrangement on Insulators,

iv) Turn and twist mechanism, clamps locks etc.

v) Bearings, housing of bearings, bushes etc.

vi) Balancing of heights

vii) Coupling pipes, joints, connection adjustments

viii) Base plates

ix) Down pipe, guides joints.

x) Brass bushes and bearings at various joints

xi) Operating mechanism, type thickness of box, degree plate, gland etc.

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xii) Nuts, bolts and fasteners

xiii) Interlocking devices

All live parts shall be designed to have smooth surfaces without any sharp points,edges and other corona producing surfaces so as to eliminate corona at specifiedextinction voltage is not specified.

2.5.1 Fasteners

Nuts, bolts and washers of 5\8" and higher size shall be hot dip galvanised. Thebolts used on tapped holes of insulator cap shall be galvanised by centrifuge

process to avoid excess deposition of zinc on threads. Nuts, bolts and washers of

less than 5\8" size shall be of stainless steel .when used on live parts and nickelplated brass in other parts.

2.5.2 Contacts

Contacts shall be made out of hard drawn electrolytic grade copper. Arcing contactswherever provided shall close first and open last. The contact surface shall be silver

plated to 15 micron thickness. Fabrication shall be made with suitable jig to avoid

deviations during production. Details of size and shape of contacts, spring, back plate,fixing arrangements, design of contact pressure, life of contacts, limit of temperature

rise etc. shall be furnished along with the tender.

2.5.3 Terminal Pad

The Terminal pad shall be made out of electrolytic grade copper silver plated to 15

micron thickness. Dimensions of the terminal pad shall be furnished with holes by

tenderer. Earth switch terminal pad shall also be made of electrolytic grade copper.

2.5.4 Mounting of contacts

Fixed contacts shall be mounted on a block or channel welded to 10 mm thick

M.S. plate with holes for fixing on insulators. Slots shall be provided for marginaladjustment of height of contacts. The contacts shall rest on a brass block and with

Initial tension. Suitable device shall be provided to prevent from dashing,

fabrication, welding etc. shall be done in suitable jig to avoid deviations during

production.

2.5.5 Moving Blades

Moving blade shall be made of electrolytic grade copper.

Contact surface of moving blades shall be silver plated to 15 micron thickness. Thesurface shall be wiped during closing and opening operations to remove any film,

oxide coating etc. Wiping action shall not cause scouring or abrasion of surfaces.

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2.5.6 Turn and twist Mechanism

Turn and twist mechanism shall be provided with adequate locking to avoid openingor closing by wind, short circuit force etc. on moving blade. The springs shall be made

out or stainless steel or phosphor bronze or any other better material to have adequatestrength and resilience and shall be encased with grease to avoid exposure in rain. The

clamps and plates shall be made out of at least 10mm thick M.S. Plate or flat.Fasteners with nylock nuts shall be used wherever necessary. Vulnerable parts shall be

fabricated by tubular gas cutting or milling. The entire mechanism shall be fabricated

in suitable jig and template to avoid deviations during production.

2.5.7 Bearings

Rotating - insulator shall be mounted on housing with bearings. The housing shall

be made of gravity die cast Aluminum with smooth surfaces and suitably

machined for seating the bearings. Two nos of bearings with adequate shaftdiameter and distance between the bearings shall be provided to avoid wobbling

during operations. The bearings shall be of at least 75 mm internal diameter for145kV class rating isolators. The bearings shall be of reputed make and

lubricated for life. All other friction locations shall be provided with suitable

bearings of stainless steel or brass bushes. The bearings bushes, joints, springs

etc. shall be so designed that no lubrication shall be required during the service.Complete details of bearings bushes, housing, greasing etc. shall be furnished

with the tender.

2.5.8 Balancing of height

Fixed insulators shall be provided with elevator base plate with four studs for

balancing of heights. Thickness of plate and diameter of stud shall be 10mm and25mm respectively, for isolators of rated voltage of 145 kv and above. Adequate

numbers of nuts, lock nuts and washers shall be provided. Taper washer shall be

provided to match inclined surface of steel sections.

2.5.9 Tandom Pipe

Tandom pipes shall be of at least 25mm ID and class B. Tandom pipes shall be

used for phase coupling of Single break, isolators. Base plate of insulators for

connection of tandom pipe shall be made out of one piece of at least 10mm thickM.S. Plate. Bolt and shackle device shall be used to connect tandem pipe to the

bass plate. Wherever unavoidable sliding clamps may be used. These

clamps shall be made out of at least 10 mm thick M.S. Flat with four nos. of nutsand bolts. A grub screw shall be provided for securing connection on tandem

pipes.

2.5.10 Down Pipe

50mm ID class B pipe shall be provided for operating disconnects. The pipe shall

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be terminated into a suitable swivel or universal type joint between the insulatorbottom bearing and the operating mechanism to take care of marginal angular

misalignment at site. All brackets, guides etc. shall be mounted on the base of the

isolator. Arrangement of mounting any guide, bracket, part etc. on support

structure except the operating mechanism and the base shall not be accepted.

2.5.11 Base

Each phase of isolator shall be provided with a rigid base fabricated from steelsections made out of hot rolled Steel. The base channel shall be a composite

frame connected back to back in the case of 245 kV rating Isolators. The base

channel size and weight shall be as per I.S. 808(1989) or any latest I.S. and shallnot be less than 125 x 65.mm for 245 kV rating Isolators. The base shall be

suitable for mounting or support structures. Fabrication, welding etc shall be

done by suitable jig, power press, templates to avoid deviations during

production. Details and dimensions of sections, jig, templates and device used forproduction of the base shall be furnished with the offer.

2.5.12 Assembly

The disconnector shall be fully assembled at the works of the tenderer. Typicaloperations shall be carried out 'on each type of fully assembled disconnector to

ascertain that all parts fit correctly and function satisfactorily.

2.5.13 Painting, galvanizing and climate proofing

All interiors and exteriors of enclosures, cabinets and other metal parts shall bethoroughly cleaned to remove all rust, scales, corrosion, grease and otheradhering foreign matter and the surfaces treated by recognized phospating (e.g.

seven tank phospating sequenced). After such preparation of surfaces, two coats

of zinc oxide primer shall be given by suitable staving and air drying ate. before

final painting. Colour of the final paint shall be of shade 631 of IS: 5 i.e. lightgray. The final painted cubical shall present asthetically pleasing appearance free

from any dent or uneven surface.

Paint inside the metallic housing shall be of anti-condensation type and the paint

on outside surfaces shall be suitable for' outdoor installation.

All ferrous parts not suitable for painting such as structural steel pipes rods,

levers, linkages, nuts and bolts used in other than current path etc. shall be hotdip galvanized. Galvanization shall be done after completion of fabrication which

shall be done after completion of fabrication which shall be capable to prevent

corrosion in view of the severe climatic conditions. Thickness of zinc coatingshall not be less than 610gm of zinc per sq. meter of surface. Zinc coating shall

be smooth clean and of uniform thickness and free from defect. Preparation of

galvanizing and the galvanizing itself shall not adversely affect the mechanicalproperties of the coated material. The affect the mechanical properties of the

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coated materials. The quality shall be established by tests as per IS2633.Galvanising of nuts and bolts shall be carried out by centrifugal or suitable

process so that the bolts will easily fit into the tapped holes/nuts.

All components shall be given adequate treatment of climate proofing as perIS:3202 so as to withstand corrosion and severe service conditions.

Complete details of painting, galvanizing and climate proofing of the equipments

shall be furnished in the offer.

2.6 TESTS

2.6.1 Type Tests

Short time current test

Lightening impulse test

(Dry/Wet) power impulse test

Temperature rise test

Mechanical endurance test

IP- 55 Test

IP- 67 Test

High volt test on solid core post insulator test

Additional Test applicable as per IS

2.6.2 Routine Test /Acceptance Test

Visual and dimension check

Voltage test on control & Auxiliary circuit

Measurement of resistance of the main circuit

Mechanical operation test

Additional Test applicable any

The equipment/material offered should have been successfully type tested in anyNABL (National Accreditation Board for Testing and Calibration Laboratories)

accredited test laboratory in line with relevant standards, amended up to date,

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Standard and Technical Specification within the last 5(five) years prior the dateof opening of the Tender. The Tenderer shall be required to submit four (4)

copies of the Type Test Reports along with the offer. In case these type tests are

conducted earlier than five years all the type tests shall be carried out by the

successful Tenderers in the presence of Customers representative free of cost.

If there is any change in the components or design in the equipment since after earlierpassing of the Type Test, the Tenderer shall bring out in his offer all such changes

made in the components, materials, designs etc. In such case the Tenderer shall

carryout the Type Tests at his cost and in the presence of Customer's representative.

Even if the equipment /material has been Type Tested earlier, the Customer reserves

the right to demand repetition on one or more tests included in the list of Type Tests inthe presence of Customer's representative. For this purpose the Tenderer shall quote

unit rates for carrying out each Type Test included in the list of type tests as per

relevant Standard and Tender Specification.

During the type test the disconnector shall be mounted on its own supportstructure of equivalent support structure and installed with its own operating

mechanism to make the type test representative. Drawing of equivalent support

structure if any and mounting arrangements made for type test shall be furnishedfor Customers approval before conducting the type tests.

The type tests shall be conducted on the disconnector along with approvedinsulators and terminal connectors.

Mechanical endurance test shall be conducted on the main switch as well as earthswitch on one disconnector of each type.

The Customer reserves the right to conduct Type Tests included in list of Type

Tests on requisite number of samples/ items from any of the lots during the

presence of Customers representatives. If the equipment/material doesntwithstand the Type Test then the equipment / material supplied till then will be

liable for rejection. These Type Tests shall however be conducted by the

Tenderer within a reasonable time. After successful passing of the Type Tests, allthe equipments/material supplied earlier shall be modified in line with the

equipment/materials which has successfully passage the Type Test. Incase

Tenderer fails to carryout the Type Tests within reasonable time or doesn't agreeto carryout the Type Tests at his cost, his equipment/material supplied earlier

shall be rejected and order placed shall be cancelled and payments made earlier

for these supplies shall be recovered by the Customer.

2.6.3 Acceptance and Routine Tests

All acceptance and routine tests as stipulated in the relevant standards shall be carried

out by the Tenderer in presence of Customer's representative.

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Mechanical operation test (routine test) shall' be conducted on the completedisconnect (Main switch and Earth switch) at Tenderer's works and a certified

test report be furnished to the Customer. Alternatively the tenderer may offer to

conduct this test at Customer's substation in which case the Customer shall makenecessary arrangement to erect the disconnector at his substation site under

supervision of tenderer's representatives (if necessary) in case this test is offered

to be conducted at site. Expenses of the tenderer's representative for supervisionshall not be borne by the Customer.

The test report of power frequency voltage withstand test conducted on theinsulator shall be furnished for Customers acceptance in lieu of conducting the

power frequency (dry) test on main circuit (routine test).

Immediately after finalization of the programme of type/acceptance/routine

testing, the Tenderer shall give three weeks' advance intimation to the Customer,

to enable him to depute representative for witnessing the tests.

2.6.4 Special Tests

Test on insulators IS:2544

Test on insulators IEC-168

Operation test on operating mechanism and interlocking.

Endurance test on auxiliary switches

Test certificates and documents in respect of following items shall be furnished at

the time of routine tests.

i) Chemical analysis of copper along with a copy of central excise

certificate/gate pass indicating genuine source or procurement of electrolyticgrade copper.

ii) Bearings

iii) Fasteners

iv) Universal / Swivel joint coupling

v) Insulators

vi) Gears

vii) Auxiliary Switch

viii) Interlocking Devices

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ix) Terminal block

The Customer may at his discretion request additional test certificates for otheritems as reasonably required to substantiate the quality of the same.

2.7 DOCUMENTATION

After award of contract, the bidder shall submit 3 sets of drawings/documents to

Purchaser/Consultant giving details, for scrutiny and approval. Once the drawingshave been approved, no alteration or modification will be carried out without prior

approval of the Purchaser.

The manufacturing of the equipment shall be strictly in accordance with the approved

drawing and no deviation shall be permitted without the written approval of thepurchaser. All manufacturing and fabrication work in connection with the equipment

prior to the approval of the drawing shall be at the BIDDER's risk.

Approval of drawing/work by purchaser shall not relieve the BIDDER of his

responsibility and liability for ensuring correctness and correct interpretation ofthe latest revision of applicable standards, rules and code of practices.

After award of contract, the bidder shall also submit 2 sets of type test reports to C.E.(Tr. Pl.) for scrutiny and approval, before commencement of supply.

Adequate copies of acceptance and routine test certificates, duly approved by the

purchaser, shall accompany the dispatch consignment.

2.8 INSPECTION

2.8.1 The inspection may be carried out by the Customer at any stage of manufacture. Thesuccessful Tenderer shall grant free access to the Customer's representative at a reasonable

time when the work is in progress. Inspection and acceptance of any equipment under this

specification by the Customer, shall not relieve the Tenderer of his obligation offurnishing equipment in accordance with the specification and shall not prevent

subsequent rejection if the equipment is found to be defective. The Tenderer shall keep the

Customer informed in advance about the manufacturing programme so that arrangement

can be made for inspection.

2.8.2 The Customer reserves the right to insist for witnessing acceptance/routine testing ofthe bought out items.

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2.9.1 The tenderer shall invariably furnish QAP for information along with his offer.

3.0 INSTRUMENT TRANSFORMERS

3.1 Scope of supply

3.1.1 132kV, single phase, outdoor and oil immersed type, 5 core current transformer 12 nos.

3.1.2 132kV, single phase, outdoor and oil immersed type, 1 core current transformer 6 no.

3.1.3 132kV, single phase, outdoor and oil immersed type, 3 winding capacitor voltage

transformer 6 nos.

3.1.4 132kV, single phase, outdoor and oil immersed type, 1 winding capacitor voltage

transformer 6 nos.

3.1.5 Engineering, Design, fabrication, manufacture, assembly, shop testing including type test

as specified and inspection at manufacturers works.

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3.1.6 Providing all labours, materials and equipment for testing at site as required.

3.1.7 Unloading and storage at site.

3.1.8 All spare parts required for commissioning of the equipment/system covered under thisspecification.

3.1.9 Recommended Spares for two (2) years of trouble free operation

3.1.10 Special tools and tackles required for operation and maintenance inspection and repair of

the equipment/system offered.

3.2 Standards

3.2.1 CURRENT TRANSFORMER

SI.No. Standard No. Title

1. IS-2165 Insulation co-ordination of highest voltages for equipment.

2. IS-2705(I-IV) Current Transformers

3. IS-2099 High voltage porcelain bushing.

4. IS-3347 Dimensions of porcelain transformer bushing.

5. IS-2071 Method of high voltage testing.

6. IS-335 Insulation oil for transformers and switchgears.

7. IS-2147 Degree of protection provided by enclosures for low

voltages, switchgear and control.

8. IEC-44-1 Current transformers.

9. IEC-270 Partial discharge measurement.

10. IEC-44(4) Instrument transformer measurement of PDs.

11. IEC-171 Insulation co-ordination.

12. IEC-60 High voltage test techniques.

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13. IEC-8263 Method of RIV tests on high voltage insulators.

14. IEC-60044 International standard.

3.2.2 POTENTIAL TRANSFORMERS

SI.No. Standard No. Title

1. IS-3156 Voltage transformers.

2. IS-2099 High voltage porcelain bushings.

3. IS-3347 Dimensions of porcelain transformer bushing.

4. IS-335 Insulating oil for transformers and switchgears.

5. IS-3202 Code of practice for climate proofing of electrical

equipments.

6. IS-2147 Degree of protection provided by enclosures for low voltage

switchgears and controls.

7. IEC-186 Voltage transformers.

8. IEC-815 Porcelain housing for instrument transformers.

3.3 PRINCIPAL TECHNICAL PARAMETERS

3.3.1 Current transformers

SI.No. Technical Parameter Requirement

1. Type of CT/ Installation Single phase, Live tank, Outdoor, Oilfilled and Hermetically sealed

2. Type of mounting Pedestal type

3. Suitable for system frequency 50 Hz

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reconnection at CT terminals

5. Method of earthing the system to

be connected to

Solidly Effectively earthed

6. Rated continuous thermalcurrent(A)

120% of the rated primary current

7. Acceptable limit of temperature

rise above the specified ambient

temperatures for continuousoperation at rated current

As per IS 2705/ IEC 44-1

8. Acceptable partial discharge level

at 1.1 times the rated voltage

As per IEC 44.1

9. Max .radio interference voltage at

1.1 times the rated voltage

Less than 500 micro volts

10. Current Ratio

Nominal system voltage 132kV

Number of core CT ratio /

Accuracy class / Burden

As Per Annexure-I

11. Rated system voltage / Highestsystem voltage (kV rms)

145kV

12. Basic Insulation level(kVp) 650

One minute dry power frequency

withstand voltage primary(kVrms) (Dry/Wet)

270

One minute power frequency

withstand voltage secondary (kVrms)

3

13. Rated short time withstand current 40

Consultant:


Bangalore & Chennai

section-4. technical specification for 220kv switchyard

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