In the event of a fire, the non-fire power supply must be forcibly removed by the fire linkage system. At the same time, the fire control host must receive a feedback signal to confirm the operation of the shunt release.
1) The fire protection linkage system receives the feedback signal of the shunt tripping action from the auxiliary contacts as a "true" signal.
2) The method of replacing the feedback signal of the auxiliary contact by the relay to obtain the action signal by the relay is called the "false" signal.
In order to obtain the "true" signal (the circuit breaker may be inoperable due to an intermediate relay action), the circuit breaker accessory of the shunt release and the auxiliary contact is usually used in the design. The feedback signal of the circuit breaker action is assisted by the circuit breaker. Contacts and input modules lead to the fire control room.