Working with regional hospital here in Green Bay and Wisconsin Public Service is hitting them with significant power factor penalties. The issue seems to be their UPS systems creating harmonics and reactive power draw even during normal operation. Hospital has about 400 KW of UPS capacity for critical loads but WPS says their overall facility PF is only 0.79. Anyone have experience with healthcare facilities and power factor correction around sensitive medical equipment?
Hospital power factor issues with UPS systems
Karen, hospitals are tricky because you can't risk any power quality issues that might affect life safety systems. The UPS units probably have 6-pulse rectifiers creating 5th and 7th harmonics which make power factor correction more complex. I'd recommend hiring a power quality consultant to do harmonic analysis before installing any capacitors. You don't want resonance issues near critical care areas.
Eleanor, that's exactly my concern. The penalties are costing about $2,400 monthly but I'm worried about creating bigger problems with traditional capacitor banks. Thinking about active power factor correction or possibly upgrading some UPS units to models with better input power factor. The hospital is planning electrical upgrades anyway so timing might be right for comprehensive solution.