Running Capacitors

Some single-phase AC electric motors require a “Run Capacitor” to energize the second-phase winding (auxiliary coil) to create a rotating magnetic field while the motor is running. Motor Run capacitors are designed for continuous duty while the motor is powered, which is why Starting Capacitors are avoided, and low-loss polypropylene capacitors are used. Run Capacitors are mostly polypropylene film capacitors and are energized the entire time the motor is running.