T&C Procedure for Transformer

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MTR CORPORATION / CONTRACTOR Contract No. 3288.66-02E

Upgrade & Reinforcement of Power Supply System at PRE & ADM DESIGN APPROVAL REOUEST

DAR NO: DATE FORWARDED TO MTRC:

C3288.66-02E/06/02/01/07/001 10 Sep. 03

CONTRACTOR REF: RELEVANT CLAUSE(S) IN THE PS: N/A

3536-L/03/P041/05/02

SUBJECT Design Submission

-DOCUMENT SUBMITTED: T & C Procedure for Transformer

DETAILS:

Site testing procedure for transformer (10 pages)

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MTRC (LL) 0000038500

ANSWER REQUIRED BY INITIATED BY: SIGNED BY: Danny Yuen

(TO AVOID DELAY): 9 Oct 2003 Danny Yuen Project Manager MTRC USE ONLY:

LEAD DESIGNER DATE RECEIVED BY MTRC:

SIGNATURE:

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MTRC CONTRACT NO. C3288.66-02E

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Upgrade and Reinforcement of Power Supply System at PRE and ADM

DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date: 9 Sept 2003

Site Testin2 Procedure for Transformer

I . CONSTRUCTION INSPECTION

General inspection for the construction of the transformer shall be carried out as per the check list in the test form.

2. VISUAL CHECK OF EARTH CONTINUITY

Check the earthing connection of the transformer frame, HV & LV cable box, LV neutral, control and marshalling cubicle visually.

3. INSULATION RESISTANCE BEFORE PRESSURE TEST

Insulation resistance test (Megger Test) for HV to LV windings, HV & LV windings to earth shall be tested by 5kV d.c. megger tester before pressure test.

4. PRESSURE TEST

AC high voltage shall be increased gradually to 19.2kV between I IkV to 415V/earth and to 3 .5kV between 415V to 1 1 kV/earth for I minute.

5. INSULATION RESISTANCE AFTER PRESSURE TEST

Insulation resistance test (Megger Test) for HV to LV windings, HV & LV windings to earth shall be tested by 5kV d.c. megger tester after pressure test.

6. TRANSFORMER RATIO TEST

Check the transformer ratio by connecting a three-phase, four wire, low voltage supply (auto-transformer) to the H.V. terminals. Measure and record the data at the L.V. side.

7. VECTOR GROUP CHECK

Measure the phase voltages for HV & LV side (refer to the test form) to check the vector group of the transformer.

8. FUNCTION TEST ON TEMPERATURE INDICATORS

(A). Check the Winding Temperature Indicator

1. Adjust and calibrate the winding temperature indicators.

Insert a thermometer (as reference) and the winding temperature indicator in boiling oil.

Record the readings of the thermometer and calibrate the indicator.

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Upgrade and Reinforcement of Power Supply System at PRE and ADM DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date: 9 Sept 2003

2. Simulate winding temperature alarm with boiled oil. The winding temperature alarm contact closes.

Record the switch setting with the reading of thermometer. (Alarm setting 1050C)

3. Simulate winding temperature trip with boiled oil. The winding temperature trip contact closes.

Record the switch setting with the reading of thermometer. (Trip setting 11 50C)

(B). Check the Liquid Temperature Indicator

1. Adjust and calibrate the liquid temperature indicators.

Insert a thermometer (as reference) and the liquid temperature indicator in boiling oil.

Record the readings of the thermometer and calibrate the indicator. 2. Simulate liquid temperature alarm with boiled oil.

The liquid temperature alarm contact closes.

3. Simulate liquid temperature trip with boiled oil. The liquid temperature trip contact closes.

Record the switch setting with the reading of thermometer. (Trip setting 950C )

9. WINDING RESISTANCE MEASUREMENT

Measure the winding resistance for H.V. side and L.V. side.

10. PHASE SOUENCE CHECK & OUTPUT VOLTAGE MEASUREMENT Check the phase sequence at L.V. side by phase sequence meter.

Measure the output voltage at L.V. side.

11. NOISE LEVEL MEASUREMENT

Check the noise level with the transformer on no load at rated voltage and frequency. The position of the noise level meter shall be I metre from transformer body.

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DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date :9 Sept2003 12. STANDBY EARTH FAULT C.T. TEST

Test the CT magnetisation with a.c. voltage to measure the knee point voltage. Test the ratio of CT up to 100% rated current by primary injection.

Check insulation resistance and measure resistance of CT.

13. INSULATING OIL SAMPLE TEST

Test the insulating oil sample in compliance with IEC 60156 (Dielectric Test) & IEC 60814 (Water Content Test) by accredit laboratory.

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DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date: 9 Sept2003

Transformer Site Test Report

Date of Testing : Site Location _

Voltage Ratio 11000/433V Serial No. :

Transformer Rating 1500KVA Vector Group Dynll

Place of Manufacture

:

Cooling Type

:

ONAN

1. CONSTRUCTION INSPECTION RESULT

- Check Transformer Body - Check HV & LV Cable Box

- Check Standby Earth CT & Bushing - Check Cable Terminal Condition

-Check Winding Temperature Indicator

- Check Liquid Temperature Indicator - Check the Condition of Liquid Level Gauge - Check Gasket Joints

Transformer Tank Joint Cable Box Covers

Valve Flanges & Pipe Joints - Check Liquid Drain Valves are closed - Check Pressure Relief Valve

- Check Radiator Valves are fully opened

2. VISUAL CHECK OF EARTH CONTINUITY RESULT

- Check Transformer Frame - Check HV Cable Box

- Check LV Cable Box - Check LV Neutral

- Check Control and Marshalling Cubicle

3. INSULATION RESISTANCE BEFORE PRESSURE TEST RESULT

(Megger Test) Using a 5kV Megger

HI.V. Windings (I IkV) to Earth (5kV)

0

LV. Windings (415V) to Earth (IkV)

0

H.V. Windings to L.V. Windings (5kV)

0

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MTRC CONTRACT NO. C3288.66-02E LP MP

4. PRESSURE TEST RESULT

11kV to 415V/earth (19.2kV AC I mins.) mA

415V to I IkV/earth (3.5kV AC I min.) nmA

5. INSULATION RESISTANCE AFTER PRESSURE TEST RESULT

(Megger Test) Using a 5kV Megger

H.V. Windings (I kV) to Earth (5kV) Q

L.V. Windings (415V) to Earth (IkV) 0

H.V. Windings to L.V. Windings (5kV) 0

6. TRANSFORMER RATIO TEST

Connect a three-phase, four wire, low voltage supply (auto-transformer) to the H.V. terminals, the following data is recorded:

T APPLIED HV LV LINE VOLTS LV PHASE VOLTS

A LINE VOLTS

P A-B B-C A-C a-b b-ca-c a-n b-n c-n

. . CAL ACT CAL ACT CAL ACT CAL ACT CAL ACT CAL ACT

1 415 415 415 15.52 15.52 15.52 8.96 8.96 8.96

2 415 415 415 15.93 15.93 15.93 9.20 9.20 9.20

3 415 415 415 16.34 16.34 16.34 9.43 9.43 9.43

4 415 415 415 16.75 16.75 16.75 9.67 9.67 9.67

5 415 415 415 17.16 17.16 17.16 9.91 _ 9.91 9.91

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DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date: 9 Sept 2003 7. VECTOR GROUP CHECK (refer to diagram 1)

Theoretical calculation: AB = 415V BC = 415V CA = 415V ab = 16.34V bc = 16.34V ca = 16.34V Aa = OV Ab = 16.34V Ac = 16.34V Ba = 415V

Bb =

'

[AB2+ ab2_-_{2(AB)(ab)cos ZBAb]} _ZBAb₌₃₀₀

=

I[4152±

16.342- 2(415)(16.34)cos 300]

= 401V Bc = Bb = 401V

Ca = 415V

Cc = I [AC2+ Ac2- 2(AC)(Ac)cos ZAcC] ZAcC = 300

=

1

[4152+ 16.342- 2(415)(16.34)cos 30°] = 401V Cb =

4

[Cc2+ bc2- 2(Cc)(bc)cos ZbcC] ZbcC = 151.16° =

4

[4012+ 16.342- 2(401)(16.34)cos 151.160] = 415.4V Bc = Ba sin ZBcC (415 4 401)

sin3O0 sin ZAcB 2 2

401 = 415 ZBcC = 62.320

sin3O0 sin ZAcB ZAcB = 148.840 ZbcB = ZAcB - 600 = 88.840 ZbcC = /bcB + ZBcC = 151.160 A-B B-C C-A B-b B-c C-b C-c Calculated 415 415 415 401 401 415.4 401 Volt ___ Measured Volt ___

*. Phase A at HV side is connected to Phase a at LV side during testing.

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MTRC CONTRACT NO. C3288.66-02E ::EPEP Upgrade and Reinforcement of Power Supply System at PRE and ADM

Diagram 1

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Upgrade and Reinforcement of Power Supply System at PRE and ADM DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date: 9 Sept 2003

8. FUNCTION TEST ON TEMPERATURE INDICATORS RESULT

(A). Check the Winding Temperature Indicator

1. Adjust and calibrate the winding temperature indicators.

Insert a thermometer (as reference) and the winding temperature indicator in boiling oil.

Record the readings of the thermometer and calibrate the indicator. 2. Simulate winding temperature alarm with boiled oil.

The winding temperature alarm contact closes.

3. Simulate winding temperature trip with boiled oil. The winding temperature trip contact closes.

Record the switch setting with the reading of thermometer. (Trip setting 11 50C)

(B). Check the Liquid Temperature Indicator

1. Adjust and calibrate the liquid temperature indicators.

Insert a thermometer (as reference) and the liquid temperature indicator in boiling oil.

Record the readings of the thermometer and calibrate the indicator. 2. Simulate liquid temperature alarm with boiled oil.

The liquid temperature alarm contact closes.

3. Simulate liquid temperature trip with boiled oil. The liquid temperature trip contact closes.

Record the switch setting with the reading of thermometer. (Trip setting 950C)

9. WINDING RESISTANCE MEASUREMENT

H.V. Side A-B1

B-C A-C

L.V. Side a-b a-n

b-c b-n

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10. PHASE SEQUENCE CHECK & OUTPUT VOLTAGE MEASUREMENT

(Measured after energization)

Phase Sequence Check

Secondary Output Voltage

RY YB RB

RN YN BN

11. NOISE LEVEL MEASUREMENT

Check the noise level with the transformer on no load at rated voltage and frequency. The position of the noise level meter shall be 1 metre from transformer body.

Ambient Noise Level: _dB

Position of Tester Noise (dB) at 1/2 tank height East

South West North

12. STANDBY EARTH FAULT C.T. TEST

Substation:

Transformer No:

Current Ratio: Rating: Serial No._

I. Inject a.c. voltage to CT coil to measure the knee point voltage

Neutral C.T. V

A

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DAR No. C3288.66-02E/06/02/01/07/001 Rev. 0 Date: 9 Sept 2003 2. Inject primary current to test the C.T. accuracy

CT RESISTANCE INJECTED PRIMARY CURRENT (A) MEASURED SECONDARY CURRENT (A) OHM 25% 50% 75% 100% 25% 50% 75% 100%

3. CT Insulation Test (500V d.c.)

CT to Earth M ohm

13. INSULATING OIL SAMPLE TEST

Referring to the attached test report from accredit laboratory:

Dielectric Test Result:

Water Content Test Result:

Tested by: Signed:

Witnessed by: Signed:

MTRCL Representative Date

Approved by: Signed:

MTRCL Representative Date