Close this search box.


AC Capacitor – Complete Guide

AC capacitors are very important as they can stop the functioning of the entire HVAC system. If there is a malfunctioning AC capacitor, you will have to replace it. In such a case, the air conditioner will be forced to provide cool air. This can result in high power bills and wear out of your AC.

Although a capacitor has a similar appearance and functionality to batteries, they are not batteries. You will have to connect capacitors to wiring inside the air conditioning system. An AC capacitor has high voltage and is very dangerous. Mishandling or touching it can lead to serious injury.

What Is The Use Of Air Conditioner Capacitor?

AC CAPACITORThe main function of an AC capacitor is to provide an initial jolt of electricity to the motor of your air conditioner. It works by storing electricity and then sending it to the motor in powerful bursts. The capacitor will reduce the energy output once the air conditioner is running and up. Even though the air conditioner may be working, there will be steady power from the capacitor.

The work of a capacitor is similar to that of a temporary battery which is to provide a constant power supply. It also absorbs and stores electrical energy so that the air conditioner works efficiently and reliably. The unit of AC capacitors is microfarads and voltage. Microfarad describes the electric current capacity of the capacitor. It can be in the range of 5 to 80 MFD. Voltage reflects the electrical current which is moving on the capacitor. If it has more voltage, the electrical current moves faster.

AC Capacitors Types: There are many types of capacitors each having different functionality. For air conditioners, control panels, coolers, and washing machines, motor run capacitors are utilized. Here are the different types of AC capacitors.

  • Motor capacitors
  • Dual capacitors
  • Fan capacitors
  • Lighting or ballast capacitors
  • Power capacitors
  • Special purpose capacitors

AC Capacitors Electrical Parameters: The electrical parameters of AC capacitors are as follows.

  • The capacitance range is from 1.0 to 400 microfarad (MFD).
  • The frequency is 50 Hz.
  • The temperature range is from -40-degree Celsius to 85-degree Celsius.
  • The tolerance is +/-5% and +/- 10%.
  • The housing can be of nylon, aluminum, plastic, M.S box, or PBT.
  • The rated voltage is 250, 440, 550, and 660 volts.

AC Capacitors Terminations: The following are AC capacitors terminations.

  • The “L” Type is for the single terminal.
  • The “U” Type is for the double terminal.
  • Screw Type.
  • “WT” (wire type). Can be with or without lugs.

AC Capacitors Special Features

Some of the special features of an AC capacitor are

  • Flame retardant capability.
  • Self-healing ability.
  • Resistant to vibration.
  • Compact size and shatterproof construction.
  • High dielectric strength and high insulation properties.
  • Low-temperature rise and low losses.
  • Approvals from UL, CE, ERDA, ERTL, CPRI, and NTH.

Replacing A Faulty Air Conditioner Capacitor

Problems with regards to the motors of the air conditioner can be due to a faulty AC capacitor. Replacing a faulty AC capacitor can be costly and therefore, you have to be sure that it needs replacement. You can get the help of a professional to find out if he recommends replacing faulty AC capacitor.

Signs of AC Capacitor Need to be Replaced

  • Increased Energy Bills:The electricity consumption will be more when the AC capacitor is having reduced strength. It will achieve cooling by consuming more power. This can lead to high energy bills.
  • Below Par Cooling:Another sign of a faulty AC capacitor is that it will not be effective. As the fan motors will stop working, the cooling performance will be reduced.
  • Visual Guesses:You can say that the AC capacitor needs replacement by having a look at it. It can become swollen or bulge outwards. There can also be leaking oil or it can blow apart. This can happen when the electrical components run at high temperatures during hot summer months.


We now know the importance of AC capacitors. When there is a faulty AC capacitor, there can be poor cooling and high energy bills. AC capacitors come with many features and they have different electrical parameters. You can easily find the different types of AC capacitors that make sure there will be an effective cooling performance by your air conditioner.

Leave a Reply

Your email address will not be published. Required fields are marked *