Dave Platt wrote:
In article , Bob F
wrote:

I just unplugged the Belkin 1200 VA UPS powering my computer, and
plugged it into my Kill-o-watt meter. After the UPS quit beeping
after power was restored, the meter shows 7-11 watts being consumed
by the UPS feeding the computer, which is way less than the computer
(quad core core-duo processor) uses.

Does the killowatt have a problem reading accurately with UPS units?

What does the meter read, if you connect the computer to it directly,
and entirely bypass the UPS?

Most of these consumer-grade "UPS" systems are *not*. That is, they
aren't "uninterruptable" - they are "standby power supply" devices.
During normal operation, when the AC mains are up normally, they
actually connect the load (PC) directly to the mains... their own
output circuitry is switched off. All they have running, internally,
is monitoring circuitry, and a trickle-charger for the battery. The
"UPS" only disconnects the load from the mains, turns on its inverter,
and begins generating AC power to feed to the load.

So, if the Belkin isn't beeping, it's probably just routing the AC
mains power through to the PC, and you'd find the meter reading almost
the same as if you plugged the PC directly into the meter...


I'll try bypassing the UPS when my computer is not busy and report the results
later.