Pgcil-latest Testing Format

FOR INTERNAL CIRCULATION ONLY DOC NO. D-2-01-03-01-02

PRE-COMMISSIONING PROCEDURES AND FORMATS FOR SUBSTATION BAY EQUIPMENT

पावर िमड कारपोरे शन ऑफ इं डया िलिमटे ड केिय ूचालन सेवाऐं POWER GRID CORPORATION OF INDIA LIMITED CORPORATE OPERATION SERVICES

APRIL-2008

POWER GRID CORPORATION OF INDIA LTD. PRE-COMMISSIONING PROCEDURES / ी किमशिनंग

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DOC NO: D-2-01-03-01-02- SECOND REVISION / ि तीय संशोधन

CONTENTS SR. NO

PAGE NOS

PARTICULARS

1.0

PRE-COMMISSIONING EQUIPMENT

PROCEDURES

FOR

SUBSTATION

BAY

01-03

2.0

TRANSFORMER AND REACTOR

04-17

2.1

Checks after receipt of Transformer/ Reactor at site

04-06

2.2

Insulating oil

06-07

2.3

Oil filling

08-11

2.4

Hot Oil Circulation using High Vacuum Filter Machine

11-12

2.5

Procedure for Dry Out of Wet Winding of Transformer/ Reactor by Vacuum Pulling, N2 filling and Heating

13-14

2.6

Relation between different units (conversion of units)

2.7

Check list for energization of Transformer/ Reactor

16-17

3.0

PRE-COMMISSIONING CHECKS/ TESTS FOR TRANSFORMERS & REACTORS

18-32

3.1

Core Insulation Check

20

3.2

Operational checks on Protection System

20

3.3

Insulation Resistance (IR) Measurement

20-21

3.4

Capacitance & Tan Delta Measurement of Bushing

3.5

Capacitance and Tan δ measurement of windings

3.6

Turns ratio (Voltage ratio) measurement

3.7

Vector Group & Polarity

24-25

3.8

Winding resistance measurement

25-26

3.9

Magnetic Balance test

26-27

3.10

Floating Neutral point measurement

27

3.11

Measurement of Short Circuit Impedance

27

3.12

Exciting/Magnetising current measurement

28

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3.13

Vibration measurement of Oil-immersed Reactor

28

3.14

Operational checks on OLTCs

29-30

3.15

Stability of Differential, REF of Transformer/ Reactor

30-31

3.16

Tests/ Checks on Bushing Current Transformers (BCTs)

3.17

Frequency Response Analysis (FRA) measurement

3.18

Dissolved Gas Analysis (DGA) of oil sample

32

3.19

Thermovision Infra-red scanning (IR thermography)

32

4.0

PRE-COMMISSIONING CHECKS/ TESTS FOR OTHER SWITCHYARD EQUIPMENTS

33-55

4.1

C & Tan δ measurement of CT, CVT, CB voltage grading capacitor & Surge Arresters

36-39

4.2

Checks/ Tests applicable for CTs

39-43

4.3

Checks/ Tests applicable for Circuit Breakers

43-50

4.4

Checks/ Tests applicable for CVTs

50

4.5

Checks/ Tests applicable for Isolators

51

4.6

Checks/ Tests applicable for Surge Arrestors

51-52

4.7

Checks/ Tests for other areas/ equipments

52-55

5.0

PRE-COMMISSIONING FORMATS FOR SWITCHYARD EQUIPMENTS

5.1

No. CF/CT/01/R-2 DATED 31/12/07 - CURRENT TRANSFORMER

08 pages

5.2

No. CF/CVT/02/R-2 DATED 31/12/07 - CVT

05 pages

5.3

No. CF/BAY/03/R-2 DATED 31/12/07 - BAY/FEEDER

09 pages

5.4

No. CF/SA/04/ R-2 DATED 31/12/07 - SURGE ARRESTOR

5.5

No. CF/CB/05/ R-2 DATED 31/12/07 - CIRCUIT BREAKER

5.6

No. CF/ICT/06/ R-2 DATED 31/12/07 - ICT

5.7

No. CF/SR/07/ R-2 DATED 31/12/07 - SHUNT REACTOR

5.8

No. CF/ISO/08/ R-2 DATED 31/12/07 - ISOLATOR/GROUND SWITCH

5.9

No. CF/WT/09/ R-2 DATED 31/12/07 - WAVE TRAP

31 31-32

03 pages 14 pages 25 pages 16 pages 05 pages 02 pages



1.0

PRE-COMMISSIONING EQUIPMENTS

1.1

Introduction

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PROCEDURES

FOR

SUBSTATION

BAY

Pre-commissioning checks/ tests are the activities carried out to ascertain the correctness, completeness of installation and healthiness of the equipment before its energization. These checks/ tests are to be carried out by Contractor’s representative in the presence of POWERGRID’s authorised representative. 1.2

Constitution of commissioning team

1.2.1

A Commissioning team should be constituted as per procedures laid down in Works & Procurement Policy and Procedures (Clause C2.15.4.6 of WPPP Vol. II), which shall oversee/ coordinate with erection agency/ manufacturer for the pre-commissioning test and charging of the equipment. In case of Substation, commissioning team shall consist of following: (i) I/C of Substation Construction (ii) O&M executive not below Manager (iii) T&C executive not below Sr. Engineer

1.2.2

The responsibilities of the commissioning team are to go through the storage history of each equipment, review the pre-commissioning test results and clear the equipment for energization (as described in section 1.2.3), go through statutory clearances and standing instructions before initial charging of new equipment, witness final commissioning tests and test charging, investigate failure of equipment during test charging, declare commencement of trial operation and evaluate guaranteed test results and recommend acceptance as may be provided in the contract, list out deviations/ exception/ incomplete work, for acceptance/ rejection (Clause C2.15.4.7 of WPPP Vol-II). Proper documentation also to be ensured by the commissioning team based upon the observations for the above for future reference.

1.2.3

The results of all pre-commissioning tests after erection of individual equipment as per requirement of guidelines issued by Corporate OS or in line with manufacturer’s recommendation, carried out jointly by the execution site in association with T&C executive and testing engineer of manufacturer/erection agency (including clearance for charging given by the manufacturer) shall be put up to the Commissioning Team for its acceptance and clearance for charging (Clause C2.15.4.8 (iv) of WPPP Vol-II).

1.2.4

The Commissioning Team shall examine the following statutory and other clearances obtained by Execution Site prior to clearance for test charging of the equipment/transmission line at rated voltage: Statutory Clearances: a) Electrical Inspector’s Clearance (provisional or final) for charging transmission line/bay equipment as per I.E. rules. b) P.T.C.C. clearance. c) Copy of notification informing public/administration regarding charging of the line. d) Forest Clearance 1of 55



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Other Clearances: a) Charging instruction from SEF Group of Corporate Engineering. b) Relay setting details from Corporate Engineering. (Clause C2.15.4.8 (v) of WPPP Vol-II) 1.2.5

The Team shall also go through the factory test reports. If such tests have been repeated during pre -commissioning, the Team shall list out deviations, if any, in the results of pre-commissioning tests with respect to the factory tests. (Clause C2.15.4.8 (vii) of WPPP Vol-II)

1.2.6

After all pre-commissioning checks and tests are found to be acceptable taking into account permissible deviation limits, the commissioning team, in consultation with regional O&M, shall give clearance for commissioning test. (Clause C2.15.4.8 (viii) of WPPP Vol-II)

1.2.7

In case of deviation in commissioning test results beyond permissible limit as per guidelines/standards in vogue, the commissioning team shall submit its report along with recommendations to the concerned DGM. In such an event, the test charging will be carried out only after obtaining approval of Head of O&M of the Region based on a proposal of execution site in consultation with regional OS. (Clause C2.15.4.8 (ix) of WPPP Vol-II)

1.3

Safety All measures and precautions should be undertaken to prevent occurrence of unsafe acts. All the personnel involved should be thoroughly apprised about the safe procedures to be adopted while performing various activities including carrying out tests in the switchyard. Warning signs and Safety barriers should be positioned in conformity to IE rules as amended from time to time.

1.4

General Procedures during Pre-commissioning of Substation Bay Equipment All the equipment after erection/assembly at site, should be tested in order to check that it has not been damaged during transport, erection/assembly to such an extent that its future operation will be at risk. The significance of various tests with brief procedure has been elaborated in the subsequent sections of this document. Regarding the detailed testing methods / procedures for conducting various pre-commissioning tests refer to Doc. No. D-2-03-XX-01-01: Maintenance Procedures for Switchyard Equipments-Part 1: EHV Transformers & Reactors and Doc No. D-2-03-XX-01-01 –Part 2: Other Switchyard Equipments.

1.5

Documentation The results of the test shall be documented on the test record formats as mentioned below, which are also part of this documentation:

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Sl. No. 1. 2. 3. 4. 5. 6. 7. 8. 9.

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FORMAT NO. No. CF/CT/01/R-2 DATED 01/04/08 No. CF/CVT/02/R-2 DATED 01/04/08 No. CF/BAY/03/R-2 DATED 01/04/08 No. CF/SA/04/ R-2 DATED 01/04/08 No. CF/CB/05/ R-2 DATED 01/04/08 No. CF/ICT/06/ R-2 DATED 01/04/08 No. CF/SR/07/ R-2 DATED 01/04/08 No. CF/ISO/08/ R-2 DATED 01/04/08 No. CF/WT/09/ R-2 DATED 01/04/08

EQUIPMENT CURRENT TRANSFORMER CVT BAY/FEEDER SURGE ARRESTOR CIRCUIT BREAKER ICT SHUNT REACTOR ISOLATOR/GROUND SWITCH WAVE TRAP

These formats have all the possible test recordings to be performed at site before energization. Switching and operational activities will be recorded in regular manner in the operator’s log. Copies of this log, notes on special observations from inspections and other measurements will constitute the test records. The test records had to be signed by the responsible personnel from the OEM, the supplier, the erection agency and the POWERGRID representative. The test formats/records are to be distributed to Regional O&M office and Concerned Sub-Station library.

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2.0

TRANSFORMER AND REACTOR

2.1

Following points to be checked After Receipt of transformer / reactor at Site:

2.1.1

N2 pressure and Dew point to be checked after receipt of transformer at Site. It should be within permissible band (as per graph provided by manufacturer & given below in Fig-1)

2.1.2

The data of impact recorder shall be analyzed jointly in association with the manufacturer. In case the impact recorder indicates some serious shocks during shipment, further course of action for internal inspection, if necessary shall be taken jointly. Impact Recorder should be detached from the Transformer/ Reactor preferably when the main unit has been placed on its foundation.

2.1.3

Oil Samples shall be taken from oil drums/ tanker received at site and sent to our Lab (CIOTL / IOTL) for oil parameter testing. The copy of test certificate of routine testing at oil refinery should be available at site for comparison of test results.

2.1.4

Unpacking and Inspection of Accessories to be carried out taking all precautions so that the tools used for opening do not cause damage to the contents. Fragile instruments like oil level gauge, temperature indicators, etc. are to be inspected for breakage or other damages. Any damaged or missing components should be reported to equipment manufacturer, so that the same can be investigated or shortage made up as per the terms/ conditions of the contract.

2.1.5

Core Insulation Test shall be carried out to check insulation between Core (CC&CL) and Ground. (Not applicable for Air Core Reactors) Graph showing variation of Pressure v/s Temperature of gas for gas filled unit during Transport or storage Lb / in 2

Gauge Pressure – Kg/ Cm2

5 4.5 4.0 3.5 3.0

0.35

A2

0.3 0.25

A1

0.2

2.5 2.0 1.5 1.0 0.5

0.15 0.1 0.05 0.05 0.05

-30

-20

-10

0

10

20

30

40

50

Temperature in ˚ C Example: For 40 ˚C Temperature (Depending upon the pressure of gas at the time of filling), - minimum pressure of gas can be 0.185 Kg/ Cm2 at point A1 - maximum pressure of gas can be 0.32 Kg/ Cm2 at point A2

Figure-1 : Graph depicting variation of N2 gas pressure w.r.t temperature 4of 55



2.1.6

2.1.7

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After receiving the accessories at site same should be inspected and kept ready for immediate erection: •

If erection work can not start immediately due to some reasons, then accessories should be repacked into their own crates properly and packing list should be retained.

•

All packings should be kept above ground by suitable supports so as to allow free air flow underneath. The storage space area should be such that it is accessible for inspection, water does not collect on or around the area and handling/transport would be easy. Proper drainage arrangement in storage areas to be ensured so that in no situation, any component get submerged in water due to rain, flooding etc.. Immediately after the receipt of main unit and also the accessories, same should be inspected and if found satisfactory, the unit should be erected completely and filled with dry transformer oil as per the instruction.

•

It is preferable to store the main unit on its own location/foundation. If the foundation is not likely to be ready for more than three (3) months, then suitable action plan has to be taken from the manufacturer regarding proper storage of the Main Unit.

•

If the transformer/ Reactor is to be stored up to three (3) months after arrival at site, it can be stored with N2 filled condition. N2 pressure to be monitored on daily basis so that chances of exposure of active part to atmosphere are avoided. In case of drop in N2 pressure, dew point of N2 has to be measured to check the dryness of the Transformer/ Reactor.

•

In case of storage of transformer in oil-filled condition, the oil filled in the unit should be tested for BDV and moisture contents once in every three months. The oil sample should be taken from bottom valve. If BDV is less and moisture contents are more than as given for service condition then oil should be filtered.

During erection, the exposure of active part of transformers should be minimized. Further either dry air generator should be running all the time or dry air cylinders may be used to minimize ingress of moisture. The transformer should be sealed off after working hours. It is practical to apply a slight overpressure overnight with dry air or N2 inside – less than 300 mbar (30 kPa or 0.3 atmospheres). Next day the pressure is checked and suspected leaks may be detected with leak detection instruments , with soap water or with plastic bags tightened around valves (being inflated by leaking air) For oil filled units whenever oil is drained out below the inspection covers, job will be treated as exposed. Other exposure activities are as below: 1) Bushing erections 2) Jumper connections of Bushings 4) Fixing bushing turrets on cover 5) Fixing bushing turrets on side 6) Core insulation checking 7) Buchholz relay pipe work fixing on cover. 8) Gas release pipes/equaliser pipe fixing. 9) Entering inside the tank for connections/inspection etc. For oil filled units depending upon the level up to which the oil is drained decides the exposure time. All such exposure time should be recorded in a log sheet to decide the oil 5of 55



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processing (drying) and oil filling of transformer. For transformers with a gas pressure of 2.5- 3 PSI, the acceptable limits of dew point shall be as under: (Source: Courtesy BHEL, Bhopal) Temperature of Maximum Maximum Temperature Permissible dew Permissible dew of Insulation Insulation in °C point in °C point in °F in °F 0 -78 -17.77 -61.11 5 -74 -15.0 -58.88 10 -70 -12.22 -56.66 15 -66 -9.44 -54.44 20 -62 -6.66 -52.22 25 -58 -3.33 -49.99 30 -53 -1.11 -47.22 35 -48 +1.66 -44.44 40 -44 +4.44 -42.22 45 -40 +7.44 -39.39 50 -35 +9.99 -37.22 55 -31 12.77 -34.99 60 -27 15.55 -32.77 65 -22 18.33 -29.99 70 -18 23.11 -27.77 75 -14 23.88 -25.55 80 -10 26.66 -23.33 85 -6 29.44 -21.11 90 -1 32.22 -18.33 95 +3 34.99 -16.11 100 +7 37.75 -13.88 110 +16 43.33 -8.88 120 +25 48.88 -3.88 130 +33 54.44 +0.55 140 +44 59.99 +5.55 TABLE 1- Variation of Dew Point of N2 Gas Filled in Transformer Tank w.r.t Temperature

2.2

Insulating Oil When oil is dispatched to site separately it is usually in sealed steel drums. The oil to be used to filling and topping up must comply with oil specification given in POWERGRID Technical Specification for acceptance criteria. Before oil is accepted, samples have to be taken and checked with respect to dielectric strength and dielectric losses. The latter is important, since dirty transportation vessels can significantly contaminate the oil. High dielectric losses cannot be removed by filter treatment, such lots have to be rejected. If the oil is supplied in railroad or trailer tanks, one or two samples are sufficient. If the oil is delivered in 200 litres drums, the following scheme for checking is recommended. 6of 55



Number of drums delivered

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No. of drums to be checked

2 to 5 6 to 20 21 to 50 51 to 100 101 to 200 201 to 400

2 3 4 7 10 15

However, before filling oil, each drum has to be physically checked for free moisture and appearance. In case any doubt arises, number of drums to be checked needs to be increased. A register needs to be maintained indicating the number of drums supplied in each lot as per LOA and number of drums of each lot used in filling a particular Transformer/ Reactor. The oil test results carried out as above should also be recorded. 2.2.1 Samples from Oil Drum Check the seals on the drums. The drum should first be allowed to stand with bung (lid) vertically upwards for at least 24 hours. The area around the bung should be cleaned & clean glass or brass tube long enough to reach to within 10mm of the lower most part of the drum should be inserted, keeping the uppermost end of the tube sealed with the thumb while doing so. Remove the Thumb thereby allowing oil to enter the bottom of the tube. Reseal the tube and withdraw an oil sample. The first two samples should be discarded. Thereafter, the sample should be released into a suitable receptacle. 2.2.2 Parameters of Transformer Oil The oil as received at site for filling and topping up in the transformer must comply with oil specification given in POWERGRID Technical Specification for acceptance criteria. The oil sample from the transformer tank, after filling in tank before commissioning should meet the following specifications as per IS: 1866 – 2000 (latest Revision) given in table-2 below: Table-2 Sr. No. 1. 2. 3. 4. 5. 6. 7 8. 9. 10. 11. a. b. 12.

Property Breakdown Voltage (BDV) (kV rms)-Min Moisture content –(ppm) Max Dielectric Dissipation Factor (Tan δ) at 90 ºC and 40-60Hz -Max Resistivity at 90 ºC-Min ( x 1012 ohm-cm) Interfacial Tension (mN/m) -Min Viscosity at 27ºC-Max – cSt Density at 29.5ºC gm/cm3 - Max Flash point ºC – Min Pour point ºC – Max Neutralization Value mg KOH/gm of oil –Max Oxidation Stability of Uninhibited Oil Neutralization Value mg KOH/gm of oil –Max Sludge percent by mass – Max Oxidation Stability for Inhibited Oil

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Highest Voltage of Equipment <72.5 kV 72.5 – 170 kV >170 kV 40 50 60 20 15 10 0.015 0.015 0.01 6 35 27 0.89 140 -6 0.03 0.4 0.1

6 35 27 0.89 140 -6 0.03

6 35 27 0.89 140 -6 0.03

0.4 0.4 0.1 0.1 Similar values as before filling



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2.3 Oil Filling (For detailed Oil filling procedure, please refer to Appendix-2 of Doc. No. D-2-03-XX-01-01: Maintenance Procedures for Switchyard Equipments-Part 1: EHV Transformers & Reactors) Introduction: For transformer dispatched with gas filled from the works, the filling of oil inside the tank is done under vacuum. Transformer of high voltage ratings and their tanks are designed to withstand full vacuum. Manufacturer’s instructions should be followed regarding the creating of full vacuum during filling the oil in the tank. Final tightness test with vacuum (i.e. leakage test or Vacuum Drop Test): Before the oil filling is started, a final check is made of the tightness of the transformer tank by applying vacuum. When any vacuum is applied to a transformer, empty of oil, a leakage test must be carried out to ensure that there are no leaks on the tank which would result in wet air being drawn into the transformer. The procedure is as follows: • • • • • • • •

Connect the vacuum gauge to a suitable valve of the tank.(Vacuum application and measurement should perform only on top of the main tank) Connect the vacuum pump to another opening. Evacuate the transformer/ reactor tank until the pressure is below 3 mbar ( 0.3 kPa or about 2 mm of Hg) Shut the vacuum valve and stop the pump. Wait for an hour and take a first vacuum reading – say P1 Take a second reading 30 minutes later- say P2 Note the quantity of oil required, according to the rating plate, and express as a volume, V, in m3 . The maximum permitted leakage is 20 bar x litres/ second Take the difference between P2 and P1, and multiply this with the oil quantity V. If the pressures are expressed in kPa, and the oil quantity in m3, then the product shall be less than 3.6. (P2 – P1) x V < 3.6

• •

The transformer is then considered to be holding sufficient vacuum and is tight. Continued readings (at least 2 to 3) at successive 30 min intervals may be taken to confirm the result. If the leak test is successful, the pumping will be continued, until the pressure has come down to 0.13 kPa (1 Torr) or less. The vacuum shall then be held for the time given in Table-4 before the oil filling starts. If the specified vacuum cannot be reached, or if it does not hold, the leak in the transformer system shall be located and corrected.

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This vacuum must be maintained for the time specified as per the voltage class in table-4 before and should also maintain during the subsequent oil filling operations by continuous running of the vacuum pumps. When filling a transformer with oil it is preferable that the oil be pumped into the bottom of the tank through a filter press or other reliable oil drying and cleaning device should be interposed between the pump and the tank. In case the transformer is provided with an On Load Tap Changer (OLTC), while evacuating the main transformer tank, the diverter switch compartment may also be evacuated simultaneously so that no undue pressure is allowed on the tap changer chamber. While releasing vacuum, the tap changer chamber vacuum should also be released simultaneously. For this one pressure equalizer pipe should be connected between main tank and tap changer. Manufacturer’s instruction manual should be referred to protect the air cell/diaphragm in the conservator during evacuation. The oil must pass from the oil tanker, or settling tanks, through an oil conditioning plant to the top oil filter valve (please refer Fig-2) and the oil must conform to the quality requirements as given in POWERGRID- Transformer Oil Specification. The oil flow at the entry valve must be controlled to maintain a positive pressure above atmospheric and to limit the flow rate if necessary to 5000 litres / hour, or a rise in oil level in the tank not exceeding one metre / hour (as measured on the oil level indicator) Continue oil filling until the level reaches approximately 200 mm above the ambient oil level indicated on the magnetic oil level gauge in the expansion vessel. Then, release the vacuum, with dry air of dew point -40deg C or better. The diverter tank can now be topped up at atmospheric pressure. Reconnect oil outlet hose to valve on flange on tap changer diverter head. Reinstate breather and very slowly top up the diverter switch such that the correct level is reached in the diverter expansion vessel. In the event the expansion vessel is overfull drain oil from flange into a suitable container until the correct level is reached. When the vacuum filling of the transformer and diverter tank is complete, the cooling system/ Radiator bank can be filled (WITHOUT VACUUM) at atmospheric pressure, via an oil processing plant. Oil must be admitted, very slowly, through the bottom cooler filter valve, with the cooler vented at the top and the top cooler filter valve unblanked and open to atmosphere. As the oil level reaches the vents and open valve, close off and shut down the processing plant. Note: Care must be taken not to pressurise the coolers/ radiators. Upon completion, open the top cooler isolating valve in order to equalise the pressure in the cooler with the transformer tank. This will also allow contraction or expansion of the oil as the ambient temperature changes.

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Valve near B. RELAY towards Conservator

B.R.

A

B VACUUM PUMP

SUMP

Compound Pressure & Vacuum gauge Filter on any 1” Sampling or 2” Filter Valve

C

Tank Oil Gauge/ Transparent hose for Level monitoring TRANSFORMER TANK

OIL STORAGE TANK

Top Filter Valve

FILTER MACHINE

D.O.F. Filter Valve If not, then BTM Filter Valve

Figure-2 : Arrangement for Evacuation and Oil filling upto tank Oil gauge & Conservator Before oil filling into conservator inflate the air cell to 0.5 PSIG i.e. 0.035kg/cm2 max. slightly by applying pressure (N2/Compressed dry air) so that it can take shape. Release pressure. Fit breather pips but do not fit breather in position, instead put wire mesh guard over and flange of the pipe. This will ensure free air movement from the air cell to the atmosphere. Use flow meter / indicator on outlet of filter machine and regulate the flow using the valve to limit oil filling rate to 2000 litres per hour max. in case filter capacity is more. Push oil slowly into conservator through the transformer via valve No. 5 (valve 2,3 & 4 to remain open) till the oil comes out first through valve Nos.2 & 3 (close these valves) and then through valve No. 4. Allow some oil to come out through valve No.4. Oil should come out freely into the atmosphere. This will ensure that air inside the conservator is expelled out and the space surrounding the air cell is full of oil. (Close valve No. 4). During all these operations valve No.1 to remain closed. Drain oil from the conservator by gravity only through valve No. 1 or through drain valve of the transformer via valve No. 5. Do not use filter machine for draining oil from the conservator. Also do not remove buchholz relay and its associated pipe work, fitted between the conservator and the transformer tank while draining oil. Stop draining oil till indicator of magnetic oil level gauge reaches position-2 on the dial, which is corresponding to 30°C reading on the oil temperature indicator. 10of 55



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Figure-3 : General Arrangement For Oil Conservator After Oil filling, Hot Oil Circulation has to be applied to all the Transformers/ Reactors expect under the circumstances when active part of Transformer/ Reactor gets wet. Following conditions can be considered to define the Transformer/ Reactor wet: 1. 2. 3.

If Transformer/ Reactor received at site without positive N2 pressure. If Dry air not used during exposure while doing erection activities Overexposure of active part of Transformer/ Reactor during erection (Overexposure when exposure > 12 Hrs)

Under above mentioned conditions, Manufacturer shall take necessary action for effective dry out of the Transformer/ Reactor. However general guidelines for dry out in such cases is given in section 1.4.2 2.4 HOT OIL CIRCULATION USING HIGH VACUUM OIL FILTER MACHINE To ensure total impregnation and absorption of possible trapped gas bubbles, the oil in the tank is to be circulated through the vacuum filter and with circulation direction as shown in Fig.-4. The circulation procedure for the main tank is as follows: 2.4.1 2.4.2

The Transformer/ Reactor is connected to the filter in a loop through the upper and lower filter valves. The direction of circulation shall be from the filter to the transformer at the top and from the bottom of the transformer to the filter. The temperature of the oil from the filter to the Transformer should be around 60 ˚ C and in no case it should go beyond 70 ˚ C otherwise this may cause oxidation of oil.

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2.4.3

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The circulation shall proceed until a volume of oil has passed through the loop corresponding to 2 times the total oil volume in the tank. (At freezing ambient temperature the circulation time is increased: circulate 3 times the volume at temperature down to minus 20 ˚ C, increase to 4 times below that temperature).

The oil will be circulated through a vacuum filtration machine till the parameters are attained as per IS 1866 - 2000, Table-3 below: KV CLASS

B.D.V ( Min )* (KV)

Moisture ( Max ) * (ppm)

Tan Delta ( MAX ) * (90 Deg C)

Resistivity ( Min ) * (Ohm-Cm)

IFT at 27 Deg. ( Min )* N/m

> 170 KV

60

10

0.01

6 x 10 12

0.035

< 170 KV But > 72.5 KV

50

15

0.015

6 x 10 12

0.035

< 72.5 kV

40

20

0.015

6 x 10 12

0.035

Table-3 * The limiting values given in the above table-3 to be revised as per revision in IS 1866 in future

Top Filter Valve

TRANSFORMER TANK Vacuum Filter

Filter Machine Inlet

Filter Machine Outlet

Figure-4: Arrangement for Hot Oil Circulation and Filteration

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Bottom Filter Valve



2.5

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PROCEDURE FOR DRY OUT OF WET WINDING OF TRANSFORMER/ REACTOR BY VACUUM PULLING, N2 FILLING AND HEATING

The drying of a new Transformer/ Reactor required when the moisture get absorbed by the solid insulation used in Transformers/ Reactors due to various reasons. The process of drying out a transformer is one requiring care and good judgment. If the drying out process is carelessly or improperly performed, a great damage may result to the transformer insulation through over heating, etc. In no case shall a transformer be left unattended during any part of the dry out period. The transformer should be carefully watched through out the dry-out process and also observations shall be carefully recorded. When the transformer is dried out it is necessary to ensure that fire fighting equipment is available near the transformer. 2.5.1

Isolation Required: All the openings of transformer main tank like openings for coolers/radiators, conservator, OLTC etc. is to be properly isolated and totally blanked.

2.5.2 Procedure: a. Fill the main transformer/ reactor tank with Nitrogen (Use only Dry N2 gas as per IS: 1747 with 50 ppm moisture and 1% oxygen by volume) until it comes to a positive pressure of 0.15 Kg/cm2. It is kept at least 48 hrs. At the end of 48 hrs, dew point of N2 at outlet is measured. If the dew point is not within acceptable limits as per Table-I, dry out method should be continued. b. Heating from outside: While N2 circulation is in progress, the heaters are to be installed around the transformer tank as shown in the Annexure. The heaters are to be kept ON until we achieve a temperature of about 75–80 deg C of the core & winding of transformer. c. Vacuum Pulling: After ascertaining that there is no leakage, pull out vacuum and keep the transformer/reactor under near absolute vacuum (1-5 torr) for about 96 hours running the vacuum pump continuously. The duration of vacuum can vary between 48 to 96 hrs depending upon the dew point being achieved. Keep Vacuum machine ON and collect condensate for measurement. Observe the rate of condensate collection on hourly basis. Depending on the value of rate of condensate, continuation of further vacuum shall be decided. d. Nitrogen Circulation: Then the vacuum is broken with dry nitrogen. The dew point of nitrogen at the inlet is to be measured and should be of the order of - 50 °C or better. When the nitrogen comes to the positive pressure of 0.15 kg/cm2, it is stopped and kept for 24 hours. Heating from outside is to be continued while N2 circulation is in progress. Then the nitrogen pressure is released and the outlet nitrogen dew point is measured. If the dew point is within acceptable limits as per Table-I then the dryness of transformer is achieved. If not again the transformer is taken for vacuum treatment and then nitrogen is admitted as mentioned above and tested. The cycle to be continued till desired dew point as per Table-I is achieved. e. Periodicity: Periodicity of vacuum cycle may vary between 48-96 hrs. Initially two N2 cycles may be kept for 24 hrs. After that it may be kept for 48 hrs depending upon dew point being achieved. 13of 55



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After completion of drying process, oil filling and hot oil circulation to be carried out before commissioning. Please ensure standing time as per table-4 given below before charging. Transformer HV Rated Voltage (in kV) Up to 145kV 145 kV and up to 420kV Above 420 kV

Application of Vacuum & holding for (before oil filling ) (in Hours) 12 HRS 24 HRS

STANDING TIME After Oil circulation and before energising (in Hours) 12 HRS 48 HRS

36 HRS

120 HRS

Table-4 After the expiry of this time, air release operation to be carried out in Buchholz relays and other release points given by the manufacturers before charging. For subsequent activities, proceed to format no. CF/ICT/06/ R-2 DATED 31/12/07 for ICT & format No. CF/SR/07/ R-2 DATED 31/12/07 for Reactor.

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2.6 RELATION BETWEEN DIFFERENT UNITS (CONVERSION OF UNITS):

Pressure: 1 bar = 105 Pa = 750 Torr = 14.5 psi = 1.02kg/cm2 1 Torr = 1.33 mbar = 0.133 kPa 1 kPa(kilo-Pascal) = 103 Pa = 10 mbar = 7.501 Torr(mm of mercury) 1 MPa = 106 Pa 1 atmosphere=0.1 MPa=1.02kg/cm2= 14.5 psi Force: 1 kp = 9.807 N Weight: 1 ton=1000 kg=2200 lbs Temperature: 5 * (° F - 32) 9 9 ° F = * (° C )+ 32 5

°C=

Volume: 1m3= 1000 litres=260 US gallons=220 Imp gallons 1 litre =0.26 US Gallons 1 US Gallons = 3.78 litres 1 litre =0.22 Imp Gallons 1 Imp Gallons Benchmarks: 1-mm mercury (Torr) is about 1 millibar or 0.1 kPa 1 m3 of oil weights 0.9 tons –say 1 ton 1000 US gallons of oil weights 3.5 tons

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2.7

CHECK LIST FOR ENERGISATION OF TRANSFORMER/ REACTOR

2.7.1

PRELIMINARY CHECKS

1. Release air at the high points, like oil communicating bushings, buchholz petcock, tank cover and the cooling devices including headers, radiators, pumps, expansion joints etc. of the transformer. Air release should be resorted from low points to high points. 2. Check the whole assembly for tightness and rectify where necessary. 3. Check the general appearance and retouch the paint work if need be. 4. Check that the valves are in the correct position : • Tank : valves closed and blanked • Cooling circuit : valves open • Conservator connection : valves open • By-pass: valves open or closed as the case may be. • On-load tap changer : valves open 5. Check that the silica gel in the breather is blue and that there is oil in the breather cup ( oil seal ) 6. Check that CC-CL-G are shorted 7. Check the oil level in the main conservator and the conservator of on-load tap changer, bushing caps, flanges, turrets, expansion bellows as per manufacturer’s recommendation. Level should correspond to 35º C mark on oil level gauges for BHEL transformers 8. Check the bushings : • Oil level ( bushings fitted with sight-glasses) • Adjustment of spark-gaps /arcing horn –gaps, if provided • Conformity of connection to the lines ( no tensile stress on the terminal heads) • Bushing CT secondary terminals must be shorted and earthed, if not in use. • Neutral bushing effectively earthed 9. Check the on-load tap changer : • Conformity of the positions between the tap changer control cubicle and the tap changer head • Adjustment of the tap-changer control cubicle coupling • Electric and mechanical limit switches and protective relays • Step by step operation- local and remote electrical operation as well as manual operation and parallel operation, if any • Signalling of positions 10. Check the quality of the oil: • Draw off a sample from the bottom of the tank • Carry out DGA and oil parameters test ( i.e. BDV, Moisture content, resistivity & tan δ at 90°C and IFT ) before energisation 16of 55



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11. Check the oil of OLTC chamber, if not good, drain and fill with filtered oil upto desired level. 12 Check that equalising link between OLTC tank and Main tank is removed 13 Extraneous materials like tools, earthing rods, pieces of clothes, waste etc. should be removed before energisation 2.7.2

CHECKING OF AUXILIARY AND PROTECTIVE CIRCUITS

1. Check temperature indicator readings and their calibrations 2. Check the setting and working of the mercury switches of winding and oil temperature indicators and presence of oil in the thermometer pockets • Follow the same procedure for the thermal replicas 3. Check the direction of installation of buchholtz relay. 4. Check the operation of the buchholz relay and the surge protective relay of the tap-changer : • Alarm and tripping • Protections and signals interlocked with these relays 5. Check the insulation of the auxiliary circuits in relation to the ground by 2 kV megger for 1 min. 6. Check the earthing of the tank and auxiliaries like cooler banks at two places. 7. Measure the supply voltages of the auxiliary circuits 8. Check the cooling system : • Check the direction of installation of oil pumps • Check the direction of rotation of the pumps and fans • Check the working of the oil flow indicators • Check the setting of the thermal overload relays • Go through the starting up sequences, control and adjust, if necessary, the relay time delays 9. Check that there is efficient protection on the electric circuit supplying the accessories and tightness of all electrical connections 10. Check the heating and lighting in the cubicles 11. Check the differential protection, over-current protection, restricted earth fault protection, over-fluxing protection etc. are in service and settings are as per CC/Engg recommendations. After the inspection / tests are completed, the transformer may be energised from the incoming side on NO LOAD. The initial magnetising current at the time of switching will be very high, depending upon the particular moment in the cycle. The transformer should always be soaked for few hours under constant care i.e. keep it energised for twelve hours. Excessive vibrations of radiator parts etc. should be located and corrected. The transformer hum should be observed for any abnormality. After that it may be checked for gas collection. Should the gas prove to be inflammable, try to detect the cause which may probably be an internal fault? If the breaker trips on differential /REF, buchholz or any other protective device, the cause must be investigated thoroughly before re-energizing the transformer/ reactor. After successful charging, performance of transformer / rector should be checked under loading; OTI/WTI readings should be monitored for 24 hours and ensured that they are as per loading. DGA samples may be sent as per Standard practice (after 24 hrs of energisation, one week, 15 days, one month and three months after charging, thereafter as per normal frequency of 6 months). Loading data may be forwarded to CC/OS and manufacturer (if requested by them). 17of 55



3.0

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PRE-COMMISSIONING CHECKS /TESTS FOR TRANSFORMERS & REACTORS Once oil filling is completed, various pre-commissioning checks/ tests are performed to ensure the healthiness of the Transformer/ Reactor prior to its energisation. Various electrical tests to be performed and their significance are given below.

Sr. No.

Name of Test Check point

/ Purpose of test/ check

3.1

Core insulation tests

3.2

Operational Checks Operational Checks on cooler bank (pumps & Fans), Breathers on protection System (silica gel or drycol), MOG, temperature gauges (WTI/OTI), gas actuated relays (Buchholz, PRD, SPR etc.) and simulation test of protection system

3.3

Insulation Resistance measurement

3.4

Capacitance and Tan Measurement of C1 & C2 Capacitance and Tanδ in UST mode. δ measurement of Changes in the normal capacitance of an insulator indicate bushings abnormal conditions such as the presence of moisture layer, short -circuits or open circuits in the capacitance network.

3.5

Capacitance and Tan Dissipation factor/Loss factor and capacitance measurement of δ measurement of winding is carried out to ascertain the general condition of the windings ground and inter-winding insulation

3.6

Turns ratio (Voltage To determine the turns ratio of transformers to identify any ratio) measurement abnormality in tap changers/ shorted or open turns etc

3.7

Vector Group Polarity

3.8

Winding resistance To check for any abnormalities due to loose connections, broken measurement strands and high contact resistance in tap changers

3.9

Magnetic test

To check the insulation between Core (CC&CL) and Ground

Test reveals the condition of insulation (i.e. degree of dryness of (IR) paper insulation), presence of any foreign contaminants in oil and also any gross defect inside the transformer (e.g. Failure to remove the temporary transportation bracket on the live portion of tap-changer part)

& To determine the phase relationship and polarity of transformers

Balance This test is conducted only in three phase transformers to check the imbalance in the magnetic circuit

3.10 Floating Neutral This test is conducted to ascertain possibility of short circuit in a point measurement winding. 3.11 Measurement of This test is used to detect winding movement that usually occurs Short Circuit due to heavy fault current or mechanical damage during transportation or installation since dispatch from the factory. Impedance 3.12 Exciting/Magnetising To locate defect in magnetic core structure, shifting of windings, current measurement failures in turn to turn insulation or problems in tap changers. These conditions change the effective reluctance of the magnetic circuit thus affecting the current required to establish flux in the 18of 55



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core To measure the vibrations of core /coil assembly in the tank of 3.13 Vibration measurement of Oil- the reactor. Movement of the core-coil assembly and shielding structure caused by the time–varying magnetic forces results in immersed Reactor vibration of the tank and ancilliary equipment. These vibrations have detrimental effects such as excessive stress on the core-coil assembly 3.14 Operational on OLTCs

checks To ensure smooth & trouble free operation of OLTC during operation.

3.15 Stability of This test is performed to check the proper operation of Differential, REF of Differential & REF protection of Transformer & Reactor by Transformer/ Reactor simulating actual conditions. Any problem in CT connection, wrong cabling, relay setting can be detected by this test. 3.16 Tests/ Checks on To ascertain the healthiness of bushing current transformer at the Bushing Current time of erection Transformers (BCTs) 3.17 Frequency Response To assess the mechanical integrity of the transformer. Analysis (FRA) Transformers while experiencing severity of short circuit current measurement looses its mechanical property by way of deformation of the winding or core. During pre-commissioning this test is required to ascertain that Transformer active part has not suffered any severe impact/ jerk during transportation. 3.18 Dissolved Gas Oil sample for DGA to be drawn from transformer main tank Analysis (DGA) of before commissioning for having a base data and after 24 hrs. of charging subsequently to ensure no fault gas developed after first oil sample charging. DGA analysis helps the user to identify the reason for gas formation & materials involved and indicate urgency of corrective action to be taken 3.19 Thermovision Infra- A thermo vision Camera determines the temperature distribution red scanning (IR on the surface of the tank as well as in the vicinity of the Jumper thermography) connection to the bushing. The information obtained is useful in predicting the temperature profile within the inner surface of tank and is likely to provide approximate details of heating mechanism. Thermovision scanning of transformer to be done at least after 24 hrs. of loading and repeated after one week.

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3.1

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CORE INSULATION TEST

This test is recommended before the unit is placed in service after receipt at site or following modifications to the transformer that could affect the integrity of its core insulation and at other times, when indicated by DGA (key gases being ethane and/or ethylene and possibly methane) or usually during a major inspection. For core-insulation to ground test, remove the cover of the terminal block, Disconnect the closing link that connects the two terminals CL-G. Apply 2.0 kV direct voltage between CL and CC + G (core grounding strap). The tank shall be grounded during the test. The insulation value after 1min. test-time should be minimum 10 MΩ for new transformer at the time of commissioning. Core insulation resistance is generally more than 100 MΩ for new assembled transformer when tested at factory. 3.2

OPERATIONAL CHECKS ON PROTECTION SYSTEM

• • • • •

• • • • 3.3

Operational Checks on Breathers (Conventional Silcagel or Drycol as supplied with the transformers) Visual check of MOG of Main Conservator Marshalling Box & Kiosk Checks Valve Operational Checks Checks on Cooling System Checks on cooling fans-rotation, speed & Control (Manual /temp /load) setting checks Checks on Cooling pumps- rotation, vibration/noise, oil flow direction Checks on temperature Gauges (OTI/WTI-Calibration and Cooler Control , alarm & trip setting tests Checks on gas actuated (SPRs/ PRDs/ Buchholz) relays –Operational checks by simulation as well as shorting the respective contacts as applicable Checks on tightness of Terminal connectors - micro-ohm measurement of each connection Checks on Transformer/ Reactor protection (differential, REF, Over-current & stability tests etc.) INSULATION RESISTANCE (IR) MEASUREMENT

IR measurements shall be taken between the windings collectively (i.e. with all the windings being connected together) and the earthed tank (earth) and between each winding and the tank, the rest of the windings being earthed. Before taking measurements the neutral should be disconnected from earth. Following table gives combinations of IR measurements for auto-transformer, three -winding transformer & Shunt Reactor. For Auto-transformer HV + IV to LV HV + IV to E LV to E

For 3 winding transformer HV + IV to LV HV + LV to IV HV + IV +LV to E

For

Shunt Reactor HV to E

Where HV-High voltage, IV-Intermediate voltage, LV-Low voltage/Tertiary voltage windings, E- Earth

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Unless otherwise recommended by the manufacturer the following IR values as a thumb rule may be considered as the minimum satisfactory values at 30°C (one minute measurements) at the time of commissioning. Rated Voltage class of winding 11kV 33kV 66kV & above

Minimum desired IR value at 1 minute (Meg ohm) 300 MΩ 400 MΩ 500 MΩ

Insulation resistance varies inversely with temperature and is generally corrected to a standard temperature (usually 20 °C) using table (Source: BHEL instruction Manual) as given below. Difference in temperatures ( °C) 10 20 30 40 50

Correction Factor (k) 1.65 2.6 4.2 6.6 10.5

The ratio of 60 second insulation resistance to 15 second insulation resistance value is called dielectric absorption coefficient or Index (DAI). For oil filled transformers with class A insulation, in reasonably dried condition the absorption coefficient at 30°C will be more than 1.3. Polarization Index Test is ratiometric test, insensitive to temperature variation and may be used to predict insulation system performance. The polarization index test is performed generally by taking mega ohm readings at the following intervals at a constant dc voltage: 1 min and then every minute up to 10 min. The polarization index is the ratio of the 10 min to the 1 min mega ohm readings. PI= R10 / R1 (dimensionless), Where PI is Polarisation Index and R is resistance The following are guidelines for evaluating transformer insulation using polarization index values: Polarization Index Insulation Condition Less than 1 Dangerous 1.0-1.1 Poor 1.1-1.25 Questionable 1.25-2.0 Fair 2.0 – 4.0 Good Above 4.0 Excellent A PI of more than 1.25 and DAI of more than 1.3 are generally considered satisfactory for a transformer when the results of other low voltage tests are found in order. PI less than 1 calls for immediate corrective action. For bushings, an IR value of above 10,000 MΩ is considered satisfactory.

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3.4

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CAPACITANCE AND TAN δ MEASUREMENT OF BUSHINGS

C& Tan δ measurement of bushings shall be done at 10kV with fully automatic test kit so as to have reliable test result. •

For 3-Ph auto-transformer, short together all 400kV, 220kV and Neutral (isolated from earth) Bushings. Also short all 33kV Bushings and earth the same. Measurement of C1 Capacitance and Tanδ: Connect the crocodile clip of the HV cable to the top terminal of the shorted HV/IV bushings. Unscrew the test tap cover, Insert a pin in the hole of the central test tap stud by pressing the surrounding contact plug in case of 245 kV OIP Bushing and remove the earthing strip from the flange by unscrewing the screw (holding earth strip to the flange body) in case of 420 kV OIP Bushing. Connect the LV cable to the test tap (strip/central stud) of the bushing under test to the C & TAN δ KIT through a screened cable and earth the flange body. Repeat the test for all Bushings by changing only LV lead connection of the kit to test tap of the Bushing which is to be tested Measurement of C2 Capacitance and Tanδ : HV lead to be connected to the test tap of the bushing under test (if required additional crocodile type clip may be used) and LV of the kit to be connected to the ground. HV of the bushing is to be connected to the Guard terminal of the test kit. Test to be carried out in GSTg mode at 1.0kV.

•

For measurement of 33kV Bushing Tan Delta, earth HV/IV Bushings (already shorted). Apply HV lead of the Test kit to shorted 33kV Bushings and connect LV lead of the test kit to Test tap of the Bushing under test.

•

Measurements shall be made at similar conditions as that of a previous measurement. The oil-paper insulation combination of bushings exhibit fairly constant tan delta over a wide range of operating temperature. Hence, effort is to be made for testing at temperature near to previous test and Correction factor need not be applied.

•

Do not test a bushing (new or spare) while it is in its wood shipping crate, or while it is lying on wood. Wood is not as good an insulator as porcelain and will cause the readings to be inaccurate. Keep the test results as a baseline record to compare with future tests.

•

It is to be ensured that C& Tan δ measurement of bushings and testing of turrets carried out before installation. This will prevent installation of bushings having C& Tan δ values beyond permissible limits.

•

It is to be ensured that Test Tap points are earthed immediately after carrying out the measurements for that particular Bushing and earthing of test tap to be ensured by carrying out continuity test.

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3.5

CAPACITANCE AND TAN δ MEASUREMENT OF WINDINGS

The combination for C & tanδ measurement of winding is same as that of measurement of IR value. The summery of probable combination is given below: AutoTransformer (Two winding) V HV + IV to LV V HV + IV to E LV to E

Test Mode

Shunt Test Reactor Mode

UST V HV to E GSTg GSTg

GST

3 winding Transformer

Test Mode

HV to LV1 HV to LV2 LV1 to LV2 HV to Ground LV1 to Ground LV2 to Ground

UST UST UST GSTg GSTg GSTg

Table 5: Combination for C & tanδ measurement of winding for various transformers/ Shunt Reactor

•

•

Ensure that test specimen is isolated from other equipments. Removal of Jumpers from Bushings is Pre-Requisite for C & Tan δ Measurement of Windings. For ICTs (Auto-Transformers): Shorting of all three phase Bushings (400kV&220kV) and neutral to be done. In case of single phase, 400kV, 220kV and neutral Bushings to be shorted Capacitance and Tan δ measurement of windings should be done in following combinations: Test No. 1.

2. 3. 4

5 6.

•

Winding Combination

Test mode

Cap Symbol

HV-IV/LV

UST

CHL

HV-IV/ LV+G HV-IV / LV with Guard HV-IV/LV

GST GSTg

CHL +C HG C HG

UST

CHL

Test lead Connection HV lead of test kit to HV/IV bushings of transformer LV lead of test kit to LV bushing of transformer -do- do-

Remarks

LV to Guarded

be

LV lead of test kit to HV/IV bushings of transformer HV lead of test kit to LV bushing of transformer -do-

LV/ HV-IV GST CHL +C LG +G LV/ HV-IV GSTg C LG -doHV to with Guard Guarded Table 6:.Winding combination for C & tan δ measurement for auto transformer

be

Measurement inter-check can be done by calculating C1= C2-C3 & C4= C5- C6 & DF1=C2DF2-C3DF3 / C2-C3= C4DF4-C5DF5 / C4-C5 Where C stands for capacitance and DF for dissipation factor or tan δ and attached suffix (1…6) denotes the sr. no. of test in above table. 23of 55



•

3.6

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For Reactors: All 400kV and neutral Bushings to be shorted. HV of the test kit to be connected to shorted Bushings and LV of the test kit to be connected to Earth connection. Measure the Capacitance and tan Delta in GST mode. Neutral connection with earth/ NGR to be isolated before the test. TURNS RATIO (VOLTAGE RATIO) MEASUREMENT

Ratio measurements must be made on all taps to confirm the proper alignment and operation of the tap changers. The test should preferably be performed by automatic Transformer turns ratio (TTR) meter. Open turns in the excited winding will be indicated by very low exciting current and no output voltage. Open turns in the output winding will be indicated by normal levels of exciting current, but no or very low levels of unstable output voltage. The turns ratio test also detects high-resistance connections in the lead circuitry or high contact resistance in tap changers by higher excitation current and a difficulty in balancing the bridge. Results of the transformation turns or voltage ratio are absolute, and may be compared with the specified values measured during factory testing. The turns ratio tolerance should be within 0.5 % of the nameplate specifications. For three phase Y connected winding this tolerance applies to phase to neutral voltage. If the phase-to-neutral voltage is not explicitly indicated in the nameplate, then the rated phase-to-neutral voltage should be calculated by dividing the phase-to-phase voltage by √3. 3.7

VECTOR GROUP & POLARITY

Polarity and phase-relation tests are of interest primarily because of their bearing on paralleling or banking two or more transformers. Phase-relation tests are made to determine angular displacement and relative phase sequence. Phase-relation or vector group verification test is performed on a three phase transformer or on a bank of three single-phase transformers. The details of Additive and Subtractive polarity are given in IS: 2026-Part 1 and IEC 60076-1. For a single-phase transformer having a ratio of transformation of 30 to 1 or less, the polarity test shall be done as following. The line terminal of high voltage winding (1.1) shall be connected to the adjacent line terminal low-voltage winding (2.1) as shown in figure below

1.1 1.2

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2.1

(a)

2.2



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Any convenient value of alternating voltage shall be applied to the full high-voltage winding and readings shall be taken of the applied voltage and the voltage between the right-hand adjacent high-voltage and low-voltage leads. When the later reading is greater than the former, the polarity is additive. When the later reading is less than the former (indicating the approximate difference in voltage between that of the high-voltage and low-voltage windings), the polarity is subtractive. The test shall be conducted with 3 phase, 415V supply. By the measured voltage data, it should be verified that the desired conditions of vector group and polarity are fulfilled Example for Y D11 - Connect neutral point and LV phase with Earth - Join 1R1 & 3R1 Terminals - Apply 415 , 3-φ supply to HV

1R1 3R1 3Y1 3B1 2R1

- Ensure 2R1-N=2Y1-N=2B1-N=Constant

N 2B1

1B1

- If 3R1-N>3Y1-N>3B1-N, and 3Y11B1>3Y1-1Y1

2Y1

1Y1

Vector group Yna0d11 is confirmed and polarity verified.

Fig 5: For HV-Star / LV-Delta Transformer Please Note: Most of the auto transformers in POWERGRID are of YD11configuration. 3.8

WINDING RESISTANCE MEASUREMENT

Preferably to be carried out using Automatic kit or V/I method. To reduce the high inductive effect it is advisable to use a sufficiently high current to saturate the core. This will reduce the time required to get a stabilized reading. It is essential that temperatures of the windings are accurately measured. Care shall be taken that self inductive effects are minimized. Care also must be taken to ensure that direct current circulating in the windings has settled down before the measurement is done. In some cases this may take several minutes depending upon the winding inductance. The winding resistance shall be preferably done when the difference in the top and bottom temperature of the winding (temperature of oil in steady-state condition) is equal to or less than 5°C. 25of 55



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The winding resistance should preferable be carried out last after completion of all other LV tests, as after this test core gets saturated and tests like magnetizing current, magnetic balance etc. carried out after winding test may be affected and indicate a misleading results, if the core is not de-magnetized before carrying out these tests. For star connected auto-transformers the resistance of the HV side is measured between HV terminal and IV terminal, then between IV terminal and the neutral AT ALL TAPS. The tap changer should be changed from contact to contact so that contact resistance can also be checked. Measurement of winding resistance to be carried out from tap position 1 to 17 and again from 17 to 9. While doing measurements in reverse order, 2 to 3 steps shall be enough. During tap changing operation, continuity check between HV to neutral to be carried out by analog multimeter while changing tap. For delta connected windings, such as tertiary winding of auto-transformers, measurement shall be done between pairs of line terminals and resistance per winding shall be calculated as per the following formula: Resistance per winding = 1.5 x Measured value Take the winding temperature reading while doing the resistance measurement. Calculate the resistance at 75°C as per the following formula R75 = Rt (235+75)/(235+t ), Where Rt = Resistance measured at winding temperature t The resistance value obtained should be compared with the factory test value. Results are compared to other phases in Star-connected transformers or between pairs of terminals on a Delta–connected winding to determine if a resistance is too high or low. Because field measurements make it unlikely that precise temperature measurements of the winding can be made, the expected deviation for this test in the field is 5.0 % of the factory test value. 3.9

MAGNETIC BALANCE TEST

This test is a low voltage test conducted at factory and site by applying single phase voltage between phase and neutral of a winding and measuring voltage induced in other two phases of the same winding. Keep the tap in nominal tap position. Disconnect transformer neutral from ground. Apply single phase 230 V across one phase of Highest Voltage (HV) winding terminal and neutral (call it v1) then measure voltage in other two HV terminals across neutral (call them v2 and v3 respectively). Repeat the test for each of the three phases. Repeat the above test for Intermediate Voltage (IV) winding also. The identical results confirm no damage due to transportation. The following points may be noted. Transformer neutral should be disconnected from ground (i) No winding terminal should be grounded, otherwise results would be erratic and confusing. (ii) Zero voltage or very negligible voltage induced in any of the other two phases shall be investigated. 26of 55



(iii)

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It is proposed that a set of readings should be taken for information and comparison later during service of the transformer.

Also the applied voltage may be expressed as 100% voltage and the induced voltage may be expressed as percentage of the applied voltage. This will help in comparison of the two results when the applied voltages are different. The voltage induced in the centre phase shall be 50 to 90% of the applied voltage. However, when the centre phase is excited then the voltage induced in the outer phases shall be 30 to 70% of the applied voltage. Zero voltage or very negligible voltage induced in the other two windings should be investigated. 3.10

FLOATING NEUTRAL POINT MEASUREMENT

This test is conducted by applying 3 phase 415 volt supply across HV windings or IV winding as the case may be after disconnecting the transformer neutral from the ground. For a healthy transformer, when 3 phase balance voltage is applied, the voltage between neutral and ground is zero or otherwise a negligible voltage will appear. But in case there is a short circuited winding, the voltage between the neutral and the ground is appreciable. This test will also help in detecting the gradual deterioration or development of fault in the winding during service. 3.11

MEASUREMENT OF SHORT CIRCUIT IMPEDANCE

This test is used to detect winding movement that usually occurs due to heavy fault current or mechanical damage during transportation or installation since dispatch from the factory. Ensure the isolation of Transformer from High Voltage & Low voltage side with physical inspection of open condition of the concerned isolators/disconnectors. In case tertiary is also connected, ensure the isolation of the same prior to commencement of testing The measurement is performed in single phase mode. This test is performed for the combination of two winding. The one of the winding is short circuited and voltage is applied to other winding. The voltage and current reading are noted. The test shall be conducted with variac of 0-280 V, 10 A, precision RMS voltmeter and ammeter. The conductors used for short-circuiting one of the transformer windings should have low impedance (less than 1m-ohm) and short length. The contacts should be clean and tight. The acceptable criteria should be the measured impedance voltage having agreement to within 3 percent of impedance specified in rating and diagram nameplate of the transformer. Variation in impedance voltage of more than 3% should be considered significant and further investigated.

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3.12

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EXCITING/ MAGNETISING CURRENT MEASUREMENT

This test should be done before DC measurements of winding resistance to reduce the effect of residual magnetism. Magnetising current readings may be effected by residual magnetism in the core. Therefore, transformer under test may be demagnetised before commencement of magnetising current test. Three-phase transformers are tested by applying Single-phase 10 kV voltage to one phase (HV terminals) and keeping other winding open circuited and measuring the current at normal, minimum and max. tap positions. Keep the tap position in normal position and keep HV and LV terminals open. Apply 1phase 10kV supply on IV terminals. Measure phase to phase voltage between the IV terminals and current on each of the IV terminals. The set of reading for current measurement in each of the tap position should be equal. Unequal currents shall indicate possible short circuits in winding. Results between similar single-phase units should not vary more than 10 % .The test values on the outside legs should be within 15 % of each other, and values for the centre leg should not be more than either outside for a three-phase transformers. Results compared to previous tests made under the same conditions should not vary more than 25%. If the measured exciting current value is 50 times higher than the value measured during precommissioning checks, then there is likelihood of a fault in the winding which needs further analysis. The identical results confirm no damage due to transportation. The availability of test data of normal condition and faulty condition results help us to analyze the problem in future. 3.13

VIBRATION MEASUREMENT OF OIL-IMMERSED REACTOR

Movement of the core-coil assembly and shielding structure caused by the time –varying magnetic forces results in vibration of the tank and ancillary equipment. These vibrations have detrimental effects such as excessive stress on the core-coil assembly. The shunt reactor under test shall be completely assembled in normal operating condition with cooling equipments, gauges and accessories. The shunt reactor shall be energised at rated voltage and frequency. Three phase excitation for 3-ph units. The shunt reactor should be mounted on a level surface that will provide proper bearing for the base, in order to eliminate the generation of abnormal tank stresses. The vibration of shunt reactor shall be measured by transducers, optical detectors or equivalent measuring devices. The measuring equipment should be accurate within +/10 % at 2nd harmonic of the exciting frequency. The peak-to-peak amplitude shall be determined by direct measurement or calculated from acceleration or velocity measurement. The average amplitude of all local maximum points shall not exceed 60 µm (2.36 mils) peak to peak. The maximum amplitude within any individual reading shall not exceed 200 µm (7.87 mils) peak to peak. . 28of 55



3.14

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OPERATIONAL CHECKS ON OLTC

Following checks should be carried out during pre-commissioning: Before applying voltage to the Transformer, the mechanical operation of tap changer and motor drive for step by step operation to be checked as follows: ¾ Manual Operation: The tap changer has to be run manually by the hand crank through the total operating cycle. In each operating position, the position indicators of motor drive and tap changer (On TC head) show the same position. ¾ Motor drive for step by step tap changing operation: Push button to be kept pressed till the motor stops i.e. driving motor should be automatically switched off when the tap changer has performed one switching operation. (Note: At the time of change over selector operation (i.e. 9b to 10 & vice-versa), higher torque is required. Tap changer end position should be checked that the same is not overrun to avoid any failure during operation. Same can be seen through the inspection glass in the tap changer head cover. With the tap-changer fully assembled on the transformer the following sequence of operations shall be performed: a. With the transformer un-energised, one complete cycles of operations (a cycle of operation goes from one end of the tapping range to the other, and back again). Check continuity of winding during this test. Ensure that the voltmeter needle does not deflect to zero. b. With the transformer un-energised, and with the auxiliary voltage reduced to 85% of its rated value, one complete cycle of operation. c. With the transformer energized at rated voltage and frequency at no load, one complete cycle of operation. The following additional check points /guide lines for OLTC is recommended in consultation with OLTC manufacturer to ensure the absence of problems and proper operation: a) Function of control switches b) OLTC stopping on position c) Fastener tightness d) Signs of moisture such as rusting, oxidation or free standing water and leakages e) Mechanical clearances as specified by manufacturer’s instruction booklet f) Operation and condition of tap selector, changeover selector and arcing transfer switches g) Drive mechanism operation h) Counter operation, Position indicator operation and its co-ordination with mechanism and tap selector positions i) Limit switch operation j) Mechanical block integrity k) Proper operation of hand-crank and its interlock switch l) Physical condition of tap selector m) Freedom of movement of external shaft assembly n) Extent of arc erosion on stationary and movable arcing contacts o) Inspect barrier board for tracking and cracking 29of 55



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p) After filling with oil, manually crank throughout entire range q) Oil BDV and Moisture content (PPM) to be measured and recorded (Min BDV should be 60 KV and Moisture content should be less than 10 PPM) 3.15

STABILITY OF DIFFERENTIAL, REF OF TRANSFORMER/ REACTOR

This test is performed to check the correctness of CT polarity, CT secondary core connections, connections at relay terminals and operation of relay under fault conditions. 3.15.1 REF STABILITY TEST FOR TRANSFORMER

1) After opening the C.B. and isolators at both side (H.V. and L.V. side) of transformer, use “Primary Test Tap (M point or PI1/PI2)” provided in the BUSHING TURRET CTs to bypass the Transformer with the help of Primary current injection leads. Now, after ensuring completion of all CT wiring & normal polarity, inject Current with the help of Primary Injection kits in the relevant Turret CTs of R phase & Neutral, subject to the maximum rating of Primary Test Tap. 2) Measure the spill current in REF relay which should be nearly zero. 3) Switch off Current Injection. 4) Reverse the polarity of R phase Bushing CT and again start Current Injection. Appreciable spill current will appear in REF relay. 5) Normalize the CT circuit which was reversed in step no. (4), after switching off Current injection. 6) Repeat the same procedure for Y and B phases and note down the results in formats. 7) Normalise the connections of CT. 8) This test has to be performed from both HV side & LV side w.r.t. Neutral. However, if Primary Test Tap is not available in the Turret CTs, adopt following procedure;

1) After opening the C.B. and isolators at both side (H.V. and L.V. side) of transformer apply 440V three phase voltage at three phase bushing of H.V. side with the help of three phase variac. 2) Earth the R phase of the LV side (through isolator earth switch or discharge rod). 3) Measure the spill voltage (in mV)/ spill current (in mA) to REF relay which should be nearly zero. 4) Switch off 440V supply. 5) Reverse the polarity of R phase Bushing CT and again switch on 440V supply. Appreciable spill voltage/ current will appear in REF relay. 6) Normalize the CT circuit which was reversed in step no. (5), after switching off 440V supply. 7) Repeat the same procedure for Y and B phases and note down the results in formats. 8) Normalise the connections of CT and remove feeding of three phase supply. 3.15.2 REF STABILITY TEST FOR REACTOR

1) After opening the C.B. and isolators of Reactor, use “Primary Test Tap (M point or PI1/PI2)” provided in the BUSHING TURRET CTs to bypass the Reactor with the help of Primary current injection leads. Now, after ensuring completion of all CT wiring & normal polarity, inject Current with the help of Primary Injection kits in the relevant 30of 55



2) 3) 4) 5) 6) 7)

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Turret CTs of R phase of Reactor & earth side CT of NGR, subject to the maximum rating of Primary Test Tap. Measure the spill current in REF relay which should be nearly zero. Switch off Current Injection. Reverse the polarity of R phase Bushing CT and again start Current Injection. Appreciable spill current will appear in REF relay. Normalize the CT circuit which was reversed in step no. (4), after switching off Current injection. Repeat the same procedure for Y and B phases and note down the results in formats. Normalise the connections of CT.

However, if Primary Test Tap is not available in the Turret CTs, adopt following procedure; 1) After opening the C.B. and isolators of Reactor, remove the jumpers of three phase bushings. Reactor Neutral will remain connected to NGR, however Earth connection of NGR Bushing will be opened. 2) Apply 415 volts, phase to phase voltage across R phase bushing of Reactor & earth side Bushing of NGR, after ensuring completion of all CT wiring & normal polarity. 3) Measure the spill voltage (in mV)/ spill current (in mA) in REF relay which should be nearly zero. 4) Switch off 415V supply to Reactor / NGR Bushing. 5) Reverse the polarity of R phase bushing CT. 6) Switch on 415V supply to Reactor / NGR Bushing. 7) Appreciable spill voltage/ current will appear in REF relay. 8) Now normalize the polarity of the Bushing CT which was reversed in step (5). 9) Repeat the same procedure for Y and B phase and note down the results in formats. 10) After completing the test for all three phases normalize the reactor CT connection and jumpers & Earth connection of NGR Bushing. 3.16

TESTS/ CHECKS ON BUSHING CURRENT TRANSFORMERS (BCTS)

Continuity, Polarity and secondary winding resistance tests of individual cores of Bushing CTs 3.17

FREQUENCY RESPONSE ANALYSIS (FRA) MEASUREMENT

Frequency Response Analysis (FRA) is conducted to assess the mechanical integrity of the transformer which may get disturbed due to transportation shocks or Short Circuit forces experienced in service. FRA signatures will be taken after assembly and oil filling and compared with factory testing to ensure the healthiness of core /coil assembly during transportation. These signatures will be benchmark for future reference. The FRA signatures should be analysed in conjunction with Impact Recorder readings. Report of Impact recorder readings is to be obtained from manufacturer. It is recommended to follow the standard procedure for the SFRA measurement as per the Table-7. It should be done on maximum, normal and minimum tap.

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Auto Transformer Test Type Series Winding (OC) All Other Terminals Floating Common Winding (OC) All Other Terminals Floating Tertiary Winding (OC) All Other Terminals Floating Short Circuit (SC) High (H) to Low (L) Short (X1-X2-X3) Short Circuit (SC) High (H) to Tertiary (Y) Short (Y1-Y2-Y3) Short Circuit (SC) Low (L) to Tertiary (Y) Short (Y1-Y2-Y3)

Test Test 1 Test 2 Test 3 Test 4 Test 5 Test 6 Test 7 Test 8 Test 9 Test 10 Test 11 Test 12 Test 13 Test 14 Test 15 Test 16 Test 17 Test 18

3Ф H1-X1 H2-X2 H3-X3 X1-H0X0 X2-H0X0 X3-H0X0 Y1-Y3 Y2-Y1 Y3-Y2 H1-H0X0 H2-H0X0 H3-H0X0 H1-H0X0 H2-H0X0 H3-H0X0 X1-H0X0 X2-H0X0 X3-H0X0

1Ф H1-X1 X1-H0X0 Y1-Y2 (Y1-Y0) H1-H0X0 Short (X1-H0X0) H1-H0X0 Short (Y1-Y2) X1-H0X0 Short (Y1-Y2)

Table-7: Various combinations for FRA measurement in Auto Transformer Shunt Reactor: In case of Shunt Reactor, FRA to be done in following combinations: ¾ H1-H0 ¾ H2-H0 ¾ H3-H0 3.18

DISSOLVED GAS ANALYSIS (DGA) OF OIL SAMPLE

Dissolved Gas Analysis (DGA) is a powerful diagnostic tool to detect any incipient fault developing inside the oil-filled equipment. The oil sample is to be taken after oil filling (before commissioning ) as a benchmark and there after 24hrs of charging, 7 days, 15 days, one month and three months after charging to monitor the gas build up if any. The oil samples are to be sent to CIOTL/IOTL/STL for DGA and first two samples for oil parameter testing also. 3.19

THERMOVISION SCANNING (IR THERMOGRAPHY)

Once the transformer/ reactor is charged and loaded, Thermovision scanning is to be carried out to see any hotspots. For detailed procedure for each test, please refer Transformer and Reactor Maintenance manual (Doc No. D-2-03-XX-01-01)-First Revision, Part B, C & D. 32of 55



4.0

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PRE-COMMISSIONING CHECKS /TESTS FOR OTHER SWITCHYARD EQUIPMENTS

Once erection is completed, various pre-commissioning checks/ tests are performed to ensure the healthiness of the switchyard equipments prior to their energisation. Various major electrical tests to be performed and their significance are given below. Sr. No.

Name of Test / Check Purpose of test/ check point

4.1

Tan δ & Capacitance measurement of CT, each stack of CVT & total capacitance, CB voltage grading capacitor & each stack of Surge Arresters

4.2

Checks/ Tests applicable for CTs

4.2.1

Polarity test for CT

To ascertain whether the polarity markings are correct or not as per drawing.

4.2.2

Magnetization characteristics of CT

To prove that the turns of CTs secondary windings are not short circuited and to check healthiness of CT cores. The magnetizing currents at KPV (Knee point voltage) shall be less than the specified value. The ratio of secondary and primary voltage shall also be measured.

4.2.3

Ratio test for CT

The ratio errors of the primary to the secondary currents should within specified ratio errors.

4.2.4

Changes in the normal IR value of CT indicate abnormal IR measurement of CT (Primary & Secondary conditions such as presence of moisture, dirt, dust, crack in insulator of CT and degradation of insulation. windings)

4.2.5

DGA test of CT oil

4.3 4.3.1

Checks/ Tests applicable for Circuit Breakers

4.3.2

Measurement of Circuit Breaker Operating Timings including PIR Timings

The purpose of the dissipation factor measurement of high voltage insulation is to detect incipient weaknesses in HV insulation. The most important benefit to be gained from this measurement is to obtain a “benchmark reference reading” on costly and high voltage equipment when the equipment is new and insulation is clean, dry and free from impurities. Tan delta & Capacitance values shall be comparable with factory test results and in no case shall be more than 0.5 %.

This test shall be conducted after 30 days of commissioning. The purpose is to identify evolving faults in the CT and DGA values shall be comparable with factory values (if available)

Dew point measurement Dew point of SF6 gas is to measure moisture content in of SF6 gas SF6 gas which shall indicate whether CB evacuation is done properly or not. This test shall be carried out preferably at rated pressure of SF6 gas. To measure closing/ tripping/ CO timings. These timings should be within permissible limits and shall be comparable with factory values. Pole discrepancies and Break to Break discrepancies shall be less than specified values. 33of 55



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4.3.3

DCRM Contact Travel Measurement / DC injected currents and trip/ close coil currents.

4.3.4

Operational lockout To ensure various lockout operation of CB by simulating checking for EHV the actual conditions at the specified pressure of oil/ air/ operating medium. Circuit Breakers

4.3.5

Measurement of static This test is conducted to evaluate healthiness of Main contact resistance contacts. 100 Amp DC is injected and voltage drop is measured across each CB contact to compute contact resistance.

4.3.6

Checking the Pumping feature

4.3.7

Checking the Anti- To check correct operation of Thermostat provided for anti Condensation Heaters condensation heaters.

4.3.8

Pole discrepancy relay To test tripping of CB in case of pole discrepancy more testing than 2.5 seconds or specified value.

4.3.9

Checking the priming pressure

4.4

Checks/ Tests applicable for CVTs

4.4.1

CVT polarity, Ratio test

4.4.2

Insulation resistance Changes in the normal IR value of CVT indicate abnormal measurement of Primary conditions such as presence of moisture, dirt, dust, crack in insulator of CVT and degradation of insulation. & secondary winding

4.5

Checks/ Tests applicable for Isolators

4.5.1

MILLIVOLT Drop test

The voltage drop gives a measure of resistance of current carrying part and contacts by injecting minimum 100 A DC current.

4.5.2

50 operation tests

To test operation of contacts etc with jumpers connected and contact resistance to be measured after 50 operations. There shall not be any change from the previous value.

4.6

Checks/ Tests applicable for Surge Arrestors

4.6.1

Third Resistive

DCRM is the technique for measuring Contact Resistance during operation (Close/ Trip) of a circuit breaker with a delay Tco of 300ms. A DC current of at least 100 Amp is injected through the circuit breaker. The current and voltage drop are measured and resistance is calculated. The resistance and travel versus time data provides useful information on the condition of the circuit breaker contacts and is used as a diagnostic tool. DCRM test signatures shall be approved by Corporate OS.

Anti- By giving simultaneous close/ trip commands, CB hunting shall not take place by operation of Mechanical/ Electrical anti pumping feature.

N2 This test is to check healthiness of N2 accumulators provided in Hydraulic drive mechanisms. N2 priming pressure shall be as per the rated pressure. This test is conducted in the same manner as for CT to determine correct CVT polarity, ratio and phasor group.

Harmonic To monitor healthiness of Surge arrestors by monitoring Current third harmonic resistive current from the leakage current. 34of 55



(THRC) arrestors

for

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surge This test is to be conducted after charging of Las. The value of THRC shall be less than 30 µA.

4.6.2

IR measurement of each Changes in the normal IR value of LA indicate abnormal stack of LA conditions such as presence of moisture, dirt, dust, crack in insulator of LA and degradation of insulation.

4.6.3

Checking of operation of This test is done to check the healthiness of LA counter. LA counter

4.7

Checks/ Tests for other areas/ equipments

4.7.1

Earth resistance To ensure value of earth resistance is below 1 ohm. measurement

4.7.2

Secondary injection test

4.7.3

Contact Tightness check of Bay contacts by Primary injection method

4.7.4

Stability check for Bus This test is performed to check the proper operation of Bus Bar Bar protection by simulating actual conditions. Any problem in CT connection, wrong cabling, relay setting can be detected by this test.

current Conducted for testing of protecting devices, circuit breakers, trip coils, motor overloads etc. Since complete bay contact resistance measurement is practically not possible because DC current may not be injected in CT primary, hence contact tightness check by primary injection method has been introduced to check overall contact tightness.

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4.1

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TAN DELTA & CAPACITANCE MEASUREMENT OF CT, CVT, CB VOLTAGE GRADING CAPACITORS AND LA STACKS

To measure dissipation factor/loss factor (Tan delta) and Capacitance measurement of EHV class CTs, CVTs, CB Voltage Grading Capacitors & LA stacks by applying test voltages upto 10kV. Dissipation Factor Dissipation factor/loss factor (Tan delta)is defined as the ratio of resistive component(Ir) of current to that of capacitive current (Ic) flowing in an insulating material. Power Factor Power factor is the ratio of resistive current to that of total current. For very low value of resistive currents, values of dissipation factor and power factor are same (upto 2%). UST Test set connected for Ungrounded Specimen Test mode. This is used when specimen is isolated from earth e.g. Transformer bushing, CTs with test tap, CVTs and CB voltage grading capacitors. The test mode is often used to reduce the effect of stray capacitance losses to ground, and to reduce the effect of interference pickup from energized apparatus. GST Test set connected for grounded specimen test mode. This is used when specimen do not have two specific points (isolated from ground) for Tan delta measurement e.g. Transformer/Reactor winding, CTs without test tap etc. GSTg This test is used to separate the total values of a GST test into separate parts for better analysis. Often this test is used with GST test to confirm the test readings made using the UST mode. TEST EQUIPMENT 10 KV or 12 KV fully automatic Capacitance and Tan delta test kit to be used for accurate measurement and repeatability of test results. PRECAUTIONS a) There should be no joints in testing cables. b) HV lead should be screened with double shield and shields should not have internal shorting otherwise tests in GST/GSTg modes, shall not be possible. Check the same by Insulation Tester(100V) c) Test leads should not touch any live part. d) Never connect the test set to energised equipment e) The ground cable must be connected first and removed at last f) High voltage plugs should be free from moisture during installation and operation. g) It should be ensured that whole testing equipment alongwith Operation Manual of the kit testing procedures are available at testing site. Testing must be carried out by testing personnel only. h) After testing with high voltage (10 kV), test terminals must be grounded before being touched by any personnel. TESTING PROCEDURE: Typical arrangement for Tan δ measurement is given below in Figure 6, 7 & 8: 36of 55



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UST Mode of Measurement

Cs Standard Capacitor

~

CHg

Unknown Specimen CHL

Power Supply

N2

N1

CLg

Null Detector

GST Mode of Measurement


~

Unknown CHLSpecimen

Power Supply

N1

CHg

N2 CLg

Null Detector

GSTg Mode of Measurement


~

Power Supply

N1

CHL

N2

Null Detector

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CHg

CLg

Unknown Specimen



A)

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CURRENT TRANSFORMERS

CTs with test taps: 1. Tan delta tap to be disconnected from ground. 2. High voltage lead from tan delta kit to be connected to primary(HV) Terminal and LV lead to be connected to the Tan delta test tap. 3. P1 and P2 to be shorted 4. Porcelain surface to be thoroughly cleaned. 5. Measurements have to be taken in UST mode with fully automatic test kit. 6. Standard procedure(as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/induced voltage conditions should be followed for measurement of capacitance and tan delta values. 7. It is to be ensured to connect the test tap to ground terminal after carrying out the test. B)

CB VOLTAGE GRADING CAPACITOR

1. 2. 3. 4. 5.

Connect LV cable to the middle of the double interrupter. Connect HV cable to the other end of the Grading capacitor to be tested. The opposite end of the grading capacitor has to be grounded using earth switch. Measurements have to be taken in UST Mode with fully automatic test kit. Disconnect the HV cable and connect the same to the other grading capacitor and ground the previous grading capacitor. Now the second grading capacitor is ready for testing. 6. Standard procedure (as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/induced voltage conditions should be followed 7. Measurements are to be carried out at 10 kV/ 12 KV. C)

CAPACITOR VOLTAGE TRANSFORMES

1. Testing procedure for Top and Middle Stacks: (a) Apply 10 KV between flanges of Top/Middle stacks (whichever is being tested) (b) Carry out measurements in UST mode at 10.0 KV (c) While measuring Middle/ Bottom stacks, Top/ middle stacks to be shorted. 2. Testing procedure for Bottom Stack connected to EMU PT. (a) Connect HV of the test kit at the top flange of bottom stack. HF point to be grounded. Earth connection of the neutral of the PT to be opened/ isolated from ground. (b) Top of CVT to be guarded. LV lead of the kit to be connected at the top of the CVT for guarding. (c) Carry out measurements in GSTg mode at 10.0 KV (d) Repeat the Test with neutral of PT connected to ground. (e) In case Tan delta value is negative or erratic, only capacitance values are to be monitored. (f) Measurement to be carried out using fully automatic kit.

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3. Standard procedure (as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/ induced voltage conditions should be followed. D)

SURGE ARRESTORS

1. Testing procedure for Top, Middle and Bottom Stacks: (a) Apply 10 KV between flanges of Top/Middle/ Bottom stacks (whichever is being tested) (b) Carry out measurements in UST mode at 10.0 KV with fully automatic test kit. (c) While measuring Middle/ Bottom stacks, the stacks above the HV lead to be shorted. 2. Standard procedure (as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/ induced voltage conditions should be followed. 3. While doing measurement of bottom stack the earth connection to be removed. 4.2

CHECKS/ TESTS APPLICABLE FOR CTs

4.2.1

POLARITY TEST FOR CT

A centre zero voltmeter is connected across CT secondary. A 1.5 Volt battery is touched to primary of CT. The deflection of pointer should be similar in case of each CT core. At any instant current entering the primary from P1 the current should leave secondary from the terminal marked S1. A setup shown in the Figure 9 can show whether the polarity markings are correct or not. When the key is pressed, current enters the primary through terminal P1, the voltmeter connected as shown, should read positive. A general arrangement of polarity test setup is indicated in Fig. 10. P2

S2

R -

-

KEY

B

Y P1

P1

P1

V

1.5 V

+

+

P1

+ -

S1

Figure – 9

Figure - 10

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+

S1 S2

V -



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4.2.2 MAGNETIZATION CHARACTERISTICS OF CTs PRECAUTIONS a) There should be no joints in testing leads/cables. b) It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing personnel only. Test Equipment: Voltage source of 5 kV, Voltmeter of range 0 to 5 kV, Ammeter, of range 0 to 500 Amps, testing leads/cables etc. Test Procedure: Make connections as per diagram shown below (Fig- 11). After making proper connections, applied voltage is increased from zero to rated Knee Point Voltage in steps of 25%, 50%, 75% and 100%. Measure the current drawn by the CT secondary core at respective applied voltages and record the test results

Figure - 11 Knee Point Voltage is normally defined as the voltage at which 10% increase in the applied voltage causes 30 to 50% increase in secondary current. The magnetization current at rated Knee Point Voltage should not be more than the specified/designed value. A curve can be drawn between applied voltage and magnetizing current. Typically, the curve drawn should be like the one given below in Fig.-12:-

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600

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10 %

VOLTAGE

500 400 300 30 % 200 100

MAGNETIZING CURRENT

TYPICAL MAGNETIZATION CURVE

Figure - 12 From the curve it can be implied that up to rated KPV (Knee Point Voltage), the VI curve should be almost a straight line. However, if this line is not linear, this indicates that the magnetizing characteristics are not desirable. If the slop of the curve starts increasing, it indicates that magnetizing induction becomes low and total primary current is utilized in exciting the core alone. Consequently, out put of CT secondary disappears. 4.2.3 RATIO TEST FOR CURRENT TRANSFORMER The ratio check has to be carried out as indicated in Fig-13 below.

A1

A2

PRIMARY CURRENT INJECTION SET

A1 : PRIMARY CURRENT A2 : SECONDARY CURRENT

Figure - 13 It is customary to conduct this in conjunction with the primary injection test. Current is passed through the primary circuit with the secondary winding circuit to its normal circuit load. The ratio of the primary to the secondary currents should approximate closely to that stamped under CT identification plate. Alternatively, ratio test is to be conducted as per the following method (Fig-14). 41of 55



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Figure - 14 Apply voltage from secondary of the CT and measure voltage in primary winding. Increase voltage in secondary up to rated KPV/ ISF and by recording Primary Voltage, compute ratio of V1/ V2. The ratio should match with the specified value. 4.2.4 INSULATION RESISTANCE TRANSFORMER

MEASUREMENT

OF

CURRENT

PRECAUTIONS a) There should be no joints in testing cables. b) Test leads should not touch any live part. c) Megger body should be earthed (if separate terminal is provided). d) Surface/terminals should be cleaned. e) IR measurement should be carried out preferably in dry and sunny weather. f) Never connect the test set to energised equipment. g) The ground terminal must be connected first and removed at last. h) High voltage plugs should be free from moisture during installation and operation. i) If oil traces are found on the surface of CT, the same should be cleaned by Methyl Alcohol only. Petrol or diesel should never be used. j) It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing engineer only. k) After testing with high voltage, test terminals must be grounded before being touched by any personnel. l) Test leads should be properly screened/ shielded. Connect the Megger as per figure-15 given below. Connect the HV terminal to the Primary terminal of CT by using crocodile clip for firm grip.

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Figure-15 Typical Arrangement for IR measurement Carry out the measurement as per standard procedure given by the kit supplier. A test voltage as specified is applied as per the above connections and successive readings are taken. Values of IR should be recorded after 15 seconds, 60 seconds and 600 seconds. Ambient temperature and weather conditions are to be recorded. 4.2.5

DGA Test of CT Oil: Oil samples to be collected in 300ml bottles and to be sent to CIOTL Hyderabad for testing. Test results should be comparable to factory values. In case of any deviation, test results may be forwarded to CC-OS for approval.

4.3

CHECKS/ TESTS APPLICABLE FOR CIRCUIT BREAKERS

4.3.1 DEW POINT MEASUREMENT OF SF6 GAS FOR CIRCUIT BREAKER Dew Point is the temperature at which moisture content in SF6 gas starts condensing. Dew Point at rated pressure of CB: Dew Point when measured keeping regulating valve in service at the outlet of dew point kit to allow required flow rate of gas, is called at rated pressure of CB. Inlet valve is opened completely. Dew Point at atmospheric pressure : Dew Point when measured by regulating the gas flow at the inlet of dew point kit and keeping outlet regulating valve ( if provided) in fully open condition so that flow rate of gas is maintained as required, is called at atmospheric pressure. TESTING PROCEDURE a) Make the connections to the kit from CB pole ensuring that regulating valve is fully closed

at the time of connections of the Dew Point kit. b) By regulating the flow rate of SF6 gas (0.2 liter/min to 0.5 liter/min - ref. IEC 60480), the

value of dew point is observed till it becomes stable.

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c) If the regulating valve is provided at outlet of the dew point kit then values as given in

Doc. no. for rated pressures are to be monitored. Dew Point of SF6 gas varies with pressure at which measurement is being carried out. This is due to the fact that Saturation Vapour Pressure decreases with increase in Pressure of the SF6 gas. Hence, dew point of SF6 gas at higher pressure is lower than dew point at atmospheric pressure Therefore, it is to be ensured that if measurement has been done at a pressure other than the atmospheric pressure, same is to be converted to the atmospheric pressure as given in the table below used at the time of commissioning for various CB manufacturers: Method for converting dew point at different gas pressures, is given/described in IEC-60480. Sl. No. 1 2 3 4

Make of CB BHEL M&G CGL ABB

5

NGEF

Dew point at rated pressure (-) 15° C (-) 15° C (-) 15° C (-) 15° C

Dew point at Atmospheric Pressure ( Limit ) - 36° C - 39° C - 35° C - 35° C - 36° C

4.3.2 MEASUREMENT OF CIRCUIT BREAKER OPERATING INCLUDING PRE INSERTION RESISTOR TIMINGS

TIMINGS

PRECAUTIONS a) There should not be any joint in testing cables. b) Test leads should not touch any live part. c) Never connect the test set to energised equipment. d) The ground cable must be connected first and removed at last. e) High voltage plugs should be free from moisture during installation and operation. f) Circuit Breaker Analyser body should be earthed (if separate earth is provided). g) It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing personnel only. h) Surface/terminals should be cleaned where the connections for testing are to be made. i) Clean earth point with sand paper/wire brush where earth terminal is to be provided. j) Ensure that all the poles trip simultaneously through single close/trip command. TESTING PROCEDURE a) Make connections as shown in the figure-16 below. It is to be ensured that R, Y, B phase marking cables are connected with the proper place in the CB analyser and colour codes are to be maintained for all the three poles of CB. b) Make connections for recording operating timings of Auxiliary contacts. c) Extend power supply to Circuit Breaker Analyzer. d) Give closing command to closing coil of CB and note down the PIR and main contact closing time. Take the print out from the analyser. 44of 55



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e) Give tripping command to trip coil-I of CB & note down the main contact tripping time. f) Give tripping command to trip coil-II of CB & note down the main contact closing time. g) Note down the timings for `CO', and `OCO' by giving respective commands. CO command to be given without time delay but 300ms time delay to be given between O and CO operation in testing for OCO. h) To find out opening time of PIR contacts, PIR assembly has to be electrically isolated from Main contacts and then PIR contacts are to be connected to separate digital channels of the Analyzer. EVALUATION OF TEST RESULTS A) CLOSING TIMINGS Closing timings and Discrepancy in operating times of PIR and main contacts should not exceed the permissible limits as specified in the DOC NO: D-5-02-XX-01-03. In any case, main contacts should not close prior to closing of PIR contacts and PIR contacts should not open prior to closing of main contacts. In case, contact bouncing is observed in operating timings for PIR and main contacts, same should be rectified by tightening the cable connections.

Figure-16 B) TRIPPING TIMINGS Trip time and pole discrepancy in operating timings should not exceed beyond permissible value given in Doc. No. D-5-02-XX-01-03. In case of ABB, NGEF and CGL make CBs, while tripping, PIR contacts should not open after opening of main contacts.

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C) ‘CO' TIMINGS CO timings should be within permissible limits as specified by different manufacturers. If operating timings of CB poles are not within limits, same may be corrected by: 1. Equalizing the SF6 gas pressure in all the poles 2. Adjusting plunger movement of trip/ close coils 3. Adjustment in operating mechanism 4. Changing of trip/ close coils (if required) It is also important to measure timings of auxiliary contacts from the point of view of variations w.r.t. the main contacts. 4.3.3

DYNAMIC CONTACT RESISTANCE MEASUREMENT (DCRM) AND CONTACT TRAVEL MEASUREMENT OF EHV CIRCUIT BREAKERS

Test Equipment: 100 Amp. DCRM kit with CB operational analyzer with 10k Hz sampling frequency. Isolation Required a) CB should be in open position. b) Isolator of both sides of CB should be in open position. c) Earth switch of one side of CB should be in open position. Precautions a) There should be no joints in testing leads/cables. b) It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing personnel only. c) Current leads should be connected such that voltage leads are not outside area of current flow. Testing Procedure 1. Follow the standard procedure as given in instruction manual of DCRM kit. 2. The tightness of connections at CB flanges is most important to ensure error free measurement. CB during CO operation generates lot of vibrations and failure of connections during this period can dramatically change the dynamic signature of CB resistance. 3. DCRM signatures should be recorded for CO operation. Open command should be extended after 300 ms from the close command. 4. Clean portions of incoming and outgoing flanges of CB with polish paper to remove paint, oxidation etc, at points where Current clamps are mounted. 5. Select this point of connection, as close as possible to the end of porcelain insulator to ensure that minimum resistance is offered by flanges, bolts, terminal connectors etc. 6. It should be ensured that Travel Transducers are properly fitted. 7. Sampling frequency during measurement should be 10 KHz. 8. Resistance, travel, injected current and Trip/ Close coil currents are to be recorded. 46of 55



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The variations in the measured resistance versus time will be seen as a finger print for the breaker contacts and can be used as a bench mark for comparing with future measurements on the same breaker. This provides information on the condition of the breaker contacts, driving mechanism, operating levers etc. Dynamic Contact Resistance Measurement for CB healthiness By application of Dynamic Contact Resistance Measurement, condition of arcing contact, main contact, operating levers, driving mechanism can be predicted. If DCRM signature shows vide variations and also there is change in arcing contact insertion time, it indicates erosion of the arcing contacts to main contacts and subsequent failure. Contact Travel Measurement Transducers are attached to the operating rod or interrupting chamber in order to record the contact travel. When CB closes, contact travel is recorded. Contact bounces or any other abnormality is also clearly indicated by the Contact Travel Measurement. If contact travel, contact speed and contact acceleration signature are compared with the original signatures, then it may indicate problems related with the operating mechanism, operating levers, main/ arcing contacts, alignments etc. DCRM along with Contact Travel measurement is useful in monitoring length of Arcing contacts. Erosion of Arcing contacts may lead to commutation failures and current may get transferred to Main contacts. Due to heat of arc, main contacts may get damaged. 4.3.4

OPERATIONAL LOCKOUT CHECKING FOR EHV CIRCUIT BREAKERS

4.3.4.1 TESTING PROCEDURE: A. SF6 GAS PRESSURE LOCKOUT a) LOW PRESSURE ALARM Close Isolation Valve between CB Pole(s) and density monitor. Start releasing SF6 gas from density monitor till the low pressure gas alarm contacts are actuated which is detected by Multimeter. Note down the pressure and temperature at which the contacts get actuated. b) OPERATIONAL LOCKOUT: Continue releasing SF6 gas from isolated zone till the operational lockout Alarm Contacts are actuated which are detected by Multimeter. Note down the pressure and temperature at which the contacts get actuated. This is called operational lockout pressure. B. PNEUMATIC OPERATING SYSTEM LOCKOUT a) COMPRESSOR START/STOP SWITCH Close the isolating valve of CB. Release air into atmosphere from the compressor. Note down the value of pressure at which Compressor starts building up air pressure and 47of 55



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pressure at which Compressor stops. b) CB AUTO RECLOSE LOCKOUT Close Isolation valve between pneumatic system and pressure switches. Release air from the isolated zone to atmosphere. Note down pressure at which A/R L/O contacts of pressure switch get actuated which are detected by Multimeter. The leads of the Multimeter should be connected to the contactor where the AR L/O of CB are made. c) CB CLOSING LOCKOUT Release air from the isolated zone to atmosphere. Note down pressure at which CB Closing L/O contacts of pressure switch get actuated which are detected by Multimeter. d) CB OPERATIONAL LOCKOUT Release air from the isolated zone to atmosphere. Note down pressure at which CB Operational L/O contacts of pressure switch get actuated which are detected by Multimeter. e) MECHANICAL CLOSING INTERLOCK (FOR ABB & BHEL CBs ONLY) CB should be in closed position. Release air from pneumatic system of CB to atmosphere and observe whether CB poles start opening, if so, note down the pressure at which tie rod starts coming down. In such case the closing interlock is to be opened for inspection and if required, replace the closing interlock. C. HYDRAULIC OPERATING SYSTEM LOCKOUT a) Pump START/STOP By opening pressure release valve, note down the pressure at which Pump starts building up oil pressure and pressure at which pump stops. b) CB AUTO RECLOSE LOCKOUT Close Isolation valve between hydraulic system and pressure switches. Release oil from the isolated zone to oil tank. Note down pressure at which A/R L/O contacts of pressure switch get actuated which are detected by Multimeter. c) CB CLOSING LOCKOUT Release oil from the isolated zone to oil tank. Note down pressure at which CB Closing L/O contacts of pressure switch get actuated which are detected by Multimeter. d) CB OPERATIONAL LOCKOUT Release oil from the isolated zone to container. Note down pressure at which CB Operational L/O contacts of pressure switch get actuated which are detected by Multimeter. D. OPERATING PRESSURE DROP TEST: For Pneumatic/ Hydraulic operating system, operating pressure drop test to be performed during OCO operation of CB, keeping AC supply of Hydraulic pump/ Compressor in off condition. Hydraulic/ Pneumatic pressure drop should be within limits (as recommended by Manufacturer)

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4.3.4.2 EVALUATION OF TEST RESULTS A. SF6 GAS PRESSURE LOCKOUT All the SF6 gas pressure switches settings should be checked and corrected with ambient temperature. Settings of SF6 gas pressure switches should be within ± 0.1 bar/ Kg/cm2 of the set value ( after taking into account the temperature correction factor). B. AIR PRESSURE LOCKOUT All the air pressure switches settings should be checked and corrected and should be within ± 0.3 bar/ Kg/cm2 of the set value. C. OIL PRESSURE LOCKOUT All the oil pressure switches settings should be checked and corrected and should be within ± 0.3 bar/ Kg/cm2 of the set value. 4.3.5

MEASUREMENT OF STATIC CONTACT RESISTANCE

The Static contact resistance of main circuit of each pole of a circuit breaker is of the order of a few tens of micro ohms. 100 A DC is injected and milli volt drop is measured across each CB contact to compute contact resistance. The values should be within specified limits as given in Doc No. D-5-02-XX-01-01. 4.3.6

CHECKING THE ANTI-PUMPING FEATURE

When the breaker is in open position and closing and opening commands are given simultaneously the breaker first closes and then opens, but does not reclose even though the closing command is maintained. 4.3.7

CHECKING THE ANTI-CONDENSATION HEATERS

Check the supervisory circuit of the anti-condensation heaters for correct functioning. With the heaters switched ON, measure their current output. 4.3.8

POLE DISCREPANCY RELAY TESTING

Pole Discrepancy is defined as the difference in closing & opening timings of different poles of CB. A. WHEN CB IN OPEN POSITION Closing Command is extended to close one pole, say R-Pole, of CB. After closing R-Pole of CB, this Pole should automatically open after 2.5 seconds (as per pole discrepancy timer settings). Repeat the test for remaining two poles of CB. B. WHEN CB IN CLOSED POSITION Tripping Command is extended to trip one pole, say R-Pole, of CB. Remaining Y and BPoles of CB should automatically open after 2.5 seconds. Repeat the same test for remaining two poles of CB. 49of 55



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C. EVALUATION OF TEST RESULTS Permissible value of pole discrepancy between two poles of CB is 3.33 msec. from system point of view and it should not be confused with the setting of pole discrepancy timer which is generally 1.0 or 2.5 sec. depending on Auto-reclose scheme. 4.3.9

CHECKING THE NITROGEN PRIMING PRESSURE

150

160

170

180

190

200

210

220

230

bar

Close the pressure release valve. Shortly after the oil pump starts, the priming pressure (200 bar at 20°C) in the accumulator can be read. The relationship between the pressure and temperature is indicated in Fig. 17.

P rim in g p re s s u re a s a fu n c tio n o f th e te m p e ra tu re N o m in a l ra tin g a t 2 0 d e g .C : 2 0 0 .1 b a r

Figure - 17

4.4

CHECKS/ TESTS APPLICABLE FOR CVTs

4.4.1

CVT POLARITY, RATIO TEST

CVT polarity is checked in the same manner as for CT, taking care to ensure that the battery is connected to the primary winding. In case of star/star winding configuration care has to be taken to ensure that the primary and secondary neutral points are not connected together. It is necessary to verify that the phase rotation sequence of the 3 phase CVT is correct. The secondary voltage between phases and neutral are measured and then phase rotation meter is connected across the three phase terminal. 4.4.2

INSULATION RESISTANCE SECONDARY WINDING

MEASUREMENT

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OF

PRIMARY

&



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4.5

CHECKS/ TESTS APPLICABLE FOR ISOLATORS

4.5.1

MILLI VOLT DROP TESTS

The milli volt drop across the isolator is measured using DC current. The voltage drop gives a measure of resistance of current carrying part and contacts. The DC current should be equal to or more than 100 A. The resistance of isolator should be measured at ambient air temperature. The temperature of specimen/environmental temperature should be recorded. The value of measured resistance should be converted to the value of temperature at which factory test results are taken. Temperature corrected value of resistance should be comparable to the factory value. 4.5.2

50 OPERATION TESTS

4.6

CHECKS/ TESTS APPLICABLE FOR SURGE ARRESTORS

4.6.1

MEASUREMENT OF THIRD HARMONIC RESISTIVE CURRENT FOR SURGE ARRESTERS

Testing Procedure a. Make the connections as per the diagram given below (Fig.18) b. The kit should be properly earthed. c. Clamp On type CT should be placed above the surge monitor to pick up the total leakage current. d. Carryout the measurements as per standard procedure supplied by the test kit manufacturer. e. Note down the system voltage and ambient temperature along with the test current value. f. Avoid measurement during monsoon.

Figure- 18 Typical arrangement for THRCM Test EVALUATION OF TEST RESULTS A. ZnO Surge Arrester continuously conducts a small leakage current (Fig.19). The resistive component of this leakage current may increase with time due to different stresses causing ageing and finally cause arrester failure.

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B. If Harmonics are present in the system voltage, it affects the value of measured third harmonic current. Compensating device provided to be used to nullify the effect. The value of Third Harmonic Resistive current shall be less than 30 µA.

Figure-19 Arrester equivalent circuit 4.7

CHECKS/ TESTS FOR OTHER AREAS/ EQUIPMENTS

4.7.1

EARTH RESISTANCE MEASUREMENT Normally Earth tester is used for measuring (a)

Soil resistivity

(b)

Earth resistance

a.

Prior to the testing of soil resistivity and earth resistance the operation manual of the testing instrument available at site may be referred for procedures to be adopted for measurement of soil resistivity and earth resistance. A typical earth tester has 4 terminals. C1, P1, C2, P2 and 4 similar electrodes are driven in the ground at equal distances and connected to the instruments in the order of C1, P1 and P2, C2. Then the handle is rotated or button is pressed and the reading of the resistance is read on the scale of the instrument. If R is the resistance measured then Specific Resistivity = 2 π a R Where ‘a’ is the distance between the electrode And R is the resistance in ohms measured on the earth tester.

b.

In order to measure earth resistance of the electrode of the substation, it could be connected to C1 and the value of R could be read in the scale with the rotation of the handle of the Insulation tester. This will give the earth resistance. The value as far as possible should be around 1 ohm. To improve the value, water should be spread at the earth pit. 52of 55



4.7.2

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SECONDARY CURRENT INJECTION TEST SETS

The primary test is essential when commissioning and new installation as a test the whole protection system and will detect current transformers connected with incorrect polarity or relays that have been set in the wrong sequence in differential system. Secondary current injection sets are very useful for conducting these tests. The standard secondary current injection test equipment consists of a 1/5 A current injection set, separate wave form filter unit and a digital counter. The equipment is designed in a portable kit for on site testing of protecting devices, circuit breakers, trip coils, motor overloads, and similar apparatus. The filter unit should be used when testing saturating core type relays to ensure that the test current has a substantially sinusoidal waveform. The typical test setup is shown in the figure 20. Details of the testing will be elaborated in the relay testing.

INSULATING TEST PLUGS P1

P1

P1

S1

INJECT CURRENT HERE

S2 A1 A2

LOAD

Figure - 20

4.7.3

CONTACT TIGHTNESS TEST OF BAY CONTACTS:

a. Isolate the Bay from Bus –Side and line side as shown in Fig.-21. b. Ensure that all the secondary cores are connected or short if not in use. c. Inject the Current at Point 1 (200A) from primary injection kit (w r t earth) and return current via earth point at 2 as shown in Fig.-21. d. Check that we are able to inject current at point 1 and measure the current at point 2. e. Injection of current is the indication of contact tightness. f. Repeat the procedure for point 1 & 3 g. Repeat the procedure for point 1 & 4 Note: Above tests can be aborted if individual contact resistances are within satisfactory limit and physical phase checking is satisfactory. 53of 55



POINT 1

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POINT 2 LINE

CB I

CB

LINE POINT 3

POINT 4

Figure-21 : Primary injection test to check contact tightness of Bay/ feeders 4.7.4

STABILITY TEST FOR BUSBAR:

Procedure given below is to be adopted phase wise 1) Isolate all the bays connected to the bus bar from line side and close bus CBs and bus isolators as shown in the Fig. 22

2

1

3 BUSBAR

4

5 BUS EARTH SWITCH

Figure-22: Status of switches for performing Stability Test 2) Inject the Primary current of 200A from point 1 to point 4 with bus earth switch open as shown in Fig 23 and check the spill current in check zone / bus zone in bus bar protection panel, measured value is to be near zero (for 2000/1 CT ratio secondary current is 100 mA and spill current may be 1 mA or below) .If spill current is more than 10% check CT bus bar wiring and correct it. 54of 55



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I 2

1

3 BUSBAR

4

5 BUS EARTH SWITCH OPEN

Figure-23: Primary injection with Bus Earth Switch Open 3) Inject the Primary current of 200A from point 1 to point 4 with bus earth switch close as shown in Fig. 24 and check the spill current in check zone / bus zone in bus bar protection panel, measured value is to be around full secondary current (for 2000/1 CT ratio secondary current is 100 mA and spill current may be near 100 mA ) .If no spill current found check the CT bus bar wiring and correct it.

I 2

1

3 BUSBAR

4

5 BUS EARTH SWITCH CLOSE

Figure-24: Primary injection with Bus Earth Switch Closed 4) Repeat the above test for all remaining CT combination i.e 1-3 , 1-5 , 1-2 etc 5) If a new bay is added to the BUS, check only new CT with any Old CT of that BUS.

55of 55

POWER GRID CORPORATION OF INDIA LIMITED CORPORATE OPERATION SERVICES

DOC NO. : MR/CF/CT/01/R-02 DATED : 01/04/08 SUB STATION : BAY NO : EQUIPMENT IDENTIFICATION NO : DATE OF TESTING :

PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS

I

REGION :

II

DATE OF ERECTION :

IV

DETAILS OF EQUIPMENT :

V

III

LOA NO

:

MAKE

:

TYPE

:

SL NO.

:

R - PHASE :

YEAR OF MANUFACTURE

:

FEEDER NAME

:

Y - PHASE :

DATE OF ENERGISATION :

B - PHASE :

RATED DATA AND DUTY CORE

RATIO

CLASS

BURDEN

KVP

PROTECTION / METERING

WINDING I WINDING II WINDING III WINDING IV WINDING V

VI SL. NO 1

2

KVp : KNEE POINT VOLTAGE IN VOLTS DETAILS : DESCRIPTION

STATUS YES

NO

REMARK RECORD DEFICIENCIES, IF ANY

EQUPIMENT IS CLEANED AND FREE FROM DUST / DIRT FOREIGN MATERIALS ETC. EQUIPMENT IS FREE FROM ALL VISIBLE DEFECTS ON PHYSICAL INSPECTION

3

CHECK CT TANK HAS BEEN PROVIDED WITH DOUBLE EARTHING (DEAD TANK CT's)

4

CHECK THAT CT JUNCTION BOX IS EARTHED.

5

ALL NUTS AND BOLTS ARE TIGHTENED CORRECTLY AS PER SPECIFIED TORQUE

6

CHECK TIGHTNESS OF TERMINAL CONNECTOR

7

ALL FITTINGS AS PER OUT LINE GENERAL ARRANGEMENT DRAWING.

8

LEVELLING AND ALIGNMENT OF STRUCTURE AND BASE FRAME IS CHECKED

9

ERECTION COMPLETION CERTIFICATE ALONG WITH LIST OF OUTSTANDING ACTIVITIES REVIEWED

10

ANY PAINT REMOVED / SCRATCHED IN TRANSIT HAS BEEN TOUCHED UP

11

CHECK PRIMARY POLARITY OF CT,S ERECTED AS PER RELEVANT DRAWING. PAGE 1 OF 8

CURRENT TRANSFORMER



PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS 12

CHECK HERMETICALLLY SEALING IS INTACT

13

CHECK THE OIL LEVEL AND LEAKAGE THROUGH ANY JOINTS / SEC. TERMINALS

14

CHECK OIL DRAIN VALVE IS PROPERLY CLOSED AND LOCKED.

15

OIL LEVEL & OIL SAMPLING

16

N2 PRESSURE CHECKED (WHEREVER APPLICABLE)

17

OIL LEVEL ON TOP CHAMBER GAUGE GLASS

18

BDV OF OIL SAMPLE TAKEN FROM TANK BOTTOM DRAIN VALVE ( ONLY IF NITROGEN PRESSURE IS MEASURED ZERO )

19

ALL THE CABLE IDENTIFICATION TAGS PROVIDED AND ALL CORES ARE PROVIDED WITH IDENTIFICATION FERRULES AT M.B.

20

CHECK SECONDARY CABLE END BOX IS PROPERLY FIXED AND ENSURE CABLE ENTRY AT THE BOTTOM AND UNUSED HOLES SEALED

21

ENSURE INTERPOLE CABLING IS COMPLETED AND CHECK THE CONTINUTY.

22

CHECK THE IR VALUE OF SECONDARY CABLE

23

CHECK EXTERNAL CABLING FROM JUNCTIONBOX TO RELAY / CONTROL PANEL COMPLETED

24

ENSURE UNUSED SECONDARY CORES, IF ANY, HAS BEEN SHORTED

25

CHECK STAR POINT HAS BEEN FORMED PROPERLY AND GROUNDED AT ONE END ONLY

26

CHECK SPARK GAP SETTING IN P1 TERMINAL (WHEREVER PROVIDED/ POSSIBLE) PERMANENT POLE LAVELLING AND IDENTIFICATION MARKINGS MADE

27

CHECK TAN DELTA TEST TAP IS PROPERLY EARTHED

28

CHECK THAT LUGS USED IN SECONDARY CIRCUIT ARE OF RING TYPE

29

CHECK DIRECTION OF PRIMARY (P1/ P2) w.r.t. BUS/ LINE ON ERECTION

30

PROVISION OF BIMETALLIC STRIPS (Cu +Al) ENSURED WHEREVER APPLICABLE

IX

INSULATION RESISTANCE MEASUREMENT : ( USING 5KV MEGGER) DETAILS OF TEST KIT: NOTE : A) REMOVE THE CONNECTED EARTHING TO SYSTEM INVOLVING CT UNDER TEST B) DISCONNECT THE CONNECTED TERMINALS OF CT M.BOX C) PERMISSIBLE VALUES IS 1000 MOHMS CORE

PHASE R

Y

B

PRIMARY - CORE I

MOHM

PRIMARY - CORE II

MOHM

PRIMARY - CORE III

MOHM

PAGE 2 OF 8

CURRENT TRANSFORMER



PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS PRIMARY - CORE IV

X

MOHM

PRIMARY - CORE V

MOHM

PRIMARY - EARTH

MOHM

INSULATION RESISTANCE MEASUREMENT : (USING 500 V MEGGER) DETAILS OF TEST KIT: PERMISSIBLE VALUES IS 50 MOHMS A

BETWEEN

R

PHASE Y

B

SECONDARY CORE I - EARTH

MOHM

SECONDARY CORE II - EARTH

MOHM

SECONDARY CORE III - EARTH

MOHM

SECONDARY CORE IV - EARTH

MOHM

SECONDARY CORE V - EARTH

MOHM

B

BETWEEN

R

PHASE Y

B

CORE I - CORE II

MOHM

CORE I - CORE III

MOHM

CORE I - CORE IV

MOHM

CORE I - CORE V

MOHM

CORE II - CORE III

MOHM

CORE II - CORE IV

MOHM

CORE II - CORE V

MOHM

CORE III - CORE IV

MOHM

CORE III- CORE V

MOHM

CORE IV - CORE V

MOHM

XII

CHECK IR VALUE BETWEEN TAN DELTA POINT AND EARTH AT 1 R -PHASE KV IN SECONDARY BOX

XIII

SECONDARY WINDING RESISTANCE (IN OHM) ( BY DIGITAL MULTIMETER ) CORE CORE I

CORE II

CORE III

CORE IV

CORE V

TERMINAL

R -PHASE FACTORY SITE

Y -PHASE FACTORY SITE

Y -PHASE

B -PHASE

B -PHASE FACTORY SITE

1S1 - 1S2

OHM

1S1 - 1S3

OHM

1S1 - 1S4

OHM

2S1 - 2S2

OHM

2S1 - 2S3

OHM

2S1 - 2S4

OHM

3S1 - 3S2

OHM

3S1 - 3S3

OHM

3S1 - 3S4

OHM

4S1 - 4S2

OHM

4S1 - 4S3

OHM

4S1 - 4S4

OHM

5S1 - 5S2

OHM

5S1 - 5S3

OHM

5S1 - 5S4

OHM FACTORY TEST REPORT REF. NO :

PAGE 3 OF 8

CURRENT TRANSFORMER

POWER GRID CORPORATION OF INDIA LIMITED CORPORATE OPERATION SERVICES PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS

XIV


POLARITY TEST : CORE CORE I

CORE II

CORE III

CORE IV

CORE V

XV

WITH 1.5 VOLT DC SUPPLY (CONNECT +VE AT P1 AND - VE AT P2 ) BETWEEN PHASE R -PHASE Y -PHASE B -PHASE

1S1 (+VE)

1S2 (-VE)

1S1 (+VE)

1S3 (-VE)

1S1 (+VE)

1S4 (-VE)

2S1 (+VE)

2S2 (-VE)

2S1 (+VE)

2S3(-VE)

2S1 (+VE)

2S4 (-VE)

3S1 (+VE)

3S2(-VE)

3S1 (+VE)

3S3(-VE)

3S1 (+VE)

3S4(-VE)

4S1 (+VE)

4S2(-VE)

4S1 (+VE)

4S3(-VE)

4S1 (+VE)

4S4(-VE)

5S1 (+VE)

5S2(-VE)

5S1 (+VE)

5S3(-VE)

5S1 (+VE)

5S4(-VE)

TAN DELTA AND CAPACITANCE MEASUREMENT (BY AUTOMATIC TAN DELTA KIT) DETAILS OF TEST KIT: A VOLTAGE

R SITE

CAPACITANCE ( MEASURED VALUE ) PHASE Y PHASE B FACTORY SITE FACTORY SITE

PHASE FACTORY

REMARK

2 KV 10 KV B VOLTAGE

TAN DELTA ( MEASURED VALUE ) R PHASE Y PHASE B PHASE SITE FACTORY SITE FACTORY SITE FACTORY

REMARK

2 KV 10 KV FACTORY TEST REPORT REF. NO : CURRENT RATIO TEST

XVI

PRIMARY INJECTION THROUGH PRIMARY INJECTION KIT AT PRIMARY TERMINAL P1 - P2 MEASURE CURRENT ON THE SECONDARY TERMINALS

A

DETAILS OF TEST KIT: R - PHASE CORE PRIMARY S1 - S2 % CORE I

20 %

(1S1 - 1S2)

40 %

CURRENT ACTUAL

SECONDARY THEORETCURRENT ICAL RATIO

ACTUAL RATIO

% OF ERROR

80 % CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

CORE V

20 %

(5S1 - 5S2)

40 % 80 %

CORE I

20 %

(1S1 - 1S3)

40 % PAGE 4 OF 8

CURRENT TRANSFORMER



PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS 80 % CORE II

20 %

(2S1 - 2S3)

40 % 80 %

CORE III

20 %

(3S1 - 3S3)

40 % 80 %

CORE IV

20 %

(4S1 - 4S3)

40 % 80 %

CORE V

20 %

(5S1 - 5S3)

40 % 80 %

CORE I

20 %

(1S1 - 1S4)

40 % 80 %

CORE II

20 %

(2S1 - 2S4)

40 % 80 %

CORE III

20 %

(3S1 - 3S4)

40 % 80 %

CORE IV

20 %

(4S1 - 4S4)

40 % 80 %

CORE V

20 %

(5S1 - 5S4)

40 % 80 %

B

Y - PHASE CORE

PRIMARY

CURRENT

S1 - S2

%

ACTUAL

CORE I

20 %

(1S1 - 1S2)

40 %

SECONDARY THEORETCURRENT

ICAL RATIO

ACTUAL

% OF

RATIO

ERROR

80 % CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

CORE V

20 %

(5S1 - 5S2)

40 % 80 %

CORE I

20 %

(1S1 - 1S3)

40 % 80 %

PAGE 5 OF 8

CURRENT TRANSFORMER

POWER GRID CORPORATION OF INDIA LIMITED CORPORATE OPERATION SERVICES PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS CORE II

20 %

(2S1 - 2S3)

40 %


80 % CORE III

20 %

(3S1 - 3S3)

40 % 80 %

CORE IV

20 %

(4S1 - 4S3)

40 % 80 %

CORE V

20 %

(5S1 - 5S3)

40 % 80 %

CORE I

20 %

(1S1 - 1S4)

40 % 80 %

CORE II

20 %

(2S1 - 2S4)

40 % 80 %

CORE III

20 %

(3S1 - 3S4)

40 % 80 %

CORE IV

20 %

(4S1 - 4S4)

40 % 80 %

CORE V

20 %

(5S1 - 5S4)

40 % 80 %

C

B - PHASE CORE S1 - S2

PRIMARY %

CORE I

20 %

(1S1 - 1S2)

40 %

CURRENT ACTUAL

SECONDARY THEORETCURRENT ICAL RATIO

ACTUAL RATIO

% OF ERROR

80 % CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

CORE V

20 %

(5S1 - 5S2)

40 % 80 %

CORE I

20 %

(1S1 - 1S3)

40 % 80 %

CORE II

20 %

(2S1 - 2S3)

40 % 80 %

CORE III

20 %

PAGE 6 OF 8

CURRENT TRANSFORMER

POWER GRID CORPORATION OF INDIA LIMITED CORPORATE OPERATION SERVICES PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS (3S1 - 3S3)


40 % 80 %

CORE IV

20 %

(4S1 - 4S3)

40 % 80 %

CORE V

20 %

(5S1 - 5S3)

40 % 80 %

CORE I

20 %

(1S1 - 1S4)

40 % 80 %

CORE II

20 %

(2S1 - 2S4)

40 % 80 %

CORE III

20 %

(3S1 - 3S4)

40 % 80 %

CORE IV

20 %

(4S1 - 4S4)

40 % 80 %

CORE V

20 %

(5S1 - 5S4)

40 % 80 %

NOTE: DURING RATIO TEST OF CT , THE CURRENT LEVEL ATTAINED SHOULD NOT BE LESS THAN 500 A XVII

MAGNETISING CURVES PERFORMANCE KNEE POINT VOLTAGE ( KVp ) _______________ VOLT DETAILS OF TEST KIT: A

B

C

R - PHASE VOLTAGE TO BE ACTUAL APPLIED VALUE

CORE - I 1S1-1S2

CURRENT MEASUREMENT CORE - II CORE - IV CORE - V 2S1 - 2S2 4S1 - 4S2 5S1 - 5S2

mA

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

Y - PHASE VOLTAGE TO BE ACTUAL APPLIED VALUE

CORE - I 1S1-1S2


O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

B - PHASE VOLTAGE TO BE ACTUAL APPLIED VALUE

CORE - I 1S1-1S2


O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

PAGE 7 OF 8

CURRENT TRANSFORMER



PRE-COMMISSIONING OF CURRENT TRANSFORMER COMMISSIONING FORMATS

NOTE : 1.0 CT SHOULD NOT SATURATE AT 110 % OF KNEEPOINT VOLTAGE ( KVp ) 2.0 IF KNEEPOINT VOLTAGE IS NOT MENTIONED THEN KNEE POINT CURRENT MAY BE TAKEN INTO CONSIDERATION 3.0 MAGNETISATION OF CORE III IS NOT DONE SINCE IT IS USED FOR METERING PURPOSE. XVIII

CONTACT RESISTANCE MEASUREMENT (WHEREVER POSSIBLE/ ACCESIBLE) DETAILS OF TEST KIT: R-PHASE

CONTACT RESISTANCE

Y-PHASE

B-PHASE

ACROSS TERMINAL P1

MICRO OHM

ACROSS TERMINAL P2

MICRO OHM

NOTE : THE VALUE OF CONTACT RESISTANCE SHOULD NOT BE MORE THAN 10 MICRO-OHMS PER JOINT / CONNECTOR XIX

TESTS FOR SF6 FILLED 765 KV CTs DETAILS OF TEST KIT: PARTICULARS

PHASE Y

R

B

DEW POINT (DEG C) SF6 LOSS ALARM (KG) SF6 LOCK OUT (KG)

XX

DGA TEST OF CT OIL

(AFTER ONE MONTH OF COMMISSIONING)

TO BE TAKEN IN 250 ml BOTTLES DISSOLVE GASES TOTAL GAS (%)

R PHASE

Y PHASE

B PHASE

REMARKS

H2 CH4 C2H4 C2H6 C2H2 CO CO2 O2 N2 XXI FINAL DOCUMENTATION REVIEW : A FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS REVIEWED AND APPROVED

YES

NO

B DOCUMENTS REGARDING SPARES, EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE

YES

NO

C AFTER MODIFICATION, IF ANY, " AS BUILT DRAWINGS " ARE AVAILABLE AT SITE

YES

NO

SIGNATURE : NAME : DESIGNATION : ORGANISATION : ( SUPPLIER REPRESENTATIVE ) (WHEREVER APPLICABLE)

SIGNATURE : NAME : DESIGNATION : ORGANISATION : ( ERECTION AGENCY )

SIGNATURE : NAME : DESIGNATION :


(POWERGRID SITE I/C)

( POWERGRID COMM TEAM )

PAGE 8 OF 8

CURRENT TRANSFORMER


SUB STATION :

PRE-COMMISSIONING OF CAPACITOR VOLTAGE TRANSFORMER COMMISSIONING FORMATS

BAY NO : EQUIPMENT IDENTIFICATION NO : DATE OF TESTING :

I

REGION :

II

DATE OF ERECTION :

IV


DOC NO. : MR/CF/CVT/02/R-2 DATED:01/04/08

III

R-PHASE LOA NO

:

MAKE

:

TYPE

:

SL NO.

:

YEAR OF MANUFACTURE

:

V

FEEDER NAME :

VI

PRIMARY VOLTAGE :

VII

SECONDARY DETAILS :

Y-PHASE

B-PHASE

Kv

WINDING 1 VOLTAGE

DATE OF ENERGIZATION :

WINDING 2

WINDING 3

:

VOLTS

VA BURDEN :

VA

CLASS PURPOSE VIII

DETAILS OF CHECKLIST :

SL. NO

DESCRIPTION

1

STATUS YES

NO


EQUPIMENT IS CLEANED AND FREE FROM DUST / DIRT FOREIGN MATERIALS ETC.

2

EQUIPMENT IS FREE FROM ALL VISIBLE DEFECTS ON PHYSICAL INSPECTION

3

CHECK CVT TANK HAS BEEN PROVIDED WITH DOUBLE EARTHING

4

CHECK THAT CVT MARSHALLING BOX IS EARTHED

5


6

CHECK TIGHTNESS OF TERMINAL CONNECTOR

7

ALL FITTINGS AS PER OUT LINE GENERAL ARRANGEMENT DRAWING.

PAGE 1 OF 5

CAPACITIVE VOLTAGE TRANSFORMER


SUB STATION :



SL. NO


DESCRIPTION

STATUS YES

8

LAVELLING AND IDENTIFICATION MARKING IS CARRIED OUT

9


10


11


12

SL. NO OF HV CAPACITOR IDENTICAL TO THE SL.NO MENTIONED ON RATING & DIG. PLATE

13

ENSURE BRASS VENT PLUG BETWEEN STACKS OF CVT'S IS REMOVED

14

CHECK THE OIL LEVEL AND LEAKAGE THROUGH ANY JOINTS / SEC. TERMINALS

15

CHECK OIL DRAIN VALVE IS PROPERLY CLOSED AND LOCKED.

16

OIL LEVEL ON TANK GAUGE GLASS

17

BDV OF OIL SAMPLE TAKEN FROM TANK BOTTOM DRAIN VALVE

18

CHECK SECONDARY CABLE END BOX IS PROPERLY FIXED AND ENSURE CABLE ENTRY AT THE BOTTOM.

19

ENSURE H.F TERMINAL OF UNUSED PHASES HAS BEEN EARTHED AND NO LOAD ON H.F TERMINAL BUSHING

20

CHECK RATING / HEALTHINESS OF FUSES AT CVT M.B AND CVT TERMINAL BOX.

21

CHECK THAT THE NEUTRAL POINT IS EARTHED

PAGE 2 OF 5

NO

REMARK RECORD DEFICIENCIES,IF ANY



SUB STATION :



SL. NO

DESCRIPTION

STATUS YES

22

ENSURE INTERPOLE CABLING IS COMPLETED AND CHECK THE CONTINUTY.

23

CHECK THE IR VALUE OF SECONDARY CABLE ( > 50 M OHMS FOR CONTROL CABLES)

24

CHECK EXTERNAL CABLING FROM M.B TO RELAY / CONTROL PANEL COMPLETED

25


IX

CONTINUITY OF WINDING : (After removing Earth Link 1,2 & 3)

X

NO

A BETWEEN TERMINALS 1a - 1n

OK

NOT OK

B BETWEEN TERMINALS 2a - 1n

OK

NOT OK

C BETWEEN TERMINALS 3a - 1n

OK

NOT OK

INSULATION RESISTANCE MEASUREMENT : USING A MEGGER OF 5KV/ 10 KV BETWEEN

XI



MIN : 1000 M OHMS

MEASURED VALUE R-PHASE Y-PHASE

B-PHASE

PRIMARY - SECONDARY CORE 1

MOHM


MOHM


MOHM

PRIMARY - EARTH

MOHM

SECONDARY WINDING RESISTANCE PHASE

CORE 1 FACTORY

IN OHMS CORE 2

SITE

FACTORY

CORE 3 SITE

FACTORY

REMARK SITE

R Y B FACTORY TEST REPORT REF. NO :

PAGE 3 OF 5



SUB STATION :



XII

INSULATION RESISTANCE MEASUREMENT : USING A MEGGER OF 500 VOLT BETWEEN


MIN : 50 M OHMS

MEASURED VALUE R-PHASE

XIII

Y-PHASE

B-PHASE

SECONDARY CORE 1 - EARTH

MOHM


MOHM


MOHM

CORE 1 - CORE 2

MOHM

CORE 1 - CORE 3

MOHM

CORE 2 - CORE 3

MOHM

VOLTAGE RATIO TEST

PHASE

PRIMARY VOLTAGE

SECONDARY VOLTAGE BETWEEN

R

1a - 1 n

R

2a - 2 n

R

3a - 3 n

Y

1a - 1 n

Y

2a - 2 n

Y

3a - 3 n

B

1a - 1 n

B

2a - 2 n

B

3a - 3 n

THEORATICAL RATIO

VALUE

ACTUAL RATIO FACTORY SITE

% ERROR

NOTE : 1. APPLY VOLTAGE OF THE ORDER OF 500V OR MORE ACROSS LINE CAPACITOR ( TOP FLANGE ) TO EARTH LIN 2. ENSURE ALL EARTH LINKS CONNECTED XIV

ALL TERMINAL BLOCKS CLOSED IN THE SECONDARY AFTER ALL TESTING

XV

PHASING ( PHASE RELATIONSHIP ) OF CVT BY MEASURING VOLTAGE BETWEEN R-PHASE, Y-PHASE AND B-PHASE AT INCOMING TERMINAL IN CONTROL CUBICLE,FOR ONE CIRCUIT OF THE CHECKED CVT AND OUTPUT TERNINALS R-PHASE, Y-PHASE AND B-PH OF A REFERENCE CIRCUIT (EXISTING CVT) WITH KNOWN PHASING REFERENCE CIRCUIT

MEASURED VALUE R-PHASE Y-PHASE

B-PHASE

R-PHASE Y-PHASE B-PHASE

PAGE 4 OF 5



SUB STATION :



XVI


TAN DELTA AND CAPACITANCE MEASUREMENT DETAILS OF TEST KIT: ACROSS STACK

PRE COMMISSIONING VALUES

R PH

CAPACITANCE Y PH B PH

R PH

FACTORY VALUES CAPACITANCE Y PH B PH R PH

R PH

TAN DELTA Y PH B PH

TOP MIDDLE BOTTOM TOTAL TAN DELTA Y PH B PH

TOP MIDDLE BOTTOM TOTAL FACTORY TEST REPORT REF. NO :

XVII FINAL DOCUMENTATION REVIEW : A FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS REVIEWED AND APPROVED B DOCUMENTS REGARDING SPARES,EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE C AFTER MODIFICATION, IF ANY, "AS BUILT DRAWINGS" ARE AVAILABLE AT SITE







PAGE 5 OF 5



SUB STATION :

PRE-COMMISSIONING OF BAY / FEEDER COMMISSIONING FORMATS

BAY NO : FEEDER / BAY IDENTIFICATION NO : DATE OF TESTING :

I

REGION :

II

ERECTION START DATE :

IV


V

FEEDER NAME

VI

VOLTAGE LEVEL :

VII

DETAILS OF EQUIPMENTS INVOLVED : EQUIPMENT

DOC NO. : MR/CF/BAY/03/R-2 DATED : 01/04/08

III

ERECTION COMPLETION DATE :

:

R - PHASE ID NO SL NO

Y - PHASE ID NO SL NO

B - PHASE ID NO

SL NO

MAKE

CT

CVT LA BREAKER TRANSFORMER REACTOR ISOLATOR

EARTH SWITCH

LINE TRAP

PAGE 1 OF 9

BAY/ FEEDER


SUB STATION :



VIII


DETAILS OF CR PANEL AND PLCC PANEL DETAILS

IDENTIFICATION NAME NUMBER



MAKE

CONTROL PANEL RELAY PANEL PLCC PANEL RTU PANEL

RECORDING INSTRUMENTS

IDENTIFICATION NAME

NUMBER

FAULT LOCATOR EVENT LOGGER DISTURBANCE RECORDER TIME SYNCRONISATION STRIP CHART RECORDER

IX

PROTOCOL DOCUMENTATION

EQUIPMENT

ALL PREALL TEST RESULTS ARE COMM TESTS WITHIN THE LIMIT OF IDENTIFICA CARRIED OUT TOLERANCE TION NO AS PER FQP YES/ NO YES/ NO

JOINT PROTOCOLS OF THE EQUIPMENT INVOLVED IN CHARGING ARE DOCUMENTED AND SIGNED BY ALL CONCERNED YES/NO

REMARKS

CT

CVT LA BREAKER TRANSFORMER REACTOR ISOLATOR

PAGE 2 OF 9

BAY/ FEEDER


SUB STATION :



EQUIPMENT


ALL PREALL TEST RESULTS ARE COMM TESTS WITHIN THE LIMIT OF IDENTIFICA CARRIED OUT TOLERANCE TION NO AS PER FQP YES/ NO YES/ NO

JOINT PROTOCOLS OF THE EQUIPMENT INVOLVED IN CHARGING ARE DOCUMENTED AND SIGNED BY ALL CONCERNED YES/NO

REMARKS

EARTH SWITCH

LINE TRAP

CONTROL PANEL

RELAY PANEL

PLCC

RTU PANEL

PAGE 3 OF 9

BAY/ FEEDER


SUB STATION :



X


CHECK OF BAY MARSHALLING KIOSK DETAILS ILLUMINATION

AND HEATER

IDENTIFICATION NUMBER OK/NOT OK OK/NOT OK

REMARKS , IF ANY

OK/NOT OK

5 /15 AMP SOCKET ALL SPECIFIED FUSES IN POSITION EARTHING AT 2 LOCATION ALL CABLES TIGHTNESS ALL CABLES ARE PROPERLY GLANDED ALL CABLES HAVE IDENTIFICATION NO ALL CORES HAVE IDENTIFICATION NO SHIELDING WIRES ARE EARTHED FREE FROM DUST AND DAMAGE DOOR HINGES AND LOCKING PAINTS UNUSED HOLES ARE SEALED XI

AVAILABILITY OF THE FOLLOWING DETAILS

1

2

STATUS YES/NO

FIRE FIGHTING SYSTEM COMMISSIONED A

FIRE PROTECTION INCLUDING ALARMS

YES/NO

B

FIRE HYDRANT SYSTEM

YES/NO

C

FIRE DELUGE (SPINKLER) SYSTEM

YES/NO

PORTABLE FIRE EXTINGUSHERS ARE IN POSITION

3

YES/NO

FIRE TENDERS CAN BE MADE AVAILABLE FOR ANY EVENTUALITY

4

YES/NO

YES / NO

EQUIPMENT IDENTIFICATION NAME PLATE ARE PROPERLY FIXED

6

7

TEL NO:

ALL EQUIPMENT ERECTION AS PER GENERAL ARRANGEMENT DRAWING ISSUED BY ENGG.

5

REMARKS TEMPORARY ARRANGEMENT,IF ANY

YES / NO

ALL BUSPOST INSULATORS ARE CLEANED AND FREE FROM DUST / DIRT FOREIGN MATERIALS ETC.

YES / NO

ALL EARTHING POINTS HAVE BEEN EARTHED

YES / NO

PAGE 4 OF 9

BAY/ FEEDER


SUB STATION :




DETAILS 8

STATUS YES/NO

ALL NUTS AND BOLTS OF BUS BAR ARE TIGHTENED CORRECTLY AS PER SPECIFIED TORQUE

9

REMARKS TEMPORARY ARRANGEMENT,IF ANY

YES / NO

ALL CLAMPS AND CONNECTORS ARE AS PER THE DRAWINGS ISSUES BY ENGG. DEPT AND CORRECTLY TIGHTENED AS PER SPECIFIED TORQUE

10

ANY PAINT REMOVED / SCRATCHED IN YARD EQUIPMENTS HAVE BEEN TOUCHED UP

11

YES / NO

BAY IDENTIFICATION AND DESIGNATION PLATE ARE ON POSITION WITH R,Y, B PHASE MARKING

12

YES / NO

GRAVEL FILLING IN THE YARD (IF DESIGNED) HAS BEEN DONE

13

YES / NO

YES / NO

THE LADDERS / TOOLS / VEHICLES / WORKBENCH / TEMPORARY EARTHING ETC. REMOVED FROM THE AREA WHICH IS TO BE ENERGIZED

YES / NO

14

DC EMERGENCY LIGHT IN OPERATION AND IN AUTO

YES / NO

15

DG SET IS AVAILABLE AND IN OPERATION

YES / NO

16

SWITCHING SEQUENSES WITH PROCEDURES ARE DOCUMENTED AND AVAILABLE IN THE CONTROL ROOM

17

YES / NO

REGULAR OPERATION IN THE CONTROL ROOM IS MANNED ROUND THE CLOCK WITH REGULAR OPERATION STAFF

18

YES / NO

ALL PTW ISSUED EARLIER ARE CANCELLED AND NOTHING ARE PENDING

19

YES / NO

OPERATION DATA LOG SHEETS, PTW AND OTHER STANDARD FORMATS OF POWERGRID ARE AVAILABLE FOR REGULAR OPERATION

YES / NO

20

CONFIRM COLOR CODING OF ALL EQUIPMENTS AND PHASE MARKING

YES / NO

21

CHECK STAR POINTS OF CT & CVT SECONDARY AND ASSOCIATED LINKS IF ANY

YES / NO

22

CHECK THAT TREATED EARTH PITS ARE COVERED AND NUMBERED

YES / NO

23

CHECK THE TIGHTNESS OF THE CONNECTING LINKS OF TREATED EARTH PITS

YES / NO

24

CORE WISE SECONDARY INJECTION TEST FOR BOTH CTs AND PTs INPUTS FROM SECONDARY TERMINAL BOX OF CT/ PT DONE TO DETECT ANY MIXING/ INTERCHANGING OF CORES/ PHASES

YES / NO

PAGE 5 OF 9

BAY/ FEEDER


SUB STATION :




25

FUSE FAIL PROTECTION CHECKED FOR M1, M2, BACKUP IMPEDANCE ETC

YES / NO

26

NECESSARY CLEARANCES AS APPLICABLE HAVE BEEN OBTAINED

YES / NO

27

CHARGING CLEARANCE IS RECEIVED FROM GRID OPERATION CPCC / IOCC / REB VIDE MSG NO :

XII

___________ TIME :___________ DATED

MEASUREMENT OF EARTH RESISTANCE HAS BEEN CARRIED OUT AND THE EARTH RESISTANCE ARE TABULATED SL. NO

LOCATION DESCRIPTION

DISTANCE BETWEEN ELECTRODE

RESISTANCE

LOCATION - 1 LOCATION - 2 LOCATION - 3 LOCATION - 4 LOCATION - 5 LOCATION - 6 XIII

CONTACT TIGHTNESS CHECK BY PRIMARY CURRENT INJECTION

CURRENT INJECTION AT CURRENT MEASURED AT

XIV

A

CURRENT MEASURED

REMARKS ON CONTACT HEALTHINESS

MEASUREMENT OF SOIL RESISTIVITY DONE EARLIER PRIOR TO COMMISSIONING MAY BE TABULATED DATE :

B

CURRENT INJECTED

DISTANCE BETWEEN ELECTRODE

SOIL RESISTIVITY

REMARK

CHECK THE MINIMUM CLEARANCE BETWEEN LIVE PARTS W.R.T GROUNG AND BETWEEN LIVE PARTS . VOLTAGE

PHASE TO GROUND

PHASE TO PHASE

132 kV

1270 mm

1473 mm

220 kV

2082 mm

2368 mm

REMARK , IF ANY

400 kV 3065 mm 5750 mm 765 KV 6400 mm 9400 mm NOTE : ALL THE CLEARANCE BETWEEN PHASES & PHASE TO GROUND ARE CHECKED AS PER THE DRGS. ISSUES BY ENGG. DEPT. PAGE 6 OF 9

BAY/ FEEDER


SUB STATION :



XV


CHECKING OF INTERLOCKS : PLEASE REFER THE RELEVENT PLANT CIRCUIT DIADRAM FOR CHECKING THE INTERLOCKS OF VARIOUS EQUIPMENTS TO BE ENERGIZED. ALL ISOLATORS AND GROUND SWITCHES INTERLOCKINGS ARE CHECKED AS PER THE

XVI

DOCUMENT NO CF/ISO/08

YES

NO

IF NOT REPEAT THE TESTING ON INTERLOCKS

YES

NO

YES

NO

PLEASE GIVE REASONS IF NO

TRIP TEST ALL BREAKERS ARE TESTED AND ALL THE TRIPTEST AS PER THE REQUIRED PLANT CIRCUIT DIAGRAMS ARE CARRIED OUT AS PER THE DOCUMENT NO CF/CB/05

XVII

STABILITY TEST FOR BUSBAR TO BE DONE IN LINE WITH APPROVED SCHEME DETAILS OF KIT USED: CONDITION 1: BUS EARTH SWITCH OPEN

PHASE R Y B R Y B R Y B

PRIMARY INJECTION BETWEEN CTs

CURRENT VALUE

SPILL CURRENT VALUE

REMARKS

CURRENT VALUE

SPILL CURRENT VALUE

REMARKS

CONDITION 2: BUS EARTH SWITCH CLOSED

PHASE R Y B R Y B R Y B

PRIMARY INJECTION BETWEEN CTs

PAGE 7 OF 9

BAY/ FEEDER


SUB STATION :



XVIII


FINAL TRIP TEST THE TRIP TEST MUST BE REPEATED PRIOR TO ENERGIZATION

AS PER APPROVED SCHEME.

TRIPPING OPERATION TO BE CHECKED FOR BOTH THE TRIP COILS FROM LOCAL/ REMOTE/ PROTECTION A

DC SOURCE 1 OFF

SL. NO

PROTECTION TYPE

I

MAIN - I

II

MAIN - II

III

OVER VOLTAGE

IV

CARRIER INTER TRIPPING

V

LBB

VI

BUS BAR

VII

TEE DIFFERENTIAL

VIII

DIFFERENTIAL

IX

RESTRICTED EARTH FAULT

X

BACK UP O/C & E/F

XI

OVERFLUXING

XII

OTI TRIP

XIII

WTI TRIP

XIV

BUCHHOLZ TRIP (MAIN )

XV

BUCHHOLZ TRIP (OLTC)

XVI

PRD

XVII

AUTO-RECLOSE - Y Ø

XIX

AUTO-RECLOSE - B Ø

SL. NO

REMARK

SIMULATION METHOD

CB TRIP RESPONCE MAIN TIE

REMARK

DC SOURCE 2 OFF PROTECTION TYPE

I

MAIN - I

II

MAIN - II

III

OVER VOLTAGE

IV


AUTO-RECLOSE - R Ø

XVIII

B

SIMULATION METHOD

CARRIER INTER TRIPPING

V

LBB

VI

BUS BAR

VII VIII

TEE DIFFERENTIAL DIFFERENTIAL

IX

RESTRICTED EARTH FAULT

X

BACK UP O/C & E/F

PAGE 8 OF 9

BAY/ FEEDER


SUB STATION :



SL. NO

PROTECTION TYPE

XI

OVERFLUXING

XII

OTI TRIP

XIII

WTI TRIP

SIMULATION METHOD

XIV

BUCHHOLZ TRIP (MAIN )

XV

BUCHHOLZ TRIP (OLTC)

XVI

PRD

XVII



REMARK

AUTO-RECLOSE - R Ø

XVIII

AUTO-RECLOSE - Y Ø

XIX

AUTO-RECLOSE - B Ø OPERATIONAL CONSTRAINTS IF ANY

1 2 3 4 5 XIX

FINAL DOCUMENTATION REVIEW : A

B

C

D

FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS REVIEWED AND APPROVED

YES

NO

YES

NO

AFTER MODIFICATION, IF ANY, "AS BUILT DRAWINGS" ARE AVAILABLE AT SITE

YES

NO

THE ABOVE BAY / FEEDER IS CLEARED FOR HIGH VOLTAGE ENERGIZATION

YES

NO

DOCUMENTS REGARDING SPARES,EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE







PAGE 9 OF 9

BAY/ FEEDER


DOC NO. MR/CF/SA/04/R-2 DATED: 01/04/08 SUB STATION : BAY NO : EQUIPMENT IDENTIFICATION NO : DATE OF TESTING :

PRE-COMMISSIONING OF SURGE ARRESTER COMMISSIONING FORMATS

I

REGION :

II

DATE OF ERECTION :

IV


III

LOA NO

:

MAKE

:

TYPE

:

SL NO.

:

R - PHASE :


Y - PHASE :

B - PHASE :

YEAR OF MANUFACTURE : FEEDER NAME : V

RATING : VOLTAGE RATING :

VI

DETAILS : CHECKLIST / TESTING SL. NO

DESCRIPTION

1

EQUIPMENT IS FREE FROM DIRT / DUST FOREIGN MATERIALS ETC.

2


3

SUPPORT STRUCTURES HAVE BEEN PROVIDED WITH DOUBLE EARTH

4


5

EQUPIMENT ERECTION IS COMPLETE IN ALL RESPECT (ATTACH REMAINING ACTIVITIES,IF ANY)

6

PERMANENT LA LAVELLING AND IDENTIFICATION IS DONE

STATUS YES NO

1 OF 3


SURGE ARRESTOR



PRE-COMMISSIONING OF SURGE ARRESTER COMMISSIONING FORMATS

SL. DESCRIPTION NO 7 LEVELLING AND ALIGNMENT OF STRUCTURE AND BASE FRAME IS CHECKED 8

ALL INSULATORS & SURGE COUNTER ARE FREE FROM ANY PHYSICAL DEFECTS

9

TIGHTNESS OF NUTS BOLTS OF TERMINAL CONNECTORS ARE CHECKED

STATUS YES NO


10 ERECTION COMPLETION CERTIFICATE ALONG WITH LIST OF OUTSTANDING ACTIVITIES REVIEWED 11 CHECK ONE END OF SURGE COUNTER IS CONNECTED TO THE BOTTOM OF LA STACK AND ONE END OF SURGE COUNTER HAS BEEN EART 12 THE DIRECTION OF THE EXHAUST VENT PORTS AWAY FROM THE PROTECTED EQUIPMENT AND OTHER ARRESTER POLES 13 CREARANCE FROM THE ARRESTER TO EARTHED OBJECTS AND FROM THE ARRESTER POLE TO ANOTHER ARRESTER POLE MAINTAINED AS PER OUTLINE DRAWING AND ALL ERECTION HAS BEEN DONE AS PER DRAWING ISSUED BY ENGG. DEPT. 14 OPERATION OF LA COUNTER CHECKED BY APPLYING APPROPRIATE VOLTAGE 15 CHECK THE SERIAL NO. AND SEQUENCE OF LA PARTS FOR ERECTION IN MULTI STACK LA 16 CHECK THE ALIGNMENT OF CORONA RING 17 CHECK ON CHARGING, THE SURGE COUNTER POINTER IS IN GREEN ZONE VII

INSULATION RESISTANCE MEASUREMENT : ( USING 5KV MEGGER) SL. NO

BETWEEN

PHASE R-PHASE Y-PHASE

MIN VALUE > 1000 M OHMS B-PHASE

1

1ST STACK & EARTH

MOHM

2

2ND STACK & EARTH

MOHM

3

3RD STACK & EARTH

MOHM

4

4TH STACK & EARTH

MOHM

5

5TH STACK & EARTH

MOHM

6

6TH STACK & EARTH

MOHM

2 OF 3

SURGE ARRESTOR



PRE-COMMISSIONING OF SURGE ARRESTER COMMISSIONING FORMATS VIII

SURGE COUNTER READING SL. NO

IX

READING

1

COUNTER SR. NO.

2 3

COUNTER MAKE COUNTER READING

PHASE R-PHASE Y-PHASE

B-PHASE

CAPACITANCE & TAN DELTA MEASUREMENT STACK

CAPACITANCE

REMARKS

TAN DELTA

TOP MIDDLE 1 MIDDLE 2 BOTTOM X

CHECKING OF HEALTHINESS OF SURGE MONITOR : REFER MANUFACTURER'S CATALOGUE FOR DETAIL CHECKING OF SURGE MONITOR

XI

THIRD HARMONIC RESISTIVE CURRENT MEASUREMENT AMBIENT TEMPERATURE SYSTEM VOLTAGE PH

TOTAL CURRENT

OK

NOT OK

: : REMARKS

3RD HARMONIC RESISTIVE CURRENT (I3 R) in µ A

R Y B

THE VALUE OF THIRD HARMONIC CURRENT AFTER COMPENSATION SHALL BE LESS THAN 30 µA. IN CASE OF DISCREPANCY, TEST RESULTS TO BE FORWARDED TO CC/OS. XII

FINAL DOCUMENTATION REVIEW

A

B

C


YES

NO

DOCUMENTS REGARDING SPARES, EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE

YES

NO


YES

NO



3 OF 3



(POWERGRID SITE I/C ( POWERGRID COMM TEAM )

SURGE ARRESTOR


DOC NO. : MR/CF/CB/05/R-2 DATED : 01/04/08 SUB STATION : BAY NO :

PRE-COMMISSIONING OF SF6 CIRCUIT BREAKER

EQUIPMENT IDENTIFICATION NO :

COMMISSIONING FORMATS

DATE OF TESTING :

I

REGION

:

II

DATE OF ERECTION :

IV


III

LOA NO

:

MAKE

:

TYPE

:

SL NO.

:


YEAR OF MANUFACTURE : FEEDER NAME : OPERATING VOLTAGE :

kV

RATED BREAKING CAPACITY : CONTROL VOLTAGE : V

kA VOLT

DC

DETAIL CHECKLIST :

SL. NO

DESCRIPTION

1

EQUIPMENT IS FREE FROM DIRT/DUST

STATUS YES

NO


FOREIGN MATERIALS ETC. 2


3

SUPPORT STRUCTURES, MARSHALLING BOX HAS BEEN PROVIDED WITH DOUBLE EARTH

4


5

EQUPIMENT ERECTION IS COMPLETE IN ALL RESPECT & ERECTION COMPLETION CERTIFICATE ALONG WITH LIST OF OUTSTANDING ACTIVITIES REVIEWED (ATTACH REMAINING ACTIVITIES,IF ANY)

6

PERMANENT POLE LAVELLING AND IDENTIFICATION IS DONE

PAGE 1 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

SL.

DESCRIPTION

STATUS

NO 7

YES

REMARK NO

RECORD DEFICIENCIES, IF ANY


8

CONTROL BOX / MARSHALLING KIOSK IS FREE FROM ANY PHYSICAL DEFECTS

9


10

i) AUXILLARY CONTACTS AND RELAYS HAVE BEEN CLEANED AND FREE FROM RUST / DAMAGE ii) ALL SPARE WIRES TO BE KEPT WITH FERRULES BUT NOT TERMINATED AT THE TERMINAL BLOCKS iii) CHECK ALL THE VALVES IN THE SF6 PIPE LINE ARE TIGHTENED, DILO COUPLING ARE TIGHTENED.

11

SLOW AND POWER CLOSING OPERATION AND OPENING DONE (WHEREVER APPLICABLE)

YES

NO (OPENING)

12

OPERATING SYSTEM : HYDRAULIC : (CLOSING)

12.1

HYDRAULIC PNEUMATIC

PNEUMATIC: SPRING

:

SPRING

OTHERS

:

OTHERS

HYDRAULIC SYSTEM R PHASE

12.1.1

ACCUMULATOR

Y PHASE

B PHASE

MAKE SL NO TYPE YR. OF MANUFACTURE

12.1.2

PUMP DETAILS

MAKE

:

VOLT

SL NO

:

AMPERES

TYPE

:

HP/KW

YEAR OF

:

O/L SETTING

MANUFACTURE

(THERMAL OVERLOAD)

PAGE 2 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

12.1.3

DETAILS OF RELAYS/CONTACTORS USED : SCHEMATIC DRAWING NO : CIRCUIT REFERENCE

MAKE

SERIAL NO.

TYPE

NO+NC

OIL PRESSURE MONITOR CLOSING LOCKOUT AUTO RECLOSING LOCKOUT GENERAL LOCKOUT ANTI PUMPING CONTACTOR POLE DESCREPANCY TIMER AUXILLARY POWER CONTACTOR OTHERS 12.1.4

OPERATION CHECKS : DATE OF FILLING HYDRAULIC OIL TYPE OF HYDRAULIC OIL AERO SHELL FLUID 4 OTHER (TYPE :__________) VENTING OF HYDRAULIC SYSTEM IS DONE (i) (ii) (iii) (iv)

PUMP PILOT VALVE ACCUMULATOR HYDRAULIC MECHANISM

PRESSURISING HYDRAULIC SYSTEM SITE TEST VALUE

FACTORY TEST VALUE PRE-FILLING PRESSURE OF N2 IN ACCUMULATOR ( BAR /

BAR AT

BAR AT

DEG. C

DEG. C

DEG. C) PUMP RUNNING TIME FOR CHARGING HYDRAULIC SYSTEM FROM INITIAL PRESSURE TO WORKING PRESSURE

MIN

CHECKING SAFETY VALVE (OPEN/CLOSE)

BAR

/

HYDRAULIC PRESSURE DROP FOR 1 HR BREAKER ON POSITION

BAR

BREAKER OFF POSITION

BAR

PAGE 3 OF 14

CIRCUIT BREAKER






DATE OF TESTING : FACTORY TEST VALUE

SITE TEST VALUE

OIL PRESSURE MONITOR PUMP ON / OFF BAR PUMP RUNNING TIME

BAR SEC

AUTO RECLOSING LOCKOUT (OIL) PRESSURE CONTACT __________MAKE/BREAK

BAR

CLOSING LOCKOUT (OIL) PRESSURE CONTACT __________MAKE/BREAK

BAR

GENERAL LOCKOUT (OIL) PRESSURE CONTACT __________MAKE/BREAK

BAR

CHECKING ANTI PUMPING CONTACTOR PRESSURE CONTACT __________MAKE/BREAK

OK/NOTOK

CHECKING LOSS OF NITROGEN PRESSURE CONTACT __________MAKE/BREAK

OK/NOTOK

FACTORY TEST REPORT REF NO: 12.1.5

OIL PRESSURE DROP DURING OPERATIONS AND PUMP RUNNING TIME IN SECONDS (i)

(ii)

(iii)

(iv)

SITE TEST VALUE

FACTORY TEST VALUE

PRESSURE BEFORE OPERATION

BAR

PRESSURE AFTER CLOSING OPERATION

BAR

PUMP RUNNING TIME

SEC


BAR

PRESSURE AFTER OPENING OPERATION

BAR

PUMP RUNNING TIME

SEC


BAR

PRESSURE AFTER CLOSE/OPEN OPERATION

BAR

PUMP RUNNING TIME

SEC


BAR

PRESSURE AFTER OPEN-CLOSE-OPEN OPER.

BAR

PUMP RUNNING TIME

SEC

FACTORY TEST REPORT REF NO:

PAGE 4 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

12.2 12.2.1

PNEUMATIC SYSTEM OPERATING SYSTEM DETAILS R PHASE

12.2.2

12.2.3

12.2.4

AIR RECEIVER NO

:

CONTROL BLOCK NO

:

PNEUMATIC DRIVE NO

:

MAGNETIC VENTIL NO

:

MOTOR DETAILS

ICU DETAILS

Y PHASE

B PHASE

MAKE

:

VOLT

SL NO

:

AMPERES

TYPE

:

HP/KW

YEAR OF MANUFACTURE

:

SETTING AMP (THERMAL OVERLOAD)

MAKE

:

SL NO

:

TYPE

:

DISCHARGE

:

CAPACITY

:

YEAR OF MANUFACTURE

:

DETAILS OF RELAYS/ CONTACTORS USED : SCHEMATIC DRAWING NO : CIRCUIT REFERENCE

MAKE

SERIAL NO.

TYPE

NO+NC

AIR PRESSURE MONITOR CLOSING LOCKOUT AUTO RECLOSING LOCKOUT GENERAL LOCKOUT POLE DESCREPANCY TIMER AUXILLARY POWER CONTACTOR IN ICU OTHERS

PAGE 5 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

12.2.5

PRESSURE SWITCH SETTING FACTORY SETTING VALUE

CIRCUIT REFERENCE

BLOCK

SITE SETTING VALUE

DEBLOCK

BLOCK

MAKE

REMARKS

DEBLOCK

OPERATION LOCKOUT -1 OPERATION LOCKOUT -2 CLOSING LOCKOUT AUTO RECLOSING CKT LOW/HIGH PRESSURE ALARM CIRCUIT ICU AUTO SETTING ICU SAFETY VALVE OPERATIONS FACTORY TEST REPORT REF NO : 12.2.6

PRESSURE DROP DURING OPERATION : ( IN KG/SQ.CM -BAR ) SL NO

DESCRIPTION

A

TRIPPING THROUGH TC - I

B

TRIPPING THROUGH TC - II

C

CLOSING CIRCUIT

D

CLOSE-OPEN OPERATION

E

OPEN - CLOSE - OPEN

FACTORY SETTING VALUE

SITE SETTING VALUE

FACTORY TEST REPORT REF NO : 12.2.7

NUMBER OF OPERATION FROM LOCAL. TANK PRESSURE ___________ KG/SQ.CM OR BAR BREAKER INITIALLY CLOSE : FACTORY TEST : O-C-

|

PLEASE KEEP INLET PNEUMATIC VALVE

SITE TEST :

|

CLOSED IN THESE OPERATION

FACTORY TEST : C-O-

|

PLEASE KEEP INLET PNEUMATIC VALVE

SITE TEST :

|

CLOSED IN THESE OPERATION

O-C-

BREAKER INITIALLY OPEN :

12.2.8

C-O-

LEAKAGE CHECK : AIR PRESSURE DROP IN 24 HRS : BREAKER

ON

DROP IN PRESSURE

:

KG/SQ.CM OR BAR

BREAKER

OFF

DROP IN PRESSURE

:

KG/SQ.CM OR BAR

PAGE 6 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

12.3 12.3.1

SPRING OPERATING MOTOR DETAILS

SYSTEM MAKE

:

VOLT

SL NO

:

AMPERES

TYPE

:

HP/KW

YEAR OF MANUFACTURE

:

SETTING (THERMAL OVERLOAD) ____________AMP

DC CURRENT TAKEN BY MOTOR FOR CHARGING THE SPRING 12.3.2

DETAILS OF RELAYS/CONTACTORS USED : SCHEMATIC DRAWING NO : CIRCUIT REFERENCE

MAKE

SERIAL NO.

TYPE

NO+NC

CLOSING LOCKOUT AUTO RECLOSING LOCKOUT GENERAL LOCKOUT POLE DESCREPANCY TIMER AUXILLARY POWER CONTACTOR OTHERS 12.3.3

SPRING OPERATING TIME : TIME TAKEN BY THE SPRING TO CHARGE FULLY AFTER CLOSING OF BREAKER. DETAILS

R-PHASE FACTORY SITE

Y-PHASE FACTORY SITE

B-PHASE FACTORY SITE

CHARGING TIME FACTORY TEST REPORT REF NO : 13.0

13.1

SF6 DENSITY MONITOR DETAILS R-PHASE

Y-PHASE

B-PHASE

MAKE

:

MODEL

:

QUANTITY OF SF6 GAS FILLED

SL.NO

:

R:

YEAR OF MANUFACTURE

:

Y: B:

ACTUAL AS PER SPEC

SF6 DENSITY MONITOR SETTINGS PHASE

DETAILS

BLOCKING FACTORY SITE

R - PHASE REFILL ALARM

DEBLOCKING FACTORY SITE

SF6 GAS FILLED AT ________ BAR ____ AT _____ DEG. C ON

OPERATION BLOCK

___/___/___

Y - PHASE REFILL ALARM OPERATION BLOCK B - PHASE REFILL ALARM OPERATION BLOCK FACTORY TEST REPORT REF NO :

PAGE 7 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

13.2

MEASUREMENT OF DEW POINT OF SF6 GAS : SL. NO

13.3

MEASURED VALUE DESCRIPTION MIN. VALUE OF DEW POINT TO BE AS PER DOC. NO. D-5-02-XX-01-03 ANNEXURE-1

NOTE: DEW POINT MEASUREMENT OF SF6 GAS NEEDS TO BE DONE POLE WISE IN CLOSE LOOP METHOD WITHOUT ANY WASTAGE OF SF6 GAS LEAKAGE CHECK : A

INITIAL FILLING OF SF6 GAS AT ____DEG C :

BAR

(AS PER TEMP. CORRECTION CHART ) B

DROP IN SF6 GAS PRESSURE IN 24 HRS :

BAR

C

FINAL SF6 PRESSURE AT ________DEG. C AFTER ALL TESTING ADDITIONAL LEAKAGE TEST BY COVERING INDIVIDUAL JOINT WITH POLYTHENE

BAR

D

14.0

YES

NO

COIL RESISTANCE MEASUREMENT : SL NO

PHASE

COIL

MEASURED SERIES VALUE RESISTOR

TRIP COIL - I A

B

C

R

Y

B

TOTAL OHMS

TRIP COIL - II

OHMS

CLOSE COIL

OHMS

TRIP COIL - I

OHMS

TRIP COIL - II

OHMS

CLOSE COIL

OHMS

TRIP COIL - I

OHMS

TRIP COIL - II

OHMS

CLOSE COIL

OHMS

PAGE 8 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

15.0

CIRCUITARY / OPEARTIONAL CHECKS : SL NO

CIRCUIT REFERENCE

CIRCUITARY CHECK LOCAL REMOTE

A

TRIPPING THROUGH TC-I

B

TRIPPING THROUGH TC-II

C

CLOSING CIRCUIT

D

ANTI-HUNTING FEATURE (CLOSE OPEN OPERATION )

E

POLE DISCREPANCY FEATURE

F

BREAKER POSITION INDICATION

G

HEATER IN SWITCH CUBICLE

H

HEATER IN CONTROL CUBICLE

I

ILLUM. IN SWITCH CUBICLE

J

ILLUM. IN CONTROL CUBICLE

OPERATIONAL CHECK LOCAL REMOTE

NOTE : IN CASE WIRING FOR REMOTE OPERATION IS NOT READY, PLEASE INDICATE TERMINAL NUMBER ALONG WITH WIRE FERRULE NUMBER IN SWITCH CUBICLE WHERE REMOTE CABLES SHALL BE TERMINATED. REMOTE OPERATION CAN BE CHECKED FROM THESE TERMINALS. 16.0

OPERATING TIME ( IN MILLI-SECONDS ) PHASE R - PH MAIN CONTACT

BREAK

CLOSE

TRIP TRIP - I TRIP -II

CLOSE TRIP USING TRIP - I TRIP - II

BREAK 1

R - PH PIR AUXILIARY CONTACT R - PH MAIN CONTACT

BREAK 2

R - PH PIR AUXILIARY CONTACT Y - PH MAIN CONTACT

BREAK 1

Y - PH PIR AUXILIARY CONTACT Y - PH MAIN CONTACT

BREAK 2

Y - PH PIR AUXILIARY CONTACT B - PH MAIN CONTACT

BREAK 1

B - PH PIR AUXILIARY CONTACT B - PH MAIN CONTACT

BREAK 2

B - PH PIR AUXILIARY CONTACT NOTE: FOR 765 KV, TAKE MEASUREMENTS FOR FOUR BREAKS

PAGE 9 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

17.0

IR VALUE OF CONTROL CIRCUIT : USING 500 VOLT MEGGER MINIMUM VALUE 2 MOHM CAUTION : ISOLATE NECESSARY DC FOR TRIP COIL I AND TRIP COIL II ,CLOSING COIL BEFORE MEGGARING. COIL DETAILS

18.0

R - PHASE TRIP COIL - I

MOHM

R - PHASE TRIP COIL - II

MOHM

R - PHASE CLOSE COIL

MOHM

Y - PHASE

TRIP COIL - I

MOHM

Y - PHASE

TRIP COIL - II

MOHM

Y - PHASE

CLOSE COIL

MOHM

B - PHASE

TRIP COIL - I

MOHM

B - PHASE

TRIP COIL - II

MOHM

B - PHASE

CLOSE COIL

MOHM

IR VALUE WITH BREAKER OPEN :

ACROSS OPEN CONTACT

19.0

MEASUREMENT VALUE

USING 5000 VOLT MEGGER MINIMUM VALUE 1000 MOHM MEASUREMENT VALUE

R - PHASE BREAK 1

MOHM

R - PHASE BREAK-2

MOHM

Y - PHASE BREAK 1

MOHM

Y - PHASE BREAK-2

MOHM

B - PHASE BREAK 1

MOHM

B - PHASE BREAK-2

MOHM

IR VALUE WITH RESPECT TO EARTH WITH BREAKER CLOSED, EARTH SWITCH AND ISOLATOR OPEN : USING 5000 VOLT MEGGER MINIMUM VALUE 1000 MOHM BETWEEN

MEASUREMENT VALUE

R - PHASE AND EARTH

MOHM

Y - PHASE

AND EARTH

MOHM

B - PHASE

AND EARTH

MOHM

PAGE 10 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

20.0

MINIMUM PICKUP VOLTAGE OF COILS COIL R - PHASE R - PHASE R - PHASE Y - PHASE Y - PHASE Y - PHASE B - PHASE B - PHASE B - PHASE

DETAILS TRIP COIL - I TRIP COIL - II CLOSE COIL TRIP COIL - I TRIP COIL - II CLOSE COIL TRIP COIL - I TRIP COIL - II CLOSE COIL

21.0

GRADING CAPACITOR :

21.1

DETAILS : DETAILS

MEASUREMENT VALUE V V V V V V V V V

R

INTERRUPTER 1 Y B

R

INTERRUPTER 2 Y B

R

INTERRUPTER 2 Y B

MAKE SERIAL NO. CAPACITANCE VALUE FACTORY VALUE YEAR OF MANUFAC. 21.2

CAPACITANCE AND TAN DELTA MEASUREMENT : TO BE DONE IN UST MODE DESCRIPTION R

INTERRUPTER 1 Y B

CAPACITANCE - SITE - FACTORY TAN DELTA -

SITE - FACTORY

FACTORY TEST REPORT REF NO : 22

CONTACT RESISTANCE MEASUREMENT : SL.NO

PHASE

A

R-PHASE

B

Y-PHASE

C

B-PHASE

ACROSS EACH POLE FACTORY SITE

ACROSS INTERRUPTR 1 ACROSS INTERRUPTR 2 FACTORY SITE FACTORY SITE

FACTORY TEST REPORT REF NO :

PAGE 11 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

23

BREAKER OPERATION COUNTER READING : COUNTER TYPE :

24

SL.NO

PHASE

ELECTRICAL :

A

R-PHASE

MECHANICAL :

B

Y-PHASE

C

B-PHASE

READING

DATE

CHECK FOR ANNUNCIATION IN CONTROL ROOM AS PER THE FOLLOWING FORMATS AND RECORD THE READING : SL DESCRIPTION NO OF TEST A SWITCH OFF THE DC SWITCH IN CONTROL CUBICLE

SOURCE OF WINDOW INITIATION DESCRIPTION CONTROL CUBICLE DC SOURCE I/II DC SWITCH ON/OFF FAIL / AC FAIL

B SWITCH OFF THE AC SWITCH IN CONTROL CUBICLE

CONTROL CUBICLE AC SOURCE I/II DC SWITCH ON/OFF FAIL / AC FAIL

C SHORT THE ALARM CONTACTS OF SF6 GAS DENSITY MONITOR (R-PHASE)

DENSITY MONITOR

SF6 GAS DENSITY LOW

D SHORT THE ALARM CONTACTS OF SF6 GAS DENSITY MONITOR (Y-PHASE)

DENSITY MONITOR

SF6 GAS DENSITY LOW

E SHORT THE ALARM CONTACTS OF SF6 GAS DENSITY MONITOR (B-PHASE)

DENSITY MONITOR

SF6 GAS DENSITY LOW

F REMOVE THE CABLE CONNECTED TO DENSITY MONITOR (R-PHASE)

DENSITY MONITOR

OPERATION/CLOSING LOCKOUT

G REMOVE THE CABLE CONNECTED TO DENSITY MONITOR (Y-PHASE)

DENSITY MONITOR


H REMOVE THE CABLE CONNECTED TO DENSITY MONITOR (B-PHASE)

DENSITY MONITOR


PAGE 12 OF 14

RESULT OK/NOTOK

REMARK

CIRCUIT BREAKER






DATE OF TESTING :

SL. DESCRIPTION SOURCE OF NO OF TEST INITIATION I GIVE TRIPPING POLE DESCRIPANCY COMMAND TO R-PH RELAY AT BREAKER ONLY AND CHECK THE CUBICLE OPERATION OF POLE DISCRIPANCY RELAY J GIVE TRIPPING COMMAND TO Y-PH ONLY AND CHECK THE OPERATION OF POLE DISCRIPANCY RELAY K GIVE TRIPPING COMMAND TO B-PH ONLY AND CHECK THE OPERATION OF POLE DISCRIPANCY RELAY

WINDOW DESCRIPTION BREAKER POLE DESCRIPANCY

POLE DESCRIPANCY RELAY AT BREAKER CUBICLE

BREAKER POLE DESCRIPANCY

POLE DESCRIPANCY RELAY AT BREAKER CUBICLE

BREAKER POLE DESCRIPANCY

PROTECTION RELAY AS PER SCHEME

BREAKER AUTO TRIP

RESULT OK/NOTOK

REMARK

L CHECK OTHER ALARMS AS PER PLANT CIRCUIT DIAGRAM M CLOSE THE BREAKER AND TRIP THROUGH PROTECTION WHICH ARE APPLICABLE

NOTE :

THE TRIPPING DETAILS ARE TO BE CHECKED AS PER THE SCHEME APPROVED BY ENGINEERING.

PAGE 13 OF 14

CIRCUIT BREAKER






DATE OF TESTING :

25.0

DYNAMIC CONTACT RESISTANCE & TRAVEL MEASUREMENT PHASE

FACTORY

SITE

REMARKS

APPROVAL FROM CC/OS OBTAINED

R Y B 26.0

OPERATION TIME MEASUREMENT OF POLE DISCREPANCY RELAY

27.0

MECHANICAL CLOSE INTERLOCK CHECKED (WHEREVER APPLICABLE)

28.0


YES

a FACTORY TEST RESULTS ARE AVAILABLE

YES

NO

b FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS REVIEWED AND APPROVED

YES

NO

c DOCUMENTS REGARDING SPARES, EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE

YES

NO

d AFTER MODIFICATION, IF ANY, "AS BUILT DRAWINGS" ARE AVAILABLE AT SITE

YES

NO

e CC-OS APPROVED DCRM SIGNATURES AVAILABLE

YES

NO



NO





PAGE 14 OF 14

CIRCUIT BREAKER

POWER GRID CORPORATION OF INDIA LIMITED

ांसफॉमर्र का

DOC NO.: MR/CF/ICT/06/R-2 DATED : 01/04/2008

ी किमशिनंग/ किमशिनंग फौमट

SUB STATION :

PRE-COMMISSIONING OF TRANSFORMER/ COMMISSIONING FORMATS

BAY NO : EQUIPMENT IDENTIFICATION NO :

TRANSFORMERS

DATE OF TESTING :

GENERAL INFORMATION 1

REGION

2

DATE OF RECEIPT AT SITE

:

:

DATE OF COMPLETION OF

3

ERECTION & OIL FILLING

:

DATE OF

4

ENERGISATION

:

DETAILS OF EQUIPMENT

5

a

LOA NO

:

b

MAKE

:

c

TYPE

:

d

RATING

:

e

SL NO.

:

f

VOLTAGE RATIO

:

g

COOLING TYPE

:

h

TYPE OF NEUTRAL GROUNDING

:

i

YEAR OF MANUFACTURE

:

j

OIL QUANTITY

:

k

Quantity of Main Tank:

:

Quantity of Radiator

:

OIL MAKE & TYPE

:

Specify oil type Inhibited/ Uninhibited/ Standard

Page 1 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

1

CHECK LIST OF ELECTRICAL TESTS CARRIED OUT FOR TRANSFORMER

NAME OF TEST

S.N

PERFORMED (YES/NO)

a

INSULATION RESISTANCE MEASUREMENT

b

VECTOR GROUP TEST & POLARITY CHECK

c

SHORT CIRCUIT IMPEDANCE TEST

d

MAGNETIC BALANCE TEST

e

FLOATING NEUTRAL VOLTAGE MEASUREMENT

f

MAGNETISATION CURRENT TEST

g

VOLTAGE RATIO TEST

h

INSULATION RESISTANCE MEASUREMENTS OF BUSHING CTs

i

CONTINUITY TEST OF BUSHING CTs

j

SECONDARY WINDING RESISTANCE OF BUSHING CTs

k

POLARITY TEST OF BUSHING CTs

l

CURRENT RATIO TEST

m

MAGNETISING CURVES PERFORMANCE

n

CONTACT RESISTANCE MEASUREMENT

o

TAN DELTA & CAPACITANCE MEASUREMENT OF BUSHING

p

TAN DELTA & CAPACITANCE MEASUREMENT OF WINDINGS

q

PROTECTION AND ALARM TESTS

r

STABILITY TEST OF DIFFERENTIAL AND REF PROTECTION

s

FREQUENCY RESPONSE ANALYSIS

t

MEASUREMENT OF WINDING RESISTANCE

SIGNATURE

:

NAME : DESIGNATION : ORGANISATION : ( SUPPLIER REPRESENTATIVE ) (WHEREVER APPLICABLE)

SIGNATURE

:

NAME : DESIGNATION : ORGANISATION : ( ERECTION AGENCY )

Page 2 of 25

TEST RESULTS (OK/ NOT OK)

SIGNATURE

:

SIGNATURE

:

NAME DESIGNATION

: :

NAME DESIGNATION

: :



TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

CHECKS AFTER RECEIPT OF TRANSFORMER AT SITE:

2

N2 PRESSURE & DEW POINT RECORD

a

N2 PRESSURE

DEW POINT

AMBIENT TEMP.

Remarks*

DURING DISPATCH AT FACTORY AFTER RECEIPT AT SITE DURING STORAGE AT SITE BEFORE COMM. * Please write 'NIL' in case of No Remarks NOTE: N2 PRESSURE AND DEW POINT SHOULD BE WITHIN PERMISSIBLE RANGE AS PER GRAPH PROVIDED BY MANUFACTURER AND ALSO GIVEN IN OS DOC NO D-2-03-XX01-01 REV-01. DURING STORAGE AT SITE, DEW POINT HAS TO BE MEASURED WHENEVER ANY DROP IN N2 PRESSURE IS OBSERVED. DURING STORAGE AT SITE BEFORE COMMISSIONING, N2 PRESSURE HAS TO BE MEASURED DAILY AND RECORD TO BE MAINTAINED IN A SEPARATE SHEET.

IMPACT RECORER ANALYSIS

b

STATUS

RECEIVED IN HEALTHY CONDITION AT SITE

ANALYSIS REPORT RECEIVED FROM MANUFACTURER BEFORE CHARGING

YES

NO

YES

NO

BRIEF ANALYSIS

Note: Impact Recorder should be detached from the Transformer/ Reactor preferably when the main unit has been placed on its foundation.

CORE INSULATION CHECK

c

APPLY 1.0 KV DC BETWEEN CL & CC+G

INSULATION VALUE

( RECOMMENDED VALUE > 10 M Ohms)'

BETWEEN CC-G BETWEEN CL-G BETWEEN CC-CL Note: SHORTING LINK BETWEEN CC, CL & G TO BE REMOVED AND IR VALUE TO BE TAKEN BETWEEN CC-G, CL-G & CC-CL

3

CHECKS/ PRECAUTIONS DURING ERECTION a

ACTIVE PART OF TRANSFORMER SHOULD MINIMUM EXPOSED TO ATMOSPHERE

b

DURING EXPOSURE OF ACTIVE PART OF TRANSFORMER TO ATMOSPHERE : YES

NO

REMARKS

YES

NO

REMARKS

DRY AIR GENERATOR/ DRY AIR CYLINDERS USED : c

WHILE ENTERING IN TRANSFORMER TANK, CHECK AVAILABILITY OF PROPER OXYGEN

d

TRANSFORMER KEPT SEALED WITH N2 IN BETWEEN DIFFERENT ERECTION ACTIVITIES

Page 3 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

4

PRE-COMMISSIONING CHECKS: DETAILS :

STATUS

SL.

REMARK

DESCRIPTION

NO 1 ICT AND ITS AUXILIARIES ARE FREE FROM VISIBLE DEFECTS ON PHYSICAL INSPECTION

2

ALL FITTINGS AS PER OUT LINE GENERAL ARRANGEMENT DRAWING .

3

CHECK MAIN TANK HAS BEEN PROVIDED WITH DOUBLE EARTHING

4

5

6

7

8

NO

RECORD DEFICIENCIES, IF ANY

CHECK NEUTRAL IS GROUNDED THROUGH SEPARATE CONNECTIONS. ENSURE METALLIC REQUIREMENTS AS PER SPECIFICATION (e.g. Cu) IN EARTHING STRIPS USED CHECK THAT MASHALLING BOX, T/C DRIVING GEAR, DIVERTER, RADIATOR BANK PUMP & FAN MOTOR ETC HAS BEEN EARTHED ALL NUTS AND BOLTS ARE TIGHTENED CORRECTLY AS PER SPECIFIED TORQUE (AS PER MANUFACTURERS RECOMMENDATION)

CHECK TIGHTNESS OF TERMINAL CONNECTORS

CHECK LEVELLING OF TRANSFORMER AND ITS ACCESSORIES

9


10


11

YES

BUSHINGS ARE CLEAN AND FREE FROM PHYSICAL DAMAGES

12 OIL LEVEL IS CORRECT ON ALL BUSHINGS

13 CHECK HERMETICALLLY SEALING IS INTACT IN ALL BUSHINGS

14 CHECK OIL LEAKAGE THROUGH ANY JOINTS / VALVES ETC.

15 CHECK OIL DRAIN VALVES ARE PROPERLY CLOSED AND LOCKED.

16 CHECK OIL LEVEL IN MAIN / OLTC CONSERVATOR TANK

Page 4 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

17

CHECK OIL LEVEL AT CONSERVATOR MATCHES WITH OIL TEMPERATURE OF TRANSFORMER

18 CHECK GEAR BOX OIL LEVEL IN OLTC

19 CHECK OTI AND WTI POCKETS AND REPLENISH THE OIL , IF REQUIRED

20 CKECK ALL VALVES FOR THEIR OPENING & CLOSING SEQUENCE

21

CHECK THE COLOUR OF BREATHER SILICA GEL ( BLUE WHEN DRY )

22 CHECK AVAILABILITY OF OIL IN THE BREATHER CUP

23 CHECK ALL ROLLERS ARE LOCKED AND TACK WELDED WITH RAILS ( WHEREEVER APPLICABLE )

24 CHECK BUSHING TEST TAP IS GROUNDED

25 CHECK NO DEBRIS , LOOSE T & P AND OIL STRAINS ON AND AROUND THE TRANSFORMER

26

CHECK DOOR SEALS OF MARSHALLING BOX IS INTACT AND ALL CABLE GLAND PLATES UNUSED HOLES ARE SEALED

27

CHECK THAT PRESSURE RELIEF VALVE IS CORRECTLY MOUNTED

28

ENSURE UNUSED SECONDARY CORES OF BUSHING CT's, IF ANY, HAS BEEN SHORTED

29

CHECK STAR POINT HAS BEEN FORMED PROPERLY AND GROUNDED AT ONE END ONLY AS PER SCHEME

30

CKECK THAT PERMANENT AND ADEQUATE LIGHITING ARRANGEMENTS ARE READY

31

CHECK THAT LABELLING AND IDENTIFICATION IS PERMANENT AND SATISFACTORY

32

CHECK THAT BUCHHOLZ RELAY IS CORRECLY MOUNTED WITH ARROW POINTING TOWARDS CONSERVATOR

33

CHECK CABLES ARE PROPERLY FIXED AND ENSURE CABLE ENTRY AT THE BOTTOM.

34

ENSURE ALL POWER AND CONTROL CABLE TERMINALS ARE TIGHTENED

Page 5 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

35

CHECK ALL CABLES AND FERRULS ARE PROVIDED WITH NUMBER AS PER CABLE SCHEDULE (CROSS FERULING TO BE CHECKED)

36 CHECK THAT ALL CABLES ARE CORRECTLY GLANDED

37

38

39

40

CHECK EXTERNAL CABLING FROM JUNCTION BOX TO RELAY / CONTROL PANEL COMPLETED

CHECK THAT AIR HAS BEEN RELEASED FROM THE RADIATORS AND THEIR HEADERS / OLTC BUCHHOLZ RELAY / MAIN TANK / TANK/ BUSHING TURRETS ETC. CHECK FIRE PROTECTION SYSTEM & EMULSIFIRE SYSTEM IS ADEQUATE & READY CHECK THAT CC-CL&G ARE SHORTED

41

CHECK THAT ALL RADIATOR BANK VALVES ON TOP AND BOTTOM HEADERS ARE OPEN

42

CHANGE OVER OPERATION OF AC SUPPLY FROM SOURCE-I TO SOURCE-II CHECKED

43

CHECK THE FLANGES OF BUSHING & OLTC FOR ANY CRACK AFTER FIXING

44 CHECK VARIOUS INTERLOCKS PROVIDED WITH FIRE FIGHTING AS PER THE SCHEMATIC

REF. DRG NO :

DESCRIPTION OF INTERLOCKS

5

CHECKED

MEASUREMENT OF EARTH RESISTANCE OF ELECTRODE

LOCATION VALUE (Before connection to grid) VALUE (After connection to grid)

NOTE: VALUE OF EARTH RESISTANCE< 1.0 OHM

6

CALIBRATION OF OTI & WTI PERFORMED AS PER PROCEDURE

7

DETAILS OF RELAYS/ CONTACTORS USED : SCHEMATIC DRAWING NO.:

CIRCUIT REFERENCE

MAKE

SERIAL NO.

Page 6 of 25

YES

TYPE

NO

NO+NC

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

8

EVACUATING AND OIL FILLING

8.1 BEFORE FILLING OIL, EACH DRUM HAS BEEN PHYSICALLY CHECKED FOR FREE MOISTURE AND APPEARANCE

YES

NO

8.2 OIL FILTER MACHINE : a)

CAPACITY

:

b)

MAKE

:

c)

LUBRICATING OIL OF VACUUM PUMP CHANGED OR NOT

:

d)

FILTER PACKS CLEANED OR NOT

:

e)

WHOLE FILTER MACHINE FLUSHED WITH FRESH OIL OR NOT

:

f)

VACUUM OBTAINED WITHOUT LOAD (milli bar)

:

8.3 VACUUM PUMP FOR EVACUATION OF TRANSFORMER : a)

LUBRICATING OIL CHANGED OR NOT

:

b)

VACUUM OBTAINED WITHOUT LOAD (milli bar)

:

c)

DIAMETER OF VACUUM HOSE (50 mm)

:

d)

DRY ICE CHAMBER EMPLOYED OR NOT

:

8.4 OIL STORAGE TANK : a)

INSIDE PAINTED OR NOT

:

b)

SILICA GEL BREATHER PROVIDED OR NOT

:

c)

ANY OPENING LEFT UNCOVERED

:

d)

CAPACITY & QUANTITY

:

e)

CLEANLINESS OF INSIDE OF PIPES/ HOSES TO THE STORAGE TANK

8.5 EXPOSURE DURING ERECTION

:

Transformer to be kept sealed with N2 in between

a)

First day

Hrs

:

b)

Second day

Hrs

:

c)

Third Day

Hrs

:

d)

N2 pressure applied after each days erection work

PSI

:

e)

Ambient Temperature

DegC

:

f)

Average Relative Humidity

g)

Weather Condition

: rainy/ stormy/ cloudy/sunny

:

8.6 N2 SEALING IN CASE OF DELAY IN OIL FILLING a)

No. of Cylinders used for displacing the air inside the tank

:

b)

N2 admitted from bottom valave

:

c)

Valve at diametriccaly opposite end at top kept open

:

d)

No. of Cylinders used for building up 2 PSI

:

INSPECTION ACTIONS

I.

TIGHTNESS TEST

a.

START EVACUATING ON COMPLETE UNIT

DATE

TIME

CHECKED

REMARKS

b. STOP EVACUATING AT 0.3 kPa (3 mbar) c. PRESSURE P1 ..... kPa 1 HOUR AFTER STOP EVACUATING d. PRESSURE P2 ..... kPa 0.5 HOUR AFTER READING PRESSURE P1 e. LEAKAGE = (P2-P1)xV= V=Oil quantity in Cu mtr

Page 7 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING : IF LEAKAGE >3.6, CONTINUE EVACUATING 2

VACCUM

a.

PRESSURE 0.13 kPa (1.3 mbar) REACHED

b.

VACUUM IS KEPT FOR

Upto 145 KV , 12 HRS 145 & upto 420 KV, 24 HRS Above 420 KV, 36 HRS 3

OIL FILLING

a.

OIL FILLING IS MADE

4. OIL CONSERVATOR OIL CONSERVATOR WITH AIR CELL 5. DIVERTER SWITCH HOUSING diverter switch housing filled and has an air cushion 6. STANDING TIME Upto 145 KV , 12 HRS 145 & upto 420 KV, 48 HRS Above 420 KV, 120 HRS

8.7 RECORD OF DRYING OUT PROCESS (IF CARRIED OUT)

DRYING OUT STARTED ON

DATE : TIME :

AMBIENT TEMP :

(HOURLY READING TO BE TAKEN) DATE

TIME

VACUUM READING IN VACUUM READING FILTRATION MACHINE IN TRANSFORMER TANK

OTI OF TANK

CONDENSATE COLLECTED TOTAL / RATE

REMARKS & SIGN OF Mtc ENGINEER

Record of filteration and Dry out shall be kept in a register and shall be made a part of the Pre-commissioning document.

Page 8 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

9

a

INSULATION RESISTANCE MEASUREMENT : (USING 500 V MEGGER) TESTING INSTRUMENT DETAILS:

:

TESTING EQUIPMENT CALIBRATION VALID OR NOT

:

SL.NO

STATUS

DESCRIPTION

YES A

CONTROL WIRING

B

TAP CHANGER

REMARK, IF ANY NO

a) MOTOR b) CONTROL C

COOLING SYSTEM a)

MOTOR FAN

b) MOTOR PUMP c) CONTROL WIRING NOTE :

b

IR VALUES SHOULD BE > 50 MOHMS FOR

INSULATION RESISTANCE MEASUREMENT :

CABLES

(USING 5000 V MEGGER)

TESTING INSTRUMENT DETAILS:

:


:

AMBIENT TEMPERATURE AT THE TIME OF TEST

:

TEMPERATURE OF OIL

:

IR VALUE MAIN

15 SEC.

WINDING

HV+IV to LV

(For auto Tr)

HV+IV Tto E

(For auto Tr)

LV to E

60 SEC. 600 SEC.

Dielectric Absorption Index (60s/15s)

Polarization Index Temperature (600s/ 60s)

(For auto Tr)

HV+IV to LV

(For 3 Wdg Tr)

HV+IV Tto E

(For 3 Wdg Tr)

HV+IV + LV to E (For 3 Wdg Tr) IN CASE THERE IS ANY TEMPERATURE DIFFERENCE BETWEEN MANUFACTURERS TEST CERTIFICATE VALUE AND SITE VALUE, USE TEMPERATURE CORRECTION FACTOR PROVIDED IN OS MANUAL DOC. NO. D-2-03-XX-01-01-Rev01

10

VECTOR GROUP TEST & POLARITY CKECKING

CONNECT NEUTRAL POINT WITH EARTH JOIN 1RI AND 3 RI TERMINALS -APPLY 415V, 3-PHASE SUPPLY TO HV TERMINALS TERMINALS

VOLTAGE MEASURED

REMARKS

1R1 -1Y1 1Y1- 1B1 1B1- 1R1 3Y1- 1B1 3Y1- 1Y1 3R1- N 3Y1- N 1R1- N 2R1- N 2Y1- N 2B1-N

Page 9 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

ENSURE 2R1 -N = 2Y1 -N = 2B1 - N = CONSTANT AS 3R1 -N > 3Y1 - N > 3B1 - N, AND 3Y1 - 1B1 > 3Y1 - 1Y1 VECTOR GROUP Ynaod11 IS CONFIRMED AND POLARITY VERIFIED

11

MEASUREMENT OF WINDING RESISTANCE (IN OHM)

a

TESTING INSTRUMENT DETAILS

:


:


:

TEMPERATURE OF OIL

:

WTI READING

:

HIGH VOLTAGE SIDE

TAP POSITION

WINDING RESISTANCE N) 1R1 - 2R1 1Y1 - 2Y1

(HV-

1B1 - 2B1

RESISTANCE AT R

Y

75 ºC

FACTORY VALUE

B

R

Y

REMARKS

B

1 2 3 4 5 6 7 8 9b 10 11 12 13 14 15 16 17 REVERSE ORDER TAP NO………………. TAP NO………………. TAP NO………………. TAP NO……………….


b

INTERMEDIATE VOLTAGE SIDE :

BETWEEN

RESISTANCE

WINDING

SITE VALUE

RESISTANCE AT 75 ºC FACTORY

REMARK

SITE

2R1 - N 2Y1 - N 2B1 - N

Page 10 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING : c

LOW VOLTAGE SIDE :

BETWEEN

RESISTANCE

WINDING

SITE VALUE

RESISTANCE AT 75 ºC

REMARK

SITE

FACTORY

3R1 - 3B1 3Y1 - 3R1 3B1 - 3Y1

NOTE: LV WINDING RESISTANCE AT FACTORY MEASURED WITHOUT FORMATION OF DELTA. HOWEVER MEASUREMENTS CARRIED OUT AT SITE ARE AFTER FORMATION OF DELTA. HENCE A CORRECTION FACTOR OF 1.5 TIMES TO BE APPLIED IN SITE RESULTS

12

a

MAGNETIC BALANCE TEST APPLY SINGLE PHASE 230 V ACROSS ONE PHASE OF HV WINDING TERMINAL AND NEUTRAL THEN MEASURE VOLTAGE IN OTHER TWO HV TERMINALS ACROSS NEUTRAL. REPEAT THE TEST FOR EACH OF THE THREE PHASES. Apply 1-PH 230 V AC across (1)

BETWEEN

BETWEEN

(2)

(3)

2R1 - N

V

2Y1 - N

V

2B1 - N

V

2Y1 - N

V

2R1 - N

V

2B1 - N

V

2B1 - N

V

V

2R1 - N

V

2Y1 - N NOTE :

b

REMARKS

VOLTAGE MEASURED IN VOLTS

1 = ( 2 + 3 ) APPROX.

FLOATING NEUTRAL VOLTAGE MEASUREMENT

DISCONNENT THE TRANSFORMER NEUTRAL FROM THE GROUND APPLY 3 PHASE 415 VOLTS TO THE HIGH VOLTAGE WINDING AND MAKE THE MEASUREMENT IN THE IV WINDING WITH RESPECT TO NEUTRAL AND NEUTRAL POINT TO GROUND.

TAP

PRIMARY WINDING

POSITION

VOLTAGE

IV

APPLIED

WINDING

NORMAL (

)

1R-N

2R-N

NORMAL (

)

1Y-N

2Y-N

NORMAL (

)

1B-N

REMARKS, IF ANY

VOLTAGE MEASURED

2B-N N - EARTH

APPLY 3 PHASE 415 VOLTS TO THE INTERMEDIATE VOLTAGE WINDING AND MAKE THE MEASUREMENT IN THE TERTIARY WINDING WITH RESPECT TO NEUTRAL AND NEUTRAL POINT TO GROUND.

IV WINDING

VOLTAGE

LV

APPLIED

WINDING

2R - N

3R - N

2Y - N

3Y - N

2B - N

VOLTAGE MEASURED

REMARKS, IF ANY

3B - N N - EARTH

Check: After the test, neutral reconnected to Ground

YES

Page 11 of 25

NO

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

13

MAGNETISATION CURRENT TEST :

a


:


:


:

TEMPERATURE OF OIL

:

APPLY 1-PHASE AC SUPPLY ON HV TERMINALS AND KEEP IV & LV OPEN

TAP POSITION

LOWEST

NORMAL

HIGHEST

b

(

(

(

)

)

)

CURRENT MEASURED

VOLTAGE APPLIED

REMARK

R-N

V

R - PH

m AMPS

Y-N

V

Y - PH

m AMPS

B-N

V

B - PH

m AMPS

R-N

V

R - PH

m AMPS

Y-N

V

Y - PH

m AMPS

B-N

V

B - PH

m AMPS

R-N

V

R - PH

m AMPS

Y-N

V

Y - PH

m AMPS

B-N

V

B - PH

m AMPS

APPLY 1-PHASE AC SUPPLY ON IV TERMINALS AND KEEP HV & LV OPEN

VOLTAGE APPLIED CURRENT MEASURED (IN LV SIDE)

TAP POSITION BETWEEN

NORMAL

VOLTS

2R -N

VOLTS

R - PH

mAMPS

2Y -N

VOLTS

Y - PH

mAMPS

2B -N

VOLTS

B - PH

mAMPS

Compare with factory test results if carried out at factory

14

VOLTAGE RATIO TEST : TESTING INSTRUMENT DETAILS

:


:


:

TEMPERATURE OF OIL

:

Remarks: To be done by Automatic Turns ratio meter a

RATIO : HV / IV TAP POS.

VOLTAGE APPLIED 1R-N

1Y-N

1B-N

VOLTAGE MEASURED 2R-N

2Y-N

2B-N

RATIO R

Y

FACTORY RATIO B

R

Y

B

1 2 3 4 5 6 7 8

Page 12 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING : 9 10 11 12 13 14 15 16 17 REVERSE SIDE TAP NO……. TAP NO……. TAP NO……. TAP NO…….

REMARKS (IF ANY) :

b

RATIO : HV / LV VOLTAGE APPLIED

TAP POS.

1R-N

1Y-N

1B-N

VOLTAGE MEASURED 3R-3Y

3Y-3B

3R-3B

RATIO R

Y

FACTORY RATIO B

R

B

R

Y

B

LOWEST NORMAL HIGHEST

REMARKS (IF ANY) :

c

RATIO : IV / LV VOLTAGE APPLIED

TAP POS.

2R-N

2Y-N

2B-N

VOLTAGE MEASURED 3R-3Y

3Y-3B

3R-3B

RATIO R

Y

FACTORY RATIO Y

B

LOWEST REMARKS (IF ANY) :

15

OIL CHARACTERISTICS : (SAMPLE TO BE TAKEN PRIOR TO CHARGING OF TRANSFORMER AND IT SHOULD FULFILL THE RECOMMENDATIONS AS PER IS 1866 - 2000, Table-I ) OIL SAMPLE

B.D.V *

MOISTURE

( MIN )

( MAX ) *

TAN DELTA RESISTIVITY ( MAX ) *

(KV)

(PPM)

(90 Deg C)

60

10

0.01

( MIN ) * (OHM-CM)

INTERFACIAL

REMARKS

TENSION AT 27 DEG. ( MIN ) N/m *

FOR kV CLASS

12 IS-1866

6 x 10

O,O35

> 170 KV

12 IS-1866

50

15

0.015

6 x 10

IS-1866

40

20

0.015

6 x 10

O,O35

<170 KV BUT>72.5 k

12 O,O35

MAIN TANK

< 72.5 kV SAMP. DATE :

OLTC

SAMP. DATE :

* The limiting values given in the above table to be revised as per revision in IS 1866 in future

Page 13 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

16

DISSOLVE

GAS

ANALYSIS

OIL SAMPLE SCHEDULE DISSOLV E GASES

JUST

24 HRS

7 DAYS

15 DAYS

01 MONTH

03 MONTH

BEFORE

AFTER

AFTER

AFTER

AFTER

AFTER

CHARGING

CHARGING

CHARGING

CHARGING

CHARGING

CHARGING

TOTAL GAS (%) H2 CH4 C2H4 C2H6 C2H2 CO CO2 O2 N2

17

TEST ON OLTC

SL.NO 1

2

STATUS

DESCRIPTION OK

VISUAL INSPECTION OF EQUIPMENT

REMARKS

NOT OK

MANUAL OPERATION ON ALL TAPS ( LOCAL ) WITH CONFIRMATION OF THE NO. OF REVOLUTIONS AND LOCKING AT EXTREME TAPS

3

OVER LOAD DEVICE OF DRIVING MOTOR

4

LOCAL OPERATION (ELECTRICAL)

5

REMOTE OPERATION (ELECTRICAL)

6

TAP POSITION INDICATOR

7

CHECK OPERATION WITH MASTER FOLLOWER SCHEME ( PARALLEL OPERATION )

8

OUT OF STEP RELAY

9

STEP BY STEP CONTACTOR

10

LIMIT SWITCH

11

WINDING RESISTANCE AT ALL TAPS

12

CONTINUITY TEST OF WINDING DURING ONE COMPLETE CYCLE OF OPERATION

OPERATIONAL TEST OF OTHER EQUIPMENTS

18 a

CHECKING OF COOLING EQUIPMENTS : i. ROTATION DIRECTION OF PUMPS

OK

NOT OK

ii. ROTATION DIRECTION OF FANS

OK

NOT OK

Page 14 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING : b

PROTECTION CHECKS EQPMT

SETTING VALUE

PICKUP VALUE

FAN NO.

SINGLE PHASING PREVENTION CHECK

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

c

PUMP NO. 1 2 3 4

19

INSULATION RESISTANCE MEASUREMENT OF BUSHING CT's

BETWEEN

HV R-PH

Y-PH

: ( USING 500V MEGGER)

IV B-PH

R-PH

Y-PH

B-PH

EARTH - CORE I

MOHM

EARTH - CORE II

MOHM

EARTH - CORE III

MOHM

EARTH - CORE IV

MOHM

BETWEEN

LV R-PH

Y-PH

NEUTRAL B-PH

EARTH - CORE I

MOHM

IR VALUE SHOULD

EARTH - CORE II

MOHM

BE AT LEAST

EARTH - CORE III

MOHM

EARTH - CORE IV

MOHM

BETWEEN

HV R-PH

Y-PH

2000 M OHMS

IV B-PH

R-PH

Y-PH

USING 500 V B-PH

MEGGER

CORE I - CORE II

MOHM

CORE I - CORE III

MOHM

CORE I - CORE IV

MOHM

CORE II - CORE III

MOHM

CORE II - CORE IV

MOHM

CORE III - CORE IV

MOHM

BETWEEN

LV R-PH

Y-PH

USING 500 V B-PH

MEGGER

CORE I - CORE II

MOHM

CORE I - CORE III

MOHM

CORE I - CORE IV

MOHM

CORE II - CORE III

MOHM

CORE II - CORE IV

MOHM

CORE III - CORE IV

MOHM

Page 15 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

20

CONTINUITY TEST OF BUSHING CT's

:

CONTINUTY, CHECK BETWEEN TERMINAL: OK / NOT OK a

CORE

BETWEEN TERMINAL

CORE I

1S1 - 1S2

CORE II

2S1 - 2S2

HV

R-PH

Y-PH

R-PH

Y-PH

IV

B-PH

R-PH

Y-PH

B-PH

CORE III 3S1 - 3S2 CORE IV 4S1 - 4S2

b

CORE

LV

BETWEEN TERMINAL

CORE I

1S1 - 1S2

CORE II

2S1 - 2S2

NEUTRAL B-PH

CORE III 3S1 - 3S2 CORE IV 4S1 - 4S2

21

SECONDARY WINDING RESISTANCE OF BUSHING CT's (IN OHM)

a

HV CORE

SIDE BETWEEN TERMINAL

R -PHASE FACTORY

SITE

Y -PHASE FACTORY

SITE

B -PHASE FACTORY

SITE

CORE I

1S1 - 1S2

OHM

CORE II

2S1 - 2S2

OHM

CORE III

3S1 - 3S2

OHM

CORE IV

4S1 - 4S2

OHM

b

IV CORE


R -PHASE FACTORY

SITE

Y -PHASE FACTORY

SITE

B -PHASE FACTORY

SITE

CORE I

1S1 - 1S2

OHM

CORE II

2S1 - 2S2

OHM

CORE III

3S1 - 3S2

OHM

CORE IV

4S1 - 4S2

OHM


c

LV CORE


d

R -PHASE FACTORY

SITE

Y -PHASE FACTORY

SITE

B -PHASE FACTORY

SITE

CORE I

1S1 - 1S2

OHM

CORE II

2S1 - 2S2

OHM

CORE III

3S1 - 3S2

OHM

CORE IV

4S1 - 4S2

OHM

NEUTRAL SIDE CORE

BETWEEN TERMINAL

CORE I

NEUTRAL FACTORY

SITE

1S1 - 1S2

Page 16 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

22

POLARITY TEST OF BUSHING CT's :

WITH 1.5 V DC SUPPLY (CONNECT +VE AT P1 AND - VE AT P2 )

a

b

23

CORE

BETWEEN

CORE I 1S1 (+VE)

1S2 (-VE)

CORE II 2S1 (+VE)

2S2 (-VE)

CORE III 3S1 (+VE)

3S2(-VE)

CORE IV 4S1 (+VE)

4S2 (-VE)

CORE

HV

R-PH

Y-PH

R-PH

Y-PH

BETWEEN

CORE I 1S1 (+VE)

1S2 (-VE)

CORE II 2S1 (+VE)

2S2 (-VE)

CORE III 3S1 (+VE)

3S2(-VE)

CORE IV 4S1 (+VE)

4S2 (-VE)

IV

B-PH

LV

R-PH

Y-PH

B-PH

NEUTRAL

B-PH

CURRENT RATIO TEST MEASURE CURRENT ON THE SECONDARY TERMINALS a

R - PHASE CORE S1 - S2

HV SIDE PRIMARY %

CORE I

20 %

(1S1 - 1S2)

40 %

CURRENT SECONDARY THEORETACTUAL

CURRENT

ICAL RATIO

ACTUAL

% OF

RATIO

ERROR

80 % CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

b

Y - PHASE CORE I

20 %

(1S1 - 1S2)

40 % 80 %

CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

Page 17 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING : c

B - PHASE CORE I

20 %

(1S1 - 1S2)

40 % 80 %

CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

d

R - PHASE S1 - S2

INTERMEDIATE VOLTAGE SIDE 20 %

CORE I

40 %

(1S1 - 1S2)

80 % 20 %

CORE II

40 %

(2S1 - 2S2)

80 % 20 %

CORE III

40 %

(3S1 - 3S2)

80 % 20 %

e

CORE IV

40 %

(4S1 - 4S2)

80 %

Y - PHASE CORE I

20 %

(1S1 - 1S2)

40 % 80 %

CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

f

B - PHASE CORE I

20 %

(1S1 - 1S2)

40 %

CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

Page 18 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

24

MAGNETISING

CURVES

PERFORMANCE

(NOT TO BE DONE FOR METERING CORE) KNEE POINT VOLTAGE (KVp) = ______________ VOLT

HV SIDE

a

R - PHASE VOLTAGE TO BE APPLIED

b

CURRENT MEASUREMENT ACTUAL VALUE

CORE - II CORE - III CORE - IV

1S1-1S2

2S1 - 2S2 3S1 - 3S2 4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

Y - PHASE VOLTAGE TO BE APPLIED

c

CORE - I


CORE - I


1S1-1S2

2S1 - 2S2 3S1 - 3S2 4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

B - PHASE VOLTAGE TO BE APPLIED


CORE - I


1S1-1S2

2S1 - 2S2 3S1 - 3S2 4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

NOTE : 1.0 CT SHOULD NOT SATURATE AT 110 % OF KNEEPOINT VOLTAGE ( KVp ) 2.0 IF KNEE POINT VOLTAGE IS NOT MENTIONED THEN KNEE POINT CURRENT MAY BE TAKEN INTO CONSIDERATION

INTERMEDIATE VOLTAGE SIDE d

R - PHASE VOLTAGE TO BE APPLIED


CORE - I


1S1-1S2

2S1 - 2S2 3S1 - 3S2 4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

Page 19 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

e

Y - PHASE

INTERMEDIATE VOLTAGE SIDE

VOLTAGE TO BE APPLIED

f


CORE - I


1S1-1S2

2S1 - 2S2 3S1 - 3S2 4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

B - PHASE


VOLTAGE TO BE APPLIED

25


CORE - I


1S1-1S2

2S1 - 2S2 3S1 - 3S2 4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

CONTACT RESISTANCE MEASUREMENT

AT 100 AMPS

NOTE : THE VALUE OF CONTACT RESISTANCE SHOULD NOT BE MORE THAN 10 MICRO-OHMS PER JOINT / CONNECTOR

R-PH

CONTACT RESISTANCE

26

Y-PH

B-PH

ACROSS HV BUSHING TERMINAL JOINT

MICRO OHM

ACROSS IV BUSHING TERMINAL JOINT

MICRO OHM

ACROSS LV BUSHING TERMINAL JOINT

MICRO OHM

ACROSS NEUTRAL CONNECTION POINT

MICRO OHM

ACROSS SURGE ARRESTOR CONNECTION

MICRO OHM

BUSHING DETAILS

STYLE NO./ DRAWING NO. :

HIGH VOLTAGE SIDE DETAILS

R-PH

Y-PH

B-PH

INTERMEDIATE VOLT. SIDE R-PH

Y-PH

B-PH

MAKE TYPE SL. NO

DETAILS

LOW VOLTAGE SIDE R-PH

Y-PH

B-PH

MAKE TYPE SL. NO

Page 20 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

27

TAN DELTA AND CAPACITANCE MEASUREMENT OF BUSHING

a


:


:


:

TEMPERATURE OF OIL

:

HIGH VOLTAGE SIDE

CAPACITANCE ( MEASURED VALUE ) VOLTAGE

R SITE

PHASE FACTORY

Y SITE

PHASE

B

FACTORY

SITE

PHASE

REMARK

FACTORY

MEASUREMENT OF C1 CAPACITANCE 2 KV 10 KV MEASUREMENT OF C2 CAPACITANCE* 1 KV

TAN DELTA ( MEASURED VALUE ) VOLTAGE

R SITE

PHASE FACTORY

Y SITE

PHASE

B

FACTORY

SITE

PHASE

REMARK

FACTORY

MEASUREMENT OF C1 TAN DELTA 2 KV 10 KV MEASUREMENT OF C2 TAN DELTA* 1 KV

b



R SITE

PHASE FACTORY

Y SITE

PHASE FACTORY

B SITE

PHASE

REMARK

FACTORY



R SITE

PHASE FACTORY

Y SITE

PHASE FACTORY

B SITE

PHASE

REMARK

FACTORY


Page 21 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

c

LOW VOLTAGE SIDE


R SITE

PHASE

Y

FACTORY

SITE

PHASE

B

FACTORY

SITE

PHASE

REMARK

FACTORY



R SITE

PHASE

Y

FACTORY

SITE

PHASE

B

FACTORY

SITE

PHASE

REMARK

FACTORY


FACTORY TEST REPORT REF NO : * NOTE

28

C2 VALUES SHALL BE ONLY FOR RECORD PERPOSE.

TAN DELTA AND CAPACITANCE MEASUREMENT OF WINDINGS


:


:


:

TEMPERATURE OF OIL

:

VOLTAGE 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV

WINDING COMBINATION

Test Mode

HV-IV/ LV

UST

HV-IV/ LV+G

GST

HV-IV/ LV with Guard

GSTg

HV-IV/LV

UST

LV/ HV-IV+G

GST

LV/ HV-IV with Guard

GSTg

TAN DELTA *

CAPACITANCE SITE

FACTORY

SITE

FACTORY

REMARK

* SHOULD BE COMPARABLE (+/- 0.001) WITH FACTORY VALUE SUBJECTED TO MAX OF 0.005.


Page 22 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

29

SHORT CIRCUIT IMPEDANCE TEST

a


:


:


:

TEMPERATURE OF OIL

:

HV TO IV

1U1 ( R )

1V1 (Y)

1W1 (B)

(IV OF R Ф AND N SHORTED, LV OPEN)

(IV OF Y Ф AND N SHORTED, LV OPEN)

(IV OF B Ф AND N SHORTED, LV OPEN)

TAP NUMBER

1

b

VOLTAGE

CURRENT

VOLTAGE

CURRENT

VOLTAGE

CURRENT

…………………….V

…………………….A

…………………….V

…………………….A

…………………….V

…………………….A

9b

…………………….V

…………………….A

…………………….V

…………………….A

…………………….V

…………………….A

17

…………………….V

…………………….A

…………………….V

…………………….A

…………………….V

…………………….A

IV TO LV TAP NO. 9b SUPPLY 2U1-N, …………………….V

SHORT ALL 3 LV BUSHINGS, HV OPEN


…………………………………………………………A …………………………………………………A

2V1-N,……………………..V 2W1-N, ……………………V

c


…………………………………………A

HV TO LV TAP NO. 9b SUPPLY 1U1-N, …………………….V

SHORT ALL 3 LV BUSHINGS, IV OPEN



…………………………………………………………A

1V1-N,……………………..V

…………………………………………………A ……………………………………………A

1W1-N, ……………………V TAP NO. 17 SUPPLY 1U1-N, …………………….V




…………………………………………………………A

1V1-N,……………………..V

………………………………………………A ………………………………………A

1W1-N, ……………………V TAP NO. 1 SUPPLY 1U1-N, …………………….V 1V1-N,……………………..V




…………………………………………………………A ……………………………………………A

1W1-N, ……………………V

………………………………………A

Page 23 of 25

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING :

30

PROTECTION

SL

AND

ALARMS

DEVICE

SET

NO

FOR

ALARM

PROVED

TRIP

1

EXCESSIVE WINDING TEMPERATURE.

2

EXCESSIVE OIL TEMPERATURE.

3

OIL FLOW FAILURE

4

PRESSURE

5

MAIN TANK BUCHHOLZ RELAY

6

OLTC BUCHHOLZ RELAY

7

FAN FAILURE

NA

8

LOW OIL LEVEL (MOG)

NA

9

DIFERENTIAL RELAY

10

OVER LOAD RELAY

RELIEF

ALARM

NA VALVE

NA

NA

NA

NA

NA

NA

TRIP

NA NA NA

NA

NA

11

EARTH FAULT RELAY ( REF )

NA

NA

12

OVER CURRENT RELAY

NA

NA

13

INTER TRIP , IF ANY

NA

NA

14

TRIP FREE CHECK

NA

NA

15

BACKUP OVER CURRENT

NA

NA

16

OVER FLUX

17

PROTECTION SETTINGS APPLIED AS PER ENGG. APPROVED SETTINGS

YES

NO

18

STABILITY TEST OF DIFFERENTIAL & REF PROTECTION:

OK

NOT OK

NOTE : PROVE THE TRIPPING OF ASSOCIATED BREAKERS BY ACTUAL OPERATION OF THE VARIOUS DEVICES AND RELAYS AS PER THE SCHEMES.

31 FREQUENCY RESPONSE ANALYSIS (FRA)

a

CARRIED OUT AFTER COMPLETION OF ALL COMMISSIONING ACTIVITIES

YES

NO

b

INTERPRETATION OF TEST RESULTS CARRIED OUT

YES

NO

c

TEST RESULTS MATCHING WITH THE FACTORY RESULTS

YES

NO

d

FACTORY & SITE FRA TEST REPORT AVAILABLE AT SITE

YES

NO

ALL ELECTRICAL TEST RESULTS COMPARED WITH

32 FACTORY TEST RESULTS AND FOUND TO BE IN ORDER

YES

NO

YES

NO

CHECKS AFTER CHARGING OF TRANSFORMER 33 RECORD THE FOLLOWING AFTER CHARGING

a

ANY ABNORMAL SOUND EMANATING FROM THE TRANSFORMER:

Page 24 of 25

REMARKS

TRANSFORMER





SUB STATION :



TRANSFORMERS

DATE OF TESTING : b

NO LOAD CURENT AT RELAY TERMINAL

c

R PHASE

A

Y PHASE

A

B PHASE

A

CT RATIO

TEMPERATURE (AT THE TIME OF CHARGING)

OTI

ºC

WTI

ºC

AMBIENT

ºC

d

MAXIMUM TEMPERATURE AFTER 24 HOURS

e

OLTC ELCTRICAL OPERATION CHECKED IN IDLE CHARGED CONDITION FROM MIN POSITION TO MAX POSITION AND BACK TO NORMAL POSITION

YES

NO

REMARKS

f

THERMOVISION SCANNING DONE ATLEAST AFTER 24 HOURS OF LOADING AND REPEATED AFTER ONE WEEK

YES

NO

REMARKS

34

ºC


a

FACTORY TEST RESULTS ARE AVAILABLE

YES

NO

b

FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS

YES

NO

YES

NO

YES

NO

REVIEWED AND APPROVED

c


d


SIGNATURE

:

SIGNATURE

:

SIGNATURE

:

SIGNATURE

:

NAME

:

NAME

:

NAME

:

NAME

:

DESIGNATION

:

DESIGNATION

:

DESIGNATION

:

DESIGNATION

:

ORGANISATION :

ORGANISATION :

( SUPPLIER REPRESENTATIVE )

( ERECTION AGENCY )



(WHEREVER APPLICABLE)

Page 25 of 25

TRANSFORMER


DOC NO. : MR/CF/SR/07/R-2 DATED : 01/04/08 SUB STATION :

PRE-COMMISSIONING OF REACTOR COMMISSIONING FORMATS

`


1

GENERAL INFORMATION

a

REGION :

b

c

DATE OF COMPLETION OF ERECTION & OIL FILLING :

d

e

DATE OF RECEIPT AT SITE : DATE OF ENERGISATION :

DETAILS OF EQUIPMENT : i

LOA NO

:

ii

MAKE

:

iii

TYPE

:

iv

RATING

:

v

SL NO.

:

vi

VOLTAGE CLASS :

vii

COOLING TYPE

:

viii TYPE OF NEUTRAL GROUNDING : ix

2

YEAR OF

MANUFACTURE

x

OIL QUANTITY :

xi

OIL MAKE & TYPE :

xii

FEEDER NAME

:

:

CHECK LIST FOR ELECTRICAL TESTS CARRIED OUT FOR REACTOR NAME OF TEST

SL. NO. 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16

PERFORMED

YES/ NO

TEST RESULTS NOTOK

OK/

INSULATION RESISTANCE MEASUREMENT CAPACITANCE & TAN DELTA OF BUSHING CAPACITANCE & TAN DELTA OF WINDING CAPACITANCE & TAN DELTA OF NGR WINDING WINDING RESISTANCE MEASUREMENT WINDING RESISTANCE MEASUREMENT OF NGR MAGNETIZING CURRENT TEST VIBRATION MEASUREMENT INSULATION RESISTANCE MEAS OF BUSHING CT CONTINUITY TEST OF BUSHING CTs SEC WDG RESISTANCE OF BUSHING CTs POLARITY TEST OF BUSHING CTs CONTACT RESISTANCE MEASUREMENT PROTECTION AND ALARM TEST STABILITY TEST OF DIFFERENTIAL & REF PROT. FREQUENCY RESPONSE ANALYSIS







PAGE 1 OF 16

SHUNT REACTOR





CHECKS AFTER RECEIPT OF REACTOR AT SITE

3 a

N2 PRESSURE AND DEW POINT RECORD N2 PRESSURE

DEW POINT

REMARKS*

DURING DISPATCH AT FACTORY AFTER RECEIPT AT SITE DURING STORAGE AT SITE BEFORE COMM. * Please write 'NIL' in case of No Remarks NOTE: N2 PRESSURE AND DEW POINT SHOULD BE WITHIN PERMISSIBLE RANGE AS PER GRAPH PROVIDED BY MANUFACTURER AND ALSO GIVEN IN OS DOC NO D-2-03-XX-01-01 REV-01. DURING STORAGE AT SITE, DEW POINT HAS TO BE MEASURED WHENEVER ANY DROP IN N2 PRESSURE IS OBSERVED. DURING STORAGE AT SITE BEFORE COMMISSIONING, N2 PRESSURE HAS TO BE MEASURED DAILY AND RECORD TO BE MAINTAINED IN A SEPARATE SHEET.

b

IMPACT RECORDER ANALYSIS RECEIVED IN HEALTHY CONDITION AT SITE ANALYSIS REPORT RECEIVED FROM MANUFACTURER BEFORE CHARGING

YES

STATUS NO

YES

NO

BRIEF ANALYSIS

Note: Impact Recorder should be detached from the Transformer/ Reactor preferably when the main unit has been placed on its foundation. c

CORE INSULATION CHECK APPLY 1.0 KV DC BETWEEN CL & CC+G INSULATION VALUE

( RECOMMENDED VALUE > 10 M Ohms)'

BETWEEN CC-G BETWEEN CL-G BETWEEN CC-CL Note: SHORTING LINK BETWEEN CC, CL & G TO BE REMOVED AND IR VALUE TO BE TAKEN BETWEEN CC-G, CLG & CC-CL

CHECKS/ PRECAUTIONS DURING ERECTION

4 a

ACTIVE PART OF REACTOR SHOULD MINIMUM EXPOSED TO ATMOSPHERE

b

DURING EXPOSURE OF ACTIVE PART OF REACTOR TO ATMOSPHERE :

c

DRY AIR GENERATOR/ DRY AIR CYLINDERS USED :

d

WHILE ENTERING IN REACTOR TANK, CHECK AVAILABILITY OF PROPER OXYGEN

e

REACTOR KEPT SEALED WITH N2 IN BETWEEN DIFFERENT ERECTION ACTIVITIES

YES

YES

PAGE 2 OF 16

NO

NO

REMARKS

REMARKS

SHUNT REACTOR




5


PRE-COMMISSIONING CHECKS: DETAILS :

SL. NO 5.1

DESCRIPTION

STATUS YES

NO


REACTOR AND ITS AUXILIARIES ARE FREE FROM VISIBLE DEFECTS ON PHYSICAL INSPECTION

5.2

ALL FITTINGS AS PER OUT LINE GENERAL ARRANGEMENT DRAWING .

5.3

CHECK MAIN TANK HAS BEEN PROVIDED WITH DOUBLE EARTHING

5.4

CHECK NEUTRAL IS GROUNDED THROUGH SEPARATE CONNECTIONS. ENSURE METALLIC REQUIREMENTS AS PER SPECIFICATION (e.g. Cu) IN EARTHING STRIPS USED

5.5

CHECK THAT MASHALLING BOX,RADIATOR BANK, PUMP & FAN MOTOR ETC HAS BEEN EARTHED

5.6

ALL NUTS AND BOLTS ARE TIGHTENED CORRECTLY AS PER SPECIFIED TORQUE (AS PER MANUFACTURER RECOMMENDATION)

5.7

CHECK TIGHTNESS OF TERMINAL CONNECTORS

5.8

CHECK LEVELLING OF REACTOR AND ITS ACCESSORIES

5.9


5.10


5.11

BUSHINGS ARE CLEAN AND FREE FROM PHYSICAL DAMAGES

5.12

OIL LEVEL IS CORRECT ON ALL BUSHINGS

5.13

CHECK HERMETICALLLY SEALING IS INTACT IN ALL BUSHINGS

5.14

CHECK OIL LEAKAGE THROUGH ANY JOINTS / VALVES ETC.

PAGE 3 OF 16

SHUNT REACTOR

POWER GRID CORPORATION OF INDIA LIMITED CORPORATE OPERATION SERVICES PRE-COMMISSIONING OF REACTOR COMMISSIONING FORMATS

5.15

DOC NO. : MR/CF/SR/07/R-2 DATED : 01/04/08 SUB STATION : BAY NO : EQUIPMENT IDENTIFICATION NO : DATE OF TESTING :

CHECK OIL DRAIN VALVES ARE PROPERLY CLOSED AND LOCKED.

5.16

CHECK OIL LEVEL IN MAIN TANK AND CONSERVATOR TANK

5.17

CHECK OTI AND WTI POCKETS AND REPLENISH THE OIL , IF REQUIRED

5.18

CKECK ALL VALVES FOR THEIR OPENING & CLOSING SEQUENCE

5.19

CHECK THE COLOUR OF BREATHER SILICA GEL ( BLUE WHEN DRY )

5.20

CHECK AVAILABILITY OF OIL IN THE BREATHER CUP

5.21

CHECK ALL ROLLERS ARE LOCKED AND TACK WELDED WITH RAILS ( WHEREEVER APPLICABLE )

5.22

CHECK BUSHING TEST TAP IS GROUNDED

5.23

CHECK NO DEBRIS , LOOSE T & P AND OIL STRAINS ON AND AROUND THE REACTOR

5.24

CHECK DOOR SEALS OF MARSHALLING BOX IS INTACT AND ALL UNUSED HOLES ARE SEALED

5.25

CHECK THAT PRESSURE RELIEF VALVE IS CORRECTLY MOUNTED

5.26

ENSURE UNUSED SECONDARY CORES OF BUSHING CT's, IF ANY, HAS BEEN SHORTED

Ì

5.27

CHECK CT STAR POINT HAS BEEN FORMED PROPERLY AND GROUNDED AT ONE END ONLY AS PER SCHEME

5.28

CKECK THAT PERMANENT AND ADEQUATE LIGHITING ARRANGEMENTS ARE READY

5.29

CHECK THAT LABELLING AND IDENTIFICATION IS PERMANENT AND SATISFACTORY

PAGE 4 OF 16

SHUNT REACTOR




5.30


CHECK THAT BUCHHOLZ RELAY IS CORRECLY MOUNTED WITH ARROW POINTING TOWARDS CONSERVATOR

5.31

CHECK CABLES ARE PROPERLY FIXED AND ENSURE CABLE ENTRY AT THE BOTTOM.

5.32

ENSURE ALL POWER AND CONTROL CABLE TERMINALS ARE TIGHTENED

5.33

CHECK THAT ALL CABLES ARE CORRECTLY GLANDED

5.34

CHECK EXTERNAL CABLING FROM JUNCTIONBOX TO RELAY / CONTROL PANEL COMPLETED

5.35

CHECK ALL CABLES AND FERRULS ARE PROVIDED WITH NUMBER AS PER CABLE SCHEDULE (CROSS FERULING TO BE CHECKED)

5.36

CHECK THAT AIR HAS BEEN RELEASED FROM THE RADIATORS AND THEIR HEADERS / BUCHHOLZ RELAY / MAIN TANK / BUSHING TURRETS ETC.

5.37

CHECK FIRE PROTECTION SYSTEM & EMULSIFIRE SYSTEM IS ADEQUATE & READY

5.38

CHECK THAT CC, CL & G ARE SHORTED

5.39

CHECK THAT ALL RADIATOR BANK VALVES ON TOP AND BOTTOM HEADERS ARE OPEN

5.40

CHANGE OVER OPERATION OF AC SUPPLY FROM SOURCE-1 TO SOURCE-2 CHECKED

5.41

CHECK VARIOUS INTERLOCKS PROVIDED WITH FIRE FIGHTING AS PER THE SCHEMATIC REF. DRG NO : NAME OF INTERLOCKS

6

CHECKED

MEASUREMENT OF EARTH RESISTANCE OF ELECTRODE LOCATION VALUE (BEFORE CONNECTION TO GRID) VALUE (AFTER CONNECTION TO GRID) NOTE: VALUE OF EARTH RESISTANCE < 1,0 OHM

7

CALIBRATION OF OTI AND WTI DONE AS PER PROCEDURE

PAGE 5 OF 16

YES

NO

SHUNT REACTOR





DETAILS OF RELAYS/ CONTACTORS USED: SCHEMATIC DRAWING NO.:

8

CIRCUIT REFERENCE

MAKE

TYPE

SERIAL NO.

NO+NC

EVACUATING AND OIL FILLING

9 9.1

BEFORE FILLING OIL, EACH DRUM IS PHYSICALLY CHECKED FOR FREE MOISTURE & APPEARANCE

YES

NO

OIL FILTER MACHINE :

9.2 a b c d e f

CAPACITY MAKE LUBRICATING OIL OF VACUUM PUMP CHANGED OR NOT FILTER PACKS CLEANED OR NOT WHOLE FILTER MACHINE FLUSHED WITH FRESH OIL OR NOT VACUUM OBTAINED WITHOUT LOAD (milli bar)

: : :

a b c d

LUBRICATING OIL CHANGED OR NOT VACUUM OBTAINED WITHOUT LOAD (milli bar) DIAMETER OF VACUUM HOSE (50 mm) DRY ICE CHAMBER EMPLOYED OR NOT

a b c d e

INSIDE PAINTED OR NOT : SILICA GEL BREATHER PROVIDED OR NOT : ANY OPENING LEFT UNCOVERED : CAPACITY & QUANTITY : CLEANLINESS OF INSIDE OF PIPES/ HOSES TO THE STORAGE TANK :

:

VACUUM PUMP FOR EVACUATION OF REACTOR :

9.3

: : : :

OIL STORAGE TANK :

9.4

EXPOSURE DURING ERECTION

9.5 a) b) c) d) e) f) g)

First day Second day Third Day N2 pressure applied after each days erection work Ambient Temperature Average Relative Humidity Weather Condition

Hrs Hrs Hrs PSI DegC rainy/ stormy/ cloudy/sunny

: : : : : : :

N2 SEALING IN CASE OF DELAY IN OIL FILLING

9.6 a) b) c) d)

No. of Cylinders used for displacing the air inside the tank N2 admitted from bottom valave Valve at diametriccaly opposite end at top kept open No. of Cylinders used for building up 2 PSI

: : : :

PAGE 6 OF 16

SHUNT REACTOR





INSPECTION ACTIONS

DATE

I.

TIGHTNESS TEST

a.

START EVACUATING ON COMPLETE UNIT

b. STOP EVACUATING

TIME

CHECKED

REMARKS

AT 0.3 kPa (3 mbar)

c. PRESSURE P1 ..... kPa 1 HOUR AFTER STOP EVACUATING d. PRESSURE P2 ..... kPa 0.5 HOUR AFTER READING PREASURE P1 e. LEAKAGE = (P2-P1)xV=.... V=OIL VOL OF REACTOR IN Cu mtr IF LEAKAGE >3.6, CONTINUE EVACUATING 2

VACCUM

a. PRESSURE 0.13 kPa (1,3 mbar) REACHED b.

VACUUM IS KEPT FOR

Upto 145 KV , 12 HRS 145 & upto 420 KV, 24 HRS Above 420 KV, 36 HRS 3

OIL FILLING

a.

oil filling is made

4. OIL CONSERVATOR oil coservator with air cell 5. DIVERTER SWITCH HOUSING diverter switch housing filled and has an air cushion 6. STANDING TIME Upto 145 KV , 12 HRS 145 & upto 420 KV, 48 HRS Above 420 KV, 120 HRS 9.7

RECORD OF DRYING OUT PROCESS (IF CARRIED OUT) DRYING OUT STARTED ON

DATE :

TIME :

AMBIENT TEMP : (HOURLY READING TO BE TAKEN) DATE

TIME

VAC IN FILT. M/C

VAC IN RE. OTI OF MAIN TANK TANK

CONDENSATE COLLECTED TOTAL/ RATE

REMARKS & SIGN OF MTC ENGINEER

RECORD OF FILTRATION AND DRY OUT SHALL BE KEPT IN A REGISTER AND SHALL BE MADE A PART OF THE PRE-COMMISSIONING DOCUMENT

PAGE 7 OF 16

SHUNT REACTOR




10



a

SL.NO

DESCRIPTION

A

CONTROL WIRING

B

COOLING SYSTEM a)

(USING 500 V MEGGER)

STATUS YES

REMARK, IF ANY NO

MOTOR FAN

b) MOTOR PUMP c) CONTROL WIRING


b

MAIN

IR VALUE TIME IN SECONDS

WINDING

15

60

600

(USING 5000 V MEGGER) DIELECTRIC ABSORPT. POLARIZATION INDEX TEMPERAT (600S/ 60S) URE INDEX (60S/ 15S)

HV - EARTH NGR WINDING

MEASUREMENT OF WINDING RESISTANCE (IN OHM)

11 a

WINDING RESISTANCE OF REACTOR WINDING TESTING INSTRUMENT DETAILS TESTING EQUIPMENT CALIBRATION VALID OR NOT AMBIENT TEMPERATURE AT THE TIME OF TEST TEMPERATURE OF OIL WINDING RESISTANCE R-PHASE Y-PHASE B-PHASE

RESISTANCEAT 75 DEG C R | Y | B |

b

FACTORY VALUE R Y

REMARKS B

|

WINDING RESISTANCE OF NGR WINDING WINDING RESISTANCE

12

: : : :

RESISTANCE AT 75 DEG C

FACTORY VALUE

REMARKS

MAGNETISATION CURRENT TEST TESTING INSTRUMENT DETAILS TESTING EQUIPMENT CALIBRATION VALID OR NOT AMBIENT TEMPERATURE AT THE TIME OF TEST TEMPERATURE OF OIL VOLTAGE APPLIED

CURRENT MEASURED

R-N

V

R - PH

m AM

Y-N

V

Y - PH

m AM

B-N

V B - PH

NGR

: : : : REMARK

m AM mAMPS

PAGE 8 OF 16

SHUNT REACTOR





OIL CHARACTERISTICS

13

(SAMPLE TO BE TAKEN PRIOR TO CHARGING OF REACTOR AND IT SHOULD FULFILL THE RECOMMENDATIONS AS PER IS 1866 ) B.D.V MOISTURE TAN DELTA RESISTIVITY INTERFACIAL REMARKS OIL ( MIN ) ( MAX ) ( MAX ) ( MIN ) TENSION AT 27 DEG. SAMPLE (KV) (PPM) (90 Deg C) (OHM-CM) ( MIN ) N/m FOR kV CLASS 12 IS-1866 60 10 0.01 6 X 10 O,O35 > 170 Kv 12 IS-1866 50 15 0.015 6 x 10 O,O35 < 170 Kv BUT > 72.5 kV 12 IS-1866 40 20 0.015 6 x 10 O,O35 < 72.5 kV MAIN TANK

SAMP. DATE :

NGR

SAMP. DATE :

The limiting values given in the above table to be revised as per revision in IS 1866 in future

DISSOLVE

14

GAS

ANALYSIS

OIL SAMPLE JUST 24 HRS 7 DAYS DISSOLVED GASES BEFORE AFTER AFTER CHARGING CHARGING CHARGING TOTAL GAS (%)

15 DAYS 01 MONTH 03 MONTH REMARKS IF ANY AFTER AFTER AFTER CHARGING CHARGING CHARGING

H2 CH4 C2H4 C2H6 C2H2 CO CO2 O2 N2

INSULATION RESISTANCE MEASUREMENT OF BUSHING CT's

15 a

BETWEEN R -PHASE

HV Y -PHASE

NEUTRAL B -PHASE

EARTH - CORE I

MOHM

EARTH - CORE II

MOHM

EARTH - CORE III

MOHM

EARTH - CORE IV b

( USING 500 V MEGGER)

MOHM

BETWEEN R -PHASE

HV Y -PHASE

B -PHASE

USING 500 V MEGGER

CORE I - CORE II

MOHM

CORE I - CORE III

MOHM

CORE I - CORE IV

MOHM

CORE II - CORE III

MOHM

CORE II - CORE IV

MOHM

CORE III - CORE IV

MOHM

PAGE 9 OF 16

SHUNT REACTOR




16

CONTINUTY TEST OF BUSHING CT's CORE

17

CONTINUTY, CHECK BETWEEN TERMINALS : OK / NOT OK BETWEEN LV NEUTRAL TERMINAL R-PHASE Y -PHASE B -PHASE

CORE I

1S1 - 1S2

CORE II

2S1 - 2S2

CORE III

3S1 - 3S2

CORE IV

4S1 - 4S2

SECONDARY WINDING RESISTANCE OF BUSHING CT's (IN OHM) a HIGH VOLTAGE SIDE CORE BETWEEN TERMINAL

Y -PHASE FACTORY SITE

B -PHASE FACTORY SITE

CORE I

1S1 - 1S2

OHM

2S1 - 2S2

OHM

CORE III

3S1 - 3S2

OHM

CORE IV

4S1 - 4S2

OHM

CORE I

NEUTRAL FACTORY SITE

1S1 - 1S2

POLARITY TEST OF BUSHING CT's CORE

19

R -PHASE FACTORY SITE

CORE II

b NEUTRAL SIDE CORE BETWEEN TERMINAL

18


BETWEEN

CORE I

1S1 (+VE)

1S2 (-VE)

CORE II

2S1 (+VE)

2S2 (-VE)

CORE III

3S1 (+VE)

3S2(-VE)

CORE IV

4S1 (+VE)

4S2 (-VE)

WITH 1.5 V DC SUPPLY (CONNECT +VE AT P1 AND - VE AT P2 ) HV NEUTRAL R -PHASE Y -PHASE B -PHASE

CURRENT RATIO TEST PRIMARY INJECTION THROUGH PRIMARY INJECTION KIT AT PRIMARY TERMINAL P1 - P2 MEASURE CURRENT ON THE SECONDARY TERMINALS a HIGH VOLTAGE CORE PRIMARY S1 - S2 % CORE I

20 %

(1S1 - 1S2)

40 %

R - PHASE CURRENT SECONDARY THEORETACTUAL CURRENT ICAL RATIO

ACTUAL RATIO

% OF ERROR

80 % CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 % PAGE 10 OF 16

SHUNT REACTOR




b


Y - PHASE CORE I

20 %

(1S1 - 1S2)

40 % 80 %

CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

c

B - PHASE CORE I

20 %

(1S1 - 1S2)

40 % 80 %

CORE II

20 %

(2S1 - 2S2)

40 % 80 %

CORE III

20 %

(3S1 - 3S2)

40 % 80 %

CORE IV

20 %

(4S1 - 4S2)

40 % 80 %

MAGNETISING

20

CURVES

PERFORMANCE

(NOT TO BE DONE FOR METERING CORE) KNEE POINT VOLTAGE (KVp) = ______________ VOLT a

R - PHASE

HV SIDE

VOLTAGE

CURRENT MEASUREMENT

TO BE

ACTUAL

CORE - I

CORE - II

CORE - III

CORE - IV

APPLIED

VALUE

1S1-1S2

2S1 - 2S2

3S1 - 3S2

4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

PAGE 11 OF 16

SHUNT REACTOR




b


Y - PHASE VOLTAGE

c

CURRENT MEASUREMENT

TO BE

ACTUAL

CORE - I

CORE - II

CORE - III

CORE - IV

APPLIED

VALUE

1S1-1S2

2S1 - 2S2

3S1 - 3S2

4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

B - PHASE VOLTAGE

CURRENT MEASUREMENT

TO BE

ACTUAL

CORE - I

CORE - II

CORE - III

CORE - IV

APPLIED

VALUE

1S1-1S2

2S1 - 2S2

3S1 - 3S2

4S1 - 4S2

O.25 X KVp

mA

O.50 X KVp

mA

O.75 X KVp

mA

1.O0 X KVp

mA

1.10 X KVp

mA

NOTE : 1.0 CT SHOULD NOT SATURATE AT 110 % OF KNEEPOINT VOLTAGE ( KVp ) 2.0 IF KNEEPOINT VOLTAGE IS NOT MENTIONED THEN KNEE POINT CURRENT MAY BE TAKEN INTO CONSIDERATION 21

CONTACT RESISTANCE MEASUREMENT CONTACT RESISTANCE

AT 100 AMPS R-PHASE

Y-PHASE

B-PHASE MICRO OHM

ACROSS HV BUSHING TERMINAL JOINT

MICRO OHM ACROSS NEUTRAL BUSHING TERMINAL JOINT NGR TERMINAL CONNECTOR NOTE: THE VALUE OF CONTACT RESISTANCE SHOULD NOT BE MORE THAN 10 MICRO OHMS PER JOINT/ CONNECTOR 22

BUSHING DETAILS DETAILS

R-PHASE

Y-PHASE

B-PHASE

NEUTRAL

MAKE TYPE SL.NO

PAGE 12 OF 16

SHUNT REACTOR




23


TAN DELTA AND CAPACITANCE MEASUREMENT OF BUSHING CAPACITANCE VOLTAGE

R SITE

PHASE FACTORY

Y SITE

( MEASURED VALUE )

PHASE FACTORY

B SITE

PHASE FACTORY

NEUTRAL SITE

FACTORY

MEASUREMENT OF C1 CAPACITANCE 2 KV 10 KV MEASUREMENT OF C2 CAPACITANCE 1 KV REMARKS :

TAN DELTA VOLTAGE

R SITE

PHASE FACTORY

Y SITE

( MEASURED VALUE )

PHASE FACTORY

B SITE

PHASE FACTORY

NEUTRAL SITE

FACTORY

MEASUREMENT OF C1 TAN DELTA 2 KV 10 KV MEASUREMENT OF C2 TAN DELTA 1 KV REMARKS :


TAN DELTA AND CAPACITANCE MEASUREMENT OF WINDING HIGH VOLTAGE SIDE VOLTAGE

BETWEEN

CAPACITANCE SITE

2 KV

FACTORY

TAN DELTA SITE

REMARK

FACTORY

HV / TANK+E

10 KV REMARKS :


PAGE 13 OF 16

SHUNT REACTOR




25


TAN DELTA AND CAPACITANCE MEASUREMENT OF NGR WINDING HIGH VOLTAGE SIDE VOLTAGE 2 KV 10 KV REMARKS :

BETWEEN

CAPACITANCE SITE FACTORY

TAN DELTA SITE FACTORY

REMARK

HV / TANK+E


26

TAN DELTA AND CAPACITANCE MEASUREMENT OF NGR BUSHING TAN DELTA (MEASURED VALUE) SITE FACTORY

VOLTAGE 2 KV 10 KV

CAPACITANCE (MEASURED VALUE) SITE FACTORY

VOLTAGE 2 KV 10 KV


VIBRATION MEASUREMENT TEST VIBRATION MEASUREMENTS ARE TO BE CARRIED OUT AFTER ENERGIZATION OF THE REACTOR. THIS WILL BE A REFERENCE DATA FOR FUTURE MEASUREMENTS.

PLAN SIDE

A

HIGH VOLTAGE SIDE VARIOUS LOCATIONS ARE TO BE SHOWN IN THE DIAGRAM WITH X,Y CO-ORDINATES FOR EASY

SIDE

SIDE

C

IDENTIFICATION.

D NEUTRAL SIDE

B

SIDE HIGH VOLTAGE SIDE

NEUTRAL SIDE

A

B

PAGE 14 OF 16

SIDE

D

SIDE

C

SHUNT REACTOR




SL. NO

28

DATE OF MEASUREMENT

PROTECTION SL NO


AND

LOCATION

VALUE

REMARKS

ALARMS

DEVICE

SET ALARM

FOR TRIP

PROVED ALARM TRIP

1

EXCESSIVE WINDING TEMPERATURE.

2

EXCESSIVE OIL TEMPERATURE.

3

PRESSURE

RELIEF

VALVE (MAIN TANK )

NA

NA

4

PRESSURE

RELIEF

VALVE ( NGR )

NA

NA

5

MAIN TANK BUCHHOLZ RELAY

6

NGR BUCHHOLZ RELAY

7

FAN FAILURE

NA

NA

8

LOW OIL LEVEL ( MAIN TANK )

NA

NA

9

LOW OIL LEVEL ( NGR )

NA

NA

10

HIGH OIL LEVEL ( MAIN TANK )

NA

NA

11

OTI ( MAIN TANK )

12

OTI ( NGR )

13

WTI ( MAIN TANK )

14

DIFFERENTIAL

NA

NA

15

BACKUP IMPEDENCE RELAY

NA

NA

16

EARTH FAULT RELAY ( REF )

NA

NA

17

INTER TRIP , IF ANY

NA

NA

18

TRIP FREE CHECK

NA

NA

19

TEED PROTECTION

20

PROTECTION SETTINGS APPLIED AS PER ENGG. APPROVED SETTINGS

YES

NO

21

STABILITY TEST OF DIFFERENTIAL & REF PROTECTION

OK

NOT OK

NOTE :

PROVE THE TRIPPING OF ASSOCIATED BREAKERS BY ACTUAL OPERATION OF THE VARIOUS DEVICES AND RELAYS AS PER THE SCHEMES.

PAGE 15 OF 16

SHUNT REACTOR





FREQUENCY RESPONSE ANALYSIS (FRA)

29 a b c d

CARRIED OUT AFTER COMPLETION OF ALL COMMISSIONING ACTIVITIES INTERPRETATION OF TEST RESULTS CARRIED OUT TEST RESULTS MATCHING WITH THE FACTORY RESULTS FACTORY & SITE FRA TEST REPORT AVAILABLE AT SITE

30

ALL ELECTRICAL TEST RESULTS COMPARED WITH FACTORY TEST RESULTS AND FOUND TO BE IN ORDER

31

CHECKS AFTER CHARGING OF REACTOR

YES YES YES YES

NO NO NO NO

YES

NO

YES

NO

RECORD THE FOLLOWING AFTER CHARGING a

ANY ABNORMAL SOUND EMANATING FROM THE REACTOR:

b

REACTOR CURENT AT RELAY TERMINAL R PHASE Y PHASE B PHASE

c

CT RATIO

TEMPERATURE (AT THE TIME OF CHARGING) OTI WTI AMBIENT

32

A A A

ºC ºC ºC

d

MAXIMUM TEMPERATURE AFTER 24 HOURS

ºC

e

THERMOVISION SCANNING DONE ATLEAST AFTER 24 HOURS OF LOADING AND REPEATED AFTER ONE WEEK

YES

NO

FINAL DOCUMENTATION REVIEW a FACTORY TEST RESULTS ARE AVAILABLE

YES

NO

b FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS REVIEWED AND APPROVED

YES

NO

c DOCUMENTS REGARDING SPARES, EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE

YES

NO

d AFTER MODIFICATION, IF ANY, "AS BUILT DRAWINGS" ARE AVAILABLE AT SITE

YES

NO







PAGE 16 OF 16

SHUNT REACTOR

DOC NO. MR/CF/ISO/08/R-2 DATED : 01/04/08 SUB STATION :



PRE-COMMISSIONING OF ISOLATOR AND GROUND SWITCH COMMISSIONING FORMATS I

REGION

:

II

DATE OF ERECTION :

IV


III

LOA NO

:

MAKE

:

TYPE

:

SL NO.

:

R - PHASE

Y - PHASE


B - PHASE

YEAR OF MANUFACTURE : V

FEEDER NAME :

VI

OPERATING VOLTAGE :

VII

CURRENT CARRYING CAPACITY :

VIII

CONTROL VOLTAGE :

IX

DETAILS :

SL. NO 1

kV

TYPE OF OPERATING MECHANISM : AMPERE

VOLT

DESCRIPTION

DC

STATUS YES NO


EQUIPMENT IS FREE FROM DIRT/DUST FOREIGN MATERIALS ETC.

2


3

SUPPORT STRUCTURES, MARSHALLING BOX HAS BEEN PROVIDED WITH TWO EARTHING PADS / POINTS

4


5

EQUIPMENT ERECTION IS COMPLETE IN ALL RESPECT AS PER INSTRUCTION MANUAL (ATTACH REMAINING ACTIVITIES,IF ANY)

6

PERMANENT ISOLATOR LAVELLING AND IDENTIFICATION IS DONE

7


PAGE 1 OF 5

ISOLATOR AND GROUND SWITCH




PRE-COMMISSIONING OF ISOLATOR AND GROUND SWITCH COMMISSIONING FORMATS

SL. NO 8

DESCRIPTION

STATUS YES NO


CONTROL BOX / MARSHALLING KIOSK IS FREE FROM ANY PHYSICAL DEFECTS

9


10

AUXILLARY CONTACTS AND RELAYS HAVE BEEN CLEANED AND FREE FROM RUST / DAMAGE

11

CORONA RINGS ARE PROVIDED AND PROPERLY FIXED

12

CABLE TERMINATION AND TIGHTNESS CHECKED AND UNUSED HOLES SEALED

13

EXTERNAL CABLING IS COMPLETED IN ALL RESPECT

14


15

ALL MOVING PARTS ARE LUBRICATED

16

ALIGNMENT OF ISOLATOR ALREADY MADE AND LOCKING BOLT PROVIDED, IF ANY

17

FREENESS OF MANNUAL OPERATION IS OK

18

GREASING HAS BEEN MADE ON THE MAIN CONTACTS ACCORDING TO THE MANUFACTURERS INSTRUCTION

19

FUCTIONAL CKECKING OF AUXILLARY CONTACTS FOR INDICATIONS AND INTERLOCKS

20


21

ALL SPARE WIRES TO BE KEPT WITH FERRULES BUT NOT TERMINATED AT THE TERMINAL BLOCKS

22

EARTH SWITCH CONNECTED TO EARTH THROUGH BRAIDED WIRES

23

INTERLOCKS CHECKED AS PER APPROVED SCHEME WITH ALL COMBINATIONS

24

CHECK THAT EARTH SWITCH BLADE ALIGNMENT IN CONDITION IS AT SUFFICIENT DISTANT FROM ISOLATOR PAGE 2 OF 5





PRE-COMMISSIONING OF ISOLATOR AND GROUND SWITCH COMMISSIONING FORMATS

25

CHECK THAT OPERATION AND POSITIONING OF THE LIMIT SWITCH & THE AUXILIARY CONTACTS ASSEMBLY ARE OK

26

CHECK THAT ALL THREE PHASE ISOLATORS ARE CLOSING & OPENING AT A TIME

27

CHECK ALL 3 EARTH SWITCHES CLOSE AT THE SAME TIME

28

PROVISION OF BIMETALLIC STRIPS ENSURED WHEREVER APPLICABLE

X

MOTOR DETAILS

XI

R PHASE MAKE : SL NO : TYPE : VOLT : AMPERES : HP / KW : YR. OF MANUFACTURE : OVERLOAD SETTING : (THERMAL OVERLOAD ) INSULATION RESISTANCE VALUE OF MOTOR WINDING

Y PHASE B PHASE

SWITCH

( USING A 500 VOLT MEGGER MEASURE RESISTANCE BETWEEN THE WINDING OF MOTOR AND EARTH ) BETWEEN

R- PHASE

PHASE Y- PHASE

B- PHASE

WINDING TO EARTH XII

OPERATIONAL CHECKS : A OPERATE THE ISOLATOR AND RECORD THE MOTOR CURRENT ISOLATOR OPERATION

R - PHASE FACTORY

SITE

MOTOR CURRENT Y - PHASE FACTORY SITE

B - PHASE FACTORY SITE

CLOSE OPEN B OPERATION OF ISOLATOR FROM LOCAL / REMOTE ISOLATOR OPERATION

CONTROL LOCAL

OK / NOT OK

PANEL REMOTE

CLOSE OPEN

PAGE 3 OF 5





PRE-COMMISSIONING OF ISOLATOR AND GROUND SWITCH COMMISSIONING FORMATS C MEASUREMENT OF OPERATING TIME OPERATION

PHASE R- PHASE

Y- PHASE

B- PHASE

OPENING TIME

SEC

CLOSING TIME

SEC

D AUXILLARY CONTACTS CHECKING ISOLATOR AUXILLARY R - PHASE OPERATRELAY ION TYPE NO

NC

OPERATION TIME Y - PHASE NO NC

B - PHASE NO

NC

CLOSE

OPEN

REFERENCE DRAWING NO : E OPERATION ON UNDER VOLTAGE CONDITION : CONDITION PICK UP VOLTAGE DROP VOLTAGE XIII

COIL

R- PHASE

PHASE Y- PHASE

CLOSING OPENING INTERLOCK CLOSING OPENING INTERLOCK

VOLT DC VOLT DC VOLT DC VOLT DC VOLT DC VOLT DC

INSULATION RESISTANCE TEST ( USING 5000 VOLT MEGGER ) ISOLATOR OPEN CONDITION BETWEEN R- PHASE MALE SIDE TO GROUND FEMALE SIDE TO GROUND MALE SIDE TO FEMALE SIDE

XIV

B- PHASE

PHASE Y- PHASE

B- PHASE

CONTACT RESISTANCE MEASUREMENT (TO BE MEASURED AFTER 50 OPERATIONS) A

ISOLATOR CLOSE CONDITION (CONTACT RESISTANCE SHOULD BE LESS THAN 10 MICRO OHMS / CONNECTOR) ACROSS PHASE R- PHASE Y- PHASE B- PHASE CONNECTOR (MALE SIDE) MICRO-OHM CONNECTOR (FEMALE SIDE) MICRO-OHM MAIN CONTACT (MALE & FEMALE) MICRO-OHM

PAGE 4 OF 5





PRE-COMMISSIONING OF ISOLATOR AND GROUND SWITCH COMMISSIONING FORMATS B

XVI

XVII

ISOLATOR OPEN CONDITION & GROUND SWITCH CLOSE (CONTACT RESISTANCE SHOULD BE LESS THAN 150 MICRO OHMS / BREAK) ACROSS PHASE R- PHASE Y- PHASE B- PHASE MAIN CONTACT (MALE & FEMALE) MICRO-OHM (GROUND SWITCH)

A

RESISTANCE OF OPERATING COIL

B

RESISTANCE OF INTERLOCKING COIL

FINAL DOCUMENTATION REVIEW : A FINAL DOCUMENT OF PRE-COMMISSIONING CHECKS REVIEWED AND APPROVED

YES

NO

B DOCUMENTS REGARDING SPARES, EQUIPMENT, O & M MANNUALS ETC AVAILABLE AT SITE FOR O & M PURPOSE

YES

NO

C AFTER MODIFICATION, IF ANY, "AS BUILT DRAWINGS" ARE AVAILABLE AT SITE

YES

NO





(POWERGRID SITE I/C) ( POWERGRID COMM TEAM )

PAGE 5 OF 5



DOC NO. :MR/CF/WT/09/R-2 DATED: 01/04/08 SUB STATION : BAY NO : EQUIPMENT IDENTIFICATION NO : DATE OF TESTING :

PRE-COMMISSIONING OF WAVE TRAP COMMISSIONING FORMATS

I

REGION :

II

DATE OF ERECTION :

IV


III

LOA NO

:

MAKE

:

TYPE

:

SL NO.

:

R - PHASE :


Y - PHASE :

B - PHASE :

YEAR OF MANUFACTURE : FEEDER NAME : V

RATING : VOLTAGE RATING : mH RATING : CURRENT RATING :

VI

BAND WIDTH :

DETAILS : CHECKLIST / TESTING SL. DESCRIPTION NO 1 EQUIPMENT IS FREE FROM DIRT / DUST FOREIGN MATERIALS ETC.

STATUS YES NO

2


3

SUPPORT STRUCTURES HAS BEEN PROVIDED WITH DOUBLE EARTH

4


5

PERMANENT LAVELLING AND IDENTIFICATION IS DONE

6


7

ALL INSULATORS & LINE MATCHING UNIT ARE FREE FROM ANY PHYSICAL DEFECTS

8

TIGHTNESS OF NUTS / BOLTS OF TERMINAL CONNECTORS ARE CHECKED 1 OF 2


WAVE TRAP


DOC NO. :MR/CF/WT/09/R-2 DATED: 01/04/08 SUB STATION : BAY NO : EQUIPMENT IDENTIFICATION NO : DATE OF TESTING :

PRE-COMMISSIONING OF WAVE TRAP COMMISSIONING FORMATS

9


10 CHECK THAT THE TUNING UNIT AND ARRESTOR ARE PROPERLY TIGHTENED AND FREE FROM ANY DAMAGE VII

INSULATION RESISTANCE MEASUREMENT : SL. NO

BETWEEN

MEGGER

1

UPPER TEMINAL AND EARTH LA OF THE WAVE TRAP

5000 V

2 VIII

IX

PHASE R-PHASE Y-PHASE B-PHASE

PERMISSIVE VALUE 1000 M.OHM

500 V

1

M.OHM

CONTACT RESISTANCE MEASUREMENT THE VALUE SHOULD NOT MORE THAN 5 MICRO-OHMS PER CONNECTOR / JOINT SL. NO

ACROSS

PHASE R-PHASE Y-PHASE B-PHASE

1

UPPER TEMINAL

MICRO OHMS

2

BOTTOM TEMINAL

MICRO OHMS

FINAL DOCUMENTATION REVIEW : A


B

NO

YES

NO

YES

NO


C

YES



SIGNATURE : SIGNATURE : SIGNATURE : NAME : NAME : NAME : DESIGNATION : DESIGNATION : DESIGNATION : ORGANISATION : ( ERECTION AGENCY (POWERGRID SITE I/C( POWERGRID COMM TEAM )

2 OF 2

WAVE TRAP

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