How Can You Tell If You Have a AC Bad Capacitor?
After a long hot summer in North Carolina, my 4 year old air conditioner decided to take a break. Prior to the house heating up, the first sign that I noticed was the condenser outside was making a soft buzzing sound. The condenser is the box that sits outside the home and contains fins that are similar to an automobile radiator with a large cooling fan. Its purpose is to remove heat from the refrigerant before it returns back into your air handler inside.
Inside the house I noticed that air handler was still running and the temperature was starting to rise. Under normal circumstance, if the air handler is running, the outdoor condenser unit should also run. At this point I realized that there was an issue with the system so I turned it off and began to investigate the problem.
My initial thought was that the cooling fan had seized but before I started to take apart the system, I did a bit of research online. After scouring several web forums, I decided that my problem may lie in the air conditioner capacitor. This device is similar in size to a can of Red Bull and gives the compressor and fan the jolt of electricity needed to get started. These devices apparently fail more commonly than fan motors. A dead giveaway that there is an issue with the capacitor is if it is bulging at the top, like a can of soda that has been left inside a freezer to freeze. The top of the capacitor should be smooth and not contain any type of bulge. Another visible sign of a bad capacitor is oil leaking from the capacitor.
After turning off the power and removing the electric access panel and locating the capacitor, I immediately spotted the problem. The top of my AC capacitor was so swollen; it looked as if it could pop any second. The capacitor had the part number 97f9833 and it was a GE Brand.
Much to my surprise, this part was only $16.00 from Grainger. This OE equivalent was produced by Dayton and the part number was 2MEE9A. The only thing that stood between me and a cool home was the fact that it was in the evening and the local store did not open until the morning. Luckily, I had just purchased a 6500 BTU window unit recently that kept us cool that night.
The next morning I rushed to Grainger to pick up a new Capacitor. In just a matter of minutes I was back home and began the process of swapping out the old for the new.
Replacing an AC Capacitor Unit
Before getting started you should always ensure that the power has been turned off to the outdoor unit. There is usually a breaker both inside panel box and outside at the unit. Turn both breakers off and use a voltmeter to ensure that there is no power going to the AC unit. There are 220 volts present which enough to cause serious injury or even death. I can not emphasis enough the importance of safety here.
Once the juice has been switch off and verified, locate the capacitor. It is usually on the side of the air conditioner unit and requires that you remove the panel. Once you have located the capacitor take a screwdriver and place it between each lead to drain any juice that remains in the capacitor. Note, there are three leads and it is important where each wire connects to. Before disconnecting the wires, use a ¼ inch socket to remove the strap which holds the capacitor in place.
Next, compare the old capacitor to the new capacitor. They should be similar but are not always exactly the same. Size and shape will likely vary between manufactures. The important thing here is the number of leads and the electrical specifications that are printed on the side. Disconnect one wire at a time from the old unit and place it on the new unit. Doing it this way ensures that you do not mix up any wires.
With the new unit connected, mount it in place and replace the access panel. Turn your power back on at the breaker box and lower your thermostat until the air conditioning turns on. Check the unit and ensure that it has turned on and the fan is running.
All together this project took around an hour, including the time it took to pick up the part. By doing it myself, I saved over $200 and the downtime of waiting for the repair man.