On Sunday, October 12, 2014 1:05:27 PM UTC-4, bob haller wrote:




I'll save it for another thread but my neighbor's electrician son solved a



very interesting puzzle in which some of the lights in his mom's house went



off for several hours early in the AM and then came back on by themselves



without resetting any breakers or GFCI's. I couldn't diagnose it, and



neither could he until I told him that a single UPS's started chirping at



3AM, which I thought was low voltage but seemed to be battery failure., so I



got up and shut it off. No other UPSs beeped so I assumed it was a local



event until my neighbor told me about her basement tenant's lights going



out, too. When I restored power to the UPS and turned it back on the next



day, everything was fine and the battery tested out as good - I was about to



replace it just in case but it was less than a year old.







You've got good analytical skills, John. What do you think it was? (-:







--



Bobby G.



transformer failure where only oner side of the power failed.



that happended here and left me wondering for a couple hours. when I finally figured it out the power company replaced the neighborhood transormer

My guess too... can be verified easily if you have a 240VAC receptacle anywhere to probe (in garage for welder, or laundry room for clothes dryer) one leg will still be hot but the other will be dead if he is correct. Or just take cover off breaker panel and measure two breakers adjacent to each other, they should be on opposite legs.

nate