From: "Glenn Meadows" 

See if you can get a powerline monitor, that expands the 100-135 volt range
to full scale, or get a Digital Volt meter, and re-wire an extension cord
so you can plug it into the wall socket, and view the power line voltage
next time the trim LED comes on.  Could be either low, or high.  Only way
to know, is to monitor it.

--

Glenn M.
"RobertB."  wrote in message
news:rb28-D1FC86.14431518112006{at}w3.nls.net...
> Any EEs out there or people who know electricity? I have two APC UPS
> SmartUPs in my office, a smallish 750 VA unit attached to my G4 iMac and
> a large 1000VA unit attached to my ancient Micron and my new iMac
> core2duo (Yowza!).
>
> Here's the deal. Previously, I used to not turn the Micron on much so I
> would shut the large SmartUPS off at night (since the computer was only
> on a couple of days a week at most). However, the new iMac, like all
> Macs, has an Energy Saver feature, so I simply put it to sleep at night.
> Easy. When it's on, the usage light on the large SmartUPS doesn't even
> go on, the machine is energy efficient. (The Micron, which has a couple
> of externals attached causes it to move up one notch). So there's no
> real voltage draw. OK. I noticed, twice now, that in the morning when I
> come into the office, the Voltage Trim light is on, indicating high
> voltage on the line. However, it only appears on one of the SmartUPS.
> Both machines are in the same room and, as far as I know, connected to
> the same circuit. After a while, the Trim light goes out.
>
> FYI, about two weeks ago, the same thing happened one night to the 750VA
> UPS. The Voltage Trim light was on for several hours, then went out. I
> have no idea why it would affect one UPS and not the other, why it seems
> to happen on a regular basis, and why it would come and go. The owner of
> the building (an old tenement) installed a new boiler about six weeks
> ago and I'm wondering if they did something weird. At one point this
> summer they were running new cabling up the walls on all the floors, but
> I have no idea if they ever connected the stuff. I can't figure it out.
> The voltage trim light just went out about 10 minutes ago. Bizarre.

--- BBBS/NT v4.01 Flag-5