How does a PSC motor differ from a capacitor start motor?

A PSC (Permanent Split Capacitor) motor is characterized by its use of only a run capacitor, which remains in the circuit during both starting and running operations. This capacitor aids in providing phase shift necessary for the motor to start and run efficiently. One of the significant features of PSC motors is their relatively low starting torque, making them suitable for applications where high start-up forces are not critical.

In contrast, a capacitor start motor typically has a higher starting torque because it incorporates a start capacitor that is disconnected from the circuit after the motor reaches a specific speed via a centrifugal switch. This switch allows for an initial boost during the start-up phase but is disengaged once the motor is running steadily.

The distinction in the use of capacitors and the operational characteristics, particularly the torque developed at start-up, highlights why the choice indicating that a PSC motor has low starting torque and utilizes only a run capacitor is the correct understanding of how these two types of motors differ.