Dear experts

In power plant common bus with 2nos of out going feeders connected with customer end common bus (13.8KV).

Power plant side we are using sensitive earth fault in both out going feeders, but customer side don't have this option & thay don't have EF relay in their incomer side.

we faced the following problems

1. both outgoing/incomer ON. While loading it was tripped due to non directional earth fault relay.

2. we desided to give one outgoing feeder (1 or 2) with both their incomer distribution, found no problem.

3. concluded power plant out going feeder distribution CBCT connection to be modified.

Both out going feeder CBCT how to connect? how it will sense both CBCT's fault current with both EF relays.

Above mentioned statement not clear please send your mail ID. I will forward the SLD connection for more clarification.

CBCT : 20VA, 50/1A, individual load current 1000A circuit.

My mail ID : harat80 [at] gmail [dot] com

 

dear friend.

it is very hard to detect this kind of problem if power is transmitted through long run cables. one of the reason for faulty tripping is due to high frequency interference on the cables. for avoiding the further tripping. it is better to use 3 ct method of protection for earth fault & over current.

hope you this will solve your problem,