Simply speaking is the difference between size, not only the size of the frame, the circuit breaker is larger than the molded case circuit breaker, and the frame breaker current level, segmentation ability is greater than the molded case circuit breaker. This is essentially different, so the frame breaker and molded case circuit breaker are used in different occasions. The frame is applied to the upper line, and the plastic case is applied to the lower level of the frame.