Question { 5448 }

what was the function of the auxillary relay?

Answer

Auxiliary relay is a relay which will repeat the operations of protective relay such as tripping, time lag, breaking of trip circuit current, giving alarms and showing flags etc..
Protective relay contacts are delicate and light weight hence it will not capable of carrying a large amount of current for a long period.
protective relays do not have enough contacts to perform all the operations of protective scheme.

Therefore auxiliary relays, auxiliary switches and repeat contacts are used to assist protective relays.