Which type of capacitor contributes to improved energy efficiency in motors?

The run capacitor is designed specifically to enhance the energy efficiency of motors during their continuous operation. It works by providing a phase shift in the motor’s electrical supply, which increases the motor's running efficiency. This phase shift improves the power factor, allowing the motor to produce more torque while consuming less electricity, leading to reduced energy costs. In applications where the motor is running for extended periods, the presence of a run capacitor will maintain better performance and lower losses compared to motors without such a component.

In contrast, start capacitors are utilized primarily to provide an extra boost of power during the initial startup of the motor. They are designed to temporarily increase the starting torque but are not intended for continuous operation, which is why they do not contribute to energy efficiency in the same way as run capacitors. Permanent capacitors operate similarly to run capacitors but are fixed and not intended to be replaced, whereas transform capacitors are not standard components in motor operation and pertain to different electrical applications.