... case circuit breaker (short for circuit breaker),AC50/60HZ,Current :63-800A,Voltage:400V,500V,690V,800V.. YKM1 series ... 690V and below, (YKM1-63: 400V), rated working current 800A to infrequently transfer and infrequently starting. The circuit breaker ... the circuit and power equipment from damage.SpecificationFrame class rated current (A)Rated current (A)Rated working voltage(V)Rated insulation ...