Magnetic Contactor | Electrical Contactors
Air Conditioners and heat pump condensing units have a big hidden switch, thats called a contactor! Contactors are an electric part inside the unit that has a 24 volt relay which, when energized by the thermostat, sends a signal to start up your outdoor unit and start cooling! When the thermostat calls for cooling, the contacts close and make the high voltage connection to your compressor and outdoor fan. This causes your outdoor unit to come on, start moving refrigerant through the system and in most cases, cooling your home!
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. The easiest way to know what type of contactor you need is to disconnect all power from your unit, open the side panel and look at it!
If you plan to replace it yourself, be sure to research properly as an incorrectly replaced contactor can cause other (sometimes costly) equipment failures.