Single-Phase Induction Motors
The single-phase motor operates under the same chain sprocket principle as the polyphase electric motor, except that the rotating magnetic field effect generated by the stator will not exist until running rpm is reached. Since no beginning 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 one main winding no start winding. This configuration causes a shift of the applied magnetic field in relationship to the rotor, creating stating torque. Applications consist of supporters and small appliances.
Split-Phase (induction start engine)
Has two models of stator windings. The “start” windings sit 90 degrees to the “run” windings and shift the magnetic field of the stator, inducing beginning torque. Applications include small grinders, small supporters, and blowers.
Capacitor-Start
The most common single-phase motor used in industrial applications. It is a modified split-stage motor with a capacitor in series with the start winding to supply a start boost. Software include small conveyors, huge blowers, pumps, and direct-drives.
Permanent-Split-Capacitor (PSC)
Uses identical primary and auxiliary windings with a capacitor to supply starting torque. They will be the most reliable single-phase motor because no centrifugal starting switch is necessary. Applications include enthusiasts and pumps in HVAC and refrigeration industries.