This is off topic for this newsgroup, but wish the readers well, and some of this would have
helped me to know before recently...

Odd features of some modern battery-backed power supplies I've owned or read about;
they're meant to supply 120 volts ac from internal batteries whenever the local electric company
power is out;

-- some will not turn off unless there are no substantial loads on them;
the other day I flipped one of our ups units to a new office, and that winbox's motherboard
draws a fairly large amount of power even when 'off', so briefly pressing the 'on/off'
switch on the ups unit simply invoked a battery test operation. Once I actually pulled the
power cord out of the computer the ups was happy to shut down when I did that same brief
button press.
I feel ill-used by this design choice. I wish they had mentioned it in the user guide.
Instead I'm having to research how to turn off the ups during a power outage, and finding
no help. I hated to just let the battery run down, but felt it would damage the unit or my health
to unplug the battery while it was in use. As it turns out, this unit had an audible hum during
this interval, that went silent once I pulled the power cord from the winbox. Hint, hint.

-- some will not turn on unless there is a load present. Maybe this is to protect the ups innards
from overvoltages or something. Have not seen this feature myself, only read about it on the
internet...

-- some can be dragged out in a field and turned on with no 120vac wall socket to sync to,
if you a) try to turn it on, b) observe it fails the bootup tests and beeps just as if the city
power had been on but recently went out c) press and hold the on/off button, only releasing
it _during_ one of the beeping episodes in step b)

Again, have only read about this, by a user that had an APC unit. Most ups units are designed
to _not_ turn on if the city power is not initially present to sync the 60 hz waveform to.
If you were planning to swap in a huge battery and run them continously out in the field you'd
probably need to arrange some massive air flow onto the ups innards to keep it from overheating
due to being on for so much longer than the normal battery could have managed.

-- some ups units are really putting out 60 volts from output ground pin to the 'hot' output lead,
and 60 volts from output ground pin to the output 'neutral' lead.
This does give 120 volts from neutral to hot, but is a booby trap for someone that goes to pull the
main power breaker on their home and tie the ups output into their home wiring {illegal to do
anyway in most jurisdictions in the US, since it tends to get workmen and city line repair crews
electrocuted. I think maybe if you put in some special changeover switch they let you do it in some
places...} The normal practice is to tie both the safety ground wire and the neutral wire to a ground
rod at or very near the home breaker box, and this would short out one of the pair of 60 volt signals
coming off the ups, hence I call it a booby trap for those tinkerers...

I have not seen this myself, only saw it in some online video. I'll assume at least a few ups units like
this exist and 'trust but verify' before relying on any of my own ups units not to be wired crazy like this
video described. Don't bother to ask my for advice on how to prove your own unit is or is not like this,
I'd be inviting lawsuits like the dickens if I gave out any such test procedures and then mishaps occurred...

-- All the ups units I've seen so far have easily-replaced batteries, with 1/4 inch spade terminals. Some but
not all of the units need the positive lead to be at a certain corner of the battery due to a rigid wiring
harness,
but other units didn't care which corner was positive. Also, 12 volts is common, but sometimes you find
units with a pair of 6 volt batteries. I'm writing this from north America, by the way. Ah, and some accounts
I've read suggest the battery is most of the cost of the whole ups unit anyway. If you do buy a replacement
battery, make sure you can ditch the old one at a local car repair shop or that the shop or vendor that
provides the new battery will let you ship them the dead battery {at their expense} for recycling...

-- Some ups units can be adjusted as to how sensitive they are to brief power dips in the city power line voltage;
either in application software that runs on your winbox, or may require you to take it to a service center to
tweak, or may have some arcane adjustment ritual involving the on/off button and the pattern of beeps you can
induce it to produce. I've never had to bother with any of this, so sorry, cannot help you with it.

-- Some application software to control the ups from a winbox is designed to mark all the winbox hard disk
drives as readonly while they command the ups that powers that winbox to shut down the ups. Have only
read about this from end-users; this sounds like a dodgy scheme to me, if it even is a true account.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Formerly APC units took a brief button press to do a battery test {queue loud hum},
long press to shut down the unit. Just got in some units that take any length press
to mean do the batt test; had to pull power cord from wall, then briefly press button
to make 'em shut down. That said, I've not read the new manual yet...

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)