Negative Power Factor...on a motor?!?! Howdy Folks, I don't post too much here, but I have run into a bit of a stumper. I am in the process of interpretting some data for an energy audit of a commercial building, it is a 15 story office building, heated by heat pumps. We hooked up our Fluke Power Quality Analyzer, which records the whole shebang, P, S, Q, PF, DPF, Vrms and I to each of the 11 pumps which supply hot water to the baseboards throughout the building and also for their water supply. The motors are 3 phase delta connected so the meter was setup accordingly. Upon reviewing the data record weve found that the power factor was negative for 9/11 of the pumps...the other two were fine. This negative power factor means that the motors are a capacitive load and are actually supplying power back to the service. This makes no sense to me whatsoever. So my question is this, what else could the observed negative power factor and in turn negative real power, physically mean when measuring the 3 phase power across the lines of a delta connedcted motor. Thank you for your time and thoughts in advance. -Dave PS- All I can think of is that perhaps in the meter there is a setting to switch the meter from capacitive load to inductive load...I will investigate this further, but I am skeptical that this will solve the problem.