YCM8C External Circuit Breaker A molded case circuit breaker (MCCB) is a type of circuit breaker that is commonly used as an external circuit breaker. MCCBs are designed to provide overcurrent and short circuit protection in electrical systems. Molded case circuit breakers are commonly used in a wide range of applications, including commercial buildings, industrial facilities, power distribution systems, and infrastructure projects. They are often installed as external circuit breakers to protec