Thanks for the responses. I think they are looking at doing some sort of active correction in a new UPS (the current one can't handle it and the harmonics). I'm not sure if they are complaining yet....we got this information second hand from the UPS vendor. I'm just trying to be proactive and find a solution in case the customer comes back and wants something. I am not sure where its being measured, I suspect on the output of the PDU's feeing the system. This is a data center, so adding motors can't be done. Dave Lag wrote: Who is actually complaining? Where is the reactance being measured Can you add an inductive motor load to the circuit or panel? -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist