ABB REF543KB127AAAA Relion® 543 Series Numerical Feeder Protection Relay

ABB REF543KB127AAAA is a multifunctional intelligent electronic device (IED) from ABB’s Relion® 500 series, designed for medium-voltage (up to 40.5kV) feeder,

motor, and transformer protection, control, measurement, and communication. It integrates advanced protection algorithms, real-time monitoring,

and flexible communication in a compact, DIN-rail mountable housing, certified to SIL2 (IEC 61508) for safety-critical applications. Ideal for utility substations,

industrial plants, and renewable energy facilities requiring reliable, arc-flash resistant protection.

Technical Specifications