What is a dual-capacitor motor?

A dual-capacitor motor is defined specifically by its use of two capacitors: one for starting the motor and another for running it. The starting capacitor provides a significant boost of electrical energy to create the necessary torque to start the motor, particularly in applications where initial inertia is high. Once the motor reaches a certain speed, a switch (often a centrifugal switch) disconnects the starting capacitor, allowing the running capacitor to take over.

The running capacitor is designed to improve the motor's efficiency during its operational phase, leading to increased performance, smoother operation, and reduced energy consumption compared to motors that utilize only a single capacitor. This dual-capacitor design effectively enhances both start and operational efficiency, making it highly valuable in various applications.

In contrast, a motor with just a running capacitor does not have the additional starting capacitor to assist with initial torque, which can be limiting in some scenarios. A motor with no capacitors will lack the phase shift needed for starting and running properly, while one that requires external capacitor support might not have the self-contained system that dual-capacitor motors provide. Thus, the dual-capacitor design distinctly contributes to the motor's capability and efficiency in various industrial or commercial applications.