Switch disconnectors are a safety device designed to power down a circuit to allow for servicing and maintenance by cutting the power supply to isolated parts of the circuit. Switch disconnectors are available in fused and non-fused. A fused switch disconnector will use fuses to break the circuit, a whereas a non-fused version will instead use a rotary switch or knife-blade disconnect. This means these switch disconnectors are easy to reset without the need for replacement fuses. A rotary switch disconnect will break the circuit by rotating a lever, while a knife blade disconnect will use a hinge to lift a lever off a particular slot within the device.
Primarily used as an isolator switch or safety switch, switch disconnectors are an electrical safety device and would not be used as regular switching component. They can be used to manually disconnect power from circuit breakers and transformers as part of a regular maintenance routine simply by turning the handle to the correct position. Commonly used in industrial automation and control settings.
Whether using a rotary or knife blade method of disconnecting, non-fused switch disconnectors are available in a variety of settings to suit the requirements including the number of poles, maximum current, voltage rating, terminal and mounting types.