[Tfug] UPS sizing

Bexley Hall bexley401 at yahoo.com
Thu Jan 1 18:53:31 MST 2009

Hi, John,

--- On Wed, 12/31/08, John Gruenenfelder <johng at as.arizona.edu> wrote:

> >Does this seem in line with what others have done?
> I've been very happy with the UPS I purchased.  I never
> needed one in Tucson.  Living on the far East side of town 
> (Houghton & 22nd), there was perhaps one short outage per year.

Yes, that's consistent with my experiences here, so far...  ;-)

> In Massachusetts, however, I was living in a 115 year
> old house with wiring from Edison's original company

heh heh heh... good ol' knob 'n' tube!  :>  Quite fun to
work on, actually (though I sure wouldn't want to *live*
with that stuff in my walls!  :>

> and phone connections in
> the basement from the original Bell Telephone.  The
> landlord strongly suggested I purchase a UPS.

I'd be surprised that you had good enough *service*
to run much in terms of electronics, etc.  Many of those
homes only had 60A services.  And, if they did NOT have
a gas stove, you can be sure the oven ate up the biggest
part of that!  :-/

> I have a APC BackUPS 700 and I've got everything
> running off of it: cable
> modem, wifi switch, Mythbox/file server, tiny TV speakers,
> desktop PC, LCD
> panel, laptop, Wii, and a few various bits (chargers,

Ah, all of your stuff is bunched together?  (I have stuff
spread around the house, hence the need for more/smaller

> etc.).  Even with all of
> that equipment, the UPS is only at about 45% capacity which
> gives me a runtime
> of approximately 15 minutes.  These are values reported by
> NUT (Network UPS Tools).
> As a side note, when I replaced my previous Mythbox/file
> server, an AthlonXP 2200 system with three drives and an
> external DVD, with a new machine, an
> Athlon64 X2 5200 with three larger drives and an internal
> DVD drive, I found
> that the idle power consumption dropped by three percentage
> points (again, as
> reported by NUT).  I'm sure a big part of that is due
> to the fact that the old
> Athlon chip had no frequency scaling whereas the new chip
> can move between 2.7GHz and 1.0GHz.

There will also be some efficiencies in the internal DVD
as well as newer disks, etc.  If you really want to track down
the relative sizes of the loads, there are toys (:-/) on the
market that will help you do that.  (I just use an AC ammeter
and a funky extension cord)


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