In a traditional pump booster system one or more pumps are operated at all times based on a preset pressure value that is selected to meet the peak water demand. However, in most applications the pressure and flow requirements will vary depending on time of day or operating process. At times therefore the pumps may cycle on and off to meet low demands or when there are leaks in the system.
Cycling creates an abrupt current surge each time the pump starts, subjecting the motor to intermittent current loads that can be up to ten times the full-load current and that could damage the pump motor. The frequent on-off operation will also lead to pressure surges in pipe work and associated water-hammer problems. This results in high energy costs and reduced equipment life.