The phase shift of 90° between the main winding and the auxiliary winding is achieved by a connected capacitor which feeds the auxiliary winding and is connected on the single-phase AC mains. The capacitor will achieve a phase shift of 90° between the main and the auxiliary winding, producing an acceptable initial torque.
To generate an acceptable initial torque, a capacitor connected to the single-phase AC power supply is used to create a 90° phase shift between the main and auxiliary windings. This phase shift is essential for proper operation of the system.