AC Capacitor Replacement - Sunset Air and Home Services - Fort Myers FL - 300 x 158

AC Capacitor Replacement

It is that time of year when Air Conditioners need replacement parts, and the AC Capacitor is the most common. This article was written to explain what an AC Capacitor is, and also, to help people understand the basic reasons why they fail.

Good and Bad AC Capacitor Comparison - Large2
The bad capacitor (Left) is bowed outward on the top and bottom from high internal temperatures.

Your air conditioning system has two types of motors, a condenser fan motor and a blower motor. It also has a compressor. Each of these three major components must use a capacitor to properly start up and run. The three capacitors store and release energy as needed within a circuit. The compressor capacitor is the largest due to the amount of voltage required to start the compressor. It is very common to see a large increase in the failure rates of capacitors during the summer heat.

Good and Bad AC Capacitor Comparison - Small2
Regular preventative maintenance can help avoid unexpected capacitor failures.

Below are a few of the main reasons that can cause a capacitor to go bad.

7 Reasons Why An AC Capacitor Can Go Bad

1) The capacitor is not designed for a continuous electrical load. For example, if the fan motor becomes blocked from turning or burns out, the capacitor in most cases will experience an overload and be destroyed. That is why it is so important to keep the outdoor unit clear of any debris that could damage the fan motor, or restrict the air flow.

2) Voltage above the rated value for the capacitor might also destroy it. For example, a power surge from a lightning strike or a power outage would cause a severe current spike and probably “burn out” the capacitor. High voltage surges can cause the internal compounds to boil. The capacitor will look like an expanded balloon when this occurs. Sometimes they explode or crack open.

Inside An AC Capacitor

3) A capacitor has a separator inside and it can dry out if the unit gets too hot, which can cause it to develop an internal short circuit. The capacitor can fail if its internal temperature routinely goes above 145 degrees Fahrenheit. In our climate, this is a common occurrence due to our extreme summer temperatures and the demand on the air conditioning system.

Your air conditioning system will eventually experience worn out and damaged parts. As this occurs, it will take a toll on the components like the capacitor. A capacitor must disengage after a few seconds or it will overheat. A compressor or fan motor that is laboring due to damaged or worn out bearings might cause the capacitor to burn up.

4) Lightning can damage a capacitor, a compressor, the fan motor or the wires in the unit.

5) A malfunctioning relay switch can also cause the capacitor to overheat by leaving it in the circuit too long.

6) Even a weak power surge can damage or destroy the capacitor, which can lead to compressor overload and subsequent failure.

Sure sign of a problem

If the capacitor is leaking oil, this is a sure sign that it has a problem and failure is soon to follow.

7) Normal wear and tear – Even when the capacitor is protected from damage, electrical surges, overheating or incorrect electrical loads, it will eventually fail due to normal wear and tear. The life expectancy of an air conditioner capacitor varies with the climate and usage pattern, but a typical life expectancy of a capacitor is about five to six years. Due to the nature of this component, it is very difficult to give an actual time frame on the life span of a capacitor.

When Will My AC Capacitor Fail?

Capacitors are a very important part of your AC System. There are many reasons why they may fail. However, regular preventative maintenance can help you avoid some part failures. Sunset Air and Home Services provides three different options to choose from. Call us today to find out which solution is best for you.

Related Topics