Are you familiar with contactors for air conditioning systems? Central air conditioning systems contain a variety of electrical parts, such as contactors. Contactors work by controlling the flow of electricity. Because they act as mediums for electricity, though, they can burn out.

Overview of Contactors

A contactor is an electrical device that either allows or prohibits electricity from traveling through it. Contactors work like a switch: They are made of a conductive material, such as copper, through which electricity can travel. A contactor can remain closed so that electricity can travel through, or it can open to block the passage of electricity.

How Contactors Work

Contactors work in conjunction with thermostats. Thermostats are interfaces that allow homeowners to control their air conditioning systems (and their furnaces). When it’s time for your air conditioning system to turn on, the thermostat will send a signal to the contactor. The contactor will then close so that electricity can travel through it.

Most condenser units contain a contactor. The condenser unit is the large box-like assembly outside of your home. Among other things, it contains your air conditioning system’s compressor, condenser coil and condenser fan.

The contactor works by providing power to electrical-driven parts like the compressor and condenser fan. When it receives the signal from the thermostat, the contactor will close so that electricity can reach these parts. After your air conditioning system has completed its cooling cycle, the thermostat will send another signal to the contactor telling it to open.

Common Problems With Contactors

One of the most common problems with contacts is burnout. Contactors are designed specifically to allow or prohibit electricity from traveling through them. Therefore, they can overheat and even burn out. As electricity travels through a contactor, it will heat up. Over time, this heat may permanently damage the contactor, in which case it may no longer be conductive.

Contactors can also get stuck. All contactors have two available positions: open or closed. They will switch between these positions based on signals sent by the thermostat. But contactors can get stuck, meaning they won’t be able to change their position.

Rather than switching, they will remain in their current position. Contactors can get stuck open, in which case electricity won’t be able to travel through them, or they can get stuck closed, meaning electricity will always be able to travel through them.