What is a molded case circuit breaker

Molded case circuit breakers are also called device circuit breakers. All parts are sealed in plastic casings. Auxiliary contacts, undervoltage releases and shunt releases are mostly modularized. Due to the very compact structure, molded case circuit breakers are basically impossible to repair. Most of them are manually operated, and electric opening and closing can be selected for large capacity. Due to the application of electronic overcurrent releases, molded case circuit breakers can also be divided into Class A and Class B. Class B has good three-stage protection characteristics, but due to price factors, the use of thermal magnetic releases Class A products have a higher market share. The molded case circuit breaker is to install the contacts, arc extinguishing chamber, release and operating mechanism in a plastic shell. Generally, maintenance is not considered. It is suitable for the protection switch of the branch circuit. The over-current release has thermal magnetic Generally, thermal magnetic molded case circuit breakers are non-selective circuit breakers, which only have two protection modes: overload long time delay and short circuit instantaneous protection. Electronic molded case circuit breakers have overload long time delay, short circuit short Four protection functions of time delay, short circuit instantaneous and ground fault. Some newly launched products of electronic molded case circuit breakers also have regional selective interlocking functions. Most molded case circuit breakers are manually operated, and some have motor operating mechanisms