What is the main operational characteristic of a capacitor start motor?

The main operational characteristic of a capacitor start motor is that it utilizes a capacitor to create an initial phase shift in the current supplied to the motor. This phase shift is crucial for generating the necessary starting torque to overcome inertia and get the rotor moving when the motor is turned on. The capacitor is temporarily connected in series with the start winding, allowing it to create a magnetic field that is out of phase with the current in the main winding. This leads to a stronger starting torque compared to other types of single-phase motors that might rely on different mechanisms.

Capacitor start motors are particularly useful in applications requiring high starting torque, such as air compressors and pumps. The design allows for efficient startup, with the capacitor typically being disengaged from the circuit once the motor reaches a certain speed, relying on the main winding alone for sustained operation.