I just checked the performance of my P12 using the PowerPlay feature, as I occasionally do. At first I thought something was wrong since all I could see was a solid blue line for 120 V out. Upon closer inspection, I found that the incoming power was very close to the nominal 120–120.2, 120.4, etc. Then I looked back into August (when people were using air conditioning) and found the same results. I remember in the past seeing incoming voltage vary from 117 to 123. So it looks like my local utility has done something to clean up their power. Is it unusual to get such consistent power?
I never do that, and now that you mentioned it, I am thinking of trying it.