An isolating switch is a device mainly used for isolating power sources, switching operations, and connecting and disconnecting small current circuits without arc extinguishing function. The main function of an isolating switch is to disconnect circuits without load current, so that the repaired equipment has a clear breakpoint with the power supply to ensure the safety of maintenance personnel. An isolating switch does not have a dedicated arc extinguishing device and cannot cut off load current and short circuit current, so it must be operated when the circuit is disconnected by the circuit breaker.