CONTENTS

1. OBJECTIVE

1. REFERENCE

2. PRE-REQUISITES

3. PRECAUTION AND NOTES

4. TEST EQUIPMENT

5. COMMISSIONING AND TESTING PROCEDURE

6. COMMISSIONING REPORT

1. OBJECTIVE

The objective of this procedure is to provide guidelines to commission 6.6kV Switchgear.

2. REFERENCE

HT Switchgear drawingMake: Siemens India.(Drawing Nos. refers to Siemens drawings)

1G71570-S5465-

F004General Arrangement and PF plan drawing for 6.6 kV Switchgear.

2G71570-S5465-

W101Schematic Diagram for Incomer-1 Panel (GTG 1A-UAT)

3G71570-S5465-

W102Schematic Diagram for Incomer-2 Panel (GTG 1B-UAT)

4G71570-S5465-

W103Schematic Diagram for Bus coupler Panel.

5G71570-S5465-

W106Schematic Diagram for Station Transformer (STR 1 & STR 2) feeder.

6G71570-S5465-

W111Schematic Diagram for Station Transformer (STR) feeder and River Water Pump House Feeder.

7G71570-S5465-

W107Schematic diagram for Excitation transformer feeder.

8G71570-S5465-

W107Schematic diagram for SFC transformer feeder.

9G71570-S5465-

W108Schematic diagram for motor feeders.

10G71570-S5465-

W109Schematic diagram for outgoing feeders.

11G71570-S5465-

W105Schematic diagram for Bus-1 PT panel.

12G71570-S5465-

W104Schematic diagram for Bus-2 PT (adapter PT) panel.

13G71570-S5465-

W113Schematic diagram Bus bar Earthing truck

14G71570-S5465-

W112Schematic diagram for cable earthing truck

15G71570-S5465-

Z005Schematic diagram for fast bus transfer (Popular switchgear make)

16G71570-S5465-

M003Bill of Materials.

3. PRE REQUISITES

3.1 Sufficient lighting inside the switchgear Room.3.2 Completion of civil works.3.3 Check the floor leveling is measured with good precision and it must meet the

Siemens requirement. 3.4 Completion of Erection of panels (includes fixing of panel to foundation, bus bar

interconnection and visual completeness checks)3.5 Agreement reached upon punch points.3.6 HT switchgear earthing termination with plant grid and inter panel in place.3.7 Completions of inter panel bus wiring and inter connection with the field

devices.3.8 Special tools like handles and keys to withdraw breaker from the panel are

available and kept in switchgear room. 3.9 220 V DC and 230 V AC Auxiliary supplies are available.

4. PRECAUTION AND NOTES

4.1 Area under commissioning shall be completely barricaded with barricading tape.

4.2 To protect personnel and the equipment in the area of commissioning, area restrictions shall be displayed.

4.3 Prior to the commencement of the commissioning, the total area around the equipment is to be totally cleaned.

4.4 Safety equipments such as fire extinguishers/fire detection systems are at place.

5. TEST EQUIPMENT

1. Digital Multimeter –3 ½ digit2. 2.5 kV Meggar / 500 V Meggar 3. 0-25 KV High Voltage Tester 4. Secondary injection test kit5. Micro ohm resistance meter6. Analog Multimeter7. Variac 0-440 Volt AC, 3 phase or 0-230 V AC with step up transformer8. Phase sequence meter

GENERAL GUIDELINES FOR INSTALLATION.

1. Floor and foundation leveling should be checked.

2. Each panel is shipped in separate packing. After unpacking, panel should be transported up to foundation on rollers pads. These panels should be positioned as per the GA drawing, at correct level and absolutely vertical. If necessary, Sims may be placed either under the frame or under the bottom rail near the 30 mm X 30 mm cut-out for foundation bolts.

3. Breaker truck should be removed with putting the panel number marking on it. After this, another panel should to be installed in the same fashion. Side bolts of the first panel are required to be removed. Second panel should be placed very near to the first panel and aligned this on the foundation. It should be matched with the side bolts hole of the first panel. Perfect matching will take place only when the second panel is properly aligned on the foundation and it is perfectly vertical. Sims may be used as per requirement. Both the panel should be bolted. Install all HT panels by following this sequence.

4. Fixing of panels with the foundation bolts is required to be done either by welding the channel of the foundation at the 30 mm X 30 mm cutout with inserting Sims to avoid weld across air gap or embedding the anchor bolts in the foundation through 30 mm X 30 mm cut out or drilling the appropriate hole in the foundation channel.

Before finalizing the welding, it is required to check that all the breakers can be easily racked in and racked out, with the proper operation of shutter drive mechanism and breaker earthing contact. Finalize the welding after satisfactory rack in rack out operations.

5. Bus bars of the adjacent panels should be joined together using the bus bars and hardware supplied. Bolts should be torque tightened. The support insulators should be cleaned properly.

6. Main earth bars of the panels must be bolted together.

7. Power Cables are terminated in the cable compartment. Cable opening at the bottom of the panel are properly sealed. Check earthing of cable shield. The shield shall be earthed at one point only.

8. Ensure that HT cables are well supported with clamps so that the weight of the cable should not be exerted on the cable terminal.

6. TESTING AND COMMISSIONING PROCEDURE

Testing and commissioning procedure includes:Pre commissioning checks.Pre commissioning tests.Commissioning.

1) Pre commissioning checks to be carried out as per attached checklist " HT switchgear Check list ".

2) Pre commissioning tests

i) Contact resistance of bus bar joint checks:

Contact resistance of bus bar joints should be checked with Micro ohmmeter.

ii) Circuit Breaker checks:

1. All the breakers should be checked for smooth rack-in, rack-out, locking of transfer operating mechanism, proper fixing of interlocking plate, door interlock during service position and cable compartment back cover opening interlock. Bus bar and cable earthing trolley should also be checked.

2. Insulation resistance of the breaker should be checked.

3. Contact resistance of each phase of the circuit breaker shall be measured by micro ohmmeter.

4. Breaker operation (manual and electrical) should be checked. Tripping

should be checked through lock-out.

5. Spring charging time should be measured with stopwatch.

6. Anti pumping operation should be checked.

7. Safety shutters operations should be checked.

8. Moving breaker earth continuity should be checked.

iii) Insulation resistance check (before HV test)

Prior to carrying out insulation resistance measurement, all PTs should be racked out. Insulation resistance of each phase bus bar with respect to earth and between the phases should be measured with 2.5 kV meggar.

iv) HV test

High Voltage withstand test is required to be carried out at 16 kV for each phase of the bus bar with respect to earth.

v) Insulation resistance check (after HV test)

After carrying out high voltage test, it is required to measure the insulation resistance of each phase bus bar with respect to earth and between the phases to check the healthiness of bus bar support insulators during high voltage test. It should be measured with 2.5 kV meggar.

vi) CT/PT testing.

Ratio and polarity check of CT/PT should be carried out.Magnetizing characteristic test should be done for PS class CT.

vii) Energizing of Control supply AC/DC.

Control compartment of all the cubicles should be energised with auxiliary AC and DC power supply. It is to be measured and to be ensured that it is within tolerance limit.

viii) Secondary injection test on relay

Secondary injection test should be carried out for the protective relays. Relay setting should be done as per co-ordination chart.

ix) Insulation resistance and continuity checks for outgoing cables

Healthiness of all the outgoing cables should be checked by measuring insulation resistance. Continuity should be checked for correct identification. In case of HT cables, high voltage test should also require to be carried out.

x) Operation check

Remote operation of the following feeders should be checked either by simulation or by actual operation depending upon the readiness of control desk.

Motor feeders through DCS

Transformer feeders through ASCP

Outgoing feeders through ASCP

Incomer-1/ Incomer-2 and Bus Coupler through ASCP and ABT panel.

Breaker closing and tripping interlock.

3) Commissioning

Commissioning checklist should be completed before energizing.

Incomer breaker should be racked-in. Line PT secondary and phase sequence is required to be checked.

Incomer breaker should be closed locally. Switchboard should be observed for any abnormal humming sound. Bus PT and its phase sequence should be checked.

Ensure that other incomer breaker is racked-out. Bus coupler should be racked in and closed locally. Observation should be continued for this portion of switchboard also for any abnormal humming sound. Bus PT and its phase sequence should be checked.

Outgoing feeder can be closed as per the commissioning schedule of individual equipments.

Date:…………

HT switchgear Check list

Pre commissioning Checks

1. Panels are positioned as per GA drawing. : OK / NOT OK

2. No gap between adjacent sections. : OK / NOT OK

3. Fixing with base frame. : OK / NOT OK

4. Provision and inter connection of earth bus between panels.

: OK / NOT OK

5. Earthing of panel to plant Grid. : OK / NOT OK

6. Proper gasket / tight closing of door. : OK / NOT OK

7. All insulators and barriers are cleaned. : OK / NOT OK

8. Electrical clearances are adequate. : OK / NOT OK

9. Proper identification of phases. : OK / NOT OK

10. Earthing of doors, protective relays and other equipment mounted on the control compartment.

: OK / NOT OK

11. Rack in / out of beaker trolley : OK / NOT OK

12. Phase sequence colour code of incomer cable

: OK / NOT OK

13. Earthing of breaker. : OK / NOT OK

14. Mounting of relays and meters. : OK / NOT OK

15. Proper labels for relays, switches, lamps : OK / NOT OK

16. Bus bar joints tightened with factory specified torque.

: OK / NOT OK

17. Panels are vermin proof after fitting the covers.

: OK/ NOT OK

18. Proper rating of fuses, relays, contactors : OK / NOT OK

19. VT fuses are intact. : OK / NOT OK

20. Relay front covers are intact and no damage observed during transit. Remove rubber

: OK / NOT OK

bands used to lock the moving part during transit.

21. No damage observed to CT and VT epoxy. : OK / NOT OK

22. No visible damage on VCB. : OK / NOT OK

22. Manual operation checks on each breaker, safety shutter, and circuit breaker racking mechanism,

: OK / NOT OK

1. Contact resistance of bus bar joints

2. Contact Resistance, Insulation resistance and HV test of breaker.

Joint No. /Identification Resistance value ( milli ohm )

Ambient temp……….

Breaker Sl. No. Feeder details

Insulation Resistance

HV TEST

ContactResistance

Ph -Ph

Ph to Earth

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

3. Insulation resistance of bus bar (Before H.V. test):

Meggar Make/ Type/ Sr. No. :Ambient temperature:

Meggar Volts I.R. (M..)

U –(V+W+ E) 2500 VV – (U+W+E) 2500 VW – (U+V+E) 2500 VU - V 2500 VV - W 2500 VW - U 2500 V

4. High voltage test:

Test Kit Make/ Type/ Sr. No.Ambient temperature:

Voltage applied Leakage current (mA)

U –(V+W+ E) 16 kVV – (U+W+E) 16 kVW – (U+V+E) 16 kV

5. Insulation resistance (After H.V. test):

Meggar Make/ Type/ Sr. No.Ambient temperature:

Meggar Volts I.R. (M..)U –(V+W+ E) 2500 VV – (U+W+E) 2500 VW – (U+V+E) 2500 VU - V 2500 VV - W 2500 VW - U 2500 V

6. C.T. Testing:

Feeder No. / Details

CT Serial No.

Description R Phase Y Phase B Phase

Ratio

Class

Burden

Insulation Resistance In M OhmSecondary- EPrimary- Secondary

Polarity Check

Ratio Test Pri. Curr.

Sec. Curr

Pri. Curr

Sec. Curr

Pri. Curr

Sec. Curr

Knee Point Voltage Checking (for Cl. PS CT):

Sr. No. Secondary Voltage Secondary Current

7. P.T. Testing:

Feeder No. / Details

PT Serial No.

Description R Phase Y Phase B PhaseRatio

Class

Burden

Insulation Resistance In M OhmSecondary- EPrimary- Secondary

Polarity Check

Ratio Test Pri. Volt.

Sec. Volt.

Pri. Volt.

Sec. Volt.

Pri. Volt.

Sec. Volt.

8. Relay testing (secondary injection)

Sr.No

Fdr No: Relay Model Function Result

9. Outgoing feeder cables checking

Meggar Make/ Type/ Sr. No. :Ambient temperature:

Feeder No.Insulation Resistance Continuity for

correct phase sequence

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

Three Phase Over current & Earth Fault Relay

Relay Type : Relay Sr. No…………………….

Test Kit Details:…………………………………………. ………………………………………….

Table: 1

A. Relay Pick up test:

Sr. No.

Phase Setting in Amp.

Measured Pick up - I Amp.

Measured Drop off –I Amp.

Remark

1 R Phase2 B Phase3 Neutral

( I - Current.)Check Operation of output contacts : …………………………………

B. Relay Timing Characteristic test:

Table: 2 NI -Normal Inverse Time Characteristics

Phase Type of Charact.

TMS Relay Operating time Remark

2 x I S 5 x I S 10 x I S

R NI 1.0R NI 0.1B NI 1.0B NI 0.1N NI 1.0N NI 0.1

C. High Set Element Pick up Test:

Table: 5

Sr. No.

Phase Setting in Amp.

Relay Pick up – I Amp.

Remark

1 R Phase2 B Phase3 Neutral

Record High set Relay Op. Time at 2 * Setting current:

High Set Operating Time: ………..m. Sec.

Core Balance Current transformer operated relay

Relay Type : Relay Sr. No…………………….

Test Kit Details:…………………………………………. ………………………………………….

A. Relay Pick up test:

Table: 1

Sr. No.

Phase Setting in Amp.

Measured Pick up - I Amp.

Measured Drop off –I Amp.

Remark

1 Neutral

Motor Protection Relay

Relay Type : motPRO Relay Sr.No :

Test Kit Details:………………………………………….

NOTE: Recheck the settings in all the service codes and configuration of output relays. It should be as per the application and schematic drawing. Disconnect CT inputs from the relay.

A. Short circuit and Earth fault Pick up/drop off test:

Set the earth fault trip time settings (Code-32) to minimum. Keep the other protection settings high so that it should not disturb the protection under test.Inject single-phase current into each of the phase and earth fault inputs, in turn. Slowly increase the current until the trip LED glows. Check the output relay contact on which this protection id configured. Record the pick-up current. Reduce the current until the trip contact drops off. Record the drop off level.Original time setting should be resumed.Operating time should be measured by injecting 2 times the set current into the relay.

Sr. No.

Phase Setting in Amp.

Measured Pick up –Amp.

Measured Drop off –Amp.

Remark

1 R Phase2 Y Phase3 B Phase4 Neutral

Sr. No.

Phase Time setting

Measured Pick up –Time

Remark

1 R Phase2 Y Phase3 B Phase4 Neutral

Operation of output contacts : …………………………………

Restore the phase and earth fault trip settings to recommended value.

B. Thermal Characteristics test:

This test checks the accuracy of the thermal characteristics and that the relay has been correctly set. The relay should be fully programmed to the calculated settings, output relays mapped to the protection scheme being used for this test. Code-10 and 22 is to be set for required thermal setting. Code-18 to be set as 1111. Code-26 to be set at 06. Code-24 to be set as OFF. Code-46 is to be selected as 56. Before testing and during consecutive tests at different values, thermal content is to be cleared.Thermal characteristic is to be tested for 1.5 times and 3 times the setting.When the single-phase current is injected, it gets split into one-third magnitude of positive and negative sequence current. So to inject a thermal equivalent current, the single phase current required is 3XIeq/ sqrt 7Keep the other protection settings high so that it should not disturb the protection under test.

Sr. No.

Heating Time constant (code-22)

Equivalent current as multiple of Is (Ieq/Is)

Current injected

Theoretical operating time

Actual operating time

Hot running condition of motor is envisaged when service code-56 shows 100. Hot operating characteristic is verified by calculating the time the relay takes to trip from 100% thermal content.

Current is injected higher than the thermal setting and thermal content is allowed to build up above 100%. Current is switched off without reducing the level. Current injection is restarted the moment thermal content reaches 100% and the time is calculated from this moment to tripping moment.

Sr. Hot to cold Current Actual

No. ratio injected operating time

C. Phase Unbalance Protection (Negative phase sequence) :

The Phase unbalance/Negative Phase sequence (NPS) protection can be verified by injecting single phase current only in one phase at a time.

The relationship between single phase current and Negative Phase sequence

current is Negative Phase seq. current= 1/3 ( I injected current)

Set the relay for recommended unbalance current (code-13). Set withstands time (code-31) setting to 0.1 second. Also set NPS characteristic (code-30) as 1111 i.e. definite time. Keep the other protection settings high so that it should not disturb the protection under test.

Inject single-phase current into each of the phase, in turn. Slowly increase the current until the trip LED glows. Check the output relay contact on which this protection is configured. Record the pick-up current. Reduce the current until the trip contact drops off. Record the drop off level.

Original time setting should be resumed.

Operating time should be measured by injecting at least 1.3 times the set current into the relay.

Sr. No.

Phase Unbalance current Setting in Amp.

Measured Pick up –Amp.

Measured Drop off –Amp.

Remark

1 R Phase

2 Y Phase3 B Phase

Sr. No.

Phase NPS definite Time setting

Measured Pick up –Time

Remark

1 R Phase2 Y Phase3 B Phase

Now set NPS characteristic (code-30) as 2222 i.e. inverse time. Inject the multiple of NPS setting and measure the operating time.

Sr. No.

Neg. Phase Seq. Setting

Injected current Amp.

Theoretical operating time

Relay Operating time.

R Phase

Y Phase

B Phase

1.2.

D. Stalling Protection

Set the relay for recommended stalling current (code-12). Set stall withstand time (code-28) setting to 1 second. Also set starting time (code-29) to 1 sec. Keep the other protection settings high so that it should not disturb the protection under test.

Inject single-phase current into each of the phase, in turn. Slowly increase the current until the trip LED glows. Check the output relay contact on which this protection is configured. Record the pick-up current. Reduce the current until the trip contact drops off. Record the drop off level.Original time setting should be resumed.

Operating time should be measured by injecting at least 1.3 times the set current into the relay.

Sr. Phase Stalling Measured Measured Remark

No. current Setting in Amp.

Pick up –Amp.

Drop off –Amp.

1 R Phase2 Y Phase3 B Phase

Sr. No.

Phase Stall Time setting

Measured Pick up –Time

Remark

1 R Phase2 Y Phase3 B Phase

E. Prolonged starting Protection

Ensure that code-6 is set for 1111. Set the relay for recommended starting current (code-16). Set starting time (code-29) 1 second. Set stall withstand time (code-28) more than 1 sec. Keep the other protection settings high so that it should not disturb the protection under test.

Inject single-phase current into each of the phase, in turn. Slowly increase the current until the trip LED glows. Check the output relay contact on which this protection is configured. Record the pick-up current. Reduce the current until the trip contact drops off. Record the drop off level.Original time setting should be resumed.

Operating time should be measured by injecting at least 1.3 times the set current into the relay.

Sr. No.

Phase Starting current Setting in Amp.

Measured Pick up –Amp.

Measured Drop off –Amp.

Remark

1 R Phase2 Y Phase3 B Phase

Sr. No.

Phase Starting Time setting

Measured Pick up –Time

Remark

1 R Phase2 Y Phase3 B Phase

Successful start is considered when current is injected higher than starting current setting and reduced gradually below 80% of the setting before the set time delay. Without switching off, if the current is increased more than set starting current, for the time more than starting time, relay should not operate.

HT switchgear Check list

Commissioning Checks

1 All the covers are in place and fully secured & recheck cover interlock solenoid is giving permissive to operate the breaker.

: OK / NOT OK

2 Power cables terminated properly : OK / NOT OK

3 Pre-commissioning test results : OK / NOT OK

4 All the panel fuse are at its place : OK / NOT OK

5 IR and continuity of cables done : OK / NOT OK

6 All the CT secondary are properly terminated or shorted.

: OK / NOT OK

7 Both the bus PT trolleys are racked in. : OK / NOT OK

8 All the breakers are racked out. : OK / NOT OK

9 All the breakers checked for operation : OK / NOT OK

10 220 V DC available in all the panels : OK / NOT OK

11 230 V AC available in all the panels. : OK / NOT OK

12 Trip circuit supervision healthy : OK / NOT OK

13 All the relay setting are checked : OK / NOT OK

14 All the relays are tested. : OK / NOT OK

15 All the CTs are tested. : OK / NOT OK

16 Arrangement available for closing the incomer and bus coupler breaker through T-N-C switch.

: OK / NOT OK

17 Motor Protection relay has been programmed.

: OK / NOT OK