120VAC / 1 AMP = 120 WATTS
120VAC / 2 AMP = 240 WATTS
get the picture....now after you figure out all your wattage, then
you select the correct UPS. I normally recommend using a UPS that is
double the size of your maximum draw. At the very least 1.5x your
max draw.
One note here, American Power amoung others have started to label
their UPS's in Volt Amperes as well as Watts. Make sure you are
looking at the Watt rating. 1400 VA does not equal 1400 watts.
Actually VA = about 2/3 of Watts. (Anyone care to give the
formula?).
Also, don't bother with the backup ups's I only buy Online UPS. That
way there's no drop in voltage (however so slight), when the UPS
kicks). Also, you don't have to worry about sags with an Online UPS.
Backup UPS's only kick in when power goes below 10+/- of 120VAC, (or
thereabouts). So, with some backup ups's you can actually be running
on 105 volts!!! Online supplies continous power at 120VAC 60hz
regardless of input power range.
This is especially important now that summer is upon us and we will
be getting those sags and spikes when the power companies switch
grids to meet demand of afternoon cooling, etc.
Regards
Rick Schryvers
> Date: Tue, 20 May 1997 19:08:42 -0500
> From: Michael Hart <michaelh@bluebonnet.net>
> To: Stavros Patiniotis <stavros@esc.net.au>
> Cc: "portmaster-users@livingston.com" <portmaster-users@livingston.com>
> Subject: Re: Power Consumption
> Reply-to: Michael Hart <michaelh@bluebonnet.net>
> I have have a Cisco Router, Adtran TSU, 2 US Robotics MP/16 modem Racks,
> PM2e30, 2 computers and 1 monitor on an APC Smart UPS 1400 and it will
> run for between 30 and 45 minutes.
>
> Stavros Patiniotis wrote:
> >
> > Slightly off topic (but its to do with my pm's):
> >
> > (1) Can someone remind me how to convert from amps and volts to Watts.
> >
> > (2) Also Power Dissipation is reffering to heat not electricity used,
> > correct?
> >
> > (3) What is a VA (Volt-Amp)?
> >
> > (4) How many watts does a average computer use (bloody computer manuals
> > don't have anything in them!) ?
> >
> > I ask this as I'm wanting to buy some UPS's for my pm's and a couple of
> > computers, and in the PM's manual there is only Voltage and Current. (oh
> > and power dissipation)
> >
> > TIA
> >
> > Regards,
> >
> > Stavros Patiniotis
> > ------------------------------------------------------------------------------
> > -System Administrator / Network Manager Escape.Net -
> > - 465b South Rd -
> > -email: stavros@esc.net.au Keswick SA 5035 -
> > -URL: http://www.esc.net.au Ph 82932526 Fax 82932949-
> > ------------------------------------------------------------------------------
>
>