In CSIM the necessary phase difference between stating current (Is) and main winding current (Im) is produced by the electrolyte type capacitor which is connected series with starting winding as shown below.
The capacitor is mounted on outside the motor because it is designed for extremely short duty services and guaranteed for note more than 20 periods of operation per hour and each period does not exceed 3 seconds.
When the motor reaches about 70% to 80% of rated speed then centrifugal switched off and hence both capacitor as well as starting winding disconnected from the motor.
The phasor diagram showed the phasor difference between stating current (Is) and main winding current (Im) is large (80 degrees) and hence torque developed by this motor is higher than other single phase induction motor.
The value of the starting capacitor must be large and starting winding resistance low to obtain high starting torque.
This motor is also reversed by reversing of any winding same as split phase motor.
Application-
This motor is used for a load of high inertia when frequent starting is required.
This motor is most suitable for pump and compressor and therefore they are used for RAC compressor.
This motor is also used for desert cooler motor, conveyer and other machine tools where high starting torque is required.