The NDW2 series of universal circuit breakers (hereinafter referred to as circuit breakers) can be applied to the distribution network with the AC 50Hz/60Hz, the rated current of 200A~6300A, the rated insulation voltage of 1000 V, the rated working voltage of AC220V/230V/240V, AC380V/400V/415V, AC440V/480V, AC660V/690V. NDW2-4000 can also be applied to the distribution network with the rated working voltage of AC1000V for distribution of electrical energy and protecting circuit and power equipment from overload, under-voltage, short circuit, single phase grounding and harm of other faults, and can also be used as isolation switch at the same time. The circuit breaker has multiple protection functions. It can avoid unnecessary sudden power failure while realizing highly accurate selective protection, and improve the reliability and security of the power supply system.