REF601/REJ601 and REM601 are members of ABB’s Relion® protection and control product family and its 605 series.

These relays provide an optimised composition of protection, monitoring and control functionality in one unit,

with the best performance and usability in its class.

The relay REF601/REJ601 offers various application configurations for Feeder protection and control while 

REM601 offers application configurations for Motor protection and control.

Protection and control

REF601/REJ601 offer three-stage overcurrent and two-stage ground fault protection functions.

The low-set stages for overcurrent and ground fault protection are equipped with selectable characteristics

– Definite Time (DT) and Inverse Definite Minimum Time (IDMT).

The relay features standard IDMT characteristics according IEC 61255-3 – Normal Inverse, Very Inverse,

Extremely Inverse, Long-time Inverse.

They also feature characteristics according to ANSI C37.112 – Moderate Inverse, Normal Inverse, Very Inverse, Extremely Inverse.

The relay has a special

characteristic RI Inverse (RI) for better coordination with the rest of the network.

Additionally the relays also support two setting groups.

Thermal overload protection for feeder, cable and transformer,

negative phase sequence protection phase discontinuity protection and circuit breaker failure protection are also offered.

An auto-reclose function for overhead line feeders is optional.

The REM601 offers protections for motors such as thermal overload protection,

short circuit protection, startup supervision, loss-of-phase protection, negative phase sequence protection,

ground fault protection, undercurrent protection and circuit breaker failure protection.

An emergency restart feature allows motor start up even when start inhibit is activated.

The residual current for CT configured relays is derived from the phase currents.