The Different Types of Capacitors for Fan Motors

By David Karanja

A capacitor is a component whose main function is to store electricity or electrical energy. It also functions as a filter which only allows AC current to flow through while inhibiting passage of DC current. Capacitors have two electrode plates placed parallel to each other and separated by an inductor or insulator. Current stops flowing through the capacitor only if it is fully charged. There are different types of capacitors used in fan motors.

Metalized Film Capacitors

Metalized polyester film capacitors are used in motors of air-conditioning systems which have two capacitors. One capacitor is used with the compressor motor while the second one is used with the fan motor. These capacitors have thin electrodes of aluminum foil interlinked with a very thin plastic dielectric. The plastic, however, can be replaced with other materials such as polyester and polystyrene in cases where high-voltage capacitors are needed.

Ceramic Capacitors

Ceramic capacitors are used in automotive and other applications such as air-conditioning systems because they offer high capacitance and high voltage. A ceramic capacitor consists of a thin ceramic dielectric that is metalized on each side and coated with a protective layer which is dipped in electrified protective material to become thick.

Ceiling Fan Capacitors

Ceiling fan capacitors are mainly used in ceiling fans. They are composed of two conductors separated by a dielectric. When voltage is detected by the two conductors, electrical energy is stored in the capacitor. This electrical energy gives rise to a mechanical force. Ceiling fans need capacitors because they convert energy into mechanical energy which is used to turn the blades. A malfunctioning or damaged capacitor can result in the fan running slowly or not at all. A capacitor may also stop working if the speed settings are not working and may need manual rotation for it to start working.