Has your AC capacitor been diagnosed as bad or failing? You might be wondering what they are and how AC capacitors work. In this post, we’ll examine the functions of AC capacitors, why they are so valuable in your HVAC unit’s electrical system, and answer questions about repair and replacement.
How Do AC Capacitors Work
Similar to a starter for a car’s engine, an air conditioner capacitor provides a powerful jolt of electricity to the cooling system motor for it to start functioning. A capacitor operates a little differently than a starter because giving the initial spark of energy, the capacitor reduces the power output and supplies a consistent, low voltage energy supply until the cooling cycle completes.
Capacitors may resemble batteries, but they serve a different purpose. They are high-voltage devices which, due to their connection with the wiring in the air conditioning system that is also connected to the home’s electrical grid, can be highly hazardous. Although the power is off, the capacitor stores energy similarly to a battery, and this is why they are so dangerous.
The power of an AC capacitor is determined by both voltage and microfarads. Microfarads refer to the amount of electricity the capacitor can hold, usually between 5 and 80 MFD. Voltage indicates the flow rate of electrical current and a higher voltage means a quicker flow. For a capacitor to be functioning correctly, it should both store and allow the right amount of electricity to pass through.
Different Types of Capacitors
Depending on your HVAC system, your AC capacitor will be one of the following types.
1. Start Capacitor
Start capacitors provide a boost of stored energy to get a motor running. They are commonly used in single-phase electric motors and feature two terminals and have enough power to start the motor.
2. Run Capacitor
The run capacitor works to run the compressor and fan motor components in an air conditioner once the start capacitor has started the motor. They feature two metal terminals and come in several different ratings such as: 6 mfd, 25 mfd, 35 mfd, 40 mfd, 50 mfd, and 60 mfd.
3. Dual Run Capacitor
A dual capacitor are dual-voltage capacitors that are used in HVAC systems for the fan motor and compressor, so it does the job of both run and start capacitors. They are available in three ratings: 15+5 mfd, 25+5 mfd, and 40+5 mfd. Run capacitors hold enough electric charge to run the unit through the entire cooling cycle.
Can AC Capacitors Be Repaired?
AC capacitor problems cannot be repaired, but if the issue lies with the wiring to the start capacitor and not a bad capacitor, then a simple repair will do the trick. Otherwise, a new capacitor will need to be installed to replace the faulty ac capacitor.
How Often Do AC Capacitors Need to Be Replaced?
Air conditioner capacitors typically need to be replaced after around 20 years, depending on the model. If you have noticed a decrease in performance from your AC recently, it may be time to check the capacitor for signs of corrosion or damage. Over time, AC capacitors can wear down and break, leading to decreased efficiency and higher energy bills. Having it serviced by a professional can help restore your AC system back to its original performance levels.
There may be other reasons to replace your capacitor before its time. For example, power surges from storms may damage the HVAC capacitor. If you experience a power outage and then notice warning signs of a failing capacitor with your AC system, contact HVAC professionals for a diagnosis.
Can I Replace My AC Capacitor?
AC capacitors have a constant charge of electricity, since it’s their job to store it. That means even an old capacitor may be storing electricity that can be dangerous, even when the power is shut off to the entire unit. It’s recommended that you don’t not attempt to replace your even diagnose your AC’s capacitor problems, but instead call an experienced HVAC technician for the job. If you’re experiencing symptoms of a failing AC capacitor, which you can read more about here, contact the experts at Dolphin Cooling and Heating.