adjustable
131Adjustable Speed Drive — An electronic device that controls the rotational speed of motor driven equipment such as fans, pumps, and compressors. Speed control is achieved by adjusting the frequency of the voltage applied to the motor …
132Adjustable speed drives — Drives that save energy by ensuring the motor s speed is properly matched to the load placed on the motor. Terms used to describe this category include polyphase motors, motor oversizing, and motor rewinding. U.S. Dept. of Energy, Energy… …
