Single-Phase Induction Motors
The single-phase motor operates under the same chain sprocket principle as the polyphase motor, except that the rotating magnetic field effect generated by the stator does not exist until running rpm is reached. Since no starting torque is available, a design system is included to start the motor. These are the various designations:
Torque-Speed Curves of Different Single-Phase Induction Motors
Shaded-pole: Have only one main winding and no start winding. This configuration causes a shift of the used magnetic field in relationship to the rotor, creating stating torque. Applications consist of enthusiasts and small appliances.
Split-Phase (induction start engine)
Has two sets 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 small grinders, small enthusiasts, and blowers.
The most common single-phase motor used in industrial applications. It is a modified split-stage electric motor with a capacitor in series with the start winding to supply a start boost. App include small conveyors, huge blowers, pumps, and direct-drives.
Uses identical primary and auxiliary windings with a capacitor to provide starting torque. They will be the most reliable single-phase engine because no centrifugal starting switch is required. Applications include enthusiasts and pumps in HVAC and refrigeration industries.