Generator Protection - Class-C Protection

Class-C Protection:

When a fault in equipment outside the “UNIT” is not isolated for some reason by the relays/switchgear of that equipment, has to be cleared by “back up” relays provided in the generator protection system. In such cases it is sufficient to isolate the unit from the system side and “run it back to house load” which will be supplied by the Generator to the 6.6 KV systems through UAT. Such trips when only 400 KV breakers (generator main CB) are opened are called “Class-C Trips”.

After restoration of normalcy in the system, the generator can be resynchronized. Such trip also initiates HP and LP by pass arrangement to save boiler from probable tripping.

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