4 Element (3 Phase + EF) over current IDMT with instant trip. Display of fault current. / Load current. Selection of Curve: Six selectable curves (Normal Inverse1 (C1), Normal Inverse2 (C2), Very Inverse (C3), Extremely Inverse (C4), Long Time Inverse (C5) & Definite Time (C6). Separate curve selection for phase and EF. Latching of fault current up-to last 5 fault. Site selectable CT secondary Programmable Annunciation Contact Trip circuit supervision function. Breaker Fail. SCADA compatibility. IEC60870-5-103 protocol.The ADR231A is a three element communicable numerical relay can having following option , 2 OC +1 EF or 3EF relay with Instantaneous high set and programmable output to simplify feeder protection wiring.