Circuit breaker is used to cut off fault circuit of power supply system of the gantry crane or bridge crane. The circuit breaker should be heavy duty, quick make, quick break type. The rating of switch will be so chosen as to get complete protection by associated O/L relay or fuse under all normal/abnormal conditions such as full load, overload, locked rotor, short circuit etc., circuit breaker will be provided with overload/short-circuit protective device.
1. Application: Cut off fault circuit.
2. It is usually composed of contact system, arc extinguishing system, operating mechanism, release and shell.
3. Two types: low voltage circuit breaker and high voltage circuit breaker. The demarcation line is not very clear, more than 3KV is usually called high voltage circuit breaker.
4. Its function is to protect power circuit and electric motor.
5. Low voltage circuit breaker, also known as air switch, is used to turn on or turn off the load circuit. It also could be used to control the infrequently started motors.
6. Brands: CHNT, Schneider, ABB, or other brands available.