BYEW series ACB is suitable for distribution network with AC 50Hz, rated working voltage of 400V / 690V and rated current of 200-6300A, which is used to distribute electric energy, protect lines as well as power equipments from overload, short circuit, under voltage, single-phase grounding, residual current and other faults. The selective protection of the circuit breaker is accurate, which can improve the reliability, continuity and safety of the power supply system.