QYW1 series intelligent universal circuit breakers are used in distribution networks with AC 50Hz, rated voltage up to 660V (690V) and below, rated current 200A-6300A, to distribute power and protect lines and power supply equipment from overload, undervoltage, short circuit, single-phase grounding and other faults. The circuit breaker has intelligent protection function and precise selective protection, which can improve the reliability of power supply and avoid unnecessary power outage. At the same time, it has open communication interface and can carry out "four remote" to meet the requirements of control center and automation system.