Single-Phase Induction Motors
The single-phase motor operates under the same chain sprocket principle as the polyphase engine, except that the rotating magnetic field effect produced by the stator will not exist until running rpm is reached. Since no starting torque is obtainable, a design mechanism is included to begin the motor. They are the various designations:
Torque-Speed Curves of Different Single-Phase Induction Motors
Shaded-pole: Have only one main winding and no begin winding. This configuration causes a change of the applied magnetic field in relationship to the rotor, creating stating torque. Applications consist of supporters and small appliances.
Split-Phase (induction start electric motor)
Has two units of stator windings. The “start” windings are positioned 90 degrees to the “run” windings and shift the magnetic field of the stator, inducing starting torque. Applications include small grinders, small fans, and blowers.
Capacitor-Start
The most common single-phase motor used in industrial applications. It really is a modified split-phase engine with a capacitor in series with the start winding to provide a start boost. Application 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 will be the most reliable single-phase engine because no centrifugal starting switch is necessary. Applications include followers and pumps in HVAC and refrigeration industries.