Run Capacitor: Not Quite The Flux Capacitor

Ok, so this round canister-looking part in the picture is not actually a flux capacitor, and it can’t help you time-travel, but it really is called a run capacitor.  The run capacitor plays a very important role in how well the air conditioner runs.

What a Run Capacitor Does

A run capacitor's function is to start compressors and motors and keep them running at a normal amp draw level.  These components will commonly fail in the middle of summer, especially during extreme heat warning days. Because of the constant wear and tear on the capacitor, the microfarads (often coded on your service invoice as “MFD”), which is the rating of the capacitor, start to diminish over time and lose the charge.  Once it loses the charge, it gets weaker and weaker until it eventually fails.  The run capacitor is a small component of an A/C unit, but plays a big role, and any problem with the run cap greatly affects the unit’s operation and efficiency. During a service call, part of our 22 point inspection is checking the microfarad readings on your run capacitor. This way, we know before it breaks if it needs to be replaced.

Where They Come From

Run capacitors are made in various countries-China, Mexico, and the USA.  Run caps made in China do not have the same durability as the ones made in North America.  This is because the parts made in China are produced with a different chemical, causing them to be less durable in extremely hot climates.  If you do have a run cap that is replaced by a different contractor, be sure to get one that was made in the USA, as it will last much longer!

Despite its inability to help you get to the future, the run capacitor is an integral part of your air conditioner.  If you want to get the run cap, or any other part of your A/C inspected to make sure it’s working at peak performance, call us today!