PRE COMMISSIONING

TESTS AT SUB STATION

DAVINDER SINGH,

BHEL

TESTING

• TYPE TESTS

• ROUTINE TEST

• ACCEPTANCE TESTS

• SAMPLE TESTS

• SITE TESTS

PRE COMMISSIONING TEST AT S/S

WHY PRE COMMISSIONING TESTS ARE NECESSARY AT SITE ?

315 MVA ,400/220KV/33KV, AUTO TRANSFORMER

• OFAF- 315 MVA RATING,

• ONAF-252 MVA RATING

• ONAN-180 MVA RATING

• OLTC +10% TO -10% IN STEP IN 16 STEPS ON 400KV SIDE/

IMPACT RECORDER ANALYSIS

• TO BE DETACHED AFTER THE TRANSFORMER IS PLACED ON PLINTH AT SITE

• CHECK NITROGEN PRESSURE INSIDE THE TRANSFORMER AFTER RECEIPT AT SITE

PRE COMMISSIONING TEST AT S/S

• INDIVIDUAL EQUIPMENT TESTING AS PER SUPPLIER’S RECOMMENDATIONS , CUSTOMER REQUIREMENT

• FIELD QUALITY PLANS FOR COMMISSIONING ARE AVAILABLE OF LEADING UTILITIES.

• RELAY TESTING

• WIRING CHECK

• SYSTEM TESTING

PRE COMMISSIONING TEST AT S/S

GENERAL GUIDELINES

NOTE DOWN THE AMBIENT CONDITIONS AT THE TIME OF TESTS

CLEAN THE EQUIPMENT –INSULATORS ETC.TAKE DUPLICATE MEASUREMENTS-TO

AVOID RETEST AT LATER DATE. THE READINGS ARE BENCH MARK FOR

FUTURE COMPARISON

PRE COMMISSIONING TEST AT S/S

GENERAL GUIDELINESFOLLOW THE INSTRUCTIONS GIVEN IN THE

OPERATION AND MAINTENANCE MANUAL OF THE EQUIPMENT SUPPLIER.

CHECK THE CUSTOMER PRE-COMMISSIONING FORMATS AND PROCEDURES IF ANY.

TEST BEFORE THE CUSTOMER REPRESENTATIVE AND NOTE THE READINGS IN A REGISTER.

FILL THE COMMISSIONING FORMATS AND GET SIGNATURE OF SUPPLIER REP., ERECTION REP. AND CUSTOMER ENGINEER.

TRANSFORMER COMMISSIONING TESTS

INSULATION RESISTANCE MEASUREMENT VECTOR GROUP & POLARITY SHORT CKT IMPEDANCE MAGNETIC BALANCE TEST FLOATING NEUTRAL VOLTAGE MAGNETIZING CURRENT TEST VOLTAGE RATIO TEST OIL, DG TESTING AFTER OIL FILTRATION IR MEASUREMENT OF BUSHING CT

TRANSFORMER COMMISSIONING TESTS

CONTINUITY TEST OF BUSHING CTPOLARITY TEST OF BUSHING CTCURRENT RATIO TESTMAGNETIC CURVE PERFORMANCECONTACT RESISTANCE MEASUREMENTCAP & TAN DELTA OF BUSHINGCAP & TAN DELTA OF WINDINGPROTECTION AND ALARM TESTFRA

IR MEASUREMENT

• IR MEASUREMENT OF TRANSFORMERWITH 500V MEGGER

CONTROL WIRING-1000M OHMTAP CHANGER

MOTOR-1000 M OHM CONTROL WIRING-1000M OHM

COOLING SYSTEM MOTOR FAN- 10.4 G OHM MOTOR PUMP-8.6 G OHM CONTROL WIRING- 1000 M OHM

ACCEPTANCE CRITERIA + GREATER THEN 1 M OHM

IR MEASUREMENT

• IR MEASUREMENT WITH 5000V MEGGER

• HV+IV TO E

MAIN WDG G OHM, 39 DEG C FACTORY TEST 33 DEG C

15 S 60 S 600 S 15 S 60 S 600 S

HV+IV TO LV 14.7 19.1 44.2 2.95 5.43 12.7

HV+IV TO LV 13.7 18.3 43.9 2.06 5.5 14.6

LV TO E 15.4 19.9 45.7 4.41 8.55 22.7

VECTOR GROUP

• VECTOR GROUP Yn 0 d 11 1R1+3R1 3Y1

3B1 2R1

N

2B1 2Y1

1B1 1Y1

APPLY 415 V 3 PHASE TO HV TERMINALS

VECTOR GROUPTERMINALS SITE RESULTS AT 415V FACTORY RESULTS AT

409V

1R1-1Y1 418V

1Y1-1B1 414V

1B1-1R1 417V

3Y1-1B1 411V 410V

3Y1-1Y1 384V 384V

3R1-N 239V

3Y1-N 220V

1R1-N 239V 236V

2R1-N 131V

2Y1-N 131V

2B1-N 130V

2R1-N=2Y1-N=2B1-N SHALL BE EQUAL

3R1-N GREATER THEN 3Y1-N & 3Y1-1B1 GREATER THEN 3Y1-1Y1, SO VECTOR GROUP Yn0d11 IS CONFIRMED

POLARITY TEST

• POLARITY TEST IS DONE BY TRANSFORMER RATIO METER OF M/S ELTEL, TYPE TRM200 OR EQUIVALENT

WINDING RESISTANCE• TO BE MEASURED ON ALL TAPS

• DIRECT DIGITAL READING METERS MEASUREMENT AT 10A OR 25A

• INDUCTIVE VOLTAGE SUPPRESSEDNORMAL TAP SITE RESULTS30 DEG C

FACTORY RESULTS34 DEG C

1R1-2R1 0.2231 0.2131

1Y1-2Y1 0.2246 0.2153

1B1-2B1 0.2231 0.2131

2R1-N 0.2879 0.2854

2Y1-N 0.2886 0.2856

2B1-N 0.2876 0.2857

MAGNETIC BALANCE TEST

• APPLY 1-PHASE 230V ON ONE PHASE OF HV WDG & NEUTRAL & MEASURE ACROSS OTHER HV WDGAPPLY -V

SITE MEASURE APPLY -V

FACTORY MEASUREMENT

1R1-N,240V

1Y1-N=227.6

1B1-N=28V

236.8V 221.5V 24V

1Y1-N ,241 V

1R1-N 135.9V

106.9V 236V 128.0V 108.0V

1B1-N, 242V

22.6V 1Y1-N 221.1V

236V 22.0V 220V

FLOATING NEUTRAL VOLTAGE• DISCONNECT THE NEUTRAL FROM GROUND

• APPLY 3-PH 415 V ON HV SIDE AND MEASURE ON IV SIDE ON NORMAL TAP POSITION

HV WDG VOLTAGE APPLIED

IV WDG VOLTAGE MEASURED

REMARKS

1R-N 238.5V 2R-N 130.4V NO FACTORY TESTING OF THIS TEST1Y-N 239.5V 2Y-N 131.4V

1B-N 240.2V 2B-N 131.1

N-EARTH 0.778

SHORT CIRCUIT CURRENT TEST

• APPLY 3-PH, 415 V ON HV WDG & SHORT LV WDG

VOLTAGE APPLIED

LV WDG SHORT COMBINATION

IR IY IB

390V 3 PH SHORT 0.622 0.632 0.632

390V 3 PH SHORT & GROUNDED

0.613 0.623 0.623

390V 2 PH SHORT 0.312 0.312 0.640

390V 2 PH SHORT & GROUNDED

0.308 0.308 0.612

390V 1 PH GROUNDED

0.001 0.001 0.001

HV RATIO TEST• APPLY 3 PH ,4 WIRE,415V ON HV TERMINALS AND

KEEP IV OPEN. IT SHALL BE MEASURED ON ALL TAPS.

• TO MEASURE BETWEEN HV/IV; HV/LV;IV/LV

VOLTAGE APPLIED VOLTAGE MEASURED

RATIOSITE/FACTORY

SPECIFIED

IR-N 1Y-N 1B-N 2R-N 2Y-N 2B-N

231.5 232.3 234 128.9 129.7 130.2 1.796/1.797

1.804/1.796

1.797/1.795

1.796

IR-N 1Y-N 1B-N 3R-3Y 3Y-3B 3B-3R

232.4 235.1 234.4 33.0 33.1 33.1 7.042/7.011

7.103/7.005

7.082/7.011

6.998

OIL TESTING• SAMPLE TO BE TESTED AND SHALL CONFIRM TO

IS 1866 BEFORE CHARGING

OIL SAMPLE

BDV MIN.

MOISTURE

TAN DELTA

RESISTIVITY

INTERF. TENSION

REMARKS

KV PPM 90 DEG C

OHM-CM DEG N/M

IS-1866 60 15 0.05 1X10 ^12 0.03 145KV ABOVE

IS-1866 50 20 0.05 1X10 ^12 0.03 145KV -72.5 KV

IS-1866 40 25 0.05 1X10 ^12 0.03 72.5KV BELOW

MAIN TANK

80KV 9 0.025 92.7 - TESTED 22.04.07

DISSOLVED GAS ANALYSIS

TO BE CHECKED

• JUST BEFORE CHARGING,

• JUST AFTER CHARGING,

• 24 HRS AFTER CHARGING,

• 7 DAYS AFTER CHARGING,

• 15 DAYS AFTER CHARGING.

PARAMETERS IN % OF TOTAL GAS IN PPM

• H2- 0.71,CH4-0.63,CO,CO2,C2H4,C2H6,C2H2,O2,N2 OTHER GASES NIL

SECONDARY WINDING RESISTANCE

• ALL CORES AND TAPPING CT WINDING RESISTANCE TO BE CHECKED

CORE BETWEEN TERMINAL

R -PH Y-PH B-PH

CORE 1 1S1-1S2 2.29 OHM 2.24 OHM 2.17 OHM

CORE 2 2S1-2S2 1.51 OHM 1.57 OHM 1.48 OHM

IR MEASUREMENT BUSHING CT

• IR MEASUREMENT WITH 500V MEGGER FOR HV, IV & LV & BETWEEN CORES OF BUSHINGS

• HV+IV TO E

BETWEEN HV G OHM, 39 DEG C

R PH Y PH B PH

EARTH- CORE-1 12.7 15.8 12.15

EARTH- CORE-2 16.8 17.3 14.8

EARTH- CORE-3 15.4 19.9 45.7

POLARITY TEST ON BUSHING CT

WITH 1.5 V DC CELL CONNECT + AT P1 AND – AT P2

CORE BETWEEN R-PH Y-PH B-PH

CORE 1 1S1( + )-1S2( - ) OK OK OK

CORE 2 2S1( + )-2S2( - ) OK OK OK

CURRENT RATIO TEST

• USE PRIMARY INJECTION KIT

CORE PRIMERY %

CURRENT

SEC CURRENT

RATED RATIO

ACTUAL RATIO

% ERROR

CORE-1 80 800A 0.794 1000/1 993/1 0.7

CORE-2 80 480 0.805 600/1 594/1 0.6

MAG CURVE OF BUSHING CT• NOT TO BE DONE FOR METERING CORES, KNEE

POINT VOLTAGE 1000V

APPLY VOL. ACTUAL VALUE

1S1-1S2 R PHmA

1S1-1S2 Y PHmA

1S1-1S2 B PHmA

0.25X KVP 250V 10.2 11.4 11.2

0.50X KVP 500V 17.4 13.6 16.0

0.75X KVP 750V 32.5 21.3 26.1

CAPACITANCE AND TAN DELTA BUSHING

• HEALTHINESS OF INSULATION. MEASURED FOR HV, IV & LV BUSHINGS

VOLTAGE

CAPACITENCE AT SITE PICO FARAD

CAPACITENCE AT WORKS PICO FARAD

R Y B R Y B

10KV ON HV

465 467 464 465 465 463

10KV ON IV

310 319 315 309 317 314

10KV ON LV

184 185 184 187 187 187

CAPACITANCE AND TAN DELTA BUSHING

• HEALTHINESS OF INSULATION. MEASURED FOR HV, IV & LV BUSHINGS

VOLTAGE

TAN DELTA AT SITE TAN DELTA AT WORKS

R Y B R Y B

10KV ON HV

0.0040 0.0039 0.0039 0.0033 0.0036 0.0032

10KV ON IV

0.0021 0.0023 0.0021 0.0018 0.0019 0.0020

10KV ON LV

0.0035 0.0034 0.0035 0.0033 0.0025 0.0027

CAPACITANCE AND TAN DELTA TRANSFORMER

• HEALTHINESS OF INSULATION. MEASURED FOR HV, IV & LV TRANSFORMER

VOLTAGE -10KV

CAPACITANCE IN PICO FARAD

TAN DELTA

SITE FACTORY SITE FACTORY

HV+IV/LV 6.801 0.005218

HV+IV/LV+G 14.81 0.004252

SHORT CIRCUIT IMPEDANCE TEST

• IT IS MEASURED BETWEEN HV/IV;IV/LV;HV/LV

TAP NO. IV OF R&N SHORTED, LV OPEN- R PH

IV OF Y&N SHORTED, LV OPEN – Y PH

IV OF B&N SHORTED, LV OPEN- B PH

V I V I V I

9 243 4.12 238 4.02 240 4.08

PROTECTION & ALARM

TO CHECK THE FOLLOWING PRESSURE RELIEF VALVE -7PSI, MAIN TANK BUCHHOLZ RELAY-ALARM & TRIP OLTC BUCHHOLZ RELAY-ALARM & TRIP OTI -ALARM AT 85 C, TRIP 100 C WTI -ALARM AT 95 C, TRIP 105 C COOLER FAN START 75 C OIL PUMP START 85 C

FREQUENCY RESPONSE ANALYSIS

• THIS DONE ON ALL WINDINGS HV, IV & LV AT DIFFERENT FREQUENCIES 10 TO 2000 HZ,100 TO 20000 HZ, AND 1000 TO 200000 HZ AND PLOTTED BETWEEN FREQUENCY AND DB

400KV CIRCUIT BREAKER

RATING OF 400KV SF6 CB

TYPE 3AT2 CB , BHEL HYD

BRAKING CAPACITY 40 KA

RATED NORMAL CURRENT- 2000A

OPERATING MECH- HYDRAULIC AND PNEUMATIC

SITE TESTS ON CB• CHECK PRESSURE OF N2 210 BAR IN R,Y,B PH

• PUMP RUNNING TIME 4.5 MIN FOR R, Y, B PH TO ATTAIN 345 BAR

• PUMP START AT 325 BAR

• AUTO RECLOSE LOCKOUT AT 300 BAR

• GENERAL LOCKOUT AT 253 BAR

• SF6 DENSITY MONITOR- ALARM 7.1 BAR, BLOCK 6.1 BAR, NORMAL 8.4 BAR

• CHECKED SF6 LEAKAGE IN 24 HRS- NIL

• CHECKED THE ANTI PUMPING CONTACTOR

SITE TESTS ON CB• CHECK TRIPPING CIRCUIT –OK

• CHECK CLOSING THROUGH CC-1 OK

• CHECK CLOSING THROUGH CC-2 OK

• ANTI PUMPING FEATURE- OK

• POLE DISCREPANCY FEATURE- OK

• BREAKER POSITION INDICATION- OK

• CHECK FOR ANNUNCIATION IN CONTROL ROOM

SITE TESTS ON CB• OIL PRESSURE DROP DURING OPERATION

R PH Y PH B PH

PRESSURE BEFORE OPERATION

325 325 325

PRESSURE AFTER OPERATION

315 315 315

PUMP RUNNING TIME

10 SEC 10 SEC 10 SEC

SITE TESTS ON CB• OPERATION TIME

R PH Y PH B P74H

BREAK I TRIP

27.2 29.3 29.7

BREAK 2 TRIP

27.3 29.1 29.7

CLOSE-I 78.6 74.2 74.9

CLOSE-2 78.6 74.7 76.9

SITE TESTS ON CB• COIL RESISTANCE MEASUREMENT IN OHM

R PH Y PH B PH

CLOSING COIL-I

79.66 80.37 79.48

CLOSING COIL-II

96.42 79.95 78.18

TRIPPING COIL-I

164.5 176.2 168.0

SITE TESTS ON CB• IR TESTING OF CONTROL CIRCUIT 500V MEGGAR

IN M OHM

R PH Y PH B PH

CLOSING COIL-I

34600 32200 23800

CLOSING COIL-II

25200 16700 20400

TRIPPING COIL-I

15500 21800 20800

SITE TESTS ON CB• IR TESTING OF CB WITH 5000V MEGGAR IN M

OHM

R PH WITH EARTH

Y PH WITH EARTH

B PH WITH EARTH

INTERRUPTER 1

214000 234000 115000

INTERRUPTER 2

505000 133000 115000

CAP & TAN DELTAINTERUPTER-1 INTERUPTER-2

CAPACITANCE

SITE 496.5 507.9 509.1 518.4 503.7 509.8

FACTORY

511 510.1 512.3 514.0 509.3 511.1

TAN DELTA

SITE 0.03484 0.0033 0.00245 0.00791 0.00935 0.00686

FACTORY

0.00133 0.00232 0.0011 0.00103 0.00072 0.00170

CONTACT RESISTANCE TESTDCRM KIT IS USED ,IT MEASURES COIL CURRENT, ARCING

CONTACT AND MAIN CONTACT RESISTANCE , SPEED OF TRAVEL

R Y B

ACROSS EACH POLE 92.6 71.5 84.1

ACROSS INTERRUPTER -1

55.4 59.1 59.4

ACROSS INTERRUPTER -2

68.5 55.3 85.6

VALUES ARE IN MICRO OHM

SITE TEST FOR ISOLATOR400KV , 2000A, ISOLATOR WITH MOTOR OPERATING

MECHANISM. TEST THE IR VALUE OF MOTOR WINDINGS TO

EARTH WITH 500V MEGGER – VALUES R PH- 2180, Y PH-2500, B-PH 730 MEGA OHM.

TEST THE IR VALUE OF ISOLATOR MALE SIDE CONTACT TO EARTH WITH 5000V MEGGER – VALUES R PH- 125000, Y PH-505000, B-PH 310000 MEGA OHM.

OPERATE THE ISOLATOR AND MEASURE THE MOTOR CURRENT- 0.83,0.87,0.93 AMPS. O/L SETTING AT 1.4

SITE TEST FOR ISOLATOR MEASUREMENT OF OPERATING TIME-

9.28,8.73,8.61 SEC FOR OPENING AND 9.06,8.83,8.17 FOR CLOSING 9.06,8.83,8.17 SEC.IT SHALL BE LESS THEN 12 SEC.

CONTACT RESISTANCE MEASUREMENT IN MICRO OHM-7.22, 12.43,27.2

OPERATION ON UNDER VOLTAGE. PICK UP 98%, DROP VOLTAGE 52% OF CLOSING , OPENING AND INTERLOCK COIL.

CHECK THE NO AND NC CONTACT OPERATION

SITE TEST FOR CT• RATING OF 400KV CT

• 2000A, 40KA FOR 1 SEC,5 CORES

• CORE 1 & 2 RATIO 2000-1000/1A, PS CLASS, KVP1000V, FOR BUS BAR PROTECTION

• CORE 3 -2000/1000/500/1 A,20 VA, 0.2

• CORE 4 & 5 RATIO 2000-1000-500/1A, PS CLASS, KVP 2000V, FOR DISTANCE PROTECTION

SITE TEST FOR CT• IR TEST –PERMITTED VALUES 400KV -400M OHM,

220KV 200M OHM

• CHECK PRIMARY WITH CORE-1,2,3,4,5& EARTH AND SEC CORE1,2,3,4,,5 WITH EARTH

R -PH Y-PH B-PH

P-CORE-1 20000 M OHM 15000M OHM 40000 MOHM

P- EARTH 20000 M OHM 15000M OHM 20000 MOHM

SEC CORE 1-EARTH

500 M OHM 500M OHM 5000 MOHM

SITE TEST FOR CT• POLARITY TEST – WITH 1.5 V CELL- OK

• SECONDARY WINDING RESISTANCE IN OHM

R -PH Y-PH B-PH

CORE5- 5S1-5S2 2.4 2.3 2.3

CORE5- 5S1-5S3 4.6 4.5 4.7

CORE5- 5S1-1S4 9.7 9.8 9.7

CAPACITANCE AND TAN DELTA CT

• HEALTHINESS OF INSULATION.

VOLTAGE

CAPACITENCE AT SITE PICO FARAD

CAPACITENCE AT WORKS PICO FARAD

R Y B R Y B

10KV 722.2 727.6 734.8 734.0 740.0 746.0

TAN DELTA

10KV 0.00185 0.00187 0.00185 0.0019 0.0019 0.0020

CURRENT RATIO TEST

• THROUGH PRIMARY INJECTION KIT MEASURE AT 20,40 AND 80% CURRENT FOR ALL CORES AND TAPINGS.

R Y B ERROR

CORE 1 1S1-1S2 AT 20 %

198 200 201

CORE 1 1S1-1S2 AT 40 %

406 406 406

CORE 1 1S1-1S2 AT 80 %

799 801 807

SITE TEST FOR CT• MAGNETIZING CURRENT IN mA TEST-TO BE

MEASURED AT 25,50,75,100,110 %R -PH Y-PH B-PH

CORE5- 5S1-5S2 AT 25%, 250V

6.6 7.4 9.5

CORE5- 5S1-5S2 AT 50%, 500V

9.8 10.6 14.1

CORE5- 5S1-5S2 AT 75%, 750V

13.8 14.6 20.2

SITE TEST FOR CVT

• 220KV CVT RATING :220KV,RATIO 220 KV/110 V BY ROOT 3,3 SECONDARY WINDING,

• SEC-1,2 , BURDEN 50VA, CLASS 3P

• SEC-3 , BURDEN 50VA, 0.2

CAPACITANCE AND TAN DELTA CVT

• HEALTHINESS OF INSULATION.

VOLTAGE

CAPACITENCE AT SITE PICO FARAD

CAPACITENCE AT WORKS PICO FARAD

R Y B R Y B

10KV 4395 4427 4382 NOT AVAILABLE

TAN DELTA

10KV 0.00311 0.00321 0.00294 NOT AVAILABLE

SITE TEST FOR CVT• IR TEST –PERMITTED VALUES 400KV -400M OHM,

220KV 200M OHM

• CHECK PRIMARY WITH SECONDARY CORE-1,2,3& EARTH

R -PH Y-PH B-PH

P- S CORE-1 5000 M OHM 5000M OHM 5000 MOHM

P-S CORE-2 10000 M OHM 5000M OHM 10000 MOHM

P-S CORE-3 10000 M OHM 5000M OHM 10000 MOHM

VOLTAGE RATIO TEST

• APPLY 230 V ON PRIMARY AND MEASURE THE VOLTAGE IN SECONDARY

SURGE ARRESTOR

• IR TEST WITH 5KV MEGGER :MEASURE IR VALUES OF EACH STACK

• TEST LEAKAGE CURRENT METER.

• TEST COUNTER READING AND ITS WORKING BY INJECTING 500V.

• TOTAL LEAKAGE CURRENT = CAP CURRENT + RESISTIVE CURRENT.

• RESISTIVE CURRENT MEASURE WITH THIRD HARMONIC. IF THIS CURRENT EXCEED 500MA, THE SA TO BE REPLACED.

RELAY TESTING

• INTERNAL PANEL WIRING CHECK

• EXTERNAL CABLES WIRING ,CONTINUITY TEST

• INDIVIDUAL RELAY TESTING AS PER RELAY SETTINGS,

• PRIMARY CURRENT INJECTION TESTING

• COMPLETE SCHEME TESTING

TOTAL SUB STATION

• CHECK THE IR VALUES BEFORE CHARGING

• CHECK THE EARTHING GRID RESISTANCE AS PER DESIGN.

• FIRE FIGHTING EQUIPMENT TO BE CHECKED AND TESTED. EMULSIFIER SYSTEM IS IN WORKING CONDITION

• GRAVEL SPREADING, DANGER PLATES, FENCING ,GATE ETC SHALL BE PROPER.

TOTAL SUB STATION

• BATTERY AND BATTERY CHARGERS ARE COMMISSIONED AND WORKING.

• AUXILIARY AC SYSTEM CONSISTING OF AUX. TRANSFORMER, HORN GAP FUSE, ACDB, LIGHTING SYSTEM ARE WORKING

• AIR CONDITIONING SYSTEM OF CONTROL ROOM/PLCC ROOM WORKING

TOTAL SUB STATION

• DG SET IS IN WORKING CONDITION

• LAYOUT DRAWINGS, EARTHING DRAWINGS, ROUTINE TEST REPORTS OF ALL EQUIPMENTS, SITE TEST REPORTS, EARTHING MEASUREMENT REPORTS ARE SUBMITTED TO ELECTRICAL INSPECTOR

TOTAL SUB STATION

• CHARGES FOR ELECTRICAL INSPECTOR AGENCY TO BE PAID

• ELECTRICAL INSPECTORS GIVES COMMENTS /CHARGING PERMISSION

• SUB STATION CHARGED

THANK YOU