Numerical Single Pole OC/EF Protection Relay : ADR211ASpecificationsBack - 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. SCADA Compatibility (RS232 and RS485 Communication For model ADR211A).The ADR211A is a single element communicable OC /EF (the setting rang cove both phase / EF requirement) relay with Instantaneous high set.