Caitlin Cunningham is contributing editor for Water & Wastes Digest. For more information, contact WWD at [email protected]
Aug 16, 2011

Continuous Control

Pumping requirements vary from application to application—that’s a no-brainer—but it is easy
to overlook the fact that they also fluctuate within each unique application.
Many water and wastewater pump operators err on the side of running systems at full throttle day
in and day out to ensure adequate performance: a costly precaution considering the amount of
unnecessary power delivered. It is no wonder the equipment has earned a reputation as a top-tier
industry energy consumer.
Controlling pump motor speed in real time, ensuring that sufficient but not excessive power
is delivered, is now a real energy- and cost-saving opportunity. The ability to adjust the speed
of drives, for example, can yield a significant return on investment (primarily in the form of
reduced power bills and energy rebates), sometimes in a matter of months. Such technology
also helps minimize maintenance requirements and extends pump life by alleviating long-term
mechanical and electrical stress. More precise flow control and pump noise reduction are other
potential benefits.
If you think energy-efficient technology might complement your water or wastewater pumping
operations, crunch the numbers—taking into account pump size, load profile, friction and other
such factors—to determine whether a similar investment could be worthwhile.