33 kv substation

For a 33kv SS we use many relays earth fault,over current,under voltage,phase failure etc. Depending on turns ratio of current transformer and PT the relay current limit is set. When a short circuit or earth fault occurs corresponding relay acts in turn opening the circuit breaker. It is done to isolate healthy part of system from faulty.

longtime delay relay,loose fault relay,short time extension relays, anti dry relay, wet sensing relay,