Troubleshooting a Capacitor
What is a capacitor? What does it do for your air conditioning system you might ask. Well, let me tell you. A start capacitor is the silver cylinder pictured in the control panel of this air conditioning condenser above. Its function is to start your compressor and your condenser fan motor. Basically a capacitor stores an electrical charge and consists of one or more pairs of conductors separate by an insulator. Its used on all single phase 240 volt, and 120 volt applications in residential HVAC systems. The amount of electrical storage capacity on a capacitor is known as capacitance. This is what every capacitor has printed on the side of it. Usually that rating is given in microfarads. A capacitor with a dual rating, like the ones used in many outdoor air conditioning units, is used to start both your compressor and fan motor. One side of that capacitor can go bad without affecting the other side. Then again, sometimes both can be bad. They’re easy to test using the MFD setting