Which component primarily influences the starting torque of a single-phase motor?

The component that primarily influences the starting torque of a single-phase motor is the starting capacitor. In single-phase motors, particularly capacitor-start motors, the starting capacitor plays a crucial role in creating a phase shift in the current that flows through the motor windings. This phase shift allows for the creation of a rotating magnetic field, which is necessary for generating the initial torque to start the motor.

When the motor is at rest, the capacitor helps to establish a difference in the voltage applied to the auxiliary winding compared to the main winding. This difference not only creates the necessary phase shift but also enhances the starting torque, enabling the motor to overcome its inertia and begin rotating.

Once the motor reaches a sufficient speed, the capacitor is often disconnected from the circuit (via a centrifugal switch or an electronic relay), allowing the motor to run efficiently on only the main winding. The effective use of the capacitor thus directly impacts how well the motor starts and the strength of the torque generated during that initial phase of operation.

The rotor and stator winding certainly contribute to the overall operation of the motor, but it is the starting capacitor's ability to create the required phase difference that is primarily responsible for influencing the starting torque. The end bell, on the other hand, provides