CDW7series multi-function Air Circuit Breaker is designed for power distribution, circiut and equipment protection against failures such as overload, under-boltage, short-circuit and single-phase earthing. so they can be widely applied in the power distribution nets with AC50Hz, rated operation voltage 400V or 690V at rated current 400A-6300A. The intelligent release is designed with an excellent selective protection as the key part of the circuit breaker, to avoid power supply fault, and provide a more reliable, continuous and more safe power supply system. International standards: IEC 60947-1 Low-voltage switchgear and controlgear-General IEC 60947-2 Low-voltage switchgear and controlgear-Low-voltage circuit breaker