JV(GV) series circuit breakers are mainly used for the overload and short. circuit prot-ection for motors in the circuit of AC 50/60Hz. rated operating voltage up to 660V rated operating current from 0.1Ato 80A as the full-voltage starters to start and cut off motors under the Ac3 load and for the circuit protection in the circuit of 0.1A-80A.