DEWA Power Transformer Site Test Report Format

MD(Trafo)/ST/02 Page of

GENERAL DATA HV LV RATING – ONAN / ONAF MVA

NOMINAL VOLTAGE kV

FULL LOAD CURRENT (RATED TAP) A

VECTOR GROUP

SHORT CIRCUIT IMPEDANCE HV/LV % Max. Tap ( 1 )

Rated Tap ( ) Min. Tap ( )

TYPE/FORM (given by manufacturer)

YEAR OF MANUFACTURE

ZERO SEQUENCE IMPEDANCE

NO OF TAPS

NO OF FANS

NO OF PUMPS

NO OF RADIATORS

TYPE OF OIL

TOTAL OIL QUANTITY

BREATHER TYPE

OLTC MAKE / MOTOR

OLTC TYPE / MOTOR

TOTAL WEIGHT

CONSERVATOR TYPE

NEUTRAL GROUNDING METHOD

TRAFO TYPE (ICT, IBT, IDT Etc.)

SUB STATION VOLTAGE

COMMISSIONING DATE OF S/S

COMMISSIONING DATE OF TRAFO.

TYPE OF INSULATION PAPER NORMAL / THERMALLY UPGRADED

DATA ENTERED CHECKED APPROVED

Signature: Signature: Signature:

Name: Designation: Dept./Company:

Name: Designation: Dept.& section:


Contract No. : Sub Station :

TRANSFORMER SITE TEST REPORT Trafo ID

Contractor Manufacturer Date of test Sl. No.

DEWA


Contract No.

Sub Station

:

:


Contractor Manufacturer Date of test Sl. No. FINAL CHECKS

Correctness of oil level in all bushings and oil filled chambers.

All air release plugs (including radiators)& Buchholz relays vented

Pressure relief diaphragm intact

All bushing connections checked

Neutral & Transformer Earth connection satisfactory

Position of all switches in MK & MDU – ON position.

All CT connections are through / shorted

WTI Ammeter circuit link connections are correct

CT test windings open

No damage for insulators and clean

No oil leakage

Rating, diagram, Id plates fitted satisfactorily

Dehydrating breathers satisfactory and pipe work joint is tight

All cabling and wiring visually satisfactory

All valves are in correct operational position with respect to valve schedule diagram (Ensure valves on both sides of relays and to HV cable box are open).

All valves labeled & locked and blanking covers provided wherever necessary

All protective and cable box covers fitted.

All pre-commissioning tests (including oil tests) completed & results are satisfactory. Copies of test reports available.

Condition of Gland earthing of all cables in MK & MDU

Permanent Identification tags for all control cables on both ends

Availability on marked up drawing copy MK & MDU

Close all opening (center cable) in to AVR panel

MK and HV/LV cable box.

CHECKED WITNESSED APPROVED





DEWA





INSULATION RESISTANCE CHECK OF DEVICES / CONTACTS Sl. No. Device/Component

Test voltage

Ambient Temp.

Terminals numbers in MK

IR value (M. Ohms)

Remarks

1 HV bushing – test tap N/A 2 HV-N bushing – test tap N/A 3 Buchholz relay 4 Oil level gauge (MT) 5 Oil level gauge (OLTC) 6 Rubber bag failure relay 7 PRD (MT) 8 PRD (OLTC) 9 OLTC surge relay 10 OTI 11 WTI - HV 12 WTI - LV 13 Heater – HV cable box 14 Heater – LV cable box 15 Heater – Marsh. kiosk 16 Heater - MDU 17 18 19 20

Instrument Name, Make & Serial no. Calibration due date

TESTED WITNESSED APPROVED





DEWA





OIL LEAK TEST OF TRANSFORMER

Hourly Reading/ details:

Date Time Ambient Temp. ( °C)

Tr. OTI reading

(°C)

Pressure at Top (Bar)

Pressure at Transformer Bottom (Bar)

Result / observation Remarks

----- Before the application of Pressure

Pressure gauges- Make & Serial no.

Top Bottom

Calibration due date TESTED WITNESSED APPROVED





DEWA





TAP POSITION INDICATION CHECK:

Tap Positi

on MDU

Input to Transducer

Transducer output for

TPI (mA) at AVR panel

Transducer (SCADA)

Output (mA)

Tap Position at AVR Panel

Tap Position at DCS

Tap Position

at SCADA

Remarks

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Instrument Name, Make & Serial no.






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TEST ON TRANSFORMER OIL AFTER COMPLETE SITE PROCESSING

Sl. No. Property Unit Requirement as per Spec.

Test Result Remarks

1 Breakdown Voltage 2 Water Content 3 Dissipation Factor at 900C. 4 Resistivity at 900C. 5 Neutralization Value 6 Interfacial Tension 7 Oxidation Stability 8 Flash Point 9 Inhibiter Content 10 Corrosive Sulphur Content (Test certificate from independent test laboratory is attached)







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TEST RESULTS / PROPERTIES OF INSULATING OIL BEFORE FILLING IN THE

TRANSFORMER

Property Unit Test Results Remarks Kinetic viscosity at 400C – 150C mm2 / S Flash Point 0C Pour Point 0C Appearance

Density at 200C kg/dm2 Interfacial tension at 250C N/m Neutralization Value mg KOH/g Corrosive Sulphur Water Content mg/kg

Antioxidant additives DBPC

Wt %

Oxidation stability Induction period

h

Breakdown Voltage

kV

Dissipation factor at 900C and 40 Hz to 60 Hz

(Copy of Test certificate from oil manufacturer is attached)







DEWA





CALIBRATION OF OIL & WINDING TEMPERATURE INDICATORS

1. OIL TEMPERATURE INDICATOR

MAKE: TYPE: SERIAL NO. BATH TEMPERATURE (0C)

INDICATOR READING (0C)

ALARM CONTACT SETTING (0C) OPERATION OF CONTACTS (0C)

TRIP CONTACT SETTING (0C) OPERATION OF CONTACTS (0C) Remarks: -

2. WINDING TEMPERATURE INDICATOR (HV)

MAKE: TYPE: SERIAL NO.

BATH TEMPERATURE (0C)

INDICATIOR READING ( 0C)


TRIP CONTACT SETTING (0C) OPERATION OF CONTACTS (0C)

Remarks: -

3. WINDING TEMPERATURE INDICATOR (LV)

MAKE: TYPE: SERIAL NO.

TEST TEMPERATURE (0C)

INDICATIOR READING (0C)


TRIP CONTACT SETTING (0C) OPERATION OF CONTACTS (0C)

Remarks: - Make and Sl.No. of Temp. Bath Calibration due date






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MEASUREMENT OF TAN DELTA & CAPACITANCE

Ambient temp. - Top oil temp. -

a) Transformer Winding:

CAPACITANCE (pF) Sl. No.

APPLIED VOLTAGE

(kV) Measured combination

Measured Value

Factory Value

Difference (%)

CURRENT (mA)

Dissipation Factor

(TAN DELTA) (%)

1

2

3

4

5

6

b) BUSHINGS

Make and Type of bushings:

CAPACITANCE (pF) Sl. No.

Applied voltage

(kV)

Measured on ( Sl. No. of bushings) Measured

value Factory

value Difference (%)

Current (mA)

Dissipation Factor

(tan delta) (%)

1 HV/LV (U)–

2 HV/LV (V)–

3 HV/LV (W)–

4 HV/LV (N)–

Instrument Name, Make & Serial no.









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COOLING EQUIPMENT

A) OPERATION / CONTROLS CHECK

MANUAL OPERATION

DIRECTION OF FANS / PUMPS

AUTO CONTROL FROM HV W. T. I

AUTO CONTROL FROM LV W. T. I

AUTO CONTROL FROM O T. I

CHECK INTERLOCKING OF COOLING FANS WITH FPS OPERATION

UNDER VOLTAGE RELAY OPERATION AND ALARM CONTACT

MAIN CONTROL MCB TRIP

FAN CONTROL SWITCH TRIP

PUMP / FAN ‘ON’ INDICATION

PUMP / FAN FAILURE INDICATIONS

OPERATION OF BUCHHOLZ RELAY WHEN SIMULTANEOUS SWITCHING OF PUMPS

CHECK FOR STAGGERED STARTING OF COOLER FANS/PUMPS

WIRING – CHECKS ( T. B NO, FERRULES, GROUPING OF ALARM CONTACTS ETC. AS PER DRAWINGS)

GROUP – 1 (START) - 0 C GROUP – 1 ( STOP ) - 0 C

GROUP – 2 (START) - 0 C GROUP – 2 ( STOP ) - 0 C







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ON LOAD TAP CHANGER – OPERATION CHECKS

Tap changer details Tap Changer Motor Make - Make - Type/Model - Motor Type - Sl. No. - Rating (KW) - MDU Type - Voltage - Year of Mfg. - Rated current - Sl.No. Description of check Remarks

1 Local operation possible when selector s/w in local position 2 Remote operation not possible when selector s/w in local position 3 Emergency switch operation 4 Handle interlock 5 End limit switches in extreme taps 6 Step by step operation 7 Position indication in MDU 8 Position indication RCP 9 No of rotations for one step operation 10 Local operation is not possible when selector s/w in Remote position 11 Remote operation is possible when selector s/w in Remote position 12 Over travel in operation is within limits 13 Starting current of motor 14 Running current of motor 15 Phase discrepancy in operation (if separate poles for each phases) 16 Time for one tap changing – Normal tap 17 Time for one tap changing – run through tap (where applicable) 18 Contacts for all alarm/indication circuits 19 Over load tripping of motor (Setting of MPR) 20 IR value of motor and wiring with 500volts Megger 21 Lighting and heater controls (operation of door switch, thermostat etc.) 22 23 24 25







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MAGNETIZING CURRENT MEASUREMENT HV Winding

Measured exciting current (mA) Tap No. Applied voltage U phase V phase W phase Remarks

LV Winding

Measured exciting current (mA) Applied voltage U phase V phase W phase

Remarks







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FAN MOTOR CHECK

Make Rating KW/HP

Type / Model

Rated current

FAN NO.

SERIAL NO.

CHECK for DIRECTION OF ROTATION

STARTING CURRENT (A)

U phase

RUNNING CURRENT V phase

(Amps) W phase

OVER LOAD SETTING (Amps)

TRIP OPERATION TIME (Sec)

BLOCKED ROTOR CURRENT (Amps)

OV

ER

LO

AD

DE

VIC

E

ALARM CONTACT (OK/Not OK)

IR VALUE AT 500 V (M Ohms)

CHECK FAN RUNNING STARTS WHEN ONE PHASE IS DISCONNECTED – RUNNING / NOT RUNNING CHECK FOR HEATING AND LIGHTING CONTROLS (DOOR S/W, THERMOSTAT ETC.) -







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HV WINDING RESISTANCE MEASUREMENT (Temp ° C)

Measured Resistance (Ohms) Tap No.

Applied current

U - N V - N W - N Average Resistance corrected to 75°C

( R ) ∆R

Factory value at

75°C

Remarks

Note : Graph plotted ( Tap no on x-axis and ∆R on y-axis) for all the three phases to be attached)

(Temp °C)

TAP No

U – V (Ohms)

V - W (Ohms)

W – U (Ohms)

Average (Ohms)

LV WINDING RESISTANCE MEASUREMENT (Temp °C)

TAP No.

u – v / u - n (Ohms)

v – w / v - n (Ohms)

w – u / w - n (Ohms)

Average (Ohms) Factory value (Ohms)







DEWA





INDEX

Sl.No. Item Page No.

1 Transformer general data 2 Final checks (To be carried out prior to energisation) 3 Insulation Resistance measurement of Transformer (Winding and core) 4 2kV test on core and clamping structure 5 Ratio and Vector group tests 6 Magnetizing current measurement 7 Winding Resistance measurement 8 Short circuit Impedance measurement 9 Measurement of Tan delta and Capacitance 10 Frequency Response analysis 11 Calibration of Temp. Indicators 12 Gradient check of Winding Temperature indicators 13 Measurement of transducer for Remote Temp. Indicator 14 Operation check of On load Tap changers 15 Tap position indication check 16 Insulation resistance check of devices 17 Fan motor check 18 Operation check of cooling equipments 19 Protective device wiring check 20 Checks on AVR 21 Tap changer and cooler alarms check 22 Parallel operation checks 23 Oil leak test 24 BDV test on insulating oil 25 Tests on insulating oil (oil characteristics) 26 Tests on transformer oil after complete processing 27 DGA test on insulating oil

PREPARED CHECKED APPROVED





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INSULATION RESISTANCE MEASUREMENT & CORE INSULATION TEST INSULATION RESISTANCE - WINDING

Measured at 5000 Volts Top Oil temperature - °C

Measured between 15 Seconds

(M. Ohms)

60 Seconds

(M. Ohms)

600 Seconds (M. Ohms)

P.I. value

(R600/R60)

HV - LV and EARTH

LV - HV and EARTH

HV – LV

Remarks:-

CORE INSULATION TEST INSULATION RESISTANCE -

Measured at 2000 volts Oil Temperature - °C

Measured between Before 2kv Test (M.ohms)

After 2kv Test (M.ohms) Remarks

Core - Earth

Clamps - Earth

Core - clamps

Remarks: -

HV TEST(2kV Test) on Core insulation 1. Applied 2kV, AC, between core & clamps connected together and tank for one minute

Leakage current - mA Result : Withstood / Failed

2. Applied 2kV, AC, between core and core clamps for one minute Leakage current - mA Result : Withstood / Failed







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GRADIENT CHECK OF WINDING TEMPERATURE INDICATORS

Indicator Sl.No. Bath Temp.

( °C)

Current injected (Amps)

Indicator Reading

(°C)

Gradient (°C)

Required gradient

(°C) Remarks

GRADIENT CHECK OF REMOTE WINDING TEMPERATURE INDICATORS

Indicator Sl.No.

Bath Temp. (°C)

RWTI output (mA)

Current injected (Amps)

Local WTIReading

(°C)

Output (mA)

Gradient (mA)

Required gradient

(mA) Remarks

Instrument Name, Make & Serial No. Calibration due date






DEWA





TEMPERATURE TRANSDUCER OUTPUT MEASUREMENT

DETAILS OF DEVICES

ROTI :

RWTI (HV) :

RWTI (LV) :

Device connected to DCS/SCADA -

OTI WTI (HV) WTI (LV) Reading at Bath temp. (°C) OTI

reading Transducer output (mA)

WTI reading

Transducer output (mA)

WTI reading

Transducer output (mA) DCS SCADA

Remarks

40 50 60 70 80 90 100 110 120 130 140 150

Instrument Name, Make & Serial No. Calibration due date






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SHORT CIRCUIT IMPEDANCE MEASUREMENT

Measured voltage on HV (volts)

Measured HV current (Amps)

Impedance (%) at ……. MVA base Tap

No. U - V V -W W -U U V W U V W Average

Factory value

Impedance (%) = *Rated current x Measured voltage x 100 *Rated voltage x Measured current (* At corresponding tap)







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RATIO AND VECTOR GROUP TESTS

HV volts LV volts Tap No. U-N V-N W-N u-v/u-n v-w/v-n w-u/w-n

Measured ratio

(Average)

Nominal ratio

Error(%) Remarks

Voltage continuity check during tap changing operations - OK / Not OK VECTOR GROUP CHECK

Connected terminals ‘U& u’ of transformer together, Tap changer being on rated tap. Applied 3-phase voltage on HV terminals.

Vector Diagram Measured voltages on

U-V V - v V - w V-W W - w W - v W-V U - n N - n Remarks :-







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PROTECTIVE DEVICES WIRING CHECK

Sl. No.

Description Initiated from

Terminal No. in MK

Terminal No. in LCC

Terminal No. in RCP/ RPs

Remarks/ Results SCS/Scada

Transformer Alarms 1 Buchholz Alarm 2 Oil temp. high 3 Wind. Temp. high( HV) 4 Wind. Temp. high (LV) 5 Rubber bag fail 6 Oil level high (MT) 7 Oil level low (MT) 8 Oil level high (OLTC) 9 Oil level low (OLTC)

Transformer Trips 1 Buchholz relay 2 Oil temp. high 3 Wind. Temp. high 4 PRD (MT) 5 PRD (OLTC) 6 Surge Relay (OLTC) 7 Pressure relay OLTC 8 PRD cable box

Buchholz Relay alarm contact operation check by N2 injection – Remarks: Instrument Name, Make & Serial no. Calibration due date






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MD(Trafo)/ST/24 Page of Contract No. : Sub Station :

TRANSFORMER SITE TEST REPORT

Trafo ID


BDV TEST ON INSULATING OIL :

Sl. No. Test no. Breakdown voltage

(in kV) Remarks

Sampling done from : 1 Test no: 1 2 Test no: 2 3 Test no: 3 4 Test no: 4 5 Test no: 5 6 Test no: 6

Average Sampling done from :

1 Test no: 1 2 Test no: 2 3 Test no: 3 4 Test no: 4 5 Test no: 5 6 Test no: 6

Average Sampling done from :

1 Test no: 1 2 Test no: 2 3 Test no: 3 4 Test no: 4 5 Test no: 5 6 Test no: 6

Average







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MD(Trafo)/ST/22 Page of Page 1of 2 of MD(Trafo)/ST/22




OLTC PARALLEL OPERATION CHECKS

A. PARALLEL MANUAL MODE

RESULT / REMARKS MASTER/ FOLLOWER/ INDEPENDENT

SWITCH SELECTIONS OLTC OPERATION

Operated from Sl.No.

MDU AVR TR - 1

TR - 2

TR - 3 TR – 1 TR – 2 TR – 3 AVR

panel DCS SCADA

1 R H R M F F OPERATE AS MASTER

OPERATE AS FOLLOWER

OPERATE AS FOLLOWER

2 R H R F M F OPERATE AS FOLLOWER

OPERATE AS MASTER

OPERATE AS FOLLOWER

3 R H R F F M OPERATE AS FOLLOWER

OPERATE AS FOLLOWER

OPERATE AS MASTER

4 R H R M F I OPERATE AS MASTER

OPERATE AS FOLLOWER

OPERATE AS INDEPENDENT

5 R H R M I F OPERATE AS MASTER


OPERATE AS FOLLOWER

6 R H R I M F OPERATE AS INDEPENDENT

OPERATE AS MASTER

OPERATE AS FOLLOWER

7 R H R M M M NO OPERATION IS POSSIBLE

8 R H R F F F NO OPERATION IS POSSIBLE

9 R H R I I I OPERATE AS INDEPENDENT



10 R H R M I I OPERATE AS MASTER



11 R H R I M I OPERATE AS INDEPENDENT

OPERATE AS MASTER


12 R H R I I M OPERATE AS INDEPENDENT


OPERATE AS MASTER

M – Master F – Follower I – Independent R – Remote A - Auto H – Hand (manual) Contd. on Page 2of 2 of MD(Trafo)/ST/22







DEWA



TRANSFORMER SITE TEST REPORT

Trafo ID


AUTOMATIC VOLTAGE REGULATOR (AVR) CHECK

Make: Sl.No. Control voltage: PT sec. voltage: Band width setting: % ( volts) Under voltage blocking: % Over voltage blocking: % Check Points

Sl.No. Status description Check point Result Remarks

1 Operation 1.1 No manual operation possible from MDU, SCC

and AVR

1.2 AVR in ‘Auto’ mode Auto operations with the variations in PT sec. voltage. Tap Raise command when PT sec. voltage reduced and vice versa

1.3 Auto operations not possible Manual operations possible from AVR 1.4 AVR in manual mode Manual operations possible from SCC

1.5 Operation possible from MDU 1.6 MDU in local position Operation not possible from AVR & SCC 1.7 Operation not possible from MDU&SCC 1.8

MDU & AVR in ‘remote’ position Operation possible from AVR

1.9 Operations not possible from MDU & AVR 1.10

MDU in remote & AVR in Supervisory Operation possible from SCC only

1.11 Under voltage blocking No operations possible 1.12 Over voltage blocking No operations possible

2 AVR Display 2.1 Voltage 2.2 Current 2.3 Tap No 2.4 Frequency 2.5 Master/Follower/Independent mode 2.6 Paragramar functions (Breaker status indication) 2.7 2.8 2.9

2.10







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TAP CHANGER & COOLER ALARMS & INDICATIONS CHECK

Sl.No. Alarm description Initiated at DCS SCADA Remarks

1. ALARMS

1.1 TC out of step 1.2 TC incomplete 1.3 TC motor supply faulty 1.4 TC control supply faulty 1.5 AVR faulty 1.6 VT supply fail 1.7 Cooling equipment Faulty 1.8 IDT/ET –

MK/MDU heating/lighting supply faulty

2. INDICATIONS

2.1 Tap Changer in ‘Remote’ 2.2 Tap Changer in ‘Supervisory’ 2.3 Tap Changer in ‘Auto’ 2.4 Tap Changer in ‘Manual’ 2.5 TC in progress 2.6 TC in ‘Independent’ mode 2.7 TC in ‘Master/follower’ mode 2.8 Tap position indications 2.9 Cooling fans running







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DGA TEST ON TRANSFORMER OIL

Date of Sampling : Oil Temperature :

Sampled by : Sampling Point :

Sample identification :

Tests carried out by :

Test report reference :

Test Results

Sl.No. Dissolved gas Concentration (ppm) Remarks

1 Hydrogen (H2)

2 Methane (CH4)

3 Ethane (C2H6)

4 Ethylene (C2H4)

5 Acetylene (C2H2)

6 Carbon Monoxide (CO)

7 Carbon Dioxide (CO2)

8 Oxygen (O2)

9 Nitrogen (N2)

10

11

12 TDCG (ppm / %)

13 CO2 / CO







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FREQUENCY RESPONSE ANALYSIS

Test report - Enclosed / Not enclosed

Report No -

Number of pages -










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DEWA Power Transformer Site Test Report Format

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