YKM1 series of molded case circuit breaker (short for circuit breaker),AC50/60HZ,Current :63- ... 800A,Voltage:400V,500V,690V,800V.. YKM1 series of molded case circuit breaker (short for circuit breaker), is the latest circuit ... functions of overload, short circuit and undervoltage protection which can protect the circuit and power equipment from damage.SpecificationFrame class rated ...