Why the first break circuit breaker, after the isolation switch off it?
when the circuit breaker is broken, the circuit has no current, pull the switch will not produce arc, There will be an accident.
Power failure, the circuit there is current, because the circuit breaker has the ability to arc, the first pull circuit breaker, there will be no problem,
can not disconnect the charged circuit, so the disconnector should be used in conjunction with the circuit breaker.
Because the circuit breaker has an arc extinguishing mechanism, you can disconnect the live circuit, and the isolation switch does not have the arc extinguishing mechanism
