Single-Phase Induction Motors
The single-phase electric motor operates beneath the same principle as the polyphase motor, except that the rotating magnetic field effect generated by the chain sprocket stator does not exist until running rpm is reached. Since no starting torque is obtainable, a design mechanism is included to begin the motor. These are the various designations:
Torque-Speed Curves of Different Single-Phase Induction Motors
Shaded-pole: Have only 1 main winding no begin winding. This configuration causes a shift of the applied magnetic field in relationship to the rotor, creating stating torque. Applications include enthusiasts and small appliances.
Split-Phase (induction start electric motor)
Has two pieces of stator windings. The “start” windings sit 90 degrees to the “run” windings and shift the magnetic field of the stator, inducing starting torque. Applications include little grinders, small fans, and blowers.
Capacitor-Start
The most common single-phase motor found in industrial applications. It really is a modified split-phase motor with a capacitor in series with the beginning winding to provide a start boost. App include small conveyors, huge blowers, pumps, and direct-drives.
Permanent-Split-Capacitor (PSC)
Uses identical main and auxiliary windings with a capacitor to supply starting torque. They are the most reliable single-phase motor because no centrifugal starting switch is necessary. Applications include fans and pumps in HVAC and refrigeration industries.