Re: On UPS monitoring



Moe Trin wrote:
On Tue, 14 Mar 2006, in the Usenet newsgroup comp.os.linux.setup, in article
<pan.2006.03.14.21.42.31.283998@xxxxxxxxxxxxxxx>, Beef wrote:

My UPS is an APC Back-UPS ES 350; when fully charged, this should power my
system for 43 minutes, if I can believe the log file:

You can't. That seems to be marketing minutes, not real time.

I am not sure about that. When new, I get about the time APC claim for their
Smart-UPS units. As the batteries age, it is another, shorter story. The
O.P. elsewhere has stated that the units are only a few months old.

Mar 14 10:52:33 bulge apcupsd[4395]: MODEL : Back-UPS ES 350
Mar 14 10:52:33 bulge apcupsd[4395]: UPSMODE : Stand Alone
Mar 14 10:52:33 bulge apcupsd[4395]: STARTTIME: Tue Mar 14 10:52:02 EST 2006
Mar 14 10:52:33 bulge apcupsd[4395]: STATUS : ONLINE
Mar 14 10:52:33 bulge apcupsd[4395]: LINEV : 121.0 Volts
Mar 14 10:52:33 bulge apcupsd[4395]: LOADPCT : 10.0 Percent Load Capacity

This claims to be running at 10 percent load - or about 35 VA / 20 Watts.
I rather doubt that.

I do not know what the numbers mean. It may be set to power down when the
battery has only 10% of its original capacity.

Mar 14 10:52:33 bulge apcupsd[4395]: BCHARGE : 100.0 Percent
Mar 14 10:52:33 bulge apcupsd[4395]: TIMELEFT : 43.5 Minutes

There's this bridge for sail in New York City...

This is G o o g l e's cache of
http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=BE350U
as retrieved on Jan 21, 2006 18:30:47 GMT.

[icon_runtime.gif] Runtime Chart

Typical Backup Time
at Half Load 9.4 minutes (100 Watts)
Typical Backup Time
at Full Load 2.2 minutes (200 Watts)
Runtime Chart Back-UPS ES

By hand, I quickly quit processes that were using the external discs and
unmounted them. I logged out of terminals.

How much load do you really have on the unit? It _sounds_ as if you've got
a bit more than 20 Watts.

Yes: difficult to believe a computer would use so little. Each hard drive
takes about 12 watts. My processors take 90 watts each. I have 13 fans, but
never counted up the power they use.

Is this a problem with apcupsd badly reporting the charge left, or with
shutdown now going through the steps quickly enough? How can I find out?

First off, get a wire-bender from Facilities to accurately measure the load
you have on the box. I strongly suspect you've got a lot more than you think,
and the unit may be undersized. Also, as Jean-David points out, batteries
loose capacity over time. We've always used external batteries on our
units that are a bit larger than spec - which of course takes longer to
recharge, but tends to hang on until the diesel generator can take over.
At home (without a backup generator), this gives enough time to hold through
the momentary outage, and I don't delay a shutdown initiation longer than 90
seconds. For me at least, if the power is out that long, it's going to be
down for a while.

Old guy

I try to have a lot of excess capacity, and run mine at about 25% load. One
of mine is so big it claims 68 minutes of run time (and more if I shut down
the BOINC processes such as setiathome). The load on the processor rather
dramatically influences the load on the power supply.

Around here in New Jersey, I get several flicks (dropouts, surges, and ugly
waveforms) a week of a second or less (enough to switch to battery). This is
the most usual problem. Once every few months (more often in summer, but
also in icy weather when people skid their Hummers into power poles, the
power goes out for longer. Not always an hour, but sometimes several hours
at a time. And once, when the air conditioner load got too high, it took out
two of the 4 transformers at the local power company substation, and it took
several days to replace these. For that, even a diesel generator might have
given up by running out of fuel. Home Despot even sell propane-powered
backup generators which may be more practical for fanatical home users than
the diesel ones. They will even run your burglar alarm, lights,
refrigerator, and projection TV at the same time.

The Smart-UPS units I use have a little strip of 5 LEDs that show the load
on them. Mine typically have only one LED lit, indicating a load of around
17%. Another way to see the load is to add up the power required from the
nameplates of your equipment. On my big machine, the power supply is rated
at 660 watts with 70% efficiency, so that is some 900 watts from the power
supply. I do not actually draw that much, but it is quite a bit. On my old
machine, the CRT monitor actually uses more power than the computer itself.
The new machine has an LCD monitor that does not use significant power.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ PGP-Key: 9A2FC99A Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 04:30:02 up 5:41, 3 users, load average: 4.31, 4.26, 4.22
.