Adjustable-speed drives can be variable-frequency speed drives(VFDs)—which refer to alternating-current drives only, or variable-speed drives (VSDs) which can be alternating-current or direct-current drives. Either of these can vary the speed of a motor, one by altering frequency and the other by adjusting voltage. But how does this affect the conductor sizing for the motor branch circuit? Does it even have an effect? Find out in this video on the topic of adjustable-speed drives.