What is an Air Conditioner Contactor and What Can Go Wrong with One?

Under the hood of an air conditioner, there is a complex system of electrical components that work together to turn your system on and off at the right times. Although it’s not necessary to understand exactly how this electrical system works, there are a few of its components that are useful to know about in the event that something goes wrong. One such component is a contactor. Today we’re going to talk about what an air conditioner contactor is and what can go wrong with your system if it malfunctions!

What is an air conditioner contactor?

A contactor is a device that controls the flow of electricity to your air conditioner. You can think of it like a drawbridge that connects a road over a river. When the drawbridge is down, cars can freely drive over the river. When the drawbridge is up, cars must wait on either side of the bridge until it is lowered back down.

In the same way, a contactor either blocks or allows the flow of electricity to your air conditioner’s condenser, compressor and motors. When your air conditioner is off, the contactors are up and they block electricity from reaching your system’s major components. When your thermostat wants to start a cooling cycle, it sends a small voltage to the contactors that lowers them and connects the flow of electricity to the rest of your air conditioner. Once your thermostat is satisfied, it sends another voltage to the contactors that signals them to lift up again and disconnect the flow of electricity.

What can go wrong with an air conditioner contactor?

• They can burn out. Over time, contactors can burn out due to either normal wear and tear or overheating. When a contactor burns out, the component that it supplies electricity to will not be able to turn on.
• They can get stuck down. A contactor can get stuck while it’s down for a number of different reasons. When this happens, electricity will constantly flow through the contactor and certain parts of your air conditioner might continuously operate even if the rest of the system is shut down.
• They can get stuck up. Alternatively, a contactor can get stuck while it’s up. When this happens, the components connected to the contactor will be starved of electricity and will not turn on when they are supposed to.

Avoid contactor problems with annual tune-ups

The best way to avoid problems with your contactors is to schedule annual tune-ups with Jerry Kelly. During a tune-up, we’ll inspect all of your system’s electrical components, including the contactors. We will clean off any dirt that has built up on the contactors since your last inspection and replace any worn out contactors when necessary.

If you have any questions about an air conditioner contactor, or if you’d like a cooling system serviced or installed in your home, contact Jerry Kelly, your St. Charles, MO, air conditioning contractor. We provide service all over the St. Louis area, including towns like Dardenne Prairie, Des Peres and Frontenac, MO.

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