SavaControls work by reducing the power when the motor is under part load, but still maintain the same speed, offering substantial savings but enabling instant power availability should full load be required. Motors do not constantly require the same power, an uncontrolled motor will keep on drawing full power. Many systems are also designed with unnecessarily large motors to provide a safety margin, and so produce even more waste.
SavaControls constantly monitor the motor load by comparing a number of paremters such as relative phase angles, the back emf and current drawn. At part load, the apparent voltage to the motor is reduced by cutting the power up to 100 times every second reducing magnetisation losses and drawing much less current. SavaWatt offers a range of units, including single and three phase controls to handle up to 250 amps per phase.
A report from the Cranfield Institute of Technology states “The results of these tests showed a considerable reduction in the power consumption in a low load situation… The maximum reductions observed approached 40%…” Other tests have shown reductions of as much as 50% in electricity consumption, but in real life applications average saving are 20% on single phase, and 15% on three phase systems.