Keeping Your AC System Cleaner

Homeowners: Is Your AC's Run Capacitor Faulty?

by Yolanda White

When the temperature outside becomes unbearably hot and stuffy, the first thing you might do is crank up your air conditioning system. But if your air conditioning system struggles to start up, take a good look at the run capacitor inside your outdoor unit. The run capacitor could be on the verge of failing. Learn more about the capacitor and what to do about your device below.

Does Your AC Need a Run Capacitor?

Although your cooling system uses electricity, the unit outside your home relies on different types of devices to run. One of the devices used by the unit is a run capacitor (or capacitor for short). A capacitor supplies energy to the compressor motor and fan inside the unit through small parts called contacts. If your capacitor or its contacts and electrical wiring weaken, it won't be able to send jolts of electricity to the parts inside the unit.

A capacitor usually comes in aluminum or another type of metal. Over time, moisture and age can cause rust to develop on the surfaces of a capacitor. Rust can cover and corrode the device's contacts as well.

Normal wear and tear can also cause a capacitor to become faulty or fail. The device may slowly lose its ability to store energy, which may affect how well the compressor motor functions over time. If the compressor doesn't obtain the proper amount of energy it needs to keep your unit running, it will eventually burn out and fail. If your cooling system stalls or doesn't come on at all, have an AC repair company check the capacitor.

How Do You Test a Faulty Run Capacitor?

An air conditioning repair service can generally tell if the run capacitor is bad by simply examining it. If the capacitor appears corroded, a repair technician may go ahead and change it. A technician may also need to change out or replace the wires attached to the device.

If the capacitor doesn't appear corroded on the surface, a contractor may test the device's ability to store and transmit power. Unless your cooling system is completely shut down or inoperable, a technician may need to turn your AC on to test the capacitor. If a contractor tests the capacitor with the system on, they may be able to obtain a better and more accurate reading of the device. A contractor can use the results of the test to determine whether or not you need to replace the run capacitor. 

If you need to replace or repair your faulty run capacitor, contact an air conditioning technician for assistance now.