The 3RR2 current monitoring relays can be directly mounted on the load feeder similar to overload relays. Even when they are primarily intended to monitor the motor current, the focus is on protection of the application. Thanks to monitoring of overcurrent, undercurrent, wire break or phase failure, V-belt tear or a stalled conveyor can be quickly detected and signaled. Thanks to direct fitting to the contactor, there is no need for additional wiring in the main circuit.

The current monitoring relays with screw-type or spring-loaded connections are available in two versions with graded functionality: A 2-phase basic version (parameterized via the potentiometer) and a 3-phase standard version (parameterized via the display). For the standard version, residual current monitoring, phase sequence monitoring and stall monitoring as well as restart delays, can be parameterized. The device also features a digital output that issues a warning signal before tripping. All diagnostic messages are simply displayed on the display of the device.

Thanks to the wide range of the control supply voltage from 24 to 240 V, and only two versions through to 40 A, a large number of different types of application are covered by a small number of variants of the SIRIUS 3RR2 current monitoring relay. For installation as a single unit, the single-unit adapter is available that is familiar from the overload relay.