substation pre commissioning tests

8/12/2019 Substation Pre Commissioning Tests

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PRE-COMMISSIONING TESTS AND CHECKS

1- Visual Check and Inspection of all Electrical Equipment

A visual check will be carried out on all electrical equipment, internally and externally, to determine

that no transit/erection damage has occurred (or where this has happened that satisfactoryrectification work has been done). All control and relay panels, local control panels, Switchgear andelectrical devices will be internally checked for compliance with the approved drawings andapproved connection wiring diagrams.

The tests carried out in order to satisfy the above will be: -

1.Internal Panel Wiring Compliance Visual Check

2.Internal Panel Wiring/Devices Insulation Check

3.D.C. Supply Checks

4.A.C. Supply Checks

5.Scheme Checks (Positive and Negative Rail Principle)

All relays will be visually checked to see that there is no packing, dirt, metal swarf, etc., present inthe magnet gaps or on the contacts. All connections will be checked for tightness on the relays and atall other wiring terminations including the terminal blocks.

All devices shall be checked to see that they are clearly numbered/identified in accordance with the

general arrangement drawings and that the phases are marked where appropriate.

2- EarthingAn earthsurveyis carried out for each substation at the beginning of the contract in order to obtaina value for the site earth resistivity which is required as part of the Earthing design brief. This shouldbe witnessed and signed by Owner.Standard earthing tests are carried out during the erection stage by the erection staff. On completionof these tests, a copy of the results obtained must be submitted to the PCE for his approval andretention.

These tests will be repeated during the acceptance testing stage by the erection staff in liaison with a

commissioning team member, when they will be witnessed by the client. www.sayedsaad.com

3- Bus Wiring

All inter-panel bus wiring will be tested and checked in accordance with the appropriate terminationdiagrams.
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Insulation checks will be made using a 500V Megger on each bus wire to earth and from each buswire to all others. These checks should be carried out with all individual fuses, links, miniature CircuitBreakers, etc., open or removed at a) the source of supply and b) all incoming and outgoing circuitpanels and Switchgear. www.sayedsaad.com

4- Multi-Core Cables

All multi-core cables will be tested and checked in accordance with the appropriate terminationdiagrams.

The insulation resistance will be measured using a 1000V megger after all the multi-corecables have been connected to the erected equipment. (These tests on the multi-corecables although done at the pre-commissioning stage to sort out any obvious problems willbe repeated during the acceptance testing stage).

5 - Batteries and Chargers

The batteries and chargers will be checked to see that they have been erected / assembledcorrectly in accordance with the manufacturers recommended procedures.

The tests that are carried out at this stage will be to determine that the batteries and chargers arefunctioning correctly, within the recommended tolerances, so that their performance can be reliedupon during the commissioning of the rest of the substation equipment.

The responsibility for carrying out the above will be taken by a SCE. The actual acceptance tests,including the time-consuming discharge tests, to be witnessed by the client, are carried out towardsthe end of the commissioning programme.

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6- 132kV GIS Site Tests

These tests are carried out in accordance with the format of the Works Site Test Report. The testsconducted are:

1.Bus-Bar and Connections - Conductivity Tests

2.Circuit Breaker - Contact Resistance Checks

3.Circuit Breaker - Contact Timing Tests4.Mechanical and Local Electrical Operational Checks5.Air and Gas Leakage Tests6.SF6 Gas Pressure Switch Setting Check7.Compressed Air System Sequence Checks


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7- 132/11.5kV 30 MVA Transformer Site Tests

The Transformers are inspected and tested in accordance with the factory check sheets forTransformer installation. As well as detailed inspection this also includes oil testing.

8- Shunt Reactor

These tests are carried out in accordance with the format of the Works Site Test Report. Thetests conducted are:-

(1)Visual Checks. www.sayedsaad.com

(2)Winding Insulation Level.(3)Oil Tests. www.sayedsaad.com

(4)Oil / Winding Temperature Gauge Calibration Fan Control

Sequence Test. www.sayedsaad.com

COMMISSIONING AND ACCEPTANCE TESTS

1- 275, 220,132 and 66kV VT Tests

The tests carried out will be:

1.Insulation test

2.Flick Test

The polarity of the VT will be checked by carrying out the flick test. 2.2

2- 275, 220,132 and 66kVCT Tests


1.Insulation Test

2.Flick Test3.Resistance Test

4.Saturation Test

Where more than one CT is in each phase of a circuit, tests where practical will be carried out toprove the CT's are positioned correctly so that arranged overlap of zones of protection is correct Thismay be carried out by a) a visual inspection b) a continuity test.

Flick tests will be done on all CT's in a group to prove that they are connected to the protection inthe same polarity. These tests will also be done on CT 's mounted in Transformer bushings. The flick


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test results should be compared with those expected from the schematic diagrams.

All CT's will have the dc secondary loop resistance and individual secondary winding resistancesmeasured.

The saturation tests will be carried out to prove there are no shorted turns associated with the CTand to establish the knee point voltage of the CT's The magnetization curve will be plotted for eachCT or superimposed on the factory curves in order to determine that the correct CT is installed.

3- 275, 220,132 and 66kVPrimary Injection

Tests these tests carried out will be:

1.CT Ratio and Polarity Test

2.Busbar Inter-Group CT Ratio and Polarity Tests-

3.Relay Operation Tests4.Busbar Protection Operation and Stability Tests5.Unit Protection Operation and Stability Tests6.Directional Over current Operation and Stability Tests

Primary current shall be passed through each CT to prove its ratio and polarity with reference toother CTs in its group. All relays and instruments will be proved to be wired in the correct phases.

All current "test terminals" will be checked for correct phasing, CT shorting Switches will be provedand any withdrawable relays should have their shorting contacts checked.

Inverse time relays shall be made to "creep'on minimum setting.

Earth fault relays shall be checked for spill Current when injecting phase to phase and minimumoperation.

Transformer biased differential protection. The two groups of CTs, (one on the 132 kV side and oneon the 11kV side of the Transformer) should each be proved for ratio and polarity, and the differentialrelay proved to operate for phase-phase, and phase-earth fault injection on each side of theTransformer. When the Transformer is energies, on load tests will be used to prove stability.

Bus zone protection. The group of CT's of each circuit shall be checked for correct ratio and

polarity. Each group of CT's should then be checked against the bus section/coupler CT's of thesame zone of protection for out of zone stability by measuring spill currents.

Directional Over current Protection Operation of the protection will be tested by primary injection ofcurrent and voltage simulating the fault direction. Reversal of the current polarity proves the stabilityof the protection.


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4 - Secondary Injection Tests

The secondary injection tests will be made to prove the relays, transducers and meters areoperating and measuring correctly.

Secondary injection tests will consist of 'a.c.'injection into the relay coils to prove that the relaycalibration is correct

A record of the relay type, serial number, and its setting range shall be recorded.

The secondary current injection shall take place from the point at which the primary injection checkswere made on the CT's.

For inverse time relays, the minimum starting current for which the relay will close its contacts with amaximum time dial setting shall be recorded. The resetting time of the disc shall be recorded, andthe time of operation for a current injection of twice, five times and ten times setting current. These

results should be carried out on the relays service setting (or nominal setting if service not known).The results should be compared with the relay curve supplied by the manufacturer. Also the timesetting multiplier characteristics will be checked at 2 points (setting point + 1 other point).

For instantaneous relaysthe operating current or voltage and the drop off value shall be recorded.

For all relays fitted with a mechanical flag, the flag should operate just before the contacts make andthe flag mechanism should not interfere with the operation of the relay.

Differential Relays(e.g. Transformer biased differential or pilot wire relays will require"on-load"

checks to prove their stability) in addition to secondary injection tests.

Distance protection relays will require current and voltage of varying magnitude injected into themto simulate different values of fault impedance and

"on-load

"checks will be required to. prove the

directional feature of the relay.

Directional elements of inverse time O / C and E / F relays will require secondary injection ofcurrent and voltage of varying phase angle between them to determine the operation andstability zone.

The calibration of all instruments and transducers will be checked at i scale and full scale by currentand/or voltage injection with varying phase angle as required.

5- 275, 220,132 and 66kV GIS Operational Tests

The tests carried out will be: -

1.Local and Remote Operations of all Isolators, Earth Switches and Circuit Breakers


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2.Local and Remote Indications of above3.Electrical Interlocks of above4.Synchronizing Sequence Tests (including secondary injection of voltage selection scheme)

(iv)5.Gas Monitoring Sequence Tests

6.Alarm Sequence Tests7.Tripping Tests

Sequence tests will be carried out to prove all electrical circuits are operating correctly as shown inthe schematic diagrams.

The control circuits will be tested by the manual operation of all close-trip Switches from all positions,for all Circuit Breakers, disconnecting Switches (line Switches), ground Switches (earth Switches),and other devices in accordance with the schematic diagrams.

The operation of all protection circuits will be proved to be in accordance with the protective gearschematic diagrams.

The tests will be conducted by manually making every main relay contact or initiating device atsource and observing Circuit Breaker tripping, auxiliary relay operation, lock-out relay operation andany others. Tripping initiated by each relay in a protection scheme will be tested with the appropriatetrip link in and out to prove that the link is connected and labeled correctly.

The annunciator circuits will be proved to be in accordance with the schematic diagrams includingalarm buzzer and/or bell, lights and any other means of alerting staff.

Operation tests of the alarm circuit will be by operating, at source, each alarm initiating relay, wherepossible, or otherwise by simulation.

Operation of each Circuit Breaker, isolator, earthing Switch or other piece of equipment will beproved to be free or locked according to the interlock condition shown on the schematic diagrams.

Synchronizing Sequence Tests will be made by secondary injection of voltage at the "VT testterminals" on the, appropriate panels. Care must be taken to ensure that the VT secondary areisolated from the VT voltage circuits so that no high Voltage is developed at the VT primary circuits.

6. 132/11.5kV 30 MVA Operational Tests and Measurement of Audible Noise

Level

The following checks will be carried out.

1.Winding Insulation Level

2.Ratio Test


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3.Vector Group Test4.Cooling System Control Sequence Test5.Local/Remote Tap Change Operations (Mech. and Elec.)6.Operation of Protective Devices

Load drop compensation and winding temperature CTs mounted in the trans-former should beproved to be in the correct phase and have the correct ratio where practicable.

Buchholz relays: the alarm and trip initiation shall be proved by means of the test button, if provided,or by shorting the appropriate terminals at the relay.

Winding temperature tripping and alarms shall be proved by operating the appropriate initiatingSwitches. The cooler control ON and OFF shall be proved when three phase

'A.C.'

supplies are

available by operating the ON/OFF Switch and the appropriate temperature indicating initiatingSwitches. The direction of the fan rotation must be checked in accordance with the mark.

Tap-changer position indicator should be proved to indicate the correct tap position. The limit Switchmust function properly to prevent the tap-changer from further movement beyond the two extremetap positions. Tap-changing shall be tested for every step ensuring stepping relayfunctions correctly.

Measurement of audible noise level on site will be carried out underthe following conditions using a sound level meter(IEC Pub 551 type 1 or equivalent):

1.The background noise level at all measuring points shall not exceed 45dBAin accordance with ANSI standard.

2. Only the Transformer under test shall be energized and shall have beenon soak for at least 24 hours prior to measurement. The tests shall be carriedout at rated voltage with all normal fans running at no load conditions.

3. The audible sound level of each Transformer in turn will be measured

at a number of points 30 meters from the substation.

4. The average value of the noise measurements for each Transformershall be taken and this value checked to ensure it does not exceed 50dBA.

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7- 11/0.433kV 250kVA Transformer Tests

These tests are carried out in accordance with the format of the Works Site Test Report. The tests


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conducted are:-

a)Winding Insulation Levelb)Ratio Test www.sayedsaad.comc)Vector Group

8- HV Pressure Tests (132kV Equipment)

These tests will be carried out in accordance with the Works Site Test Reports.

The magnitude and duration of the test voltage is given in Table below.An opportunity to check VT

calibration will be taken during these tests.

EquipmentTest Voltage

KVTest Duration

132 GIS 115 10 min.11 KV 24 1 min

9- Supervisory Interface Test


a)Initiation of the appropriate alarms or indications at source and checking that the correct logicsignals are received at the telemetry terminal (TTB) cabinet.

b)Applya 50V DC voltage to the (TTB) cabinet terminals and check that the correct Circuit Breakeror tap changer command is received and executed.

10 - 11kV VT Tests. www.sayedsaad.com


a)Insulation Test. www.sayedsaad.comb)Flick Test. www.sayedsaad.com

The polarity of the VT will be checked by carrying out the flick test.

11 - 11kV CT Tests


a)Insulation Test. www.sayedsaad.comb)Flick Test. www.sayedsaad.comc)Resistance Testd)Saturation Test


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Where more than one CT is in each phase of a circuit, tests where practical will be carried out toprove the CT's are positioned correctly so that arranged overlap of zones of protection is correct Thismay be carried out by a) a visual inspection b) a continuity test.

Flick tests will be done on all CT 's in a group to prove that they are connected to the protection inthe same polarity. These tests will also be done on CT's mounted in Transformer bushings. The flicktest results should be compared with those expected from the schematic diagrams.

All CT's will have the dc secondary loop resistance and individual secondary winding resistances

measured. www.sayedsaad.com

The saturation tests will be carried out to prove there are no shorted turns associated with the CTand to establish the knee point voltage of the CT's The magnetization curve will be plotted for eachCT or superimposed on the factory curves in order to determine that the correct CT is installed.

12- 11kV Primary Injection

Tests the tests carried out will be:

a)CT Ratio and Polarity Test

b)Relay Operation Testsc)Unit Protection Operation and Stability Tests

Primary current shall be passed through each CT to prove its ratio and polarity with reference toother CTs in its group. All relays and instruments will be proved to be wired in the correct

phases.www.sayedsaad.com

All current "test terminals" will be checked for correct phasing, CT shorting Switches will be provedand any withdrawable relays should have their shorting contacts checked.

Inverse time relays shall be made to "creep' on minimum setting.

Transformer biased differential protection. The group of CTs should be proved for ratio and polarity,and the differential relay proved to operate for phase-phase, and phase-earth fault injection.

Transformer Restricted Earth Fa u l t Protections. The groups of CTs shall be proved for ratio and

p o la r i t y and stability by measuring spill currents.

13- 11kV Secondary Injection Tests

The secondary injection tests will be made to prove the relays, transducers and meters areoperating and measuring correctly.


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Secondary injection tests will consist of a.c. injection into the relay coils to prove that the relaycalibration is correct

A record of the relay type, serial number, and its setting range shall be recorded. -

The secondary current injection shall take place from the point at which the primary injection checkswere made on the CTs.

For inverse time relays, the minimum starting current for which the relay will close its contacts with amaximum time dial setting shall be recorded. The resetting time of the disc shall b_ recorded, andthe time of operation for a current injection of twice, five times and ten times setting current. Theseresults should be carried out on the relays service setting (or nominal setting if service not known).The results should be compared with the relay curve supplied by the manufacturer. Also the timesetting multiplier characteristics will be checked at 2 points (setting point +1 other point).

For all relays fitted with a mechanical flag, theflag should operate just before the contacts make and

the flag mechanism should not interfere with the operation of the relay.

The calibration of all instruments and transducers will be checked at scale and full scale by currentand/or voltage injection as appropriate.

14. 11kV Switchgear Contact Resistance Checks

The contact resistance of all primary contacts will be checked by current injection and voltage dropmeasurement.

15. 11kV Switchgear Operational

Tests The tests carried out will be:

a)Local and Remote Operations of all Circuit Breakersb)Local and Remote Indications of abovec)Electrical Interlocks of aboved)Gas Monitoring Sequence Testse)Alarm Sequence Testsf)Tripping Tests including Arc Fault Tripping schemewww.sayedsaad.com

Sequence tests will be carried out to prove all electrical circuits are operating correctly as shown inthe schematic diagrams.

The control circuits will be tested by the manual operation of all close-trip Switches from allpositions, for all Circuit Breakers and other devices in accordance with the schematic diagrams.

The operation of all protection circuits will be proved to be in accordance with the protective gear


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schematic diagrams.

The tests will be conducted by manually making every main relay contact and observing CircuitBreaker tripping, auxiliary relay operation, lock-out relay operation and any others. Tripping initiatedby each relay in a protection scheme will be tested with the appropriate trip link in and out to prove

that the link is connected and labeled correctly.

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The annunciator circuits will be proved to be in accordance with the schematic diagrams includingalarm buzzer and/or bell, lights and any other means of alerting staff.

Operation tests of the alarm circuit will be by operating, at source, each alarm initiating relay contact,where possible,-or otherwise by simulation.

Operation of each Circuit Breaker disconnect Switch and earthing Switch will be proved to be free or

locked according to the interlock condition shown on the schematic diagrams.

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16.HV Pressure Tests (11kV Equipment)

These tests will be carried out in accordance with the Marugame Works Test Sheets. Themagnitude and duration of the test voltages are given in Table 1

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17. Battery and Charger Tests

The batteries and chargers will have already been assembled, checked and put into service duringthe pre-commissioning stage by members of the commissioning team.

However certain further tests are now done and others repeated during the acceptance testing stageto be witnessed by the client. These tests will be carried out in accordance with the manufacturersrecommended testing procedures and will include the battery discharge tests.

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18. Multi-Core Cable Tests

All the multi-core cables will have already been checked to be in accordance with the appropriatetermination diagrams during the pre-commissioning stage.

The insulation resistance tests will be repeated during the acceptance testing stage when they will be


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witnessed by the client.

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19. Earthing Tests

The erection staff will have originally conducted earthing tests but these will be repeated during theacceptance testing stage when they will be witnessed by the client.

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20. Fire Fighting Equipment Tests

The Subcontractor will have already carried out limited post erection checks, i.e. mechanical checksincluding a pressure test on the main tank and air leakage tests on the air receiver.

The commissioning tests for water spray system will be:-

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a)Compressor Sequence Tests

b)Alarm Sequence Tests

c)Indication Sequence Tests

d)Deluge Valve Sequence Tests

e)Discharge and Water Spray Tests

f)Inter-tripping Tests

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The commissioning for the other systems will be:

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a)Detector Operation Tests

b)Detector Line Supervision Tests

c)Pushbutton Function Tests


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d)Tripping Tests

e)Halon Discharge Test

f)Dry Powder Discharge Test

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