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 conducted are:‑

a)     Winding Insulation Level

b)     Ratio Test  www.sayedsaad.com

c)      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.

Equipment Test Voltage KV Test Duration
132 GIS 115 10 min.
11 KV 24 1 min

9- Supervisory Interface Test

 The tests carried out will be:

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

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

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

The tests carried out will be:

a)     Insulation Test. www.sayedsaad.com

b)     Flick Test. www.sayedsaad.com

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

11 - 11kV CT Tests

The tests carried out will be:

a)                 Insulation Test. www.sayedsaad.com

b)                 Flick Test. www.sayedsaad.com

c)                  Resistance Test

d)                 Saturation Test

Where more than one CT is in each phase of a circuit, tests where prac­tical will be carried out to prove the CT's are positioned correctly so that arranged overlap of zones of protection is correct This may 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 in the same polarity. These tests will also be done on CT's mounted in Transformer bushings. The flick 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 resistances measured. www.sayedsaad.com

The saturation tests will be carried out to prove there are no shorted turns associated with the CT and to establish the knee point voltage of the CT's The magnetization curve will be plotted for each CT 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 Tests

c)      Unit Protection Operation and Stability Tests

 Primary current shall be passed through each CT to prove its ratio and polarity with reference to other 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 proved and 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 Fault Protections. The groups of CTs shall be proved for ratio and polarity 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 are operating and measuring correctly.

Secondary injection tests will consist of 'a.c.' injection into the relay coils to prove that the relay calibration 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 checks were made on the CTs.

For inverse time relays, the minimum starting current for which the relay will close its contacts with a maximum time dial setting shall be recorded. The resetting time of the disc shall b_ recorded, and the 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 time setting multiplier characteristics will be checked at 2 points (setting point +1 other point).

For all relays fitted with a mechanical flag, the flag 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 current and/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 drop measurement.

 15. 11kV Switchgear Operational

 Tests The tests carried out will be:

a)                 Local and Remote Operations of all Circuit Breakers

b)                 Local and Remote Indications of above

c)                  Electrical Interlocks of above

d)                 Gas Monitoring Sequence Tests

e)                 Alarm Sequence Tests

f)                    Tripping Tests including Arc Fault Tripping scheme

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

The control circuits will be tested by the manual operation of all close-trip Switches from all positions, 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 schematic diagrams.

The tests will be conducted by manually making every main relay contact and observing Circuit Breaker tripping, auxiliary relay operation, lock-out relay operation and any others. Tripping initiated by 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.


The annunciator circuits will be proved to be in accordance with the sche­matic diagrams including alarm 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.


16.HV Pressure Tests (11kV Equipment)

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


17. Battery and Charger Tests

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

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


18.        Multi-Core Cable Tests

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

The insulation resistance tests will be repeated during the acceptance testing stage when they will be witnessed by the client.


19.        Earthing Tests

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


20. Fire Fighting Equipment Tests

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

The commissioning tests for water spray system will be:‑


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


The commissioning for the other systems will be:


a)     Detector Operation Tests

b)     Detector Line Supervision Tests

c)      Pushbutton Function Tests

d)     Tripping Tests

e)     Halon Discharge Test

f)        Dry Powder Discharge Test