AC Drives

AC Variable Frequency Drives (VFD) control the speed of an AC Induction motor by varying both the voltage and frequency of its output power to the motor. They only work with 3-phase motors, not single-phase motors.   VFD drives coupled with AC motors are quickly replacing DC drives and DC motors as the preferred method of varying the speed of an electric motor due to the much lower cost of the AC systems. 

VFD drives can also run 3-phase motors from single-phase supply.  This is possible on smaller sized motors, usually up to about 5 HP.  This makes it possible to run 3-phase motors with variable speed from standard home AC power. 

Caldwell Electric is an authorized distributor for Lenze, AC Tech, Weg, and Worldwide drives. We have been repairing and selling electric motors and motor controls for more than 40 years and can offer expertise in selecting drives for specific applications as well as diagnosing problems with motors and motor control systems.