In
electrical engineering, a
disconnector,
disconnect switch or
isolator switch is used to ensure that an electrical circuit is completely de-energized for service or maintenance. Such switches are often found in
electrical distribution and
industrial applications, where machinery must have its source of driving power removed for adjustment or repair. High-voltage isolation switches are used in electrical substations to allow isolation of apparatus such as
circuit breakers,
transformers, and transmission lines, for maintenance. The disconnector is usually not intended for normal control of the circuit, but only for safety isolation. Disconnector can be operated either manually or automatically (motorized disconnector).