Is the zero line going through the circuit breaker?
if there is a device leakage or short shell, circuit breaker (fuse) can not be broken, So that all the lines on the line of the device shell to bring the leakage voltage.
Three-phase three-wire, the use of protection to zero system, the zero line is absolutely not allowed to go through the circuit breaker, because the zero line is broken,
Three-phase four-wire zero line is absolutely not allowed to go through the circuit breaker, because the zero line is broken, the line of all 220V appliances will withstand 380V line voltage and burned.
220V single-phase line, the zero line through the circuit breaker, because the single-phase line wiring staff complex, chaotic, many times can not tell the line of fire, zero line, so the two have to go through the circuit breaker to avoid electric shock accidents.
