What does An Air Conditioning Capacitor Do?

With so many components jam-packed inside of your air conditioning system, it’s easy to overlook a small, yet important part – your air conditioning capacitor. If you don’t know what this is or how it works, then don’t worry. Let’s dive into why this part is such a big deal for your AC unit.

A Little Part with a Big Purpose

Your air conditioner capacitor looks sort of like a battery. However, it’s anything but. Unlike ordinary batteries, capacitors store and discharge strong jolts of energy – usually in excess of what batteries can deliver and sustain.

You’ll find the capacitor deep within the outdoor cabinet on your AC system. You can look, but don’t touch – as high-voltage devices, capacitors are extremely dangerous to handle even when power to the AC unit is shut off.

Why Your AC Needs a Capacitor

Your air conditioner needs power – and lots of it – to successfully start up when needed. However, that takes more energy than your home’s power wiring can reliably deliver. That’s where the air conditioning capacitor comes into play.

Think of the capacitor as a tiny jump-starter that gives your AC an extra boost when it needs one. The capacitor supplies additional current to the compressor and blower fan motors on start-up, ensuring your entire AC system works properly.

Start vs. Run Capacitors

Some air conditioners have a pair of capacitors – one for start-up and another that supplies additional current as the unit runs. These “start” and “run” capacitors work in tandem to keep your AC unit going without wasting unnecessary amounts of energy.

If one or both capacitors fail inside of your AC system, your HVAC technician may replace both with a “dual capacitor.” Smaller and lighter, these capacitors perform the same duties as separate start and run capacitors while taking up less space.

What If Your AC Capacitor Fails?

Like any other component, your air conditioning capacitor can fail unexpectedly. Most failures come from age, but exposure to excessive heat can also shorten a capacitor’s lifespan. Power surges and lightning strikes can also do a number on an AC capacitor, not to mention other sensitive electronics on your AC unit.

You may run into the following issues if there’s something wrong with your air conditioning capacitor:

  • The unit takes a long time to start its cooling cycle
  • The unit won’t start at all or randomly shuts off
  • You can hear a humming noise while your AC unit runs
  • The unit runs, but does not produce cold air
  • You can see or smell smoke while the unit runs
  • You’re using more energy than usual

Attempting to replace your own AC capacitor could result in serious injury or even death. Instead, leave the troubleshooting and replacement to the pros at Gulf Coast Air Systems.

Similar Posts