[Discuss] APC repair/replacement

[Alan W. Irwin]

On 2006-06-21 09:13-0700 Nathanael D. Noblet wrote:

> On Tue, 2006-06-20 at 09:40 -0700, Alan W. Irwin wrote:
>
>> Is there any UPS user in the Victoria area on this list that doesn't
>> encounter several short power events per week?
>
> For the past 2 years in Victoria, Gorge area and View Royal. I could
> probably count on one hand, maybe just barely needing two hands the
> number of times the UPS beeped. Only one was long, middle of the night
> and woke me up, as it lasted quite a while.

Your report (and two others) show that there are some regions of Victoria
where some UPS's don't beep that often.  That is contrary to my consistent
experience at the same location (in Saanich between Glanford and Carey) for
the last 10 years and the experience of several others that I have talked to
in Victoria. I guess it depends very much on local (variable) load
conditions, quality of installed BC hydro equipment, etc.

How often you get beeps from the UPS also depends on the settings for that
UPS as well as its internal design.  For old APC Back-UPS units such as
mine, the transfer voltage (voltage where it transfers to battery) can be
set anywhere from 103 to 88 Volts in steps of 5 Volts.  Both my UPS's are
set at the factory default of 103 volts. If your transfer voltage is set
lower, you will hear fewer beeps (but then your equipment will experience
larger voltage swings).  Presumably all UPS brands also differ from each
other in how they handle short-term events (which are much more numerous
than longer events). My two APC Back-UPS units almost always beep
consistently with each other for the short-term brownouts so it appears
their internal design (including degree of filtering) is the same even
though they were bought 5 years apart. However, even for the same 103 Volt
transfer voltage setting and the same location as mine, it's possible that a
different brand of UPS or different APC line would beep less often because
they might use different handling of the extremely short brownouts that are
causing the APC Back-UPS beeps.  For example, they could choose to use
heavier filtering of short term events so that the transfer to battery (and
accompanying beep) occurs much less often.

In sum, this whole topic is complicated because there are differences in the
local quality of the power delivered by BC Hydro, UPS transfer voltage, and
UPS internal handling of short-term events. However, one firm conclusion is
there are clearly regions of Victoria where UPS's (even the el-cheapo
Back-UPS variety) make a large difference.  For example, from reliability
comparisons over the last 10 years between my UPS-protected PC's and similar
PC's at the UVic astrogroup which are not UPS protected, it appears that
UPS's were a wise investment for me.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the Yorick front-end to PLplot (yplot.sf.net); the
Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
__________________________

Linux-powered Science
__________________________