The main objective of the test is to check the proper operation
function of the Breaker; in this test we do the following:
A. Close Operation Test – Local—Remote
This test is conducted by manual, Local & Remote. For the manual Operation test, we will charge the spring manual and breaker is also closed my manual and opening also done. For the Local operation we give Control supply and A.C supply for spring charge motor. We close the Breaker using the TNC switch. We observe for the closing coil function and spring charging of motor operation. For remote operating is the site is ready (such as plc or BMS) then remote operation is done using the remote system. If its site is not ready for this, we provide a local signal to the remote terminal and observe the operation of breaker.
B. Trip Operation Test – Local—Remote
This test is conducted by manual, Local & Remote. For the manual Operation test, The manually charged breaker is opened using the Trip switch.. For the Local operation we give Control supply and A.C supply for spring charge motor. We open the Breaker using the TNC switch. We observe for the tripping coil function. For remote operating is the site is ready (such as plc or BMS) then remote operation is done using the remote system. If its site is not ready for this, we provide a local signal to the remote terminal and observe the operation of breaker.
C. Protection Trip
For this test the breaker has in closed position at initially. We provide an auxiliary rated voltage to Master trip relay, and observe the opening of the breaker and the position of the trip coil.
Functional Check:-
A. Emergency Trip:--
For this test the breaker has to be in charged or ON position, we operate the emergency push button. We observe the operation of circuit breaker opening.
B. Aux. Switch Operation:-
When the breaker is in open condition we check the Aux. contact of the breaker using continuity tester, to conform the contact is in NO /NC. Then we close the Circuit Breaker and check the same contact with continuity tester, to conform the contact is in NC /NO.
C. On-Off Indications (Lamp + Flag)
When the breaker is in open condition we check the Lamp + Flag of the relay. Then we close the Circuit Breaker and check the same Lamp operation.
D. Trip / Trip circuit healthy Lamp Indication
The relay is operated and we observer the Trip lamp indication.
E. Limit Switch for spring charge motor
On this test we observe the operation of the limit switch of the spring charging motor. We give an A.C power to motor and observer the operation of motor and charging of spring, on the indication of fully charged spring the motor operation has to get stopped.
F. Test / Service Limit Switch
This test is conducted to check the Test / Service Limit SwitchOperation. During rack out the Breaker we obverse the indicator to change to test position & during rack in the breaker we obverse the indicator to change to serviceThis test is conducted if operational counter provision is available in breaker. We operated the breaker and look for the change in counter for counting the operation.
H. Heater / Heater Switch / Thermostat
The control A.C supply is given for heater and we look for heater
operation.
I. Function of illumination & socket switchIn this test we look for the panel internal illumination & socket switch operation. We operate the limit switch manually and observe the operation of illumination circuit.Appendix D contains the detailed pre-commissioning test report.
5.4 Commissioning Procedure before & after Power Up
All the protective relays and circuit breakers are tested for proper working.
The relay settings are kept at a low value so that the transformer will get isolated if there is any internal fault.
Now the transformer may be test charged from the incoming side on no-load and operated for about two hours.
Observe the transformer hum for any abnormality.
Any vibration or abnormal magnetizing current may also be observed.
After continuous operation for about two hours, isolate the
transformer and check for abnormality.
If there is no abnormality in transformer charged again on no-load.
All connected instruments may be checked for any abnormal
indication.
Now gradually load the transformer to full capacity and keep it under constant observation for at least 24 hours of operation.
Check the winding temperature at full load and compare with factory test values.
If the test results and observations are found normal, the transformer may be cleared for regular service.
After the transformer is put in service for some weeks with normal working temperature, all sealed joints shall be re-tightened.
The results of the various tests shall be recorded and kept in the station as a permanent record for future reference. Details such as place of erection, date of commissioning, protection given to the transformer etc. may be furnished to the manufacturer after commissioning.
Appendix E contains the commissioning checklist and has to be completed before commissioning.