What is a Square D Disconnect Switch?

A Square D disconnect switch is a device which allows an electrician to kill the power to an air conditioning unit or other high-draw equipment so maintenance can be safely performed. These switches are required by law and are designed for safety purposes. Turning the unit off is not enough to protect from an electrical shock. A Square D disconnect switch should be installed on the exterior of the unit and be easily accessible when needed during maintenance operations. While it is technically possible to install a disconnect switch inside a system such as an air conditioning unit, it is not advised. In addition to needlessly increasing the danger for an electrician or maintenance person, internally installed disconnect switches may be in violation of both building codes and the warranty for the unit. A Square D breaker and disconnect switch should be used only in accordance with their intended purpose and according to building codes.