Problem

A new lift station was built with two dry well pump chambers with each chamber housing two submersible sewage pumps. Each pump is controlled by a VFD. Both chambers can be run together or individually so that one can be taken off-line for maintenance. The entire load was non-linear and the harmonic mitigation solution had to work with either both chambers in operation or just one.

Solution

A single 100A HGA active harmonic filter was installed in the lift station. The one filter can address the harmonics produced by both chambers running together or immediately adjust to the harmonics produced by only one chamber in operation. And in the event that the lift station needs to switch to its on-site back-up generator, the active filter will continue to operate normally regardless of the power source.