Why Does My Air Conditioner Have Capacitors?
Why Does My Air Conditioner Have Capacitors?

July 20, 2015


When electricity flows, it isn’t in an even manner. It surges and ebbs, and as such, needs help being streamlined. Your air conditioner runs on alternating current, which is electricity that runs on alternating polarity. This means the electricity changes between positive and negative, which is necessary for electro-mechanical systems like your air conditioner. However, this kind of electricity needs help being streamlined, and this is where your capacitors come in.

Two Kinds of Capacitors

Your air conditioner has three different components with their own motors: two fan motors (the indoor blower and condenser fan) and the compressor motor. Because your air conditioner uses alternating current for power, these motors need some help in both starting up and managing the flow of electricity that powers them; this help comes from capacitors. These capacitors are:

  • Start capacitor

  • Run capacitor

Start capacitors store energy for when the component needs a boost of energy, such as at start-up. For instance, when the compressor motor starts, it needs a great deal more energy than it does to run; the start capacitor provides this boost of energy. Once the motor is running, it needs a steady flow of electricity at a specific rate; because electricity doesn’t naturally flow like this, help is needed, and this is where the run capacitor comes in. The run capacitor smooths out the voltage surges in the alternating current, providing electricity to flow to the motor steadily at 1.5 times higher the nominal voltage.

Capacitor Breakdown

Capacitors have a lifespan of about 6 years. Signs of capacitor breakdown can include hard starting, overheating, electrical overload or the non-working of a motor. Because of the electrical complexity of your air conditioning system, it’s imperative to allow only a trained expert to perform any work.

The cooling pros at Bronco Plumbing Heating and Air are here to help with all of your air conditioning repair needs in Fair Oaks, CA, so if you suspect you may have an electrical problem with yours, call us today!