On a capacitor start motor, when is the capacitor connected into the circuit?

In a capacitor start motor, the capacitor is specifically designed to provide an initial boost of energy to help start the motor. When the motor is turned on, the capacitor is connected into the circuit during start-up, which improves the phase shift of the current supplied to the motor’s windings. This phase shift creates a stronger starting torque that is necessary to overcome the inertia of the load and initiate rotation.

Once the motor reaches a certain speed, typically around 70-80% of the rated speed, a centrifugal switch or an electronic relay disconnects the capacitor from the circuit. This disconnection is crucial because, once the motor is running, the capacitor is no longer required for its operation and could lead to inefficiencies or overheating if left connected.

The options referring to continuous connection, connection upon reaching half speed, or connection during full load operation do not accurately describe the function and operation of a capacitor start motor, which relies on the temporary assistance of the capacitor only during the initial start-up phase.