What effect does lower voltage have on the starting torque of a compressor motor?

Lower voltage applied to a compressor motor affects its starting torque negatively, resulting in a decrease. When a motor is designed to operate at a specific voltage, the electrical characteristics, such as current and power, are closely linked to that voltage. When the voltage is reduced, the motor does not receive enough electrical energy to generate the necessary magnetic field strength to produce adequate torque.

Starting torque is crucial for getting the compressor moving, especially in applications where it must overcome initial resistance from the system (like pressure in a refrigeration circuit). If the voltage is below the design specification, the motor will struggle to start. This often leads to insufficient torque to initiate its operation, causing the compressor to stall or fail to start entirely.

In contrast, if the voltage were to remain stable or increase, the starting torque would improve, providing the motor with the ability to start effectively under load conditions. Lower voltage ultimately hampers the motor’s ability to perform its intended function reliably.