CDM7 Series moulded case circuit breaker is designed for power distribution network with AC 50/60Hz, rated work voltage 690V and rated insulation voltage 690V. It is used to non-frequent making and breaking operation under normal conditions for overload and short circuit protection. The circuit breaker with rated frame class current less than and including 400A can be used in the squirrel cage type motor for non frequent starting, breaking in operation, and it also can provide overload,short circuit and under-voltage protections for motor.