electrical system- commg. check list

8/6/2019 Electrical System- Commg. Check List

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ELECTRICAL

STATION STANDARD CHECK LIST SHEET 1 OF 5

PLANT AREA: HT BREAKER

UNIT NO. ______________________________ PANEL. NO. __________________

BOARD TITLE _________________________ CIRCUIT TITLE __________________

MODULE TYPE ______________________ SERIAL NO. ______________________

MANUFACTURER ______________________ SUPPLIER ______________________

CONTRACTOR / MANUFACTURER _______________________________________

TYPE __________________________________ RATING _____________________

CONTROL CIRCUIT VOLTAGE : _________________________________________

NO. ACTIVITY REMARKS

GENERAL INSPECTION AND CHECKS

1.

2.

3.

4.

5.

Check that the poles are securely maunted/assembled

HV Connections made properly.

Control cables laid up and connected as per scheme.

Breaker body and structure properly earthed.

Check that panel is clean and dry.

Defective & Omission Continuation Overleaf

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2/35

ELECTRICAL



TAG NO. UNIT


6.

7.

8.

9.

10.

11

Check that all the devices fitted in the breakers are

a. as specified in the scheduleb. complete and undamagedc. Securely mounted

d. Free from packing materials applied during transit.

Check that all equipments and parts of the panel areeffectively grounded.

Check that all the power & control cables are properlydressed and supported.

Check that incoming power cable phase markings andbusbar phase markings are in agreement for both the

incoming supplies.

Check the tightness of all the electrical connections.

Check the protection relay connections as per drawing.Also, no relay is found physically damaged and no relaycover is found, broken. Relay rotor lock is given for transportation is released in case of electromechanicalrelays.


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3/35

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TAG NO. UNIT


12

13

14

15

16

17

18

Check the Breaker mechanism as per manufacturesinstruction.

Check the operation of reset levers in case of manual reset

relays is found OK.

Check that the spring charging circuit, closing & trippingcircuit are wired as per wiring diagram

Check that the illumination & space heater circuit are OK.

Check that clearance between HT Panel & wall as per IS

specification.

Check that the door is properly closed before testing.

Check the breaker auxiliary contacts are OK by manualoperations.


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4/35


5/35

ELECTRICAL



TAG NO. UNIT

ACTIVITY

2

3

4

Contact Resistance Measurement using Micro-ohm meter inBreaker closed condition.

R R

Y Y

B - B

Breaker closing and opening time

During TimeClosing

RYB

During Opening

RYB

Breaker closing & Tripping operation from local, Remote &Protection.


REMARKS

N.T.P.C.

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6/35

ELECTRICAL


PLANT AREA : NEUTRAL GROUNDING TRANSFORMER

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________


ACTIVITY

1

2

3

4

5

6

7

8

9

GENERAL INSPECTION AND CHECKS ,Check that the cubicle is properly installed on foundation.

Check that the cubicle is earthed at two places.

Check that the connection from N.G.Transformer to Gen.Tr.neutral is complete.

Connection to earth from N.G. Tr. Is complete.

All control cables laid, & terminated as per scheme.

Check that the CT / PT ratio & polarity and verify with scheme.

Check that all the connections are tight.

Check the auxiliary contacts from NGT to control room & control& protection panels are OK.

Check that the 100% earthfault protection is connected acrossthe secondary of NGT.


REMARKS

N.T.P.C.

SIGNATURE

BHEL

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7/35

ELECTRICAL


PLANT AREA : NEUTRAL GROUNDING TRANSFORMER

TAG NO. UNIT

ACTIVITY

1

2

TEST PROCEDURE

IR value of N.G. Transformer

Temp.

Py E

Sy E

Py Sy

Measured with ----------------------------- megger.

Winding Resistance

Temp.

Py :

Sy :

Measured with Micro-ohm meter.


REMARKS

N.T.P.C.

SIGNATURE

BHEL

SIGNATURE

DATE


8/35

ELECTRICAL


PLANT AREA : PT CARRIAGE & CUBICLE

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________


ACTIVITY

1

23

4

5

6

GENERAL INSPECTION AND CHECKS ,Check that the PT securely bolted to structure

Check that the PT body & structure earthed at two places

Check that the HT leads connected properly

Check that the LT cables kid, terminated as per scheme.

Check that the Bushings cleaned and, on visual inspection, nodefect detected.

Check that view glasses are not broken & clean to see PTconnection from outside.


REMARKS

N.T.P.C.

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9/35

ELECTRICAL



TAG NO. UNIT

ACTIVITY

7

8

9

10

11

Check that the carriage & cibicle is clean & dry.

Check that the carriage is moving freely without anyobstructions and in position it is making proper contact with HT

Bus.Check that all MCBs provided in the circuit are OK.

Check that the HT fuse is seated properly and making proper contact.

Check for proper operation of limit switches to give output whilePTs are in service.

Check illumination circuit as per the schematic diagram given.


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10/35

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TAG NO. UNIT

ACTIVITY

1.0

2.0

3.0

TEST PROCEDURE

The IR value of PT measurement ust & 2500v megger for HT side& 500v megger for sec. Side.

IR value of Control Cable

Secondary Winding Ressistance


REMARKS

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ELECTRICAL


Phase R Phase Y Phase B

Py E

Sec E

Py Sec

Phase Resistance Temperature Remarks

R

Y

B


11/35

PLANT AREA : BUS DUCT

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________


ACTIVITY

1

2

3

4

GENERAL INSPECTION AND CHECKSCheck that the Bus duct erected properly with supporting structureand Insulator.

Check that the Busduct aligned properly.

Check that the Seal off bushings are fixed properly and both endconnections are complete.

Check that the fiexible connectors are as per specification andfixed properly.


REMARKS

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12/35

ELECTRICAL



TAG NO. UNIT

ACTIVITY

5

6

7

8

9

10

11

Check that the Bus enclosures properly earthed as per drawing

Check that the CTs PTs are mounted properly, and Insulatorssecurely bolted to mounting channels. No crack can be viewed ininsulators at CTs & PTs

Check that the secondary connections of PTs / CTs arecomplete as per drawing

Check that the Bus duct is clean and dry.

All joints are checked for tightness as per recommendations.

Check that the insulators are cleaned.

Check that the clearance between Bus duct & busbaland casingare within the available limit.


REMARKS

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13/35

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TAG NO. UNIT

ACTIVITY

1

TEST PROCEDURE

Disconnect both end connections and measure insulationresistance. (Use megger as per manufacturers recommendation)


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IR measuredbetween Value Temp. Remarks

R E

Y-E

B-E

R-Y

Y-B

B-R


14/35

ELECTRICAL



TAG NO. UNIT

ACTIVITY

2

3

Measurement contact resistance of 10% of joints

Loop Resistance- Short two phases of one end and measure

resistance of the loop with low resistance measuring bridge.Short the third phase with any other phase and measure theresistance similarly. Evalvate Resistance per ph.


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Joint No. Value Remarks

Loopbetween

LoopResistance

Resistance/phase Remarks

R Y

Y B

B -- R


15/35

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TAG NO. UNIT

ACTIVITY

4High Voltage Test

This test is to be carried out after completion of all other commng.Checks so that the Busbar is not distorbed further. Fquipmentsconnected to the Busbers are to removed and during test all other phases are to be shorted & earthed.

Test Voltage is as recommended by Manufacturers.


REMARKS

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Phaseunder Test

TestVoltage

LeakageCurrent

TestDuration Remarks


16/35

ELECTRICAL


PLANT AREA : GENERATOR CIRCUIT BREAKER

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________

CONTROL CIRCUIT VOLTAGE : ________________________________________


1.0 ENERGISING OF AUXILIARY CIRCUITS

1.1

2.0

2.1

2.2

Before the auxiliary circuits are energised, make sure thatthe external connections comply with the wiring diagramand that the supply voltages are actually those required bythe characteristics of the relays and electrovalves referredto on the nameplate of the breaker.

FILLING WITH COMPRESSED AIR

Very first, that there are no substantial leaks bypressurising the breaker to a reduced pressure of 8 to 10bars (110 to 150 psig).

Proceed to filling, respecting the following instructions.


REMARKS

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17/35

ELECTRICAL



TAG NO. UNIT

ACTIVITY

2.2

2.3

2.4

2.5

3.0

3.1

3.2

3.3

Proceed to refilling, respecting the following instructions.

Isolate the H.P. receiver from the compressors, and energizethe reducing electrovalve: Pressure stabilizes at intermediatepressure.

Isolate the C.B. from H.P. receiver, then return to nominalpressure in H.P.receiver by starting compressors.

Proceed as in 2.2.2, until nominal pressure is reached in theC.B.

INSPECTION OF PRESSURE SWITCHES, REDUCERS ANDSAFETY VALVES

Refer to the operating pressure levels on the relevant pneumatic

diagram. Adjust the pressure through the main valves of theinstallation and make certain, by reading the pressure gauges,that the operating pressure of each pneumatic component iscorrect. The pressure switches must be checked on loweringpressure as well as on rising pressure.

Check the logic sequence of the operating pressure level.

Check the proper operation of each motorcirculator as well asthe condition of the motor supply wires.


REMARKS

N.T.P.C.

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18/35

ELECTRICAL



TAG NO. UNIT


3.4

3.4a

3.5

3.6

3.6a

3.6b

3.6c

Check the rotation direction of the motors: an arrow paintedon the case provides the relevant indication. Proceed asfollows for this checking:

Check the rotation direction through the hole left free.Checking is not easily carried out at full speed, it isrecommended to proceed with this operation at low speedwhen the motor is no longer supplied and runs idle.

Check that resistance across each pole with breaker isclosed.

CHECKING OF OPENING AND CLOSING TIMES

Operating times can be checked more summarily before

commissioning: only abnormal conditions resulting fromassembling or transport need be detected.

An oscillograph or graph recorder may be used. Whenthese measurements are taken, the instant the electrovalvecoils are energised must appear on a separate track aswell as the time basis.

Check the operating times, disconnect the groundconnection (connection from main chamber to auxilliarychamber) (see Section entitled Chamber).


REMARKS

N.T.P.C.

SIGNATURE

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SIGNATURE

DATE


19/35

ELECTRICAL


PLANT AREA: ESP AUX. CONTROL PANEL

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________



1.

2.

3.

4.

Ensure that all breakers, PTs, modules installed in positionand Bom as per drgs.

Check that panel earthing connection as per standard.

Ensure minimum clearance of live parts to earthed body asper standard.

Ensure tightness of cable connection, main bus bar jointsand auxiliary circuit bus bars.


REMARKS

N.T.P.C.

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SIGNATURE

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20/35

ELECTRICAL


PLANT AREA: ESP AUX. CONTROL PANEL


5.

6.

7.

8.

9.

10.

11.

12.

Check that internal panel wiring as per drawing check thatthe continuity of main bus bars & Aux bus bar.

Check that IR Valve of power circuit with help of 1000Vmegger. The value should be above 2 Mr

Phase to phase .. Mr

Phase to earth . Mr Ensure that healthiness of Indication and Alarm as per drawings / schemes.

Check the Healthiness of space heater.

Carryout Primary injection test on Incomming CT andRandam test on Thermal over load relay of feeders.

Measure IR Valve of incoming cable to panel and connectProperly to the incoming terminal.

Check the incoming cable up to panel Terminal Block andmeasure the voltage.

For conducting functional test of the panel out going terminalshall be disconnected and remove the power fuse andtemporally short the themostot and Local PB.


REMARKS

N.T.P.C.

SIGNATURE

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21/35


22/35


23/35


24/35

ELECTRICAL


PLANT AREA: ELECTRIC CONTROLLER PANEL IN ESP


5.

6.

7.

8.

9.

10.

11.

Measure the insulation resistance with 500 Volt megger between group A & Earth E, B & E and between A & B itshould be as follow

A to E > 2 Mr

A to B > 30 Mr B to E > 30 Mr

Remove the shorting after insulation check and connectcontroller.

Connect a load resistor of approximately 4A, 2000W, 500Vat Terminal C & D of the panel.

Connect supply 415 VAC across the Terminal A & B andclose the isolator and check indication for mains on, displayand flickering of processor health indication LED of controller.

Check 24V AC at terminal 1 & 5 of TB2 wrt ground Check18 VAC at across pin 1 & 2 of firing circuit.

Check interlock key is in classed position

Check voltage at various test point of the cards. (Disconncetthe transformer from panel end switch on power supply)


REMARKS

N.T.P.C.

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25/35

ELECTRICAL




12.

13.

14.

15.

16.

17.

18.

19.

20.

Check all the connections in the interfacing board withBAPCON Cable.

Ensure that the power input to BAPCON and panel are inthe same phase angle.

Check all the auxiliary relays provided in the interfactingboard are properly fixed.

Check the thyrister Gate & Cathode lugs are properlyinserter.i. Gate & Cathode signals should not be interchanged.II. Thyrister phase angle sequence should be maintained.

Ensure all safety measures and preparations applicable tothe ESP are performed.

Remove the output cables leading to T/R set from thecontrol panel.

PUT the REMOTEL/LOCAL Switch in LOCAL mode.

Switch ON the main SFU.

Check the whether following display appears momentarily.


REMARKS

N.T.P.C.

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26/35

ELECTRICAL




21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

This display denotes the program version no. and revisionno. of the BAPCON.

Check whether the Alive LED flickers at contstant interval.

Check whether all the control parameters are matching withdefaultvalues, using the display select switches.

Simulate T/R alarms and ALI alarm by momentarily byshorting the respective terminals in the control panel.Check whether the respective LEDs are glowing.Check whether the LEDs are extinguished by pressingRESET switch.

Switch OFF the main SFU of the control panel.

Connect two series connected 500W incandescent lampsacross the output terminals of the panel.

Connect a voltmeter (Range:0-500V AC) across the outputterminals the panel.

Turn the 1 s Limit Pot meter to fully counter clockwiseposition.

Switch on the main SFU of the control panel.

Select the UV Limit Display and adjust the value to 104%using the Pot No.5.


REMARKS

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27/35

ELECTRICAL




31.

32.

33.

34.

35.

36.

37.

38.

39.

Push the H.T. ON/OFF switch to make the main contactor ON.

Check whether T/O switch LED glows for some time.

Slowly turn the CURRENT LIMIT Pot meter towards

clockwise direction.Check the voltmeter whether it indicates full voltage as thatof input voltage and is varying as per the current limitsetting. If the bulbs are not becoming ON, switch OFF thepanel, interchange the AC power supply lines to theBAPCON. If the bulbs are flickering* and the output voltageis low, switch OFF the panel and check for the looseconnections. After correcting the problem, repeat theprocedure.

Turn the I s LIMIT Pot. Meter fully towards counter clockwisedirection.

Push the HT ON/OFF switch to the make the main contactor off & check the LED inset extinguishes.

Resume the value of the UV limit to 10%

Switch OFF the main SFU of the control panel.

Remove the incandescent lamps & volt meter.


REMARKS

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28/35

ELECTRICAL




40. Re-connect the output cables heading to T/R set.

* This problem happens because of the single thyristor firing, which may destroy the TR set during operationbecause of core saturation. Care should be taken by

checking the proper functioning of thyristory during pre-commissioning.


REMARKS

N.T.P.C.

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BHEL

SIGNATURE

DATE


29/35

ELECTRICAL


PLANT AREA: ESP H.V. TRANSFORMER RECTIFIES

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________



1.

2.

3.

4.

Check Transformer rollers are arrested from movement.

Check any damage / oil leaks in bushing of Transformer andinsulation.

Ensure the Break down value of oil used in transformedshall comply with standard and free with moisture.

Check that pressure reliet diagram infact. Check thatfunctioning of mercury switches of Buchholz relay for Alarm& Trip by injection air through test pet-cock, when full of oil.


REMARKS

N.T.P.C.

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BHEL

SIGNATURE

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30/35


31/35


32/35

ELECTRICAL


PLANT AREA: ESP DISCONNECTING SWITEHES

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________



1.

2.

3.

4.

5.

6.

Ensure that insulators are healthy, clean and rigid.

Ensure that HV bus terminals and earth connections insideare tight.

Ensure that operation of moving blade with HV and earthcontacts is smooth and proper

Ensure that Copper cable between moving arm insulator head is properly connected. Each disconnecting switch isprovided with a danger plate and two external earthconnections to earth mat.

Ensure that door are closed tightly

Ensure that interlocks provided at doors and handles areworking properly.


REMARKS

N.T.P.C.

SIGNATURE

BHEL

SIGNATURE

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33/35

ELECTRICAL


PLANT AREA: INSULATOR HOUSING

UNIT NO. ______________________________ PANEL. NO. __________________





TYPE __________________________________ RATING _____________________ CONTROL CIRCUIT VOLTAGE : _________________________________________


1.

2.

3.

4.

5.

6.

7.

Ensure that insulators are clean, healthy and rigid.

Ensure that copper tubes are straight and not loose.

Ensure that heating elements are properly fixed.

Ensure that earthing is proper.

Ensure that screw legs and nuts for placement of alignment jigs are welded.

Ensure that doors are closed tightly.

Ensure that interlocks are working properly.


REMARKS

N.T.P.C.

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34/35

ELECTRICAL


PLANT AREA: INSULATOR HOUSING


8.

9.

10.

1.

2.

3.

4.

1.

2.

3.

4.

Ensure that each insulator housing is provided with a danger plate and two external earth connection to earth grid.

Ensure that flanged joints are provided with gaskets andearthing cables.

Ensure that copper tubes are straight and tightly connected.

HEATINGELEMENTSEnsure that IR value is above 2 M Ohm

Ensure that continuity is ascertained.

Ensure that cables are terminated properly with crimpedlugs and glands and terminal box cover is water tight.

Ensure that cable armour and earth points are connected tothe earth.

THERMO STATSEnsure that cables are terminated properly.

Ensure that cover is water tight

Ensure Recommended setting for thermostat is 120 0C and140 0C for hopper and support insulator heaters respectively.

Ensure that contact continuity is verified.


REMARKS

N.T.P.C.

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electrical system- commg. check list

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