circuit breaker Circuit Breakers Function: mini circuit used for line overload, short circuit protection and infrequent conversion of lines. It can also work as on-off switch for load circuits. Easy Installation: Modular sturcture, can be easily installed on the DIN standard guide rail in distribution box, bistable locking clip. Applications: miniature circuit breaker is mainly used for the illumination of office buildings and residential buildings. It is used for distribution and protection the facilities from damages caused by overload and short-circuit.