Why do capacitors fail

They plagued early 90s Amigas and Macs, early s PCs, and cheap hardware even today. So why do capacitors fail?

And how can you tell when a failed capacitor is a problem? Capacitors fail when the electrolyte dries out, or when the gas inside them builds up to a point that it opens a safety valve and the electrolyte leaks out. A good capacitor takes decades to dry out, but a cheap capacitor can leak within a few short years. Why do capacitors fail? The one in the middle exploded completely, due to excessive buildup. The ones to the right side are bulged, due to excessive but less extreme buildup.

Capacitors can fail for any number of reasons. Many of them simply die of old age. The most common electrolytic capacitors consist of three layers: a layer of metal foil, some kind of paper insulator, and a liquid electrolyte.

When this happens, there are no visible signs from the outside. But when you test the capacitor out of circuit, you find it no longer behaves how it did when new.

Once it drifts too far from its original properties, other components malfunction, since the capacitor is no longer doing the same work it used to do. How long it takes varies. The caps in old tube radios, which usually date to the s or earlier, are almost always shot. The caps in ZX Spectrum computers are usually worn out and need replacing for the computer to work right. But the caps in the similarly-aged Commodore 64 are usually fine.

The capacitor is essentially like a rechargeable battery. This usually requires anywhere from to volts. Without a functioning capacitor, your AC unit will not turn on. The amount of capacitors that are inside an AC unit will solely depend on the type of AC unit that you have, as well as the size of the unit and your home. Our heating and AC repair technicians in St.

Paul, MN will take a look at your AC unit to give you a good idea of what to expect. There are actually two different types of AC capacitors. These types of capacitors have different subtypes and they also do different jobs. Start capacitors are responsible for producing the electricity needed to start the motor and the fans.

These capacitors only engage long enough to ensure that the AC unit is running. Once the AC unit is running, start capacitors will disengage and wait for the next time that they are needed. Run capacitors are used more often than start capacitors. This is because these capacitors need to run the entire time that the AC unit is running. It creates a magnetic field that keeps the coil motors moving throughout the entire operation.

Unlike start capacitors, there are two different types of run capacitors: single-stage run capacitors and dual-stage run capacitors. Single-stage run capacitors will start and power only a single motor or device.

They have two terminals at the top. On the other hand, dual-stage run capacitors will run more parts and will usually be found in AC units with a condensing unit. Dual-stage run capacitors have three terminals at the top. As you can see, the capacitors do a fairly tough job. They also go through a lot of wear and tear, as their work will easily take a toll on them physically.

AC capacitors are extremely sensitive to heat, which is why they are normally hidden deep inside the AC unit. Heat will cause this part to lose its ability to hold an electrical charge. This can cause the capacitor to become much less efficient. Or, in worst case scenarios, it could cause the capacitor to fail.

When this happens, most heating and AC repair technicians are going to recommend that you replace the part with a new one. I called precision at 6am and they were here before noon. Simple problem fixed, cool house. I love these guys! Thank you Ray at Precision Air This morning Ray was there to replace the compressor and had us feeling the cool air again in no time. Great customer service Ray even offered to clean the filters! Thank you!!

Austin was professional, super friendly and answered all my questions. Precision Air will have all my hvac business going forward!! Thanks for being a reputable and honest company!!! He did a great job; professional and knowledgeable! Precision Air is a company of integrity. I signed up with them August 1st, for their AC maintenance plan for 2 years Someone from their office called me a week ago to set up their yearly maintenance visit.

Precision Air and Plumbing is a wonderful company to work with! They are very experienced and professional. It was time to replace our AC, and so our choice was Precision Air, as we've been with them for over 20 years. Feel free to contact us any time at for immediate assistance. We offer 24 hour emergency service, and would be happy to schedule an appointment for you, or simply answer any questions you may have.

Services Services. Areas We Serve. What is a Capacitor? Why Good Capacitors Go Bad Capacitors fail every day — they do a tough job and, unfortunately, their work takes a toll. These include: Heat exposure. Precision January 14, Share This Post:. Precision We want to help you learn about about all things air conditioning and heating!