Why is the run capacitor put in the PSC Motors?

The incorporation of a run capacitor in Permanent Split Capacitor (PSC) motors primarily serves the purpose of enhancing efficiency and performance by enabling the motor to operate effectively with both the start and run windings engaged throughout its functioning. This capacitor improves the phase shift in the motor windings, allowing for a more uniform distribution of current and a smooth operation.

When the motor is running, the run capacitor works in conjunction with the start winding, creating a more balanced magnetic field which is crucial for the motor's continuous operation. This balance minimizes vibrations and improves overall reliability. Without the run capacitor, the start winding would be disconnected after a brief initial phase, causing the motor to operate less efficiently and potentially leading to issues in performance.

This design ultimately allows the motor to maintain a consistent torque and enhances operational stability, which is integral for applications needing extended periods of reliable function. Other options, such as improving motor speed or reducing noise, are secondary benefits but not the primary reason for the capacitor's use in PSC motors.