nigerian electricity management services agency - …

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NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY

INSPECTORATE FIELD OFFICE, KADUNA, KADUNA STATE

REPORT ON INSPECTION AND TESTING OF 2X60MVA, 132/33KV SUBSTATION KUDENDA, KADUNA

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NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY

INSPECTORATE FIELD OFFICE, KADUNA

INSPECTION AND TESTING OF 2 X 60MVA, 132/33KV SUBSTATION AT KUDENDA, KADUNA

BETWEEN 10TH – 12TH DECEMBER, 2018

CLIENT: Federal Ministry of Power

CONTRACTOR: SKIPPERSEIL LIMITED

CONSULTANT: SEWA

INSPECTING/TESTING AUTHORITY: Nigerian Electricity Management Services Agency (NEMSA)

INTRODUCTION:

The inspection and testing of a 2x60MVA 132/33kV transmission substation was carried out between Monday

10th and Wednesday 12th December 2018 by NEMSA’s team of Engineers and technical officers led by the

Managing Director/CEO and Chief Electrical Inspector of the Federation. The following were in attendance;

ATTENDANCE:

S/NO NAME ORGANISATION DESIGNATION E-MAIL PHONE 1 ENGR. PETER O. EWESOR NEMSA HQ MD/CEO &CEIF [email protected] 08036745149

2 ENGR. ALIYU TUKUR NEMSA HQ GM(TSIS) HQTRS [email protected] 08033493741

3 Engr. William C. Metieh NEMSA HQ SA [email protected] 08033288754

4 Engr. U.O Momoh NEMSA HQ PM(TS&IS) [email protected] 08059234975

5 Engr. Simon T.Y NEMSA HQ SM(TS&IS) [email protected] 08036312808

6 Engr. E.I Alobo NEMSA KD IFO AIE(Kaduna) [email protected] 07035866084

7 Engr. Mubarak Gidah NEMSA KD IFO ASSISTANT MANAGER [email protected] 08034645780

8 Tijjani B.Abiso NEMSA KD IFO [email protected] 07032202637

9 Junaidu Abdullahi NEMSA KD IFO OFFICER II 07034203666

10 Engr. Shehu Magaji NEMSA KD IFO OFFICER III 08021140828

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11 Engr. Ogboma Augustine SeWa (Consultant) [email protected] 08032949281

12 Ishaya Zee SeWa (Consultant) [email protected] 07031146874

13 Engr George Tambe SeWa (Consultant) [email protected] 08179689174

14 Engr. O. Joshua SKIPPER SEIL [email protected] 08066139421

15 Engr. Ahmed Asekun SKIPPER SEIL [email protected] 08053204862

16 Niranjan Gupta SKIPPER SEIL [email protected] 09075921337

17 E. siva Rama K. SKIPPER SEIL [email protected] 09078142609

18 Haidi Singh SKIPPER SEIL [email protected] 07059331377

PROJECT DESCRIPTION:

Client: Federal Ministry of Power, Works & Housing

Project consultant: SeWa West Africa Ltd.

Project contractor: Skipper Electricals Ltd

Transformer Capacity 2X60 MVA 132/33KV

132KV Incoming Feeder Two (2)

Source I of 132KV Feeder Gurara Hydropower plant

Source II of 132KV Feeder New power plant under construction

33KV Outgoing Feeder Six (6) (Four outgoings and two spares)

OBJECTIVE OF PROJECT:

The project aim and objective is to improve the efficiency and quality of electricity supply to Kaduna

Industrial Estate.

mailto:[email protected]








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SUMMARY OF OBSERVATIONS AND RECOMMENDATIONS REQUIRING URGENT ATTENTION

The summary of our observations and recommendations requiring urgent attention include:

1. There are no Phase indicators on the gantries and all the line equipment. This is dangerous and

unsafe for operation. Phase indication should be provided on top of gantries, on line equipment, by the

bus bars, etc.

2. Some bolts were too short and not providing adequate grip for the structures. Bolts used should be

long enough to provide proper tightening/grip. All bolts should be replaced with longer bolts and

adequately tightened.

3. Some bolts and nuts were completely missing and may impair the stability of the steel support

structures. A careful overview of all the support structures/gantries should be carried out to identify any

other missing bolts and nuts which should be replaced with appropriate galvanized bolts/nuts/washers.

4. Some earth switches at the 33kV side were not closing and some contacts of those closing were not

latching properly. This is major issue that should be adequately rectified for safety of operations. Earthing

switches should be adjusted for correct and safe operations.

5. Bent arcing spike on one isolator. Bent arcing spike should be straightened.

6. Loose earth continuity conductor not properly terminated on the steel structure. Loose earth continuity

conductor should be cable lugged and properly terminated on the steel structure.

7. A few broken cable lugs were seen in the switchyard. This could lead to failure of electrical continuity.

All broken cable lugs should be replaced.

8. Rusted bolts/nuts were also seen. All rusted bolts/nuts should be replaced with galvanized type. All

rusted bolts/nuts should be replaced with galvanized type.

9. All the switchyard equipment including marshalling kiosks, control panels, circuit breakers, isolators,

transformers, etc have not been labeled for ease of identification. This is not acceptable and can lead to

confusion during operations. All switchyard equipment should be appropriately labeled with same

nomenclature as in the control panels inside the control room and the HMI.

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10. Many nuts and bolts seen rusted as they were not galvanized. Over time these will degrade and

oxidize away. All bolts, nuts and washers should be replaced with galvanized types.

11. Cable entries not filled in. All cable entries inside PVC pipes should be filled up with urethane foam or

compound.

12. Nut not tightened on the control panel support. Nuts should be tightened for firmness of the steel

supports.

13. The wave traps have not been connected to the incoming line. Prior to putting into use, the wave

traps should be adequately and appropriately connected.

14. Unused gland holes seen in several panels, and lizards were seen in some. This will also allow

ingress of moisture / dust into the panels causing corrosion and contactors to fail. All unused gland holes

should be adequately plugged to prevent ingress of dust and moisture and access to reptiles/rodents.

15. Transformer T1 has not been provided with any form of earthing on its frame. The frame of the

transformer should be adequately earthed with earth resistance value of 2 Ohms or less.

16. The termination of the neutral of transformer 2 on the bushing is loose (not tight). Appropriate lugs

and plates should be used to terminate the neutral to have a firm contact.

17. Oil was seen seeping from the transformers flanges. Although tightened, some slight leakage

persists. Oil leakages should be stopped by tightening the flanges and if need be replacing the gaskets.

18. Unused gland holes seen in several panels, and lizards were seen in some. This will also allow

ingress of moisture / dust into the panels causing corrosion and contactors to fail. All unused gland holes

should be plugged to protect the terminals from corrosion and dust and prevent access to rodents and

reptiles.

19. The cooling fans on one side of the 60MVA transformers are offset and covering only part of the fins.

This appears to be due to wrong positioning of the foundations for the fans. Appropriate brackets should

be constructed to make the fans cover fully the transformer cooling fins.

20. Steel support structure for the station transformer not galvanized and showing signs of rust. The

steel supports for the J&P fuses should be made of galvanized steel.

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21. J&P fuses seen installed between transformer and down-drop cable. This is not safe for operation.

The J&P fuses should be installed on the opposite side of current position for safety of operations.

22. Station transformers were seen fused with J&P fuses. This is not standard practice as the fuses

could rupture and put the station operations in jeopardy. The station transformers should be connected

directly to the 33kV supply.

23. Remnants of the cut off steel supports and unused earth conductors left dangerously exposed in the

switchyard. This should be address properly.

24. There is an opening to the outside from the control room allowing rain water into the control room,

and free access to reptiles/rodents. The control room should be sealed off from the outside to prevent

storm water and entry of reptiles and rodents.

25. Too many cables lumped together on one cable tray which has caused section of it to collapse. Also,

some cables have been pulled too tightly against the edge of the cable trench. This could cause internal

damage to the cables in time. The cable tray should be adequately supported and cables should be re-

arranged to prevent mechanical damage to the conductors.

26. Cables trench was seen rusted indicating that they are not galvanized. Galvanized cable trenches

should be use.

27. Gap between the tower base and the pillar surface was observed. All gaps between the tower base

and the pillar surface must be grouted.

28. Street light poles were seen planted on an erosion path. Erosion path along the street light should

be control.

29. Standby generator of 100KVA capacity was not earthed. Generator main frame (body) should be

appropriately earthed.

30. The water tank steel structure was not earthed. The water tank steel support should be properly

earthed.

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31. Control room spacious; good working environment, clean and well air conditioned. However, the

HMI has not been installed, and the SCADA has not been fully pre-commissioned. All control workstations

and SCADA should be installed and commissioned.

32. Cable labeling has not been adequately provided. This will be a maintenance nightmare as it will be

difficult to identify the cables in case of fault finding. All cables should be adequately labeled/ identified at

both ends as a minimum.

33. Name plate shows 415/240Volts but A/C control voltage indicates 230 Volts. Medium/Low voltage

system in Nigeria is 415/240Volts.

34. The batteries were in deplorable condition with acid spill seen all over the battery banks. Use of lead

acid batteries with leakages is unsafe/dangerous and the conductive links were not insulated. NiCad or

AlCad sealed batteries should be provided and all terminal links should be insulated.

35. Use of lead acid batteries has consequent maintenance challenges. Preferably use NiCad or Alcad

sealed batteries.

36. Appropriate fire extinguishers with long expiry dates have been provided but the quantities need to

be increased for better adequacy. More fire extinguishers should be provided in the control room and

around the switchyard.

37. Inadequate safety signs on the perimeter fence, gates and the substation generally. Adequate and

appropriate safety signs should be provided all over the substation.

38. Control room entrance door was seen not earthed. Control room entrance doors should be

grounded.

39. 132KV tie R2 protective glass was seen missing. The glass should be replaced immediately.

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OBSERVATIONS WITH PICTURES AND RECOMMENDATIONS:

Our observations and recommendations are as follows:

S/N.

PROJECT AREA

OBSERVATIONS PICTORIAL VIEW OF ITEM RECOMMENDATIONS

1. SWITCH

YARD 1.1

There are no Phase indicators on the gantries and all the line equipment. This is dangerous and unsafe for operation.

Phase indication should be provided on top of gantries, on line equipment, by the busbars, etc.

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1.2 Some bolts were too short and not providing adequate grip for the structures.

Bolts used should be long enough to provide proper tightening/grip. All bolts should be replaced with longer bolts and adequately tightened.

1.3 Some bolts and nuts

were completely missing and may impair the stability of the steel support structures

A careful overview of all the support structures/gantries should be carried out to identify any other missing bolts and nuts which should be replaced with appropriate galvanized bolts/nuts/washers.

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1.4 Some earth switches at

the 33kV side were not closing and some contacts of those closing were not latching properly. This is major issue that should be adequately rectified for safety of operations. See picture 1.5 below.

Earthing switches should be adjusted for correct and safe operations.

1.5 See comment in picture

1.4

Earthing switches should be adjusted for correct and safe operations.

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1.6 Bent arcing spike on one isolator.

Bent arcing spike should be straightened.

1.7 Loose earth continuity

conductor not properly terminated on the steel structure.

Loose earth continuity conductor should be cable lugged and properly terminated on the steel structure.

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1.8 i. A few broken cable lugs were seen in the switchyard. This could lead to failure of electrical continuity. ii. Rusted bolts/nuts were also seen.

All broken cable lugs should be replaced. ii. All rusted bolts/nuts should be replace with galvanized type.

1.9 All the switchyard

equipment including marshalling kiosks, control panels, circuit breakers, isolators, transformers, etc have not been labeled for ease of identification. This is not acceptable and can lead to confusion during operations.

All switchyard equipment should be appropriately labeled with same nomenclature as in the control panels inside the control room and the HMI.

13

1.10 Many nuts and bolts seen rusted as they were not galvanized. Over time these will degrade and oxidize away.

All bolts, nuts and washers should be replaced with galvanized types.

1.11 i. Cable entries not filled in. ii. Nut not tightened on the control panel support.

i. All cable entries inside pvc pipes should be filled up with urethane foam or compound. ii. Nuts should be tightened for firmness of the steel supports.

14

1.12 The wave traps have not been connected to the incoming line.

Prior to putting into use, the wave traps should be adequately and appropriately connected.

15

1.13 Unused gland holes seen in several panels, and lizards were seen in some. This will also allow ingress of moisture / dust into the panels causing corrosion and contactors to fail.

All unused gland holes should be adequately plugged to prevent ingress of dust and moisture and access to reptiles/rodents.

1.14 Transformer T1 has not been provided with any form of earthing on its frame.

The frame of the transformer should be adequately earthed with earth resistance value of 2 Ohms or less.

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1.15 The termination of the neutral of transformer 2 on the bushing is loose (not tight).

Appropriate lugs and plates should be used to terminate the neutral to have a firm contact.

1.16 Oil was seen seeping from the transformers flanges. Although tightened, some slight leakage persists.

Oil leakages should be stopped by tightening the flanges and if need be replacing the gaskets.

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1.17 Unused gland holes seen in several panels, and lizards were seen in some. This will also allow ingress of moisture / dust into the panels causing corrosion and contactors to fail.

All unused gland holes should be plugged to protect the terminals from corrosion and dust and prevent access to rodents and reptiles.

1.18 The cooling fans on one side of the 60MVA transformers are offset and covering only part of the fins. This appears to be due to wrong positioning of the foundations for the fans.

Appropriate brackets should be constructed to make the fans cover fully the transformer cooling fins.

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1.18 i. Steel support structure for the station transformer not galvanized and showing signs of rust. ii. J&P fuses seen installed between transformer and down-drop cable. This is not safe for operation.

i. the steel supports for the J&P fuses should be made of galvanized steel. ii. The J&P fuses should be installed on the opposite side of current position for safety of operations.

1.19 Station transformers were seen fused with J&P fuses. This is not standard practice as the fuses could rupture and put the station operations in jeopardy.

The station transformers should be connected directly to the 33kV supply.

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1.20 Control pole for earthing switch is not galvanized steel type as it was observed Rusted.

The pole should be replaced with galvanized steel type.

1.21 Control cables were seen exposed under the control panel at the switch yard with the cable ducts open.

The cables laid under the panel must be covered to prevent intrusion of reptiles and rodents.

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1.22 Earthing conductor was reduced to fit into the cable lug and the loose strands twisted around it.

Appropriate size of earthing conductor should be used without removing any strands.

1.23 It was observed that the Silica gel in the breather of Transformer one was not full and it is already getting saturated.

Silica gel should be replaced with fresh ones and of adequate quantity.

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1.24 Rusted meter casing was observed for the surge arrester counter. This will result in water entering resulting in damage of the counter

The meter casing should be replaced with a good one or painted with antirust to prevent further rusting.

1.25 Earthing conductor was seen not connected to the gantry.

Earthing conductor must be properly connected to the tower.

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1.26 Insufficient clearance was observed between one of the newly constructed 33kV O-H line feeders and the lighting steel pole column for security light of the transmission switchyard. This is dangerous and unsafe especially during maintenance of the lighting columns.

Ensure sufficient clearance between 33KV line and the lighting steel pole column for security light.

1.27 Bolts and nuts were observed not fixed.

Bolts and nuts must be fixed to ensure all members of the gantry structure are firm.

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1.28 Manual operating kiosk for Isolator control panel was observed with an open hole at the side. This can allow in rain water which can affect the operation.

The hole should be plugged.

1.29 Trench covers seen were well-constructed and well laid out.

Good

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1.30 There is an opening to the outside from the control room allowing rain water into the control room, and free access to reptiles/rodents.

The control room should be sealed off from the outside to prevent storm water and entry of reptiles and rodents.

1.31 i. Too many cables lumped together on one cable tray which has caused section of it to collapse. ii. Also, some cables have been pulled too tightly against the edge of the cable trench. This could cause internal damage to the cables in time.

i. The cable tray should be adequately supported. ii. Cables should be re-arranged to prevent mechanical damage to the conductors.

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2. Utilities 2.1 Generator House

Standby generator was not earthed.

i. Generator main frame (body) should be appropriately earthed

2.2 Water

Tank The water tank steel structure was not earthed.

The water tank steel support should be properly earthed.

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3.

Conformance Tests

Ratio tests were carried out on the two (2) 132/33kV 60MVA Transformers and the readings recorded in Table 2. Transformers are standard.

4. Control

Room 4.1

Control room is standard, with adequate spacing between panels.

Okay

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4.2 i. Control room spacious; good working environment, clean and well airconditioned. ii. However, the HMI has not been installed, and the SCADA has not been fully precommissioned.

All control workstations and SCADA should be installed and commissioned.

4.3 Panels were adequately

earthed. Also, the trench covers were adequately earthed.

Okay

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4.4 Cable labeling has not been adequately provided. This will be a maintenance nightmare as it will be difficult to identify the cables in case of fault finding.

All cables should be adequately labeled/identified at both ends as a minimum.

4.5 Name plate shows

415/240Volts but A/C control voltage indicates 230 Volts

Medium/Low voltage system in Nigeria is 415/240Volts

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5. Battery room 5.1

i. The batteries were in deplorable condition with acid spill seen all over the battery banks. ii. Use of lead acid batteries with leakages is unsafe/dangerous. iii. the conductive links were not insulated.

i. NiCad or AlCad sealed batteries should be provided. ii. All terminal links should be insulated.

5.2 Use of lead acid

batteries has consequent maintenance challenges.

Preferably use NiCad or Alcad sealed batteries.

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6. Safety Equipment

Appropriate fire extinguishers with long expiry dates have been provided but the quantities need to be increased for better adequacy.

More fire extinguishers should be provided in the control room and around the switchyard.

6.2 Inadequate safety signs

on the perimeter fence, gates and the substation generally.

Adequate and appropriate safety signs should be provided all over the substation.

GENERAL OBSERVATIONS

1. The 2x60MVA 132/33 TCN transmission substation at Kudenda, Kaduna, Kaduna State is largely well constructed

with quality/standard equipment and materials. The substation is well laid out with adequate system protection and

monitoring devices in place. The protection system was demonstrated and found satisfactory.

2. Alignment issues with some of the isolators during functional tests were rectified and the interlock of the earth

switches and the relevant isolators have been rectified.

3. Most of the observations pointed out to the contractors were promptly attended to and closed out before we left

the site.

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CONCLUSION

Please note that the inspection and certification of the 2x60MVA 132/33kV TCN transmission substation at Kudenda,

Kaduna, Kaduna State have been carried out in line with NEMSA Act 2015. You are to make the necessary payment of

inspection fees** of ONE MILLION, TWO HUNDRED THOUSAND NAIRA ONLY (N1,200,000.00) ONLY into TSA/CBN/

NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY ACCOUNT CBN/NEMSA/IS-KDN/…………………….

Signed by:

INSPECTING /TESTING AUTHORITY: NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY………………………………….DATE……………..

NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY………………………………….DATE……………..

CONTRACTOR: SKIPPERSEIL LIMITED, ABUJA:…………………………..……………………………………………….DATE……………….………………………….

NOTES: (i) THIS IS NOT A CERTIFICATE (ii) Inspection Fees based on Substation Capacity of 120MVA.

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FUNCTIONAL CHECKS LINE ONE (1)

EQUIPMENT OPERATION OK NOT OK REMARK

Isolator Manual OK Satisfactory Electrical OK Satisfactory

Circuit Breaker Manual OK Satisfactory Electrical OK Satisfactory


Earthing Switch Manual NOT OK Need to be greased and aligned.

LINE TWO (2)

EQUIPMENT OPERATION OK NOT OK REMARK Isolator Manual OK Satisfactory

Electrical OK Satisfactory Circuit Breaker Manual OK Satisfactory

Electrical OK Satisfactory


Earthing Switch Manual NOT OK Need to be greased and aligned.

CONCLUSION

Please note that the inspection and certification of the 2x60MVA 132/33kV TCN transmission substation at Kudenda,

Kaduna, and the 132kV transmission substation bay extension at Mando, Kaduna, Kaduna State have been carried out

in line with NEMSA Act 2015. You are to make the necessary payment of inspection fees** of ONE MILLION, TWO

HUNDRED THOUSAND NAIRA ONLY (N1,200,000.00) ONLY into TSA/CBN/ NIGERIAN ELECTRICITY MANAGEMENT

SERVICES AGENCY ACCOUNT CBN/NEMSA/IS-KDN/…………………….

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Signed by:

INSPECTING /TESTING AUTHORITY: NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY………………………………….DATE……………..

NIGERIAN ELECTRICITY MANAGEMENT SERVICES AGENCY………………………………….DATE……………..

CONTRACTOR: SKIPPERSEIL LIMITED, ABUJA:…………………………..……………………………………………….DATE……………….………………………….

NOTES: (i) THIS IS NOT A CERTIFICATE (ii) Inspection Fees based on Substation Capacity of 120MVA.

APPENDIX 1: KUDENDA SUB-STATION TRANSFORMERS DETAILS

KUDENDA 2 X 60MVA, 132/33KV SUB-STATION TRANSFORMERS

Table : 1-Transformer Details

DESCRIPTION TRANSFORMER I TRANSFORMER II Make SKIPPER ELECTRICALS INDIA

LTD SKIPPER ELECTRICALS INDIA LTD

Serial No. 51200128644 51200128645

Rated Power 60MVA 60MVA Rated voltage 132/33Kv 132/33kV

Rated current 262.4/1049.7A 262.4/1049.7A

Year of Manufacture 2012 2012

% Impedance 10.16 10.16

Mode of Cooling ONAN ONAN Frequency 50Hz 50Hz

Insulation Level ??? ???

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Vector Group Ynd11 Ynd11

Country of manufacture INDIA INDIA

KUDENDA SWITCHYARD STATION SERVICE TRANSFORMER AND REACTORS/EARTHING TRANSFORMERS.

Table : 2-Transformer Details

DESCRIPTION STATION SERVICE TRANSFORMER I

EARTHING TRANSFORMER I

EARTHING TRANSFORMER II

Make SKIPPER ELECTRICALS INDIA LTD

SKIPPER ELECTRICALS INDIA LTD

SKIPPER ELECTRICALS INDIA LTD

Rated Power 300KVA 300KVA 300KVA

Rated Voltage 33/415KV 33000V 33000V Year of Manufacture

2012 2012 2012

Serial Number 5120012115 5120012118 5120012117

Mode of Cooling ONAN ONAN ONAN Frequency 50Hz 50Hz 50Hz

Vector Group Dyn11 ZN0 ZN0 Percentage Impedance

5.89% 5.25% 5.25%

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APPENDIX 2: KUDENDA TRANSFORMER RATIO TESTS

T1-60MVA TRANSFORMER

NAME OF TRANSFORMER: T1 SERIAL NO: 51200128644 %IMPEDANCE: 10.16

YEAR OF MANUFACTURE: 2012 AS MET TAP: ………… NOMINAL TAP: 5

Table: 3.1-Transformer windings Insulation Resistance Results

Instrument used: 10KV insulation Megger.

HV – G 41.9GΩ 244nA

LV – G 49.7GΩ 103nA

HV – LV 47.4GΩ 216nA

Table: 3.2 -RATIO TEST (WITHOUT NUETRAL)

TAP POSITION

Voltage High/Low PRIMARY (V) SECONDARY (V) MAGNETIZING CURRENT (mA)

36

AB BC CA ab bc ca A B C

5 Nominal 132,000 33,000 392 394.5 388 99.0 97.7 96.9 2.4 1.4 1.8

Table: 3.3-SHORT CIRCUIT TEST

Tap Position PRIMARY APPLIED VOLTAGE (V)

PRIMARY MEASURED CURRENT(A)

I(SHORT CIRCUIT CURRENT) (A)

R-Y Y-B B-R IR IY IB Ir Iy Ib

5 (NOMINAL TAP)

384 382 383 7.4 7.1 7.1 27.3 27.8 29.8

REMARKS: OKAY

Table: 3.4-MAGNETIC BALANCE TEST (HV) T1

R-N (VOLTS) Y-N (VOLTS) B-N (VOLTS)

390.0 311.4 77.4

184.3 391.0 206.9

53.8 328.2 382.0

REMARKS: OKAY

Table: 3.5-MAGNETIC BALANCE TEST (LV) T1

R(b-r) Y(r-y) B(y-b) I(mA)

388.7 205.4 183.2 17.6

298.9 389.6 90.1 18.6

232.5 153.7 387.2 17.6

REMARKS: OKAY

37

Table: 3.6-MAGNETIC CURRENT TEST (LV)

r-y y-b b-r Remarks

Voltage (V) 387 390 382 OKAY

Current (mA) 18.4 20.1 28.6 OKAY

T2-60MVA TRANSFORMER

NAME OF TRANSFORMER: T2 SERIAL NO: 5120012865 %IMPEDANCE: 10.16

YEAR OF MANUFACTURE: 2012 AS MET TAP: ……………… NOMINAL TAP: 5

Table: 4.1-INSULATION RESISTANCE TESTS

Instrument used: 10KV insulation Megger

HV – G 35.6GΩ 287nA

LV – G 27.8GΩ 184nA

HV – LV 21.6GΩ 474Na

REMARKS: OKAY

Table: 4.2-RATIO TEST (WITHOUT NEUTRAL)

TAP POSITION

PRIMARY (V) SECONDARY (V) MAGNETIZING CURRENT (mA)

38

AB BC CA ab bc ca A B C

5 Nominal 132,000 33,000 377 380 370 96.5 94.8 94.0 1.6 1.7 2.2

REMARK: OKAY

Table: 4.3-SHORT CIRCUIT TEST T2

Tap Position PRIMARY APPLIED VOLTAGE (V)

PRIMARY MEASURED CURRENT(A)

I (SHORT CIRCUIT CURRENT) (A)

R-Y Y-B B-R IR IY IB Ir Iy Ib

5 (NORMINAL TAP)

384 382 383 7.4 7.7 7.1 29.3 29.8 29.8

REMARKS: OKAY

Table: 4.4-MAGNETIC BALANCE TEST (HV) T2

R-N (VOLTS) Y-N (VOLTS) B-N (VOLTS)

390.0 311.4 77.4

184.3 391.0 206.9

53.8 328.2 382.0

REMARKS: OKAY

Table: 4.5-MAGNETIC BALANCE TEST (LV) T2

R(b-r) Y(r-y) B(y-b) I(mA)

379 190 187 18.5

281 380 98 23.9

100 277 379 24.5

39

REMARKS: OKAY

Table: 4.6-MAGNETIC CURRENT TEST (LV)

r-y y-b b-r Remarks

Voltage (V) 379 382 373 OKAY

Current (mA) 23.1 21.4 30.8 OKAY

T3-300KVA TRANSFORMER

NAME OF TRANSFORMER: STATION SERVICE TRANSFORMER I SERIAL NO: 5120012115 %IMPEDANCE:

5.89

YEAR OF MANUFACTURE: 2012 AS MET TAP: 3 NOMINAL TAP: 3

Table: 5.1-INSULATION RESISTANCE TEST. (AUXILLARY TRANSFORMER)

Equipment Used: 10KV INSULATION MEGGER TESTER

TRANSFORMER CONNECTION:

OHMS LEAKAGE CURRENT

HV-G 128GΩ 49.5nA

LV-G 102GΩ 52.7nA

HV-LV 134GΩ 41.6nA

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REMARKS: OKAY

Table: 5.2-SINGLE PHASE RATIO TEST.

Equipment Used: M8037 Megger Multi-meter and single-phase generator

S/N. Phase Connection

R-Y

Y-B

B-R

r-y

y-b

b-r

r-n

y-n

b-r

Auxiliary Transformer (5120012115)

Red-Yellow 229.6 182.1 44.6 2.9 1.0 1.9 1.6 1.3 0.3

Yellow-Blue 110.6 230.2 116.6 2.4 2.4 0.1 0.7 1.6 0.8

Blue-Red 37.6 189.1 225.3 1.0 2.9 1.9 0.2 1.3 1.6

Table: 5.2-EXCITATION CURRENT-CONTINUITY TEST

Equipment Used Multi-meter, Clamp meter and single-phase generator

CONNECTION At LV Side

LV MEASURED VALUES (VOLTAGE) EXCITATION CURRENT MEASURED (AMPS)

r-n

y-n

b-n

r-y

y-b

b-r

5120012115

r-n 234.2 153.0 84.7 384.4 77.6 316.3 3.9

y-n 117.9 235.5 118.7 351.2 356.2 2.0 2.7 b-n 85.5 153.1 234.7 78.2 385.3 317.2 3.8

T4-300KVAR TRANSFORMER

41

NAME OF TRANSFORMER: EARTHING TRANSFORMER I SERIAL NO: 5120012118 %IMPEDANCE: 5.25

YEAR OF MANUFACTURE: 2012 AS MET TAP: NOMINAL TAP:

Table: 6.-INSULATION FOR GROUNDING TRANSFORMER.




R-G 13.86GΩ 369nA

Y-G 11.78GΩ 435nA

B-G 15.08GΩ 340nA

r-g 10.20GΩ 243nA

y-g 9.70GΩ 357nA

b-g 13.60GΩ 231nA

T5-300KVAR TRANSFORMER

NAME OF TRANSFORMER: EARTHING TRANSFORMER I1 SERIAL NO: 5120012117 %IMPEDANCE:5.25

YEAR OF MANUFACTURE: 2012 AS MET TAP: NOMINAL TAP:

Table: 7-INSULATION FOR GROUNDING TRANSFORMER.




R-G 13.86GΩ 369nA

Y-G 11.78GΩ 435nA

B-G 15.08GΩ 340nA

42

r-g 10.20GΩ 243nA

y-g 9.70GΩ 357nA

b-g 13.60GΩ 231nA

APPENDIX 3: EARTH RESISTANCE TEST VALUES

TRANSFORMERS, GANTRIES AND OTHER EQUIPMENT

Equipment Used: DET4TC2 Digital Megger Earth Resistance Test equipment. Table: 8- Earth Resistance Values UNITS TESTED RESISTANCE VALUES (Ω) REMARK

TRANSFORMER 1 60MVA - No transformer body earth-link

TRANSFORMER 2 60MVA 1.08 Okay

GROUNDING TRANSFORMER 1 2.0 Okay GROUNDING TRANSFORMER 2 2.0 Okay AUXILLARY TRANSFORMER 2.0 Okay TOWER 1 0.81 Okay TOWER 2 0.96 Okay TOWER 3 0.77 Okay

43

TOWER 4 0.87 Okay TOWER 5 1.26 Okay TOWER 6 1.26 Okay TOWER 7 1.26 Okay TOWER 8 1.45 Okay TOWER 9 1.45 Okay TOWER 10 1.45 Okay TOWER 11 0.6 Okay TOWER 12 0.6 Okay ISOLATOR 1 (132KV LINE) 1.26 Okay ISOLATOR 2 1.27 Okay ISOLATOR 3 1.25 Okay ISOLATOR 4 1.20 Okay ISOLATOR 5 1.20 Okay ISOLATOR 7 1.50 Okay CT 1 1.26 Okay CT 2 0.76 Okay CT 3 0.25 Okay CT 4 1.25 Okay CT 5 1.26 Okay CT 6 1.45 Okay CT 7 1.45 Okay ISOLATOR 1 (33KV FEEDER LINE) 1.25 Okay ISOLATOR 2 1.27 Okay ISOLATOR 3 0.60 Okay ISOLATOR 4 0.60 Okay ISOLATOR 5 1.25 Okay ISOLATOR 7 1.27 Okay VT 1 0.80 Okay VT 2 0.80 Okay VT 3 0.78 Okay

44

VT 4 0.79 Okay VT 5 0.73 Okay VT 6 0.30 Okay VT 7 0.30 Okay

APPENDIX 4:

Table: 9-ISOLATORS/CIRCUIT BREAKERS DETAILS/ FUNCTIONAL TEST

MAKE R.K. ENGINEERS

VOLTAGE 110V DC

SERIAL NO.

YEAR OF MANF. 2011/2012

ISOLATOR S/NO. LINE (132KV) FUNCTIONAL TEST REMARK

ISOLATOR M-712 LINE 1 Manual & Electrical OKAY



CIRCUIT

BREAKER

1HSBO1333096 LINE 1 Electrical OKAY

ISOLATOR M-709 LINE2 Manual & Electrical OKAY

45



CIRCUIT

BREAKER

1HSBO1333093 LINE2 Electrical OKAY

ISOLATOR M-706 LINE1&2 TIE Manual & Electrical Need alignment (Red

phase), greasing

ISOLATOR M-720 LINE1&2 TIE Manual & Electrical Line 1& 2 need alignment

CIRCUIT

BREAKER

1HSBO1333097 LINE1&2 TIE Electrical OKAY

ISOLATOR M-693 TRANSFORMER 1 Manual & Electrical OKAY



CIRCUIT

BREAKER

1HSBO1333098 TRANSFORMER 1 Electrical OKAY




CIRCUIT

BREAKER


ISOLATOR M-711 T1&T2 TIE Manual & Electrical OKAY

ISOLATOR M-696 T1&T2 TIE Manual & Electrical OKAY

CIRCUIT

BREAKER


Table: 11-132KV CIRCIUT BREAKER DETAILS

S/N YEA

R

TYPE VOLT CURRENT FREQ IS SHORT

CCT BRK.

CURRENT

SHORT CCT.

WITHSTAND

CURRENT

SHORT

CCT.

MAKING

CURRENT

1HSB01333096 2013 LTB145D1/ 132kV 2000A 50Hz ≤1000m 40kA 40kA 3s 1000kA

46

B

1HSB01333095 2013 LTB145D1/

B

132kV 2000A 50Hz ≤1000m 40kA 40kA 3s 1000kA

1HSB01333093 2013 LTB145D1/

B

132kV 2000A 50Hz ≤1000m 40kA 40kA 3s 1000kA

1HSB01333099 2013 LTB145D1/

B

132kV 2000A 50Hz ≤1000m 40kA 40kA 3s 1000kA

1HSB01333097 2013 LTB145D1/

B

132kV 2000A 50Hz ≤1000m 40kA 40kA 3s 1000kA

1HSB01333098 2013 LTB145D1/

B

132kV 2000A 50Hz ≤1000m 40kA 40kA 3s 1000kA

Table: 12- 33KV CIRCUIT BREAKER DETAILS.

Make ABB

Current 1250 A

Voltage 36 V

Freq. 50Hz

Insulation Level 70 kV/170kV Peak

Short circuit break current 25 kA rms

Short circuit making current 62.5 kA Peak

Short circuit withstand current 25 kA

Closing / Opening supply voltage. 110 V DC

Table: 12.1: LINE 1 FEEDER BY T2 (33KV LINES)

FEEDER 1 S/N FUNCTIONAL TEST REMARK

ISOLATOR - MANUAL & ELECTRICAL OKAY

47

CIRCUIT BREAKER 1VYNO30117000140 ELECTRICAL OKAY

FEEDER 2


CIRCIUT BREAKER 1VYNO30117000138 ELECTRICAL OKAY

FEEDER 3



Table: 12.2: LINE 2 FEEDER BY T2 (33KV LINES)

FEEDER 4 S/N FUNCTIONAL TEST REMARK



FEEDER 5


CIRCIUT BREAKER 1VYNO30117000139 ELECTRICAL OKAY

FEEDER 6



Table: 13 - 33KV OUTGOING FEEDER CIRCUIT BREAKER FULL DETAILS

13.1: 33KV FEEDER 1

MAKE ABB

S/NO. 1VYN030117000140

CURRENT 1250A

VOLTAGE 36V

FREQ. 50Hz

TYPE OVD-VBF-36-20-25

INSULATION LEVEL 70kV/170kV PEAK

SHORT CIRCUIT BREAKING CURRENT 25kA rms

SHORT CIRCUIT MAKING CURRENT 62.5kA PEAK

SHORT CIRCIUT WITHSTAND CURRENT 25kA 3SECOND

CLOSING AND OPENING SUPPLY VOLTAGE 110VDC

48

13.2: 33KV FEEDER 2

MAKE ABB

S/NO. 1VYN030117000138

CURRENT 1250A

VOLTAGE 36V

FREQ. 50Hz






CLOSING AND OPENING SUPPLY

VOLTAGE

110VDC

13.3: 33KV FEEDER 3

MAKE ABB

S/NO. 1VYN030117000144

CURRENT 1250A

VOLTAGE 36V

FREQ. 50Hz







VOLTAGE

110VDC

13.4: 33KV FEEDER 4

49

MAKE ABB

S/NO. 1VYN030117000142

CURRENT 1250A

VOLTAGE 36V

FREQ. 50Hz







VOLTAGE

110VDC

13.5: 33KV FEEDER 5

MAKE ABB

S/NO. 1VYN030117000141

CURRENT 1250A

VOLTAGE 36V

FREQ. 50Hz







VOLTAGE

110VDC

13.6: 33KV FEEDER 6

MAKE ABB

S/NO. 1VYN030117000139

50

CURRENT 1250A

VOLTAGE 36V

FREQ. 50Hz







VOLTAGE

110VDC

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