A circuit breaker is an automatically operated electrical switch which is designed to protect an electrical circuit from damage caused by overload or short circuit. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.
A high capability provides a reliable protection against thermal overload and short circuits at both the building sector and the industrial electrical installations and equipment. They are noted for a very short breaking time assured by a reliable switching mechanism, simple and fast electromagnetic release and perfect extinguishing system. Smart Circuit Breaker connected with the undervoltage release is designed for tripping it in case of voltage drop: using the shunt trip enables the indication of ON/OFF position of the main contacts.