Single-Phase Induction Motors
The single-phase motor operates beneath the same principle as the polyphase motor, except that the rotating magnetic field effect generated by the stator will not exist until running rpm is reached. Since no starting torque is available, a design mechanism 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 no start winding. This configuration causes a change of the used magnetic field in relationship to the rotor, creating stating torque. Applications include followers and small appliances.
Split-Phase (induction start motor)
Has two sets of stator windings. The “start” windings are chain sprocket positioned 90 degrees to the “run” windings and change the magnetic field of the stator, inducing starting torque. Applications include small grinders, small supporters, and blowers.
Capacitor-Start
The most typical single-phase motor found in industrial applications. It really is a altered split-phase electric 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 are the most reliable single-phase engine because no centrifugal starting switch is necessary. Applications include enthusiasts and pumps in HVAC and refrigeration industries.