Technical Parameters Parameter Description / Value Product Series ABB Relion® / REF 54x (Feeder Protection) Device Type Numerical Bay Controller & Protection Relay Application Feeder, Motor, Transformer Backup Protection & Control Standard Protection Functions (Based on firmware M129): Non-directional phase & residual overcurrent (50/51, 50N/51N), Thermal overload (49), Breaker Failure (50BF), Multiple setting groups. Control Functions Circuit breaker control (open/close), interlocking, synchrocheck, auto-reclosing. Rated Input Current 1 A or 5 A (from Current Transformers - CTs) Rated Input Voltage 100-120V or 220-240V (from Voltage Transformers - VTs), depending on order. Auxiliary Supply Voltage Determined by first "A": Wide range AC/DC (e.g., 48-250V) or specific (e.g., 110V DC). Must be verified from code table. Binary Inputs (BI) Number and voltage level (e.g., 24/48/110/220V DC) determined by module choices ("A"s). Binary Outputs (BO/Relays) Number and contact rating (e.g., 250V AC, 5A) determined by module choices ("A"s). Communication Interfaces Determined by module choices ("A"s): Typically includes: • Front port: RS-232/RS-485 for local PC. • Rear ports: Ethernet (IEC 61850, Modbus TCP), optical serial (IEC 60870-5-103). Protocols IEC 61850, IEC 60870-5-103/104, Modbus TCP/RTU, DNP3.0, PROFIBUS-DP. Standards IEC 60255, IEC 61850, IEEE C37.90