Process Control Panels
VFD Control Panels
Duplex Control Panels
Frequently Asked Questions
After turning off power and letting the capacitors discharge, swap any two leads to the motor. Some drives can also change rotation with programming; this should be done with caution as many impellers are threaded on! Note, because the VFD is controlling the frequency output to the motor, changing the incoming feeds will NOT change the rotation.
Variable Speed Drives take incoming line alternating current (AC) power and change it to direct current (DC) power, and then use high speed switches to simulate alternating current output to the drive, which allows control of the frequency of the power going to the drive. Even when the incoming power is single phase because the drives are rectifying the power to DC, They are designed to output three phase power because three phase motors are more efficient and use lower current.
It comes down to your pump sizing and details of your use and application. For example, if you are constantly throttling a centrifugal pump with a control valve, A variable speed drive can save energy making for a quick payback time. Alternately, if your pump is ideally sized for your service and runs at the best efficiency point (BEP) regularly, you may not benefit from variable speed control (unless you need a soft start, dry run, or run out protection). Please contact us to discuss your needs.
Often, no! Modern VFDs can perform many functions, like process variable control or multi-pump coordination, without an additional PLC. However, some applications are enough “out of the box” that an additional controller is needed. Please contact us to discuss your equipment.