Draw a neat sketch of earth fault protection of auxiliary circuit of electric loco. State the function of relay and isolating resistance.
Ans: Earth fault protection for auxiliaries in Loco: Function of relay: The earth fault occurring anywhere in the auxiliary circuit gets monitored by the relay which acts to trip the main CB. Function of isolating resistance: Since earth fault is not dangerous, the locomotive can be worked temporarily by isolating the relay which connects the star point to earth through a high resistance so that the relay operation is avoided.