MCCB Moulded case circuit breaker is a kind of economic breaker, has the features as following, such as steady and reliable property, reasonable structure, beautiful style, small volume, etc. This breaker applies to the circuit with AC 50/60Hz, rated insulation voltage 660V, max. rated current 1250A as on-off operation, and take effect, it also can be used as unfrequent conversion of line and unfrequency.