On Sun, 08 Jan 2006 20:59:21 GMT, "David Kuhajda"
. wrote:


Actually this is exactly how a typical computer should be sized to the UPS.
As MOST computers only draw approximately 1/2 the power supply rating 90% of
the time,

There is no relevance to what % of the power supply is used.
The relevant parameters are amperage and uptime.

rating the UPS to backup JUST the computer (not the monitor also)
is correct and standard recommendation.

Again, no.
The UPS rating is a maximum. As with any supply (including
the system power supply) you saw it was rated for MORE than
the system used. Similarly the UPS should be rated for more
than the PSU uses. "Uses", not what it's rating is in
watts.

If an individual has not checked
the typical current/wattage pull of their computer, and since very few
computers draw near the full rating of the power supply, the later
recommendation for typical home use still gives plenty of extra power
margin.

Mentioning the full rating of the power supply as a means to
pick the ups is simply invalid. It may be true that some
marketing departments do it merely because they know the
average consumer would not be expected to know the actual
current of their system. However, even these UPS tend to
have more than one outlet so it still can't apply.


If longer run times are required, more than the expected 15-30 minutes, then
make sure the UPS will actually run longer when it is not under a larger
load. Most cheaper UPSs run x-minutes regardless of the load connected.


Wrong, they run until the lower battery shutdown kicks in or
the temp rises too high (if thermally protected). Any UPS
that unnecessary shuts off after X # of minutes is a bad
design- though certainly their software might be set to shut
the system off after a period.