Selection of Electric Motor Starting Capacitors

The selection, installation, testing, and use of electric motor starter start and run voltage capacitor used on various electric motors found in or at buildings, such as air conditioner compressors, fan motors, some good pumps, and some heating equipment, are explained in this series of articles on electric motor capacitor.

These electric motors start and operate effectively thanks to a capacitor. We also go over how to choose the right hard start capacitor and wire it to a compressor motor, fan motor, the compressor for a refrigerator or freezer, or electric motor (such as a good pump) that has trouble starting. A device’s capacitance is its capacity to hold an electrical charge.

An electric motor capacitor is a device that initially stores, then releases, an electrical charge to assist with starting an electrical motor (starting capacitor) or maintaining it in motion (run capacitor). The electrical charge or potential energy stored in the capacitor is used to give the motor a power boost so that it can overcome inertia and begin rotating.

Motor Capacitor Types

You should be aware that some motors utilize a combined start/run capacitor while others don’t use either at all before attempting to replace a capacitor.

• A single start and run capacitor

A secondary run capacitor maintains the motor spinning smoothly while a start capacitor kick-starts it into motion.

• Start/run capacitor combined

A start/run capacitor integrates the operations of a start capacitor and a run capacitor into one unit. Three electrical connections will be included on these caps:

· S = start wire connector

· R = Run wire connector

· C = common connector

Your electric motor may thus be a model that includes both start and run characteristics if it only has one physical capacitor. Examining the labeled terminals of the motor capacitor will reveal this.

• Dual capacitor

One physical capacitor is used to power a higher-amperage motor, such as the compressor in an air conditioner compressor/condenser unit, and a second, smaller capacitor is used to power a smaller motor, such as the cooling fan motor. These two physical capacitors are combined inside of one physical device as a dual capacitor.

How do you identify whether an electric motor’s starting or running capacitor needs to be replaced?

• Bad start capacitor

The START cap is likely damaged if the electric motor hums while beginning or has problems starting but will run if prodded. The START cap is probably damaged if the motor hums but does not begin to rotate and the thermal overload safety switch has not activated.

• Bad Run Capacitor

The RUN cap could be damaged if the electric motor uses a lot of currents when it’s operating. Other factors include damaged motor bearings and overworked motors.

In conclusion, a failing motor may be difficult to start, but since replacing the cap is relatively inexpensive compared to replacing the motor, the expert will frequently attempt it first to see if she can prolong the motor’s life before replacing it. You must trust reliable suppliers and manufacturers for an electrical condenser, capacitors, and other electrical components.