S280 3 phase ac power circuit breaker is mainly used for special occasions where two main circuits can not work at the same time. To prevent the simultaneous closing of the circuit breaker, the product can switch the line safely and quickly. It realize the switching between stand-by power supply circuits and other protection functions. Iiâ??s mainly used in the overload protection and short-circuit protection of the circuit which is DC 50Hz/60Hz, 1 pole230v, 2/3/4 poles DC1000V.