Air Conditioner Capacitor: Uses and Detection

On a warm and sunny day, you may find that the air conditioner, or A/C, is nothing less than a blessing from God. You turn it on for some time, and soon enough, it is as if you are in a different, cosy place of comfort. It can turn your room or apartment bracing and relaxing. It is a marvellous machine. But as is with all electronic machinery, it can face some problems with its parts and equipment. Capacitor, for example. Capacitor plays a crucial role in the working of an air conditioner. Its malfunction can lead to reduced efficiency of the entire air conditioning unit. So it is critical to replace the faulty capacitor with a new one to keep the A/C in perfect running conditions.

Uses of a capacitor

First things first, let’s understand a capacitor in brief. A capacitor is an electronic device that stores electrical energy. Its working is not very complex. Talking about an A/C unit, the capacitor used in an A/C unit is called a run capacitor. Its role in A/C is to start the fan. It is critical equipment as it stores the charge before giving it to the motor. A capacitor makes sure that a uniform electrical power is reaching the fan, which elongates its life. So if its life starts deteriorating over time, it affects the fan’s life and working too. Various reasons can lead to a faulty capacitor and hence inefficient cooling from your A/C. Some of these reasons are-

  1. A worker may have installed a bad capacitor.
  2. High outside temperature.
  3. There is a short circuit in the A/C.
  4. There is an unstable power transmission from the source.
  5. You are using the A/C unit for a long time, leading to overheating.

Any of these factors can cause problems in the capacitor, whether it is old or new. In such a situation, it is best to replace it.


Now that you know what may cause your capacitor to stop working, you need to look out for signs of defects. Here’s how you can detect if your A/C’s capacitor is faulty or not working-

  1. You hear your fan making sounds.
  2. The fan will not run as fast as before.
  3. Cooling is not as efficient as it was.
  4. You can see or smell smoke from the A/C components outside.
  5. Your energy or electricity bills are high.

There are more symptoms, but these are the most obvious ones. If you observe any of these signs, it is high time to consider replacing your A/C capacitor.

While you need comfort in harsh summers, safety still trumps comfort every time. Now you know what a capacitor is and why it malfunctions. You also now know how to detect a faulty capacitor. As emphasized earlier, a capacitor is a vital component in the working of an A/C. It controls the flow of charge and protects the fan and motor. If you notice any of the before-mentioned defects in the A/C unit, or you think that your capacitor is getting old, you can try to repair it. Remember to take necessary precautions and safety measures, like turning off the main switch and using rubber gloves. If you are unsure, it is always safe to call a professional for help. They know how to detect a faulty capacitor and locate it. The correct rating of the capacitor is vital, so professionals install a capacitor that is fit for your A/C at a reasonable cost.