Variable Speed Drives

Rising energy prices create a need for energy-efficient motor control solutions.

To help reduce energy waste and spiralling electricity bills, engineers are turning to variable speed drives as an alternative to fixed speed controllers and throttling devices such as dampers in the case of fan systems and valves in the case of pumping.

Advancements in drive technology, careful selection of the hardware and power system configuration along with intelligent motor control strategies produce improved starting and running performance, speed control so that supply can match demand and in case of fans and pumps potentially large energy savings.

Traditionally slowing down the rate of flow from a fan or pump has been achieved by partially closing a damper or valve on either side of it. However this does not slow down the fan or pump and high losses and energy wastage occur as a result.

Centrifugal loads such as fans and pumps offer the greatest potential for energy savings by using drives to control speed. Energy consumption in a centrifugal fan or pump application follows the affinity laws, which means that flow is proportional to speed, pressure is proportional to the square of speed, and power is proportional to the cube of speed. This means if an application only needs 80 percent flow, the fan or pump will run at 80 percent of rated speed and only requires 50 percent of rated power. In other words, reducing speed by 20 percent requires only 50 percent of the power.

Things to consider when considering fitting a variable speed drive to save energy are:

  • Has an energy survey been carried out to identify potential savings?
  • Is the variable speed drive the correct type for the application?
  • Is the variable speed drive listed on the UK governments’ Technology List?
  • Will the equipment be installed and set up by a competent installer?
  • Will the installer give full support for the newly installed equipment?

Here at Parker Energy, we have many years experience in energy saving and can offer a complete package from initial free-of charge site survey through to quotation, supply and installation of the equipment.

As soon as the equipment is installed your fans and/or pumps will be running super efficiently with a low carbon footprint and much reduced electricity bills.