For single phase or three phase coil breakers. Through a small supervision current the whole circuit is supervised, in both positions of the circuit breaker (open or closed).
The correct state of the circuit is showed with a green LED on the front plate of the relay. The output contacts change their position if the relay detects a failure in the continuity of the circuit.
The single coil trip circuit supervision relay can be manufactured with diﬀerent LED indicator configurations, refers to selection chart for more detailed information.
There are two types of tripping circuit supervision relays: