Updated at: 20-10-2022 - By: Sienna Lewis

One of the most prevalent causes of AC failure is a defective AC capacitor. Each and every one of an air conditioner’s electrical components would be incomplete without capacitors. Because of this, we recommend that you check your air conditioner’s capacitor if it’s having issues. You should first learn what an AC capacitor works before attempting to repair one.


Capacitors are devices that store electrical energy. Allowing maximum current to flow, a fully charged capacitor discharges its charge. Until the current is minimal and the voltage is highest, the capacitor discharges, and the voltage rises steadily. As a result, the voltage is not in sync with the current.

AC Capacitor Cost: Average Replacement Prices – Upgraded Home

Without a capacitor, the voltage and the current are in phase — as the voltage rises, so does the current. Using a capacitor, the voltage is brought out of phase with the current.

What Does an AC Capacitor Do?

capacitors are cylindrical cylinders that can hold a lot of power (in other words: a short-term battery). In order for the unit to function, the motors need to be supplied with electricity. An AC unit contains a number of capacitors. Start capacitors (which provide signals to start the motor) and run capacitors (which send signals on a regular basis to keep the motor running) are two examples of this. Each compressor, exterior fan, and blower motor often has its own capacitor.

An AC unit contains a number of capacitors. Start capacitors (which provide signals to start the motor) and run capacitors (which send signals on a regular basis to keep the motor running) are two examples of this. Each compressor, exterior fan, and blower motor often has its own capacitor.

What Is A Capacitator In An Aircon?

In an air conditioner, what does a capacitor do? Let’s get to know this air conditioning component first.

The charge is stored in the electrostatic field by means of this electrical mechanism.

In a nutshell, it is a gadget that stores power for a short period of time. The cooling system motors are also started and the voltage is stabilized.

An air conditioner’s power supply is critical since it powers the motors, which are essential for its operation. It follows that the air conditioner will not work if its capacitator malfunctions. Then it would be less efficient if it were to do so.

When an air conditioner fails, the failure of its capacitator is generally to blame.

Air Conditioner Motors

There must be a rotating magnetic field generated by an electric current that travels ahead of the magnetic field generated by an electric motor. The rotor’s opposing magnetic field is pulled by the revolving magnetic field, causing the motor shaft to rotate. Single-phase alternating current can only provide one of the two required magnetic fields for a motor’s start up. There are two north and south poles in every field.

To start under the weight of the compressor, the single-phase motors found in air conditioners require a powerful, supplementary field. Without the additional field, the motor hums, but it does not turn.

AC Capacitor - LA Construction Heating and Air

Capacitor Start Motors

Capacitors placed in line with an additional winding cause voltage to fall behind current. This creates an extra magnetic field that is out of phase with the primary winding’s field. The rotor begins to rotate as the fields between the motor windings rotate in response to the alternating current’s rise, fall, and reversal.

In order for an air conditioner’s motor to start turning, it needs a high current flow from a starting capacitor. The starting capacitor is disconnected when the motor reaches full speed, which is controlled by a switch.

Capacitor Run Motors

Air conditioner motors are no longer provided with an extra magnetic field when the switch disconnects the starting capacitor. However, a larger motor would require more electricity and be less efficient even if it could continue to turn without the additional field.

The additional magnetic field can still be provided by a smaller capacitor, but it consumes less current. The air conditioner may use a smaller, more efficient motor because of the phase-shifted magnetic field created by the run capacitor, which is permanently linked to the motor’s auxiliary winding.

But What Causes Capacitator Failure?

If you use the device for a lengthy amount of time, the capacitator is likely to fail. It’s a regular occurrence in tropical nations, where the climate is humid and hot.

Due to the abuse of the air conditioner, the capacitator may malfunction due to the high temperature outside and the overheating.

When your air conditioner’s fan is operating and you hear a humming noise, it’s an indication that your capacitor needs to be replaced.

What Does A Capacitor Do In Your Air Conditioner?

Your air conditioning unit’s capacitator should be preserved by regular maintenance and good use in order to extend its lifespan.

If you live in an area with a hot climate, this is especially true. Keep in mind that your air conditioner has to work twice as hard to maintain a comfortable indoor temperature.

The unit will be overworked if it is continuously utilized throughout the year. During the cooler months, you may want to leave your AC off.

It’s also a good idea to operate it in its dry mode, as it will use less electricity. It’s also possible to turn off your unit when the room temperature reaches the desired level.

As long as the windows are closed, the room will remain at a comfortable temperature.

How to Diagnose an AC Capacitor Problem

You should be able to figure out whether your AC capacitor is failing on your own if you know what to look for. The capacitor is the most likely culprit if you hear a buzzing noise yet the fan is not running. This is particularly common in the summer, when the hot weather and the motor’s heat combine to cause more damage to the capacitors.

If you want to be sure, you can take a test to see. Try lightly pushing one of the fan blades with a long, slender stick. There is a good chance that your “start” capacitor is failing. The cogs of the machine aren’t turning because of the capacitor’s lack of power.

How to Diagnose and Repair An Air Conditioner Capacitor - Dengarden

How to Repair an AC Capacitor

Do-it-yourself starter capacitor repair instructions can be found here:

To begin, turn off the electricity at the circuit breaker or disconnect switch: This matters! There is a risk of injury if you don’t. Don’t attempt this repair if you aren’t confident in your abilities.

To find out where the capacitor is, remove the service panel from your AC unit. Here’s a sample of what you can expect:

Removing power from the capacitor: This is a critical phase, so be careful! Even if you’ve shut off the unit’s power, there is still electricity in the capacitor. Never contact the terminals with your bare hands because of this. There will be a need to discharge your capacitor. To understand how this video works, pay close attention. Using Richard Lloyd/video, YouTube’s you can see how it works.

Disconnect the capacitor once it has been discharged to prevent it from overheating. A screw from a metal band will very certainly need to be removed.

Before disconnecting the wires, make a note of how the wires join. This will make the installation of the new one substantially simpler. Take a picture of them so you can look back to it later.

Pull the wires from the old capacitor with needle-nose pliers and a gradual rocking motion.

The microfarads and voltage rating of a new capacitor are the most significant factors to bear in mind when purchasing a new capacitor. The new capacitor does not have to be the same size as the old one.

Visit Appliance & A/C Parts Today if you live in the Tampa Bay, FL area. Capacitors are among the many A/C appliance parts that we stock. The sooner you get in touch with us, the better.

It’s A Wrap!

You now understand the purpose of an air conditioner’s capacitor.

It’s our hope that the information we’ve shared with you thus far will help you keep your air conditioner from breaking down. Call a professional if you can’t fix it yourself.

However, if you use and maintain your device properly, you can avoid costly repairs.

Maintaining and using an air conditioning system incorrectly might lead to malfunctions.