How does the direction of rotation change in a single-phase motor?

In a single-phase motor, the direction of rotation can be altered primarily by reversing the connection of the start winding. This is because single-phase motors often operate using a main winding and a start winding to create a rotating magnetic field. The start winding is responsible for establishing the initial phase difference required for motor operation.

When the connections of the start winding are reversed, the phase relationship between the two windings changes, which in turn alters the direction of the rotating magnetic field. Consequently, this causes the motor to rotate in the opposite direction. This method is the simplest and most common way to change the motor's rotation direction without modifying any physical components or adjusting power settings.

In contrast, other options, such as altering the rotor design or reversing the power supply phase, do not effectively change the rotation direction in single-phase motors. The rotor design is fixed, and reversing the power supply phase would primarily apply to three-phase motors rather than single-phase configurations. Adjusting speed controller settings typically influences the speed of the motor but does not directly impact the direction of rotation.