I often see two types of motors used in heavy appliances. One with a capacitor and one with the starting relay. The relay has a very thick winding connected in series with the main winding that holds the phase winding in the circuit until the motor comes up to speed and the phase winding is switched out of the circuit. (In the application with the relay, I'm not sure if the term *phase winding* is corect.) I believe the capacitor types are called PSC (permanent split capacitor). In either case I see a field wound with finer wire that is offset (angular displacement) from the main field coil. This phase winding is used to produce starting torque. In either case, removing the capacitor or starting relay, the motor will hum and not spin (draws heavy current and can overheat). Manually spinning the shaft in either direction gets it started in the direction turned.
On PSC motors, removing the capacitor while it is running does not change the speed, but current draw is increased by several percent.
My question is: Can the motor that starts with the current relay be adapted to use a capacitor or is the angular displacement if the phase/starting winding different from the PSC motors?