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.

Where is the disconnect switch?

A disconnect switch is often located on the exterior of a residence near the exterior unit of the central air-conditioning system. A disconnect is an added safeguard to quickly disconnect the electricity from an electrical device rather than disconnect it at the main breaker panel.

What does a disconnect do?

Electrical disconnects are switches that isolate all wiring in a home or other building from the source of power, typically the utility power service. ... This disconnect may be a special breaker switch housed in an exterior box enclosure, or it may simply be the main circuit breaker on the home's main service panel.