Fault induced delayed voltage recovery (FIDVR) is a phenomenon where the bus voltages remain at excessively low values for a considerable duration of time, that is about 3-20s. This occurs mainly due to the stalling of single phase induction machine loads, after fault clearance, consuming more reactive power and therefore slow recovery of voltage. This can be observed predominantly at a location where there is a huge concentration of single-phase induction machines. Initially, FIDVR events were observed at a distribution network of Southern California Edison utility. Because of excessive lower voltages for a considerable duration, there is a chance of mal-operation of zone-3 distance relay. The impedance trajectory might enter the zone-3 reach even after the fault clearance. A method has been proposed in literature using time varying voltage severity indices and relay margin to block the zone-3 operation of critical distance relay, during FIDVR event. However, the limitations of the method are that the fault clearing time is implicitly assumed to be known and the voltages successfully restores after the fault clearance. This may not be the case always. There are some cases where the voltages do not restore successfully after the fault clearance. Hence, there is a chance for the impedance trajectory to be inside the zone-3 reach even after the fault clearance. A distribution entropy based method is proposed to identify the fault occurrence and clearance events. Based on the estimation of fault occurrence and clearance an algorithm is proposed to identify mal-operating relays. All the mal-operating relays are then blocked. The proposed method is implemented on IEEE 39 bus system. The simulation results will be presented in the seminar.