PEP Tech

Energy Savings and Variable Frequency Drives (VFD's)

By Brad Dowsett

 

Variable Frequency Drives (VFD's) are becoming more common on both residential & commercial swimming pool pumps. For the last 10-years, VFD's have become common industry jargon but how do they work? How do VFD's reduce power consumption and ultimately save the end user / pool owner's money? Let us take a more detailed look.

VFD's when paired with a pump motor provide the ability to ramp down the motors RPM's (slow down the motor), decreasing the amount of power (amps) to the pump motor resulting in lower power consumption and energy costs. Commercial pool pumps usually run 24-hours a day. Without a VFD commercial pool motors are running full power day and night. In addition, when designers and architects specify pool pumps, they oversize to accommodate for dirty filters and other unforeseen conditions. With a VFD installed, power to the pump motor can be reduced significantly when the pool is closed and most often power can be reduced slightly when the pool is open due to the circulation system design being oversized. It is still important that while the pool is open the flow rate achieve a 6-hour turnover rate. 6-hour turnover rate is Code in most jurisdictions for commercial pools. See info below for more detailed information.

Without a VFD:

Commercial Pool Pump Motor: Run 24-hours a day at 100% power. Maximum Amp draw 100% of the time resulting in maximum power consumption.

With a VFD:

Commercial Pool Pump Motor: Run with 40% power at night for 12-Hours a day while pool is closed. Run with 90% power while pool is open

A 5HP Pump running 220v 3-Phase at 100% Power will draw approximately 13-amps. With power reduced to the motor by the VFD to 40%, the amp draw will be at approximately 6.5-6.8 amps. The higher the amp draw the more power consumption and cost to operate the swimming pool circulation system.

The VFD is also able to work in conjunction with a digital flow meter. This allows for precise operation of the VFD and to fine-tune the flow rate needed resulting in additional cost savings.
PEP distributes Speck Vacon Series & Pentair Acu-Drive VFD's. Please feel free to contact me with any questions or for an Energy Savings Audit on any of your pools. I will be happy to help!

Brad Dowsett
Commercial Sales Manager

Pool & Electrical Products , Inc.
1595 E. 6th St. Ste. 101
Corona, CA 92879
Ph: 909-212-8183 (Direct)
Cell: 949-228-5975
Fax: 866-284-2751
Email: bdowsett@poolelectrical.com