Before conducting any tests, visually inspect the GCB for any signs of physical damage, loose connections, or corrosion.
Primary Injection Test: –
This test involves injecting a high-current signal directly into the primary side of the GCB to simulate a fault condition.The purpose is to verify that the GCB can trip and interrupt the current flow within the specified time
Secondary Injection Test:-
This test involves injecting a signal into the secondary side of the GCB to simulate the operation of protective relays. It checks the coordination between the GCB and protective relays and ensures that the GCB operates correctly in response to relay signals.
Timing Test: –
Timing tests are conducted to verify that the GCB operates within the specified time limits. This includes checking the opening time (trip time) and closing time of the GCB under different operating conditions.
Contact Resistance Measurement: – Measure the contact resistance of the GCB to ensure that it is within acceptable limits. High contact resistance can lead to overheating and reduced performance.
Insulation Resistance Test: –
This test measures the insulation resistance of the GCB to ensure that there are no short circuits or insulation breakdowns.
Mechanical Operation Test:-
Operate the GCB manually or electrically to ensure that it moves freely without any sticking or binding.
Overcurrent Test:–
Apply a gradually increasing current to the GCB to determine its rated breaking capacity and verify that it can withstand the expected fault currents without damaging.
Trip Coil Test:-
Test the trip coil of the GCB to ensure that it operates correctly and can generate enough force to trip the circuit breaker.
Functional Test:– Finally, perform a comprehensive functional test of the entire GCB system, including all control and protection functions, to ensure that it operates as intended under normal and fault conditions.
