The RD3 residual current relay provides protection against fault currents and monitoring functions in accordance with IEC/EN 60947-2: 2006, Annex M. It requires an external transducer and can be used together with a suitable disconnection device in industrial plants and installations for protection against electric shock, fault protection, and fire protection. It can be used with all S200 circuit breakers and Tmax series compact circuit breakers up to T5 in industrial applications. RD3 residual current relays can indicate status through two output contacts and an LED light bar (in RD3P).