[NBLUG/talk] UPS for brownouts

Eric Eisenhart eric at nblug.org
Sun Aug 12 10:03:55 PDT 2007


On Sun, Aug 12, 2007 at 09:32:57AM -0700, William Tracy wrote:
> The laptop has a battery with 2-4 hours of life (depending on, among
> other things, whether Linux or Windows is booted...) so we're good for
> power outages. We have a power strip with a heavy-duty surge
> protector, so we're good for power spikes. What I'm still worried
> about is brownouts.
> 
> Does anybody have any good recommendations for UPSes that will protect
> against damage from brownouts? Best Buy just wants to sell something
> based on how long the battery will last after the power goes
> completely out. That's not what we need. :-P
> 
> I don't care if she finds herself without power for the computer for a
> few hours. What I care about is her winding up in the middle of
> nowhere with a computer with a dead motherboard. :-(

I understand that most damage from brownouts is actually due to small spikes
that tend to occur during brownouts ("noise"), or the large spike that tends
to occur at the end.

Any UPS should protect against brownouts.  Lower-end models will treat a
brownout as being identical to a power outage, switching to battery power
entirely.  That's only problematic if you get brownouts extremely often.

What you're describing, though, is a UPS with voltage regulation included (a
line interactive UPS).  Look for "line interactive", "automatic voltage
regulation" or "AVR" in the description of the UPS.  These will
automatically adjust voltage of line-power to the proper voltage, avoiding
the need to go on battery.  However, they may still end up going on battery
during a brownout due to noise (mini spikes) on the line.

Make sure to include surge protection for the modem and/or ethernet
connections.

And, of course, ignore the people at best buy and look at the boxes the
UPSes come in.  :)
-- 
Eric Eisenhart
NBLUG Co-Founder
The North Bay Linux Users Group -- http://nblug.org/
eric at nblug.org, IRC: Freiheit at fn AIM: falschfreiheit
Jabber/XMPP/GTalk: freiheit at gmail.com



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