A local sand and gravel operation had a problem starting their large sand pump. Every time they started, the high electric power draw resulted in reduced voltage to their residential neighbors. This brownout was not acceptable.

Reviewing the situation, they found that the existing power lines were inadequate for the power draw to start the large system. It would be extremely expensive to replace the supply lines. They tried an electronic soft start, but the problem remained.


We reviewed their operation and options. In this instance, it was a fixed speed drive so we had the opportunity to consider centrifugal devices.

Our choices included a shoe type mechanical design or a large fluid coupling. Based on the data available, we opted for the fluid coupling approach because it offered greater flexibility in matching the acceleration curve to an acceptable power draw. Secondly, our fluid coupling offered a sheave-mount design allowing it to drop right into the existing installation.

Our sales engineer Don Morrissey worked with them during trial startups. He instructed them on the appropriate oil fill level that optimized start-up without brownout.

If your process causes your neighbors to have brownouts, maybe we can help.