Check List of 6.6kv Panel

7/30/2019 Check List of 6.6kv Panel

1/22

Sr.No. ACTIVITY Comments1 Closing circuit

2 tripping circuit

3 annunciation/indications

4 relays through secondary injection

5 current transformers through primary injection

6 Knee point of PS class CT

7 relay setting procedure

8 features of relays

9 high voltage test of ht bus bar chamber, breakers

10 breaker rack in rack out

11 matching of moving and fix contacts

12 shrouds on all joints

13 sealing of panels

14 wiring as per drawing

15 tag on each components of panel

16 anti pumping feature

17 door inter lock

18 mechnical closing and tripping

19 spring charging mechanism

20 trip circuit supervision

21 tightness of all joints

HT SWITCHBOARD-- CHECK LIST


2/22

6


3/22

DATE : - 05/07/10

SR. NO DESCRIPTION1 BEFORE PANEL ERECTION REQUIRED MATERIAL, DRAWINGS, DOCUMENTS & CLEARANCE AT SITE

1.1 PANEL TECHNICAL SPECIFICATION

1.2 PANEL AT SITE

1.3 PANEL BOQ

1.4 PANEL PACKING LIST

1.5 PANEL GA DRAWING

1.6 PANEL BASE FRAME DRAWING

1.7 PANEL CONTROL CIRCUIT WIRING DIAGRAM

1.8 PANEL INTERCONNECTION CABEL SCHEDULE

1.9 PANEL TEST REPORT

1.10 PANEL ALL METERING & PROTECTION CT'S & PT'S TEST REPORT

1.11 RELAY CONFIGRATION, TEST REPORT & MANUAL

1.12 ALL EQUIPMENT SPECIFICATION AS PER BOQ

1.13 BREAKER TEST REPORT

1.14 MAIN BUS BAR SPECIFICATION & ARRANGEMENT DRAWING.

1.15 PANEL EARTHING SYSTEM DRAWING

1.16 PANEL FIELD QUALITY PLAN

1.17 CIVIL CLEARANCE

1.18 STRUCTURAL CLEARANCE

1.19 PHYSICALLY CHECKED AND PANEL SHIFTED AT ERECTION LACATION WITH SUITABLE ARRANGEMENT1.20 PANEL ROOM EARTING LAYOUT

1.21 EARTHING MATERIAL

1.22 IN-CASE OF PANEL ERECTION TOP OF THE TRENCH

1.23 CABLE TRENCH GA DRAWING

1.24 CHECK THE TRENCH AS PER TRENCH DRAWING

1.25 CHECK INSERT PLATE WHERE ERECTED THE TRAY SUPPORT

1.26 CABLE TRAY LAYOUT

1.27 CABLE TRAY DETAIL DRAWING

1.28 CABLE TRAY EARTHING DRAWING

1.29 CABLE TRAY MATERIAL & ACCESSORIES AT SITE

1.30 FABRICATION OF CABLE TRAY SUPPORT AND PAINTING AS PER DRAWING

1.31 ERECTION OF CABLE TRAY WITH SUPPORT

1.32 ERECTION OF EARTHING WITH TRAY AS PER DRAWING

2 ERECTION PROCEDURE

2.1 CHECKED CUT OUT FOR THE PANEL AS PER DRAWING

2..2 PANEL BASE FRAME FABRICATION AS PER BASE FRAME DRAWING

2.3 PANEL BASE FRAME ERECTION AS PER DRAWING

2.4 CHECK THE BASE FRAME ALIGNMENT

2.5 OPEN THE PANEL BOX

2.6 CHECK THE PANEL AS PER BOQ

2.7 ERECTION OF THE PANEL IN BASE FRAME AS PER DRAWING

2.8 OPEN THE PANEL DOORS & PHYSICALLY CHECKED ALL EQUIPMENT AS PER BOQ

2.9 PANEL TO PANEL COUPLING WITH NESSECORY ARRANGEMENT AS PER DRAWING

A SUITABLE NUTS & BOLTS AS PER DRAWING

B SUITABLE SEALING MATERIAL (REDIENT RUBBER SEAL)

2.12 PANEL TO PANEL MAIN BUS BAR COUPLING WITH NESSECORY ARRANGEMENT AS PER DRAWING

A SUITABLE NUTS & BOLTS WITH DOUBLE PLATE WISER, SINGLE SPRING WISER.

2.10 CHECK MAIN BUS BAR COUPLING TIGHTNESS SUITABLE TOOLS (TORQUE RANGE) ACCORDING TO SPECIFICATION

A SUITABLE HT TAP FOR INSULATION OF JOINTS.

2.11 PANEL TO PANEL EARTHING LINK CONNECTED AS PER DRAWING

2.12 MAIN EARTHING CONNECTED TO THE BOTH END SIDE OF PANEL2.13 ALL EQUIPMENT PHYSICALLY CHECKED, CLEANING & SUITABLE TIGHTNESS

2.14 PANEL TO PANEL CONTROL WIRING CONNECTED AS PER INTERCONNECTION WIRING DRAWING / SCHEDULE

2.15 LOOP CHECKING

2.16 ALL FEEDER CHECK PHYSICALLY RACK IN & RACK OUT

2.17 MATCHING OF MOVING AND FIX CONTACTS

2.18 MECHNICAL CLOSING AND TRIPPING

2.19 CHECK CLOSING & TRIPPING CIRCUIT

2.20 PACKING OF GIVEN EXTRA HOLE IN PANEL

2.21 HT POWER CABLE, LT POWER CABLE , CONTROL CABLE LAYING AS PER CABLE SCHEDULE

2.22 HT POWER CABLE, LT POWER CABLE , CONTROL CABLE TERMINATION AS PER CABLE SCHEDULE

2.23 TESTING & LOOP CHECKING OF CONTROL & POWER CABLE

3 PRE - COMMISSIONING CHECK LIST

3.1 BRAKER TESTING

A BREAKER RACK IN RACK OUT

B MATCHING OF MOVING AND FIX CONTACTS

PANEL ERECTION PROCEDURE


4/22

SR. NO DESCRIPTIONC CHECKED ALL NUTS & BOLTS TIGHTNESS

D MECHNICAL CLOSING AND TRIPPING

E MANUALY SPRING CHARGING MECHANISM

F TRIP CIRCUIT SUPERVISION

G IR VALUE

H CONTECT RESISTANCE

I ELECTRICALLY CLOSING AND TRIPPINGJ ELECTRICALLY SPRING CHARGING MECHANISM

K CHECK CONTINUTY OF PHASE TO PHASE BKR OFF POSISTION

L CHECK CONTINUTY OF PHASE TO PHASE BKR ON POSISTION

M CHEKED LIMIT SWITCH TEST / SERVICE POSITION

N CLOSING CIRCUIT OF BKR

O TRIPPING CIRCUIT OF BKR

P ANNUNCIATION/INDICATIONS

Q CHEKED ALL POSITION (TEST, SERVICE & ISOLATED POSITION)

R ANTI PUMPING FEATURE

S CHECK BKR TIMING (OPEN - CLOSE - OPEN) THROUGH TIMING KIT

3.2 RELAY TESTING (DOUBLE KIT)

A FEATURES OF RELAYS

B RELAY SETTING PROCEDURE

CRELAYS TESTING THROUGH SECONDARY INJECTION KIT AS PER RELAY FEATURES AND CHECK ALL PROTECTION

(ONE BY ONE)D CHECK RELAY COFIGRATION

3.3 CT(CURRENT TRANSFORMERS) TESTING THROUGH PRIMARY INJECTION KIT

A IR VALUE

B WINDING RESISTANCE

C CT RATIO AS PER RATIO

SECONDARY(S1 - S2) SHOULD BE SHORTED

D KNEE POINT TEST OF PS CLASS CT

3.4 MAIN BUS BSR CHAMBER TESTING

A BUS BAR JOINT CONTECT RESISTANCE (MICRO OHM METER)

B IR VALUE

C HIGH VOLTAGE TEST OF HT BUS BAR CHAMBER

3.5 PT (POTENTIAL TRANSFORMERS) TESTING

A IR VALUE

B WINDING RESISTANCE

C PT RATIO AS PER RATIO

3.6 WIRING AS PER DRAWING

A LOOP CHECKING

3.7 CHECK SPACE HEATER

3.8 AC & DC SUPPLY READYNESS

A AC & DC SUPPLY ON

B CHECK ALL LAMP INDICATION GLOW AS PER CONDITION

3.9 CHECK SHROUDS ON ALL JOINTS

3.10 CHECK SEALING OF PANELS

3.11 CHECK TAG ON EACH COMPONENTS OF PANEL

3.12 CHECK DOOR INTER LOCK

3.13 CHECK TIGHTNESS OF ALL JOINTS

3.14 CHECK LINE PT / BUS PT

3.15 CHECK CT / PT POINT IN PANEL JB TIGHTNESS

3.16 CHECK ALL LOGIC AS PER DRAWING

3.17 FINAL MAIN BUS MEGGER (IR VALUE)

4 PANEL CHARGING CLEARANCE FROM ELECTRICAL INSPECTOR

5 SWITCHGEAR CHARGE


5/22

DATE:- 05/07/10

SR. NO DESCRIPTION1 TRANSFORMER DATA

1.1 CUSTOMER :

1.2 CUSTOMERS ORDER NO. :

1.3 SITE :1.4 SL.NO. OF UNIT :

1.5 TRANSFORMER :

1.6 RATING MVA :

1.7 HV KV CLASS :

1.8 LV KV CLASS :

1.9 TV KV CLASS :

2 RECEIPT AND STORAGE CHECKS

2.1VISUAL INSPECTION OF TRANSFORMER AND ACCESSORIES AT THE TIME OF RECEIPT AT SITE.

COMPLAINTS SHOULD BE IMMEDIATELY REPORTED TO AGENCY

2.2 SHOCK RECORDER READINGS TO BE INFORMED TO AGENCY.

2.3 Nitrogen Gas Pressure at the time of despatch

2.4 STORAGE OF OIL / NITROGEN

2.5 NITROGEN PRESSURE/OIL LEVEL TO BE MONITORED REGULARLY AND SEPARATE CHECK-LISTFOR THE SAME AVAILABLE.

2.6ACCESSORIES SHALL BE STORED IN A CLEAN AREA AND PROTECTED FROM RAIN WATER, MUD

ETC.

3 ERECTION CHECK-LIST :-

3.1 OIL FILTER MACHINE

3.11 CAPACITY

3.12 MAKE

3.13 LUBRICATING OIL OF VACUUM PUMP TO BE CHANGED :

3.14 CLEANING OF FILTER PACKS :

3.15 FLUSHING OF WHOLE FILTER M/C WITH FRESH OIL :

3.16 VACUUM OBTAINED WITHOUT LOAD (MILLI BAR)

3.2 VACUUM PUMP FOR EVACUATION OF TRANSFORMER

3.21 LUBRICATING OIL TO BE CHANGED :

3.22 VACUUM OBTAINED WITHOUT LOAD (MILLIBAR) :

3.23 DIAMETER OF VACUUM HOSE (50 MM) :

3.24 DRY ICE CHAMBER EMPLOYED OR NOT

3.3 OIL STORAGE TANK

3.31 INSIDE SHALL BE PAINTED :

3.32 SILICA GEL BREATHER PROVIDED :

3.33 NO OPENING SHALL BE LEFT UNCOVERED :

3.34 CAPACITY AND QUANTITY :

3.35 CLEANLINESS OF INSIDE OF PIPES/HOSES TO THE STORAGE TANK :

3.4 EXPOSURE DURING ERECTION

3.41 FIRST DAY HRS :

3.42 SECOND DAY HRS :

3.43 THIRD DAY HRS :

3.44 NITROGEN PRESSURE APPLIED AFTER EACH DAYS ERECTION WORK PSI :3.45 AMBIENT TEMPERATURE OC :

3.46 AVERAGE RELATIVE HUMIDITY :

3.47 WEATHER CONDITION

3.5 NITROGEN SEALING IN CASE OF DELAY IN OIL FILLING

3.51 NO. OF N2 CYLINDERS USED FOR DISPLACING THE AIR INSIDE THE TANK :

3.52 N2 ADMITTED FROM BOTTOM VALVE :

3.53 VALVE AT DIAMETRICALLY OPPOSITE END AT TOP KEPT OPEN :

3.54 NO. OF CYLINDERS USED FOR BUILDING UP 2 PSI

3.6 HEATING AND VACUUM CYCLETIME

CHECK LIST TRANSFORMER ERECTION & COMMISSIONING PROCEDURE


6/22

SR. NO DESCRIPTION3.61 GAP BETWEEN COMPLETION OF ERECTION AND STARTING OF OIL FILLING OPERATION HRS

3.62 OIL FILLED THROUGH (BUCHHOLZ RELAY PIPE) :

3.63 FILTER OIL OUTLET TEMPERATURE OC :

3.64 DURATION OF FILTERATION AFTER FILLING HRS :

3.65 TIME REQUIRED TO DRAIN THE HOT OIL HRS :

3.66 REQUIREMENT OF INSTRUCTION MANUAL UNDERSTOOD AND IN CASE OF COPS AIR CELL.INSTRUCTION IS READ AND FOLLOWED.

3.67 OIL FILLING HOSE CONNECTED TO (VALVE ON TANK TOP) HRS :

3.68 EQUALISER CONNECTION FOR OLTC :

3.69 LEAK RATE AT 60 MILLI BAR (BELOW 20 MB.LT/SEC) :

3.61 FINAL VACUUM ACHIEVED IN TANK (MILLIBAR) :

3.611 DURATION OF VACUUM AT ABOVE LEVEL HRS :

3.612 VACUUM DURING OIL FILLING (MILLIBAR) :

3.613 FILLING LEVEL :

3.614 VACUUM BROKEN WITH NITROGEN HRS :

3.615 TOTAL DURATION OF FILTERATION HRS :

3.616 DURATION OF FILTERATION THROUGH DOF HRS :

3.617 IR VALUES 10/60 SECS AT _______OC :

3.618 OIL BDV (2.5 MM GAP) KV :

3.619 OIL MOISTURE PPM :

3.62 OIL TOPPING UP :

3.621 VACUUM PULLED THROUGH (MILLIBAR) HRS :

3.622 TIME GAP BETWEEN COMPLETION OF FILLING HRS AND CONNECTING THE BREATHER :

3.7 FILTERATION OF OLTC OIL:

3.71 TEMPERATURE OF FILTER OUTLET OIL OC :

3.72 DURATION OF FILTERATION HRS :

3.73 OIL BDV (2.5 MM GAP) KV :

3.74TIME GAP BETWEEN COMPLETION OF FILTERATION & COMPLETE FILLING OF OTLC

CONSERVATOR HRS :

3.75 IS THE OLTC, BREATHER ATTACHED HRS

3.8 OIL FILLING IN CONSERVATOR (COPS):

3.81 IN CASE OF COPS, INSTRUCTIONS IN BROCHURE TO BE FOLLOWED :

3.82 OIL FILLING RATE < 2000 LPM4 ASSEMBLY CHECKS:

4.1 OIL HANDLING AND INSULATION PROCESSING TO BE DONE STRICTLY AS PER CG INSTRUCTIONS :

4.2RADIATORS AND PIPE CONNECTIONS SHOULD BE CHECKED INSIDE BEFORE ASSEMBLY, IN

ORDER TO ENSURE THAT THERE ARE NO FOREIGN PARTICLES. :

4.3 BEFORE MOUNTING THE PUMPS, CHECK THE MOUNTING DIRECTION :

4.4 IR VALUE OF PUMP USING 2 KV MEGGAR (IF APPLICABLE) :

4.5BEFORE MOUNTING THE OIL FLOW INDICATOR, CHECK THE OIL FLOW DIRECTION MARKED ON

THE DIAL :

4.6 UNLOCK THE MAGNETIC OIL LEVEL GAUGE BEFORE MOUNTING :

4.7 CHECK CONTACT OPERATION OF MAGNETIC OIL LEVEL GAUGE BEFORE MOUNTING :

4.8 IR VALUES OF FANS BEFORE MOUNTING (IF APPLICABLE)

4.9 RUN THE FANS SEPARATELY BEFORE MOUNTING AND OBSERVE THE PERFORMANCE :

4.10 UNLOCK THE MAGNETIC OIL LEVEL GAUGE BEFORE MOUNTING :

4.11 Check contact operation of magnetic oil level gauge before mounting

4.12COUPLING BETWEEN OLTC AND DRIVING MECHANISM SHOULD BE DONE STRICTLY AS PER

INSTRUCTIONS. ABSOLUTELY NO MISMATCHING CAN BE ALLOWED IN THE TIMING :

4.13LEAD-LAD TEST TO CHECK CORRECT COUPLE BETWEEN PHASES (POLES) OF OLTC. ABSOLUTELY

NO MISMATCHINGS CAN BE ALLOWED IN THE TIMING. :

4.14IF SPECIFIED, GEAR OIL SHOULD BE FILLED TO THE REQUIRED LEVEL FOR THE GEARS IN THE

DRIVING MECHANISM :

4.15 ELECTRICAL OPERATION OF THE OLTC SHOULD BE CHECKED ONLY AT THE MIDDLE TAP :


7/22

SR. NO DESCRIPTION4.16 ELECTRICAL CHECKING OF LIMIT SWITCH OPERATION

4.17 IF SPECIFIED FILL GEAR OIL IN THE GEAR BOD OF THE OFF CIRCUIT TAP CHANGER :

4.18 CHECK OIL LEVEL IN THE SURGE CAPACITORS, IF SUPPLIED :

4.19BEFORE MOUNTING THE BUSHING TURRETS, CHECK THE CONTINUITY OF CTS INSIDE THE

TURRETS. :

4.20 2 KV TEST ON CTS INSIDE THE TURRETS BEFORE MOUNTING THE TURRETS :4.21

IR VALUES OF CONDENSER BUSHINGS BEFORE MOUNTING SHALL BE AT LEAST 5000 MEGA OHMS

:

4.22 COVER ON THE CAPACITANCE TAP OF BUSHINGS SHALL BE TIGHT :

4.23 AFTER MAKING THE CONDENSER BUSHINGS VERTICAL, CHECK FOR ANY PHYSICAL DAMAGES

LIKE HAIRLINE CRACKS ON THEPORCELAIN. ALSO LOOK FOR ANY OIL LEAKAGES. :

4.24 OIL LEVEL IN CONDENSER BUSHINGS :

4.25 WHILE MOUNTING THE 245 KV & 145 KV BUSHINGS, THE THE TUBE/LEAD ATTACHED TO THE

WINDINGS SHOULD ENTER THE BOTTOM OF THE BUSHING WITHOUT BEING HIT BY THE BUSHING :

4.26ENSURE THAT NO BARE PART OF CONDENSER BUSHING IS SEEN OUTSIDE THE BOTTOM TUBE/

SHIELD :

4.27

AFTER MOUNTING THE BUSHINGS, THE TERMINAL CAPS SHOULD BE TIGHTLY FITTED WITH

GASKET SEALING. :

4.28IN CASE OF ADAPTERS BOLTED TO BUSHING STEM, IS THE NUT ON THE STEM TIGHTENED FULLY

AND LOCKED :

4.29 CHECK THE MOUNTING DIRECTION OF MAIN BUCHHOLZ RELAY BEFORE MOUNTING :

4.3CHECK CONTACT OPERATION AFTER MOUNTING THE BUCHHOLZ RELAY AND LOCK IN THE

SERVICE POSITION :

4.31CONTACT OPERATION OF SUDDEN PRESSURE RELAY SHOULD BE CHECKED BEFORE MOUNTED,

IF PROVIDED. :

4.32 CONTACT OPERATION OF PRESSURE RELIEF DEVICE SHOULD BE CHECKED USING THE TEST

4.33 ELECTRICAL OPERATION CHECKED ON MARSHALLING BOX :

4.34COMPLETE ASSEMBLY OF THE TRANSFORMER SHOULD BE CHECKED FOR CONFORMITY WITH

GENERAL ARRANGEMENT DRAWING. :

4.35 AIR RELEASING FROM ALL POINTS IN THE SEQUENCE. :

4.36 ELECTRICAL TESTS, AS PER COMMISSIONING CHECK LIST MAY BE CARRIED OUT AT THIS STAGETO ENSURE THE SOUNDNESS OF THE TRANSFORMER. :

5 PRE-COMMISSIONING CHECKS MECHANICAL ASPECTS

5.1TIGHTNESS OF BUSHING TERMINAL CONNECTORS (CABLE SIDE) NUTS AND LOCK NUTS BUSHING

SIDE NUTS END LOCK NUTS :

5.2 TIGHTNESS OF BUSHING TERMINAL CAPS WITH BUSHING STEM :

5.3 SEALING BETWEEN BUSHING CAP AND ITS SEATING ON THE HELMET TIGHTNESS :

5.4 OIL LEVEL :

5.5 GROUNDING OF BUSHING TEST TAPS :

5.6OVERHEAD CONNECTIONS TO BUSHINGS TO BE SUFFICIENTLY FLEXIBLE SO THAT EXCESSIVE

TENSION IS NOT APPLIED TO BUSHINGS :

5.7IN CASE OF ADAPTERS BOLTED TO BUSHING, KEEP THEM SUFFICIENTLY FLEXIBLE SO THAT

EXCESSIVE TENSION IS NOT APPLIED TO BUSHINGS :

5.8OVERHEAD CABLES SHOULD NOT BE HANGING WITH EXCESSIVE CURVATURE, WHICH COULD

SWING VIOLENTLY DURING EXTERNAL SHORT CIRCUITS AND DAMAGE BUSHINGS :

5.9

SUFFICIENT FLEXIBILITY SHOULD BE BUILT INTO THE CONNECTION BETWEEN LV/NEUTRAL

BUSHINGS TO TUBULAR CONDUCTORS/EARTHING BARS SO THAT EXCESSIVE FORCE IS NOT

APPLIED TO THE BUSHINGS. :

5.1

IN CASE STEEL EARTHING THERE SHOULD BE A FLEXIBLE COPPER CONNECTION BETWEEN

BUSHING AND STEEL FLAT SO THAT ANY OVERHEATING OF STEEL BAR DUE TO BAD SURFACE

CONDITIONS MAY NOT AFFECT THE BUSHING AND ALSO A MATCHING JOINT (WITHOUT SLANTING)

IS ENSURED ON THE BUSHING. SUCH A COPPER FLEXIBLE TO BE TINNED AT EITHER END,

ATLEAST 600 MM LENGTH. :


8/22

SR. NO DESCRIPTION5.11 THE STEEL GROUNDING BAR SHOULD BE GALVANISED AND OF GOOD SURFACE CONDITION :

5.12 BREATHER PIPE CONNECTIONS TO BE SUFFICIENTLY TIGHT :

5.13 BUCHHOLZ PIPE VALVES OPEN :

5.14 ALL VALVES OPEN TO ATMOSPHERE BLANKED :

5.15 RADIATOR TOP AND BOTTOM VALVES OPEN :

5.16 COOLER PIPE VALVES OPEN :5.17 PIPES ON EITHER SIDES OF EXPANSION JOINTS,IF PROVIDED, SHALL BE PERFECTLY IN LINE :

5.18 RAIL LEVELS UNDER EACH ROLLER SHALL BE SAME (CHECK WITH WATER TUBE) :

5.19 ALL VALVES SHALL BE LOCKED USING PAD LOCK :

5.2 ALL GASKETED JOINTS LEAK TIGHT :

5.21 MTJ/TJB SHALL BE PROPERLY SEALED (CABLE GLAND PLATE HOLES TO BE BLOCKED)

6 PRE-COMMISSIONING CHECKS EXTERNAL TO TRANSFORMER

6.1 SETTING FOR DIFFERENTIAL RELAY NOT TO EXCEED 1% :

6.2 OVER-CURRENT AND RESTRICTED EARTH FAULT PROTECTING PROVIDED :

6.3 OVER FLUXING PROTECTION PROVIDED :

6.4 OVER FLUXING LIMIT SET ADEQUATELY :

6.5 OVER FLUXING RELAY ACTUATED BY VOLTAGE ON UNTAPPED WINDING :

6.6 SURGE CAPACITORS FOR TERTIARY WINDING :

6.7 ALL TERMINALS OF THE DELTA WINDING SHALL BE UNGROUNDED :

6.8 TRIPPING CIRCUIT FOR GROUND FAULT ANY TERMINAL OF DELTA WINDING :

6.9THE OSR TRIP CIRCUIT SHOULD BE CONNECTED INDEPENDENTLY OF THE MAIN TRANSFORMER

BUCHHOLZ :

6.1THE PROTECTION CIRCUIT SHOULD RUN ON DC SUPPLY AND IN THE EVENT OF FAILURE OF DC

SUPPLY, A FAIL SAFE MECHANISM TO TRIP THE TRANSFORMER :

6.11

TRANSFORMER MAINTENANCE REGISTER TO BE OPENED, WHICH SPECIFIES FREQUENCY OF

CHECKS/ MAINTENANCE OPERATIONS AND ACCEPTABLE LIMITS FOR OIL CHARACTERISTICS AS

PER IEC-296-1 CHANGING SILICAGEL OF BREATHER OIL IN THE OIL CUP OF BREATHER CLEANING

THE BUSHING PORCELAIN OIL LEVEL IN BUSHINGS/CONSERVATORS BUSHING TAN

DELTA/CAPACITANCE CONTACTS OF BUCHHOLZ RELAYS, PRESSURE RELIEF DEVICES, SUDDEN

PRESSURE RELAY, TEMPERATURE INDICATORS, OIL FLOW METERS, ETC. OLTC DIVERTER

CONTACTS / OIL PAINTING TIGHTNESS OF FASTENERS OF ELECTRICAL CONNECTIONS TO

BUSHINGS SCALES / LEAKS IN WATER COOLERS SAMPLING OF OIL FROM STANDBY OIL-TO-

WATER HEAT EXCHANGERS TO DETECT WATER LEAKS DISSOLVED GAS ANALYSIS

6.12 LIGHTNING ARRESTOR NEUTRALS SHALL BE SOLIDLY EARTHED :

6.13 LIGHTNING ARRESTORS SHALL BE CLOSE TO THE TRANSFORMER :

6.14IN THE CASE OF SHUNT TRANSFORMERS, A PROTECTION SYSTEM SHALL TRIP THE EQUIPMENT IF

THE IMPEDANCE CHANGES BY MORE THAN 5% :

6.15 BIMETALS SHALL BE PUT AT COPPER-ALUMINIUM JOINTS :

6.16 IF SO, THE COPPER FACE TO TOUCH TO COPPER AND ALUMINIUM FACE TO ALUMINIUM :

6.17PREPARATION OF ALL INSTRUMENTS FOR ELECTRICAL TESTS FOR COMMISSIONING. ENSURE

RIGHT WORKING AND CALIBRATION. :

6.18CHECK ALL PROTECTIVE EQUIPMENTS AND RELAYS FOR CORRECT FUNCTIONING AND RIGHT

SETTING :

7 COMMISSIONING CHECK-LIST FOR TRANSFORMERS

7.1 AUDITING OF PREVIOUS SITE CHECK-LISTS:

7.11 RECEIPT AND STORAGE CHECK LIST :

7.12 ERECTION CHECK-LIST :

7.13 OIL HANDLING AND INSULATION PROCESSING CHECK-LIST :

7.14 PRE-COMMISSIONING TESTS

7.2 COMMISSIONING CHECK-LIST

7.21RATIO AT ALL TAPS, PREFERABLY WITH A RATIO METER, COMPARE WITH FACTORY TEST

RESULTS :


9/22

SR. NO DESCRIPTION

7.22SINGLE PHASE SHORT CIRCUIT TEST AT SUITABLE VOLTAGE (230 V OR LESS). CALCULATE

IMPEDANCE AT ALL TAPS :

7.23 MAGNETISING CURRENT AT 415 V :

7.24 MAGNETIC BALANCE TEST :

7.25INSULATION RESISTANCE VALUES AT 10 SECS AND 60 SECS POLARISATION INDEX SHOULD

PREFERABLY BE COMPARABLE TO FACTORY TEST RESULTS :7.26 BREAK DOWN STRENGTH OF OIL WITH 2.5 MM GAP SPACING (AVERAGE OF SIX READINGS) :

7.27 MOISTURE CONTENT IN OIL IN PPM

7.28AIR RELEASING FROM ALL POINTS IN THE RIGHT SEQUENCE. STANDING TIME AND AIR RELEASE

AFTER STANDING TIME. :

7.29 OIL LEVEL IN MAIN CONSERVATOR :

7.210 SILICAGEL COLOUR :

7.211 CONDITION OF BREATHER (CRACKS, HOLES, ETC.) AND OIL IN THE OIL CUP. :

7.212 BUCHHOLZ RELAY SHALL BE IN SERVICE POSITION AND LOCKED :

7.213 ALL INTERCONNECTING VALVES SHALL BE OPEN :

7.214 VALVES OPEN TO ATMOSPHERE SHALL BE CLOSED AND BLANKED :

7.215 SELECT WTI CT TERMINALS AS PER MANUAL :

7.216ALL CT SECONDARIES SHOULD BE SHORTED EITHER THROUGH RESPECTIVE INSTRUMENTS OR

DIRECTLY :

7.217 OTI ALARM/TRIP SETTINGS SHOULD BE 85/95OC :

7.218 WTI ALARM/TRIP SETTINGS SHALL BE 100/110OC :

7.219 EARTHING OF TANK COVER TO TANK :

7.220 RTD (IF PROVIDED) CONNECTION SHALL BE AS PER DRAWING :

7.221ALARM INDICATION SHALL BE CHECKED BY CLOSING ALARM CONTACTS OF OTI, WTI, BUCHHOLZ

RELAY AND OIL FLOW INDICATOR :

7.222 BREAKER TRIPPING SHALL BE CHECKED BY CLOSING THE TRIP CONTACTS OTI, WTI, BUCHHOLZ

RELAY, SUDDEN PRESSURE RELAY, PRESSURE RELIEF DEVICE, AS APPLICABLE. :

7.223SETTING AND OPERATION OF DIFFERENTIAL AND REF PROTECTION SHALL BE VERIFIED. ALSO,

IMPEDANCE PROTECTION FOR SHUNT TRANSFORMERS :

7.224 SEPARATE ANNUNCIATIONS SHALL BE AVAILABLE FOR DIFFERENT ALARMS :

7.225THE SURROUNDINGS SHALL BE CLEAN AND DEGREE OF POLLUTION WITHIN TOLERABLE LEVELS.

:8 FINAL CHECKS PRIOR TO COMMISSIONING

8.1 RECEIPT AND STORAGE : YES/NO

8.2 PRE-COMMISSIONING CHECKS MECHANICAL ASPECTS : YES/NO

8.3 PRE-COMMISSIONING CHECKS EXTERNAL TO TRANSFORMER : YES/NO

8.4 COMMISSIONING CHECK-LIST FOR TRANSFORMER : YES/NO

8.5 RATING PLATE/CAUTION PLATE INSTRUCTIONS READ AND REQUIRED ACTION TAKEN : YES/NO

8.6 STANDING TIME AS PER MANUAL GIVEN BEFORE FINAL AIR RELEASE OPERATION : YES/NO

8.7ANY PRESSURE APPLICATION/OIL DAMAGE/DISTURBANCE TO OIL CIRCUIT DONE DURING

STANDING TIME : YES/NO

8.8IF (1.8.4) ABOVE IS YES, STANDING TIME TO BE COUNTED AFTER SUCH OPERATIONS AND

STANDING TIME AS PER MANUAL GIVEN : YES/NO

8.9 FINAL AIR RELEASE DONE AS PROPER SEQUENCE AFTER STANDING TIME : YES/NO

8.1 BUSHING TEST CAP TIGHTNESS ENSURES : YES/NO

8.11BUSHING TAN DELTA/CAPACITANCE MEASURED AND WITHIN LIMITS AS PER SUPPLIER LEAFLETS :

YES/NO

8.12 BUSHING OIL LEVEL ENSURED : YES/NO

8.13 TANK COVER/BELL CURB EARTHING STRIPS CONNECTED : YES/NO

8.14 ALL PRE-COMMISSIONING TEST RESULTS SATISFACTORY : YES/NO

9 CHECKS IMMEDIATELY AFTER COMMISSIONING

9.1 TRANSFORMER HUMMING / NOISE / VIBRATION :

9.2 ANY ABNORMAL NOISE FROM BUSHING/OLTC :

9.3 NO ABNORMAL NOISE SHALL BE HEARD FROM BUSHING / OLTC :


10/22

SR. NO DESCRIPTION

9.4RECORD ANY OTHER ABNORMALITY OBSERVED AND OBTAIN CLARIFICATION FROM CGL ON SUCH

:

9.5 IF NOISE FROM ANY LOOSE ITEMS DUE VIBRATION, TIGHTEN SAME AND OBSERVED :

9.6 OBSERVE FOR 12 HOURS FOR ANY ABNORMALITY :

9.7 NO OIL LEAKS FROM ANY POINT :

9.8 DGA AFTER 24 HOURS :9.9 ANY OTHER OBSERVATION. OBTAIN CONFIRMATION FROM AGENCY IN SUCH POINTS.


11/22

SR. NO1

1.11.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2

2.1

2.2

2.32.4

2.5

2.6

3

3.1

3.11

3.12

3.13

3.14

3.15

3.16

3.23.21

3.22

3.23

3.24

3.3

3.31

3.32

3.33

3.34

3.35

3.4

3.41

3.42

3.43

3.44

3.45

3.46

3.47

3.5

3.51

CHE


12/22

3.52

3.53

3.54

3.6

3.61

3.62

3.633.64

3.65

3.66

3.67

3.68

3.69

3.610

3.611

3.612

3.613

3.614

3.6153.616

3.617

3.618

3.619

3.620

3.621

3.622

3.7

3.71

3.72

3.73

3.74

3.75

3.8

3.81

3.82

4

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.84.9

4.10

4.11

4.12

4.13

4.14

4.15


13/22

4.16

4.17

4.18

4.19

4.20

4.21

4.22

4.23

4.24

4.25

4.26

4.27

4.28

4.29

4.30

4.31

4.324.33

4.34

4.35

4.36

5

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

5.10

5.11

5.12

5.13

5.14

5.155.16

5.17

5.18

5.19

5.20

5.21

6

6.1


14/22

6.2

6.3

6.4

6.5

6.6

6.7

6.86.9

6.10

6.11

6.12

6.13

6.146.15

6.16

6.17

6.18

7

7.1

7.11

7.12

7.13

7.14

7.2

7.21

7.22

7.23

7.24

7.25

7.26

7.27

7.28

7.29

7.30

7.31

7.327.33

7.34

7.35

7.36

7.37

7.38

7.39

7.40


15/22

7.41

7.42

7.43

7.44

7.45

8

8.1

8.2

8.3

8.4

8.5

8.6

8.7

8.8

8.9

8.10

8.118.12

8.13

8.14

9

9.1

9.2

9.3

9.4

9.5

9.6

9.7

9.8

9.9


16/22


17/22

DESCRIPTIONTransformer Data

Customer :Customers Order No. :

Site :

Sl.No. of Unit :

Transformer :

Rating MVA :

HV kV Class :

LV kV Class :

TV kV Class :

Receipt and Storage Checks

Visual inspection of Transformer and Accessories at the time of receipt at site. Complaints should be immediately

reported to Agency

Shock Recorder readings to be informed to Agency.

Nitrogen Gas Pressure at the time of despatchStorage of oil / nitrogen

Nitrogen pressure/oil level to be monitored regularly and separate check-list for the same available.

Accessories shall be stored in a clean area and protected from rain water, mud etc.

Erection Check-List :-

Oil Filter Machine

Capacity

Make

Lubricating oil of vacuum pump to be changed :

Cleaning of Filter Packs :

Flushing of whole filter m/c with fresh oil :

Vacuum obtained without load (milli bar)

Vacuum pump for evacuation of TransformerLubricating oil to be changed :

Vacuum obtained without load (millibar) :

Diameter of vacuum hose (50 mm) :

Dry ice chamber employed or not

Oil Storage Tank

Inside shall be painted :

Silica gel breather provided :

No opening shall be left uncovered :

Capacity and quantity :

Cleanliness of inside of pipes/hoses to the storage tank :

Exposure During Erection

First Day Hrs :

Second Day Hrs :

Third Day Hrs :

Nitrogen Pressure applied after each days erection work PSI :

Ambient Temperature OC :

Average Relative Humidity :

Weather Condition

Nitrogen Sealing in case of delay in oil filling

No. of N2 cylinders used for displacing the air inside the tank :

CK LIST TRANSFORMER ERECTION & COMMISSIONING PROCEDURE


18/22

N2 admitted from bottom valve :

Valve at diametrically opposite end at top kept open :

No. of cylinders used for building up 2 PSI

Heating and Vacuum CycleTime

Gap between completion of erection and starting of oil filling operation Hrs :

Oil filled through (buchholz relay pipe) :

Filter oil outlet temperature OC :Duration of filteration after filling Hrs :

Time required to drain the hot oil Hrs :

Requirement of Instruction Manual understood and in case of COPS air cell. Instruction is read and followed.

Oil filling hose connected to (valve on tank top) Hrs :

Equaliser connection for OLTC :

Leak rate at 60 milli bar (below 20 mb.lt/sec) :

Final vacuum achieved in tank (millibar) :

Duration of vacuum at above level Hrs :

Vacuum during oil filling (millibar) :

Filling level :

Vacuum broken with nitrogen Hrs :

Total duration of filteration Hrs :Duration of Filteration through DOF Hrs :

IR values 10/60 Secs at _______OC :

Oil BDV (2.5 mm gap) kV :

Oil Moisture ppm :

Oil topping up :

Vacuum pulled through (millibar) Hrs :

Time gap between completion of filling Hrs and connecting the breather :

Filteration of OLTC Oil:

Temperature of filter outlet oil OC :

Duration of Filteration Hrs :

Oil BDV (2.5 mm gap) kV :

Time gap between completion of filteration & complete filling of OTLC conservator Hrs :

Is the OLTC, Breather attached Hrs

Oil filling in conservator (COPS):

In case of COPS, instructions in Brochure to be followed :

Oil filling rate < 2000 LPM

Assembly Checks:

Oil handling and insulation processing to be done strictly as per CG instructions :

Radiators and pipe connections should be checked inside before assembly, in order to ensure that there are no

Before mounting the pumps, check the mounting direction :

IR value of pump using 2 kV meggar (If Applicable) :

Before mounting the oil flow indicator, check the oil flow direction marked on the dial :

Unlock the magnetic oil level gauge before mounting :

Check contact operation of magnetic oil level gauge before mounting :

IR values of fans before mounting (If Applicable)Run the fans separately before mounting and observe the performance :

Unlock the magnetic oil level gauge before mounting :

Check contact operation of magnetic oil level gauge before mounting

Coupling between OLTC and driving mechanism should be done strictly as per instructions. Absolutely no

mismatching can be allowed in the timing :

Lead-lad test to check correct couple between phases (Poles) of OLTC. Absolutely no mismatchings can be

If specified, gear oil should be filled to the required level for the gears in the driving mechanism :

Electrical operation of the OLTC should be checked only at the middle tap :


19/22

Electrical checking of limit switch operation

If specified fill gear oil in the gear bod of the off circuit tap changer :

Check oil level in the surge capacitors, if supplied :

Before mounting the bushing turrets, check the continuity of CTs inside the turrets. :

2 kV test on CTs inside the turrets before mounting the turrets :

IR values of condenser bushings before mounting shall be at least 5000 mega ohms :

Cover on the capacitance tap of bushings shall be tight :After making the condenser bushings vertical, check for any physical damages like hairline cracks on

theporcelain. Also look for any oil leakages. :

Oil level in condenser bushings :

While mounting the 245 kV & 145 Kv Bushings, the the tube/lead attached to the windings should enter the

bottom of the bushing without being hit by the bushing :

Ensure that no bare part of condenser bushing is seen outside the bottom tube/ shield :

After mounting the bushings, the terminal caps should be tightly fitted with gasket sealing. :

In case of adapters bolted to bushing stem, is the nut on the stem tightened fully and locked :

Check the mounting direction of main buchholz relay before mounting :

Check contact operation after mounting the buchholz relay and lock in the SERVICE position :

Contact operation of Sudden Pressure Relay should be checked before mounted, if provided. :

Contact operation of Pressure Relief Device should be checked using the testElectrical operation checked on marshalling box :

Complete assembly of the Transformer should be checked for conformity with General Arrangement Drawing. :

Air releasing from all points in the sequence. :

Electrical tests, as per commissioning check list may be carried out at this stage to ensure the soundness of the

Pre-commissioning checks Mechanical Aspects

Tightness of bushing terminal connectors (cable side) nuts and Lock nuts Bushing side nuts End Lock nuts :

Tightness of bushing terminal caps with bushing stem :

Sealing between bushing cap and its seating on the helmet tightness :

Oil Level :

Grounding of bushing test taps :

Overhead connections to bushings to be sufficiently flexible so that excessive tension is not applied to bushings :

In case of adapters bolted to bushing, keep them sufficiently flexible so that excessive tension is not applied to

Overhead cables should not be hanging with excessive curvature, which could swing violently during external

short circuits and damage bushings :

Sufficient flexibility should be built into the connection between LV/Neutral Bushings to tubular

conductors/earthing bars so that excessive force is not applied to the bushings. :

In case steel earthing there should be a flexible copper connection between bushing and steel flat so that any

overheating of steel bar due to bad surface conditions may not affect the bushing and also a matching joint

(without slanting) is ensured on the bushing. Such a copper flexible to be tinned at either end, atleast 600 mm

The steel grounding bar should be galvanised and of good surface condition :

Breather pipe connections to be sufficiently tight :

Buchholz Pipe Valves open :

All valves open to atmosphere blanked :

Radiator top and bottom valves open :Cooler Pipe valves open :

Pipes on either sides of expansion joints,if provided, shall be perfectly in line :

Rail levels under each roller shall be same (check with water tube) :

All valves shall be locked using pad lock :

All gasketed joints leak tight :

MTJ/TJB shall be properly sealed (cable gland plate holes to be blocked)

Pre-commissioning Checks External to Transformer

Setting for differential relay not to exceed 1% :


20/22

Over-current and restricted earth fault protecting provided :

Over fluxing protection provided :

Over fluxing limit set adequately :

Over fluxing relay actuated by voltage on untapped winding :

Surge capacitors for tertiary winding :

All terminals of the delta winding shall be ungrounded :

Tripping circuit for ground fault any terminal of delta winding :The OSR trip circuit should be connected independently of the main transformer buchholz :

The protection circuit should run on DC supply and in the event of failure of DC supply, a fail safe mechanism to

trip the transformer :

Transformer maintenance register to be opened, which specifies frequency of checks/ maintenance operations

and acceptable limits for Oil characteristics as per IEC-296-1 Changing silicagel of breather Oil in the oil cup of

breather Cleaning the bushing porcelain Oil level in bushings/conservators Bushing tan delta/capacitance

Contacts of buchholz relays, pressure relief devices, sudden pressure relay, temperature indicators, oil f low

meters, etc. OLTC diverter contacts / oil Painting Tightness of fasteners of electrical Connections to bushings

Scales / Leaks in water coolers Sampling of oil from standby oil-to-water Heat exchangers to detect water leaks

Lightning arrestor Neutrals shall be solidly earthed :

Lightning arrestors shall be close to the transformer :

In the case of shunt Transformers, a protection system shall trip the equipment if the impedance changes byBimetals shall be put at copper-aluminium joints :

If so, the copper face to touch to copper and aluminium face to aluminium :

Preparation of all instruments for electrical tests for commissioning. Ensure right working and calibration. :

Check all protective equipments and relays for correct functioning and right setting :

Commissioning Check-list for Transformers

Auditing of Previous Site Check-lists:

Receipt and Storage check list :

Erection check-list :

Oil handling and insulation processing check-list :

Pre-commissioning tests

Commissioning Check-list

Ratio at all taps, preferably with a ratio meter, compare with factory test results :

Single phase short circuit test at suitable voltage (230 V or less). Calculate impedance at all taps :

Magnetising current at 415 V :

Magnetic balance test :

Insulation resistance values at 10 secs and 60 secs polarisation index should preferably be comparable to factory

Break down strength of oil with 2.5 mm gap spacing (average of six readings) :

Moisture content in oil in ppm

Air releasing from all points in the right sequence. Standing time and air release after standing time. :

Oil level in main conservator :

Silicagel Colour :

Condition of breather (cracks, holes, etc.) and oil in the oil cup. :

Buchholz Relay shall be in service position and locked :All interconnecting valves shall be open :

Valves open to atmosphere shall be closed and blanked :

Select WTI CT terminals as per manual :

All CT secondaries should be shorted either through respective instruments or directly :

OTI alarm/trip settings should be 85/95OC :

WTI alarm/trip settings shall be 100/110OC :

Earthing of tank cover to tank :

RTD (if provided) connection shall be as per drawing :


21/22

Alarm indication shall be checked by closing alarm contacts of OTI, WTI, Buchholz Relay and oil flow indicator :

Breaker tripping shall be checked by closing the trip contacts OTI, WTI, Buchholz Relay, Sudden Pressure Relay,

Pressure Relief Device, as applicable. :

Setting and operation of differential and REF protection shall be verified. Also, impedance protection for shunt

Separate annunciations shall be available for different alarms :

The surroundings shall be clean and degree of pollution within tolerable levels. :

Final Checks prior to Commissioning

Receipt and storage : YES/NO

Pre-commissioning checks mechanical aspects : YES/NO

Pre-commissioning checks external to Transformer : YES/NO

Commissioning check-list for Transformer : YES/NO

Rating Plate/Caution Plate Instructions read and required action taken : YES/NO

Standing time as per manual given before final air release operation : YES/NO

Any pressure application/oil damage/disturbance to oil circuit done during standing time : YES/NO

If (1.8.4) above is YES, standing time to be counted after such operations and standing time as per manual given

Final air release done as proper sequence after standing time : YES/NO

Bushing Test cap tightness ensures : YES/NO

Bushing tan delta/capacitance measured and within limits as per supplier leaflets : YES/NOBushing oil level ensured : YES/NO

Tank cover/bell curb earthing strips connected : YES/NO

All pre-commissioning test results satisfactory : YES/NO

Checks immediately after Commissioning

Transformer humming / noise / vibration :

Any abnormal noise from Bushing/OLTC :

No abnormal noise shall be heard from Bushing / OLTC :

Record any other abnormality observed and obtain clarification from CGL on such :

If noise from any loose items due vibration, tighten same and observed :

Observe for 12 hours for any abnormality :

No oil leaks from any point :

DGA after 24 hours :

Any other observation. Obtain confirmation from Agency in such points.

Start Up transformer charging

Civil Clearence

Cable routing Layout


22/22

Supply Trays & Accessories

Cable Tray support fabrication, tray erection & routing

L.T Cable Supply

Control Cable Supply

LT Power cable, Control cable Schedule at site

Interconnection Schedule at site

LT Power cable, Control cable layingLT Power cable, Control cable Termination

Testing & loop checking of control & power cable

132/11.5KV, 31.5MVA, ONAN/ONAF,on load tap changer, Transformer erection

6.6KV NGR Erection

RTCC Panel Erection

CCC panel

Pre-commissioning Test

Electrical inspector clearance

Testing & Commissioning

Transformer Charging

Documents

Check List of 6.6kv Panel