Numerical Numerical O/C + REF Protection Relay For Transformer :ADR221BGeneral DescriptionADR221B is second generation Numerical Integrated Over Current Relay for Traction Application. It consist all the necessary protection and monitoring functions required for LV side and HV side of Traction Transformer Feeder.Disturbance Recorder. 50 cycles of actual waveform of voltage & current (45 pre-fault & 5 post fault) are captured & saved in the builtin memory with date time stamping, for analyzing fault condition. Separate Communication Ports for SCADA (RS485) as well as Local testing (RS232C) Fully communicable with IEC standard open protocol. Very low burden on CT (less than 0.5VA). Online display of Primary current i.e. load current and unbalance current. Continuous monitoring of module’s internal hardware and alarm generation in case of failure of any critical components. Facility to synchronised Relay time with external GPS network. 10 Digital Output contacts for local alarm as well as tele-signalling. 9 Optically isolated digital status input for monitoring of status and avoid used of external relay logic. 100 nos of event memory, event such CB close, Trip, digital status change, relay pkp etc. All events are with date and time stamped up to 1ms. Instantaneous Over-Current Protection. Large 20x4 LCD display for Parameter and setting display.Specially designed for Traction OHE protection. As per RDSO specs TI/SP/PSI/PROTCT/4050. 2 Element (1 OC + 1 CUR) over current IDMT with Current Unbalance Relay. Two stage Protection (IDMT for Fault and Definite Time for overload). Breaker Failure detection. In-built CB trip circuit monitoring during close as well as open condition.