Re: External APC Batteries?

["Andy Whitfield" <andywhitfield2002@xxxxxxxxxxx>]

Keith
What UPS have you got?
Some of the older ones can cold start but it's not obvious how you
do so.
Andy
--- In ukha_d@xxxxxxx, ukha@... wrote:
>
> Quoting Andy Whitfield <andywhitfield2002@...>:
> >
> > I'm so tempted to reply with just a smiley!   ;-)
> >
> > But seriously......
> > So often I tell people about the dangers of batteries Even a
small
> > 12v 7Ah battery has a short circuit current of up to
> > 500 amps.  So if someone did short out the battery with, lets
say,
> > their metal watch strap, they could find the watch strap welded
to
> > their wrist bone!  (me resists temptation to put in a smiley)
> >
>
> Thinking back to the "batteries" that used to be in the old
Strowger
> exchange at Great Yarmouth......
>
> Each CELL was a tank about 4 foot x 4 foot x 4 foot. The circuit
> breaker on the end of the battery rack was designed to trip at
> something like 20,000 amps and had super strong springs to pull
it
> open fast enough to break the arc which would have occured. It
then
> had a hydralic damper so stop it before it hit the end stop or it
> would have ripped itself off the rack due the the force involved.
>
> If a spanner was dropped on the bus bars is wouldnt melt...... it
woud
> VAPOURISE !!!
>
> How technology has changed over the years. Back then the exchange
> would use virtually zero power in the early house when no one was
on
> the phone but thousands of amps during the morning peak. Even
without
> the generators the exchange could run for hours without power.
Now
> with electronic exhanges the peak power is a fraction of what it
used
> to be but power consumption is almost contant irrespective of
traffic
> meaning that standby generators are essential.
>
> Getting back to the origianl topic..... Will the UPS's be able to
be
> fired up without mains power ?
>
> I have a couple that cant be used if there is no mains input to
start
> them, when the mains fails the UPS takes over but it cant be
started
> without mains. Might need a cheap inverter to trick it into life
> unless you leave it running continuouslywhich obviously reduces
run
> time.
>