For a 240-volt single-phase motor, how many power poles are needed in its starter?

In a 240-volt single-phase motor, the correct number of power poles needed in its starter is one. This is because a single-phase motor operates using a single phase of electrical power, which requires only one set of contacts in the starter. The basic function of the starter is to provide the necessary electrical connection to the motor, allowing it to start effectively.

In a single-phase system, the starter typically includes a contactor and overload protection. The contactor will have one power pole to close the circuit to the motor when energized. The simplicity of this setup is fundamental to single-phase motor operation, as these types of motors do not require multiple poles to function. Understanding this helps in grasping the design and function of motor starters for single-phase applications.