Numerical Single Pole OC/EF Protection Relay : ADR111A Specifications Back - lit LCD display for settings. Display of fault current / Load current. Selection of Curve: Six selectable curves (Normal Inverse 1 (C1), Normal Inverse 2 (C2), Very Inverse (C3), Extremely Inverse (C4), Long Time Inverse (C5) & Definite Time (C6). Design using DSP technology. Latching of fault current up-to last 5 fault. Site selectable CT secondary. Relay can be made either IDMT or Define time. Programmable operating time in instantaneous element. Breaker Fail Function. Suitable For REF Protection. The ADR111A is a single element OC /EF (the setting rang cove both phase / EF requirement) relay with Instantaneous high set.