Gary L. Olson, Technical Counsel, Cummins Power Generation, Minneapolis

UPS and Gensets: Better, but Still a Potential Problem

Over the years as UPS and generator equipment manufacturers have worked together to solve the problems that arise from operating uninterruptible power supply (UPS) equipment with gensets. Solutions to common problems have been uncovered and designers are increasingly aware of these issues: %%POINT%% Since UPS equipment is a non-linear load to a generator set, the harmonic currents drawn by the UPS were recognized to cause incremental alternator heating. Designers, recognizing this, can specify oversized alternators to serve this type of load.