Protection functions

REB611 offers phase-segregated (three phases) high

impedance differential protection and non-directional earth

fault protection for busbars, motors and generators. The relay

also offers high-impedance differential-based restricted earth

fault protection for motors, generators, reactors and power

transformers. REB611 is ideally suited for backup protection.

Application

REB611 offers bus-differential protection in a single zone with

bus-wire supervision. It also offers the possibility for bus

differential protection over two zones using two REB611 relays.

The combined restricted earth-fault and residual earth-fault

protection functionalities of the relay enable its use in the

protection of a motor or generator. Due to the individuality of

the high-impedance protection functions, a single relay can be

used for restricted earth-fault protection of both the high and

low voltage sides of a power transformer.