Under Constant Pressure—Pump Industry Transitions to VFDs

Dynamic changes in market trends are driving changes in Pump system application and design, leading to a transition from traditional starting methods to Variable Frequency Drives (VFDs). One prevalent example is the increasing trend toward constant pressure systems. Whether in Irrigation, Building or even Residential applications, constant water pressure is likely required or desired. These systems typically include some type of electronic pressure sensor, which sends a signal to the VFD, allowing the pump to run only as fast as necessary to maintain constant water pressure. A recent heightened sensitivity to Energy Efficiency in the Pump World is also a factor in the increasing adoption of VFDs. Pumping applications account for approximately 25 percent of all energy consumed by electric motors--whether in Municipal, Commercial or Industrial applications--making them the single largest target for energy savings in both new and existing installations. While pump system efficiency is a function of numerous variables, the use of a VFD to control the system is integral to maximizing energy reductions in most applications. A final trend emerging in the Pump market is VFDs that have intelligent control algorithms built into the drive. Traditionally, customers have had to use complicated control schemes, often combining PLCs and a variety of other control components to meet the Pump control needs. Today, VFD manufacturers are integrating the “smarts” into VFDs, utilizing what Schneider Electric refers to as a “Controller Inside Card.” This allows users to integrate intelligence into the drive - eliminating the need of separate PLCs and controls – while reducing overall panel space, and ultimately reducing costs.