What type of starting method does a split-phase motor primarily use?

A split-phase motor primarily uses the resistance starting method. This motor type is designed with two windings: the main winding and the auxiliary winding. The auxiliary winding is connected in series with a resistor at startup, introducing phase shift due to impedance. This phase shift allows the motor to develop a starting torque that is necessary for it to begin running.

Once the motor reaches a certain speed, a centrifugal switch typically disconnects the auxiliary winding (and its series resistor), allowing the motor to operate solely on the main winding. This method is particularly effective for lower torque applications, such as fans and small pumps, where simplicity and cost-effectiveness are important.

The other starting methods, such as capacitor starting, are employed for different types of motors, particularly in applications that require higher starting torque. Direct starting is less common for split-phase motors, as it would not provide the necessary torque for starting, while induction starting relates more to asynchronous motors that do not use auxiliary methods like resistors or capacitors for starting aid.