Protocol for 33by11kv Ss

8/8/2019 Protocol for 33by11kv Ss

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COMMISSIONING PROTOCOLS

FOR

33/11KV SUB STATION



INDEX

Sl

No

Equipment Format no

1 POWER & STATION TRANSFORMER

2 CIRCUIT BREAKER

3 CURRENT TRANSFORMER

4 VOLTAGE TRANSFORMER

5 LIGHTENING ARRESTER

6 ISOLATOR

7 BATTERIEY & CHARGER

8 EARTH RESISTANCE MEASUREMENT

9 STABILITY CHECK



PRECOMMISSIONING CHECK LIST/SITE TEST REPORT

Doc. No.

Equipment

POWER TRANSFORMER /STATION TRANSFORMER

Sr. No. Date Rev.Nil

Location & Designation Drawing No. Sheet1 of 6

Customer Project Job order No.

Tested by(name) Witnessed by(name)

Signature

Date

Signature

Date

A. Name Plate details:

a) Make:

b) Rated KVA:_________

c) No load Voltage: Primary Volts l Secondary Volts

d) Rated Current Primary : Amps , Secondary Amps

e) Taps : _______ % to _______% in steps of _______ %

f) Vector group:

g) Losses : a) No load . _______ watts, Full load __________ watts

h) Oil : In Kgs _________ , In Ltrs.___________

i) Total Weight________ Kg

B. GENERAL CHECKS

1. Ensure that all electrical work of the transformer and associated equipmentare complete in all respects.

2. Check that no part of transformer and associated equipment is damaged.

3. Ensure that oil drainage system is complete.

4. Check that all external fittings are as per the external arrangement drawings

5. Examine the transformer for oil leaks from all gasket joints, valves etc.




Doc. No.

Equipment






Signature

Date

Signature

Date

6. Check that air has been released from all points of the oil circuit

7. Check bushings are not damaged and clean in all respects.

8. Check buchholz relay is mounted with arrow pointing towards conservator

9. Check that all the cables in Marshalling & Control Cubicle box are correctly glanded and

terminated and check wiring is as per the relevant drawings.

10. Check that all the spare cable holes are sealed with rubber groumets.

11. Check that IR and continuity of all control & power cables.

12. Ensure that the following points are effectively earthed to the station earth

a. Main tank (2 points) b. Marshalling box. c. Control cubicle.

13. Check Silica gel breather is correctly installed and Silica gel colour is blue

14. Check tap changer operation manually over its entire range and confirm mechanical

position indication is correct

15. Check pressure relief diaphragm is undamaged and equalizing pipe mounting is

satisfactory where ever provided.

16. Check that the transformer neutral earthing and body earthing is done at two different

earth pits

17. Calibrate WTI & OTI gauge by using oil bath(both heating and cooling cycle)

18. Check WTI & OTI alarm circuit in the remote panel

19. Check WTI & OTI trip circuit in the upstream side breaker




Doc. No.

Equipment






Signature

Date

Signature

Date

20. Check the buchholz relay alarm and trip circuit either by actuating the test lever (if

provided in the relay) or by oil drainage method.

21. Check the buchholz relay alarm and trip circuit logic by externally shorting the alarm and

trip contacts in the buchholz relay TB, one after another

C. SITE TESTS

1-OIL TEST

2-INSULATION RESISTANCE TEST With transformer disconnected from HV & LV carry out IR test on the following sides and

equipment completely isolated

Date Sampling PointElectric Strength(BDV) OIL TEMP Moisture (ppm)

HV to Earth IR15_______Mohms IR60_______Mohms PI =

LV to Earth IR15______Mohms

HV to LV IR15________Mohms IR60_______Mohms PI =

Megger Used : _____________kV Make ___________________

Ambient Temp________deg C




Doc. No.

Equipment






Signature

Date

Signature

Date

3-RATIO AND MAGNETIZING CURRENT TEST

Carry out the ratio and magnetizing current test by connecting a 3-phase 4 - wire low voltagesupply to HV terminals with normal Earth connection of the star point disconnected.

Measure the voltages at HV and LV side for all tap positions. At the same time measure the

HV magnetizing current at the minimum, normal and max tap positions RATIO TEST

MAGNETIZING CURRENT TEST

Voltage in VoltsTap

no.

R-Y Y-B B-R r-y y-b b-r r-n y-n b-n

1

2

3

5

6

7

8

Voltage in Volts Current in Amp

Tap

no.

R-Y Y-B B-R R Y B

1

2

3

5

6

7

8




Doc. No.

Equipment






Signature

Date

Signature

Date

4-MAGNETIC BALANCE TEST Apply single phase low voltage supply in one phase of HV side and record voltages inothers.

From above test check that the magnetic balance of the core is OK / not OK

5-VECTOR GROUP TEST A 415 V, 3 phase supply connected to HV terminals with normal earth connections of star

point disconnected and R-r connected together ( at nominal tap position )

Voltage

Applied

Volts

Y-BR- Y

B-R

B-RY- B

R-Y

R-YB- R

Y-B

Volts Volts Volts

R-Y r-n Rn

Y-B y-n Yn

B-R b-n Bn

R-r Y-r B-r

R-y Y-y B-y

R-b Y-b B-b




Doc. No.

Equipment






Signature

Date

Signature

Date

Check for desired vector group - OK or not OK.

6. SHORT CIRCUIT TEST Short LV terminals and apply a regulated 3 -phase, A.C. supply from a 3 -phase variac (fed with 3 -phase, 415 V A.C. supply) to HV winding.

Volts Amps

Tap no RY YB BR R Y B138

Z = Vsc / Isc ; % Z = (Z x (MVA)base ) x 100 / (kV)base2

7. DC RESISTANCE TEST

Resistance in mili Ohms

TapNo. RY YB BR rn yn bn

12345678

Remarks:




Doc. No.

Equipment

Outdoor/Indoor CircuitBreaker





Signature

Date

Signature

Date

1

A. Name Plate details:

a) Make:

b) Type:

c) Rated Volts:

d) Rated Current:

e) Rupturing Capacity: Sym. _______ KA Asym. __________ KA

B. GENERAL CHECKS

1. Check the erection of CB and its accessories are completed

2. No physical damages are there in any part of CB assembly

3. Check the earth connections are complete as per drawing

4. Check all NO/NC contacts of Aux. Switch unit of breaker:

5. Check for control panel

a) Fuses/MCBS provided are of rating as shown in the approved drawing

b) Check that the labeling of devices is as per the approved drawing

c) Check the wiring is completed as per the approved drawing

d) External Cabling and termination are completed as per the cable schedule




Doc. No.

Equipment






Signature

Date

Signature

Date

2

b) Check the terminal connections are tightened properly

c) Cable tags, ferrules for cores are provided as per cable schedule

d) Dressing and clamping of cables is done properly

e) Insulation resistance of all control cables OK (250/500v megger)

f) Check Functioning of relays/selector switches/contactors etc.

6. All insulators are cleaned and free from dust/dirt etc.

7. Check Clearances for following (mm):

a) Phase to Phase (between individual pole units)

R-Y ____ , Y-B ____, B-R_____

b) Phase to Earth. R-E ____ , Y-E ____, B-E_____

C. SITE TESTS




Doc. No.

Equipment






Signature

Date

Signature

Date

3

1. Insulation resistance test: (values in Mega Ohms, 5kv megger)

Status Megger Used Rph Yph BphPole to Earth ( CB Closed)Across Poles (CB Open)Between poles(CB closed)

Across poles (CB closed)

2. Resistance measurements :(Ohms) Temp.:

Trip Coil I Trip Coil II Close Coil

3. Operating time: (in milli seconds)

R Y B RYB inseries

RYB inparallel

ClosingTripping

4. Contact Resistance Test: (in micro ohms) Temp.:

R ph Y ph B ph




Doc. No.

Equipment






Signature

Date

Signature

Date

4

D. OPERATION CHECK

1. Check the operation of CB for following:

a) Closing & tripping through CB Control switch in Local/Remote mode

b) Tripping through emergency trip

c) Indications

d) Check Anti pumping feature of CB

2. Chek manual charging operation of spring.

3. Check the operation with castle lock in service

4. Check for proper operation of breqaker sounter

5. Check the operation of space heater and cubicle lamp

Remarks:



PRECOMMISSIONING CHECK LIST/ SITETEST REPORT

Doc. No.

Equipment

Outdoor/Indoor CurrentTransformer





Signature

Date

Signature

Date

[ BAY # ]A. NAME PLATE DETAILS

TYPE MAKE -

‘R’ Ph SL.NO. :- ‘Y’ Ph SL.NO. :- ‘B’ Ph SL.NO. :-

Rated Dynamic Current :- NO. OF CORES :-

Rated System Voltage :- Type of Insulation :-

Rated Primary Normal Current :- Rated Continuous Thermal Current :-

Rated Short Time Thermal Current :- Total Creepage Min :-

Rated Insulation Levels :- Rated Frequency :-

Rated Extended Primary Current :- Rated Thermal Current :- .

G. A. Drawing No. :- Weight Of Oil :- Total Weight :-

Whether Auxiliary C T / Reactor Provided for Metering Winding :- .

CORE DETAILS

Core

No.

Current Ratio(Amps)

Output

Burden

( VA )

Accu-

racyclas

s

ISF/

ALF

Min. KneePoint

Voltage(KVP) in

Volts

Max C T SecWdg. Res. ( Ω

)( Rct at 75

deg C )

Iexcitation

at KVP( m A )

1

2

3 - -

CAUTION

01. Secondary Terminals must be short circuited before the burden isdisconnected.02. Ensure C (Tan Delta) point connection with Earth.




Doc. No.

Equipment






Signature

Date

Signature

Date

B. SITE TESTS

A. I. R. VALUES :Instruments Used - Megger –

01. ‘R’ Ph C. T. SL.NO. :-

MEASUREDBETWEEN

IRVALUE( M.Ω )

MEASUREDBETWEEN

IR VALUE( M.Ω )

Primary – Earth Core 1 -Core 2

Primary + E -Core 1

Core 1 -Core 3

Primary + E -Core 2

Core 2 -Core 3

Primary + E -Core 3

Core 3 - EarthCore 1 –

EarthCore 2 – Earth

02. ‘Y’ Ph C. T. SL.NO.

MEASUREDBETWEEN

IRVALUE( M.Ω )

MEASUREDBETWEEN

IR VALUE( M.Ω )

Primary – Earth Core 1 -

Core 2Primary + E -

Core 1Core 1 -Core 3

Primary + E -Core 2

Core 2 -Core 3

Primary + E -Core 3




Doc. No.

Equipment






Signature

Date

Signature

Date


EarthCore 2 –

Earth

03. ‘B’ Ph C. T. SL.NO. :-

MEASUREDBETWEEN

IRVALUE( M.Ω )

MEASUREDBETWEEN

IR VALUE( M.Ω )

Primary – Earth Core 1 -Core 2

Primary + E -Core 1

Core 1 -Core 3

Primary + E -Core 2

Core 2 -Core 3

Primary + E -

Core 3


EarthCore 2 –

Earth

B. SECONDARY WINDING RESISTANCE:-

Instrument Used:.

01. ‘R’ Ph C. T. SL.NO. :-




Doc. No.

Equipment






Signature

Date

Signature

Date

CORE TERMINALS Resistance

1 S 1 - 1 S 21 S 1 - 1 S 3

2 S 1 - 2 S 22 S 1 - 2 S 33 S 1 - 3 S 23 S 1 - 3 S 3

02. ‘Y’ Ph C. T. SL.NO. :-


1 S 1 - 1 S 2

1 S 1 - 1 S 32 S 1 - 2 S 22 S 1 - 2 S 33 S 1 - 3 S 23 S 1 - 3 S 3

03. ‘B’ Ph C. T. SL.NO. :-


1 S 1 - 1 S 21 S 1 - 1 S 32 S 1 - 2 S 22 S 1 - 2 S 33 S 1 - 3 S 2

3 S 1 - 3 S 3




Doc. No.

Equipment






Signature

Date

Signature

Date

C. KNEE POINT VOLTAGE TEST:-

Instruments Used:

01. CORE – 1.

Measured Current in

mA

Measured Current in

mA

Core

Terminal

Applie

dVoltag

e ‘R’Ph

‘Y’Ph

‘B’Ph

Core

Terminal

Applie

dVoltag

e ‘R’Ph

‘Y’Ph

‘B’Ph

1S1-1S2

____ A

1S1-1S3

____ A




Doc. No.

Equipment






Signature

Date

Signature

Date

D. CURRENT RATIO:-

Instruments Used:-

C. T. ‘R’ ‘Y’ & ‘B’ PHASES

01. CORE – 1

MEASURED CURRENT IN SECONDARY (in m A)Injected Currentin Primary in(Amps)

‘R’ Phase C.T.

‘Y’ PhaseC.T.

‘B’ Phase C.T.

Actual Current

CoreNo. &Ratio

Actual

Ratio Sec Current Sec Current Sec Current 1

POLARITY TEST:-

Inst. Used :

01. ‘R’ Ph C. T. SL.NO. :-

CORE – 1 CORE – 2 CORE – 3

02. ‘Y’ Ph C. T. SL.NO. :-

CORE – 1 CORE – 2 CORE - 3

03. ‘B’ Ph C. T. SL.NO. :-

CORE – 1 CORE – 2 CORE – 3




Doc. No.

Equipment

VOLTAGE TRANSFORMERSr. No. Date Rev.

Nil




Signature

Date

Signature

Date

A. NAME PLATE DETAILS & SPECIFICATIONS :-

TYPE :- MAKE :-

Sl. Nos OF PT ‘R’ Phase - ‘Y’ Phase - ‘B’ Phase -

Highest System Voltage :- NO. OF CORES :- 2

Type of Insulation :- CLASS

Rated Voltage :- KV

Total Thermal Burden :-. TOTAL CREEPAGE MIN :- mm

Nominal Intermediate Voltage :- KV Rated Frequency :- 50Hz

Rated Insulation Levels KVp Voltage Factor :-.

Weight :- Kg

CORE DETAILSCore Rated Secondary

Voltage ( Volts )Terminal Markings Rated Burden

( VA )Accuracy Class

Core - 1 110 / √ 3 1 a - 1 nCore - 2 110 / √ 3 2 a - 2 n

SIMULTANEOUS LOADING OF SECONDARIES

B. INSULATION RESISTANCE TEST

Instruments used:

‘R’ PHASE ‘Y’ PHASE ‘B’ PHASEHV-ELV1-ELV2-E

HF-ELV1-LV2HV-LV1HV-LV2

Voltage Ratio TestApplied Primary Voltage(V) Measured Secondary Voltage(V)R-E Y-E B-E r-E y-E b-E




Doc. No.

Equipment

LIGHTENING ARRESTERSr. No. Date Rev.

Nil




Signature

Date

Signature

Date

[BAY# , ]

A. NAME PLATE DETAILS & SPECIFICATIONS:-

MAKE:

SERIAL NOS OF LA'S 'R' Phase 'Y' Phase 'B' Phase

Type:- Style:- Class & Type: - Gapless (Zn O Block), Station Class

Rated Voltage :- 30 kV Max Continuos Operating Volt. :- KV

Max Continuos Operating Volt. :- KV Rated Frequency :- 50 HZ

DISCHARGE COUNTER DETAILS (For 33KV):-

MAKE.

Year of Manufacturing :-

Previous Reading of the Counter atthe Time of Pre Commissioning.

‘R’ Phase - ‘Y’ Phase - ‘B’ Phase -

Counter Reading at the Time ofCommissioning.

'R' Phase - ‘Y’ Phase - 'B' Phase -

Counter Sl.no. 'R' Phase -'

Y’ Phase - 'B' Phase -




Doc. No.

Equipment

LIGHTENING ARRESTERSr. No. Date Rev.

Nil




Signature

Date

Signature

Date

B. I. R. VALUES:-

Instrument Used: - HV Digital Insulation Tester - V, MAKE - , MODEL - , SL. NO. :- .

I. R. VALUE IN M.Ω I. R. VALUE MEASURED

BETWEENVOLTAGE

L. A. ‘R’PHASE

L. A. ‘Y’ L. A. ‘B’PHASE

GROUND TO STACK – 1(If applicable)

GROUND TO STACK – 2( If applicable)

COMPLETE LA




Doc. No.

Equipment

ISOLATORSr. No. Date Rev.

Nil

Location & Designation Drawing No. Sheet

1 of 2



Signature

Date

Signature

Date

[BAY # , ISOLATOR NO. ]

A. NAME PLATE DETAILS & SPECIFICATIONS:-

SERIAL NUMBER ISOLATOR -EARTH SWITCH -

MAKE :-

Rated Voltage :- Type of Isolator :- HCB - Outdoor TypeType of Earth Switch :-

Number of Poles :- Three Control Voltage :- .

Rated Normal Current :- Motor Voltage :-Type of Drive :- Operating Mechanism of Isolator & Earth Switch :- Manual.Rated Insulation Level :- No. of Earth Switch :- Rated Frequency :- 50 HZ

Rated Short Time Withstand Current - Isolator & Earth Switch :- 25 KA ( RMS ) / for 1 sec.

B. I. R. VALUES OF ISOLATOR: -

(Instruments Used: - HT MEGGER - V, MAKE –)

ISOLATOR IN OPEN CONDITION:-

MEASURED BETWEEN ‘R’ PHASE ‘Y’ PHASE ‘B’ PHASE

Male side to Ground M.Ω M.Ω M.Ω Female side to Ground M.Ω M.Ω M.Ω

C.CONTACT RESISTANCE:-

(Instrument Used - )

a). ISOLATOR IN CLOSED CONDITION :-

‘R’ PHASE ‘Y’ PHASE ‘B’ PHASEMEASUREDBETWEEN

Current( Amps )

Contact Res.

( in μΩ )

Current( Amps )

Contact Res.

( in μ. Ω )

Current( Amps )

Contact Res.

( in μ. Ω )

Main contact ( Male &Female)

100 100 100

b). ISOLATOR IN OPEN CONDITION :-

‘R’ PHASE ‘Y’ PHASE ‘B’ PHASEMEASUREDBETWEEN

Current( Amps )

Contact Res.

( in μΩ )

Current( Amps )

Contact Res.

( in μ. Ω )

Current( Amps )

Contact Res.

( in μ. Ω )

Earth Contact 100 100 100




Doc. No.

Equipment

ISOLATORSr. No. Date Rev.

Nil

Location & Designation Drawing No. Sheet

2 of 2



Signature

Date

Signature

Date

PRECOMMISSIONING CHECKS

1 Check for level and spacing of base frames.2 Check alignment and verticality of Support Structure.

3 Check alignment and horizontally of male & female blade.4 Check that coupling f has at least two bolts fitted.5 Ensured MOM boxes mounted on the correct side.6 Check for braided flexible copper connection between moving blade of

earth switches and base frame. (Only in case of Earth Switches).7 Check for contact alignment & free movement of Isolator/engagement

and disengagement of male / female contacts.8 Check for Isolator closing / opening operation manually.9 During manual operation, confirmed position of operating handle coincid-

es with the marked ”OPEN” & “CLOSE” position on the MOM boxes ofIsolator / earthing switch.

10 Check electrical clearance during operation.11 Check mechanical interlock between isolator and Earth Switch for correct

functioning.

12 Check for cleaning of all support insulators and application of contactgrease in Isolator & Earth Switch contacts before starting for site testing.

13 Check for earthing of Isolator Structure, Base Frame, MOM Boxes & LineEarthing Switch.

14 Rating Plate Details OK as per Single Line Diagram.15 Earthing of structure, Base frame & MOM boxes.

16 Rating of fuses in the MOM boxes check OK.17 Ensured plugging of all unused holes & other openings.18 Check local Operation.

.



PRECOMMISSIONING CHECK LIST

Doc. No.

Equipment

Battery & Battery ChargerSr. No. Date Rev.

Nil




Signature

Date

Signature

Date

1. BATTERY:

a. Name Plate Details:

a) Make:

b) Type:

c) AH rating:

d) Rated voltage/ cell:

e) No. of cells in battery bank:

f) Rated voltage of battery bank:

g) Specific gravity:

b. General checks

1. The quantity, ratings, type and make of the devices are as per the BOM asgiven in approved drawings

2. No physical damages are there in any devices of the panels

3. The inter panel Earth bus connections & connection to the earthing grid aretightened properly

4. Fuses provided are of rating as shown in the approved drawing

5. Check that the labeling of devices is as per the approved drawing




Doc. No.

Equipment


Nil




Signature

Date

Signature

Date

6. Check the wiring is completed as per the approved drawing

7. External Cabling and termination are completed as per the cable schedule

8. Cable tags, ferrules for cores are provided as per cable schedule

9. Dressing and clamping of cables is done properly

10. Check the phase sequence of the Mains supply to the battery charger

11. Check Functioning of all relays/meters/selector switches etc.

12. All Alarms & Annunciations, indications are functioning properly

13. Check the Float & Boost charger operation, set the o/p voltage (if reqd)

14. Check the current limiting feature of charger & set the current limit (if reqd.)




Doc. No.

Equipment


Nil




Signature

Date

Signature

Date

c. Tests

I.Before Charging: Battery Voltage:

II.During Charging: Time:Charging current:Battery Voltage:

Cell No. Cell Voltage Specific gravity(whwereverapplicable)

Temperature




Doc. No.

Equipment


Nil




Signature

Date

Signature

Date

III.Discharging: Time:Discharge current:Battery Voltage:

Cell No. Cell Voltage Specific gravity Temperature




Doc. No.

Equipment


Nil




Signature

Date

Signature

Date

2.-BATTERY CHARGER:

a. Name Plate Details:a) Make:

b) Type:

c) Rated voltage:

d) Float Voltage

e) Float current:

f) Boost Voltage:

g) Boost current:

GENERAL CHECKS

1. The cabling from Battery Charger to first, last and tap cell is completed

2. The inter cell connections and cable connections are tightened properly

3. There is no physical damage to any cell and cell terminals

4. Check the cells are correctly numbered.

5. Check all the cells are connected in correct polarity

6. Check availability of accessories like apron, gloves, hydrometer,

cell voltage tester, thermometer etc.

7. Check the specific gravity of the electrolyte prior to pouring in thecells(wherever applicable)




Doc. No.

Equipment


Nil




Signature

Date

Signature

Date

8. Check the polarity of the DC connection from Battery charger to Battery

9. Charging is carried out as per the instruction manual

i. Insulation resistance test: Temp.:

R-E Y-E B-E R-Y Y-B B-R

Insulation resistance(in Mega Ohms)

ii. Load Test:

Time Load Current

Remarks:




Doc. No.

Equipment

EARTH RESISTANCE MEASUREMENTSr. No. Date Rev.

Nil




Signature

Date

Signature

Date

INSTRMENTS USED :- Earth Resistance Magger, MAKE :-

Sl.No

BAY Name EQUIPMENTS EARTHRESISTANCE

( in Ohms )

Remarks

1 __ Earth mat

NB: EARH RESITANCE TO BE TAKEN AT ALL T RANSFORMERS LA, VT, ISOLATORS,CB, TOWERS , ELECRODES.




Doc. No.

Equipment

STABILITY TESTSr. No. Date Rev.

Nil




Signature

Date

Signature

Date

33/11 T/F # 1 Schematic P-2 P-1 → P-1 P-2

‘R'

→ ‘Y’

→

PRIMARY INJECTION FROM BAY # 1 C.T. AT P-1 TERMINALS & P-2 SHORTED.

Instruments Used MAKE MODEL SL. NO. REMARK

Clamp on Meter,MAKE

.

Primary InjectionKit, MAKE

SinglePhase variac,MAKE

.

[ 33 KV Transformer BAY # 1]

01. CORE – 1

PRIMARY CURRENT INJECTED IN‘R’ph -----------A, ‘Yph-------------A’, ‘B’ ph ------------ A

CURRENTMEASURED AT

‘R’ Ph. CT ‘Y’ Ph. CT ‘B’ Ph. CT NEUTRAL

1 C.T. M. B. T.B No. Current T.B No. Current T.B No. Current T.B No. Current

1 S1 – 1S2

Control & RelayPanel

02. CORE – 2


CURRENTMEASURED AT





Doc. No.

Equipment


Nil




Signature

Date

Signature

Date


2 S1 – 2S2Control & RelayPanel

03. CORE –3


CURRENTMEASURED AT



3 S1 – 3S2

Control & relaypanel

[ 33 KV Transformer BAY # 2]

01. CORE – 1

PRIMARY CURRENT INJECTED IN

‘R’ph -----------A, ‘Yph-------------A’, ‘B’ ph ------------ A

CURRENT

MEASURED AT



1 S1 – 1S2


02. CORE – 2


CURRENTMEASURED AT



2 S1 – 2S2


03. CORE –3




Doc. No.

Equipment


Nil



PRIMARY CURRENT INJECTED IN

‘R’ph -----------A, ‘Yph-------------A’, ‘B’ ph ------------ A

CURRENT

MEASURED AT



3 S1 – 3S2

Control & relaypanel

Documents

Protocol for 33by11kv Ss