Which type of overcurrent protective device is described as a molded case circuit breaker?

• A. Current-limiting fuse
• B. Insulated case circuit breaker or low voltage power circuit breaker
• C. Molded case circuit breaker
• D. Thermal overload relay

Answer: (C)

Overcurrent protection devices come in fuses and breakers. A molded case circuit breaker is a circuit breaker built in a molded insulating case, designed to interrupt current if a preset overload or short circuit occurs and then be reset after tripping. The description in the question points to this exact device because it names a molded case circuit breaker.

A current-limiting fuse, by contrast, is a fuse that melts open and cannot be reset. A broader term like insulated-case circuit breaker or low-voltage power circuit breaker refers to a similar family of devices but is not the specific term that matches the description given. A thermal overload relay protects motors and is used with a contactor rather than acting as a standalone molded case circuit breaker.