Abstract: A protective relaying system for detecting and clearing high impedance faults on a polyphase electrical distribution circuit. First and second ratio ground relays are located at first and second circuit breakers, respectively. The first circuit breaker is located at the substation, and the second circuit breaker is remote from the substation, usually operating with a reclosing relay. A zero sequence directional relay, located at the second circuit breaker, coordinates the ratio ground relays by adjusting the trip delay time of the second circuit breaker according to the flow direction of a zero sequence quantity at the second circuit breaker.