Contactors

Air Conditioning Contactors have a 24 volt relay that is energized by the thermostat. When the thermostat calls for cooling, the contacts close and make a high voltage connection to your compressor and outdoor fan. This causes your outdoor unit to come on.

There are several types of contactors, but most of them are fairly inexpensive and easy to replace by the consumer. Contactors with covers are your best bet as they keep out the dirt and insects which can cause wiring shorts and buildup - the 2 primary reasons for contactor failure. If you plan to replace it yourself, be sure to research properly as an incorrectly replaced contactor can cause other (sometimes costly) equipment failures.