A couple weeks ago right after the big snow storm we had here, my APC UPS computer battery backup gave up the ghost. Since it was over 5 years old I assumed the battery had gone through one too many power cycles during a recent power outage, so I ordered a replacement APC unit from Amazon.
When the unit arrived I plugged it in and it came up with a green flashing light, the unit was providing battery power but no AC—not a good sign. After a few hours of charging the green light changed from flashing twice every few seconds to constantly flashing—not a good sign. Finally a few hours later it started flashing red and green, beeping, and clicking—not a good sign.
I went through the manual and could not see that I was doing anything wrong so I figured I got a bum unit from China. Amazon offered to replace the defective unit but would not take it back since it contained a hazardous material—lead. So I was stuck with disposing of a hazardous unit along with the other lead acid battery backup that failed in the first place.
So a couple days later the replacement arrived. I plugged it in and turned it on—you guessed it, same flashing green light. This progressed to rapidly flashing and finally red and green flashing, beeps, and clicks—not a good sign! Monday I called APC support and they went through the checklist, confirmed a defective unit, and offered that either they could replace it or Amazon could. Well I was not about to get bit a third time so I just told Amazon to refund my money and let me drop off the dead units at the local Whole Foods. Of course they refused to accept them so I was stuck with two anchors.
Today I mentioned this to my neighbor who is an electronics geek (would make a great model railroader) and he said he had similar problems with his APC units—not a good sign. He also had checked his outlets and was seeing 137-140 volts AC—really not a good sign! I checked mine and they were coming in at 137-140 VAC.
A quick call to Duke Energy brought a guy in a truck with a lift bucket to see what we were smoking or drinking. Sure enough he got a reading of 140 VAC at the transformer on the pole that feeds both our houses—now we were getting somewhere. Within about an hour they had the old transformer off and a new one mounted in its place.
After thanking the guys for the new transformer, I checked my voltage and it came in at 124 VAC, exactly what the guy in the bucket said it should. Now here’s the part you’ll really like. I plugged in the “defective” APC units and pushed the on button, up came a solid green light with no flashing at all—a really good sign.
So what was going on? These devices not only switch to the battery when the power goes off, they also switch to battery power when it goes too high! With my AC pushing 140 VAC the unit was switching to battery, it would then discharge the battery and go into total failure mode.
So now I guess I owe Amazon for the two “defective” APC units. I also found that the original one that I thought was dead had simply discharged also because of the high voltage. I’m really glad though that the high voltage didn’t kill any of the other sensitive electronics in the house, especially my DCS240!