Single-Phase Induction Motors
The single-phase motor operates beneath the same principle as the polyphase chain sprocket 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 available, 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 and no start winding. This configuration causes a shift of the applied magnetic field in romantic relationship to the rotor, creating stating torque. Applications include supporters and small appliances.
Split-Phase (induction start engine)
Has two pieces of stator windings. The “start” windings are positioned 90 degrees to the “run” windings and change the magnetic field of the stator, inducing beginning torque. Applications include little grinders, small fans, and blowers.
Capacitor-Start
The most typical single-phase motor used in industrial applications. It is a modified split-phase motor with a capacitor in series with the start winding to supply a start boost. Application include small conveyors, large blowers, pumps, and direct-drives.
Permanent-Split-Capacitor (PSC)
Uses identical main and auxiliary windings with a capacitor to provide starting torque. They will be the most reliable single-phase electric motor because no centrifugal starting switch is required. Applications include fans and pumps in HVAC and refrigeration industries.