What to do about excessive power usage

In our continuing series on Rotary Pump Troubleshooting, we'll take a look at the condition of "Excessive Power Usage".  As always, consult the factory or your local service representative for additional assistance.

Excessive power consumption can be caused by either mechanical or hydraulic problems.  For rotary pumps, the pump power requirements are directly proportional to pressure and speed.  If either has increased, the required input power will increase.  Power required will also increase if the fluid viscosity has increased.  This can happen if the liquid has been changed to something new or the liquid operating temperature has been reduced.  Some liquids (grease, for example) are shear sensitive and can become more or less viscous with shear (pumping action) as well as undergo permanent viscosity change from shear over time.

Mechanical causes of high power usage include bearing wear out, pumping elements rubbing (a situation that can lead to pump failure), very bad shaft alignments and poor pulley alignments for belt drive arrangements.