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What Capacitors Do in an Air Conditioning System

The modern air conditioning system is a complex piece of refrigeration equipment. It relies on numerous precision parts in order to operate correctly. One of the key components inside an AC is the capacitor, which forms part of the electrical system that provides power to the air conditioner. Each AC contains a number of capacitors that serve various motors. At times, capacitors may fail and require an HVAC technician to replace them in order to restore the system to full operation.

The job of a capacitor in an AC

A capacitor is a component that stores energy within an electric field. In some ways, it is like a temporary battery. There are many roles that capacitors serve in electronic appliances. In an air conditioning system, capacitors serve to transmit electrical voltage to the motors to start them (start capacitors) and then keep them running (run capacitors). Capacitors are used to send voltage to the motors that operate the fans and the compressor, and then continue to send voltage periodically to keep the motors working.

Capacitor failure

One of the most common reasons for an inoperable air conditioner is a non-functional capacitor. There are some signs that will indicate a capacitor that is going bad or has already failed. The most common is a humming sound you can hear even when the fan is not operating. Although it is possible to force-start a motor and get fans running again when a capacitor has failed, please do not attempt this. The capacitor must be replaced, and only a professional should do this job. A technician will be able to carry out the replacement without the risk of electrical shock and see that the right type of capacitor is put in place.

If you need air conditioning repair in Fresno, CA or elsewhere in the Central Valley, call on the skilled professionals at Purl’s Sheet Metal & Air Conditioning. We are here for you 7 days a week.

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