[nSLUG] UPS

Dop Ganger nslug at fop.ns.ca
Mon Dec 19 09:21:48 AST 2005


On Sun, 18 Dec 2005, Rich wrote:

> I checked the site, the model is a BK650MC made in 1998.
[snip]
>
> I ran two computer boxes and a firewall server on the UPS for  many
> years.  Its only since I got a bigger system and bigger monitors that I
> noticed it couldn't maintain that.  It ran fine for 233Mhz, 450Mhz, and
> and 1Ghz for years.  The bigger machines are requiring more power now.

Looking at the spec page 
(http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=BK650MC&language=en&LOCAL.APCCountryCode=us) 
that UPS is rated for a 400W max draw. I'm mildly surprised you managed to 
plug all those devices in and keep going - especially if the monitors were 
on there too. It's a bit tricky to tell what the draw is if the UPS 
doesn't tell you (and I'm not sure if an early model like that does); if 
not, you'll have to get something like a Kill A Watt 
(http://www.p3international.com/products/special/P4400/P4400-CE.html) and 
test each unit individually.

> I talked to NovaScotia Power about the numerous spikes in the lines
> causing brownouts and surges.  The lady told me there is NO such thing
> as a brownout or spike.  When she asked me "Do the lights dim?  Do they
> get Bright?  Do they flicker?"

If you're in an apartment it could be that either the internal wiring 
isn't up to snuff, or the building as a whole is drawing more power than 
it's rated for (quite possible in this era of stupidly large televisions, 
multiple computers, home audio, etc). This is particularly noticeable in 
older buildings that weren't designed for the high power draw of modern 
life. I believe it is your landlord's responsibility to get this checked, 
but I'm not (fortunately) a lawyer, nor an expert in building codes - I 
just run into issues similar to this on a semi-regular basis.

What I *would* note is that when it comes to UPSen, there's three things 
to consider. The first is the quality of the incoming power, which 
obviously needs to be addressed. The second is the peak power draw; bear 
in mind that the peak power draw is usually passed straight on to the 
incoming line, so you can't simply use a UPS as a buffer to avoid tripping 
a circuit breaker (and speaking from experience on that one!) Finally, 
there's the average power draw, if you constantly pull more current 
through than the UPS is rated for you will burn the UPS out.

The UPS also has a finite (though unpredictable) life, much like a surge 
protector power bar. If it's exposed to a lot of spikes then it will, 
after a while, turn into a plain power bar with only fuse protection (same 
as a surge protector turns into a plain power bar). I'm sure Jason Kenney 
can point you to some useful reading material on Metal Oxide Varistors... 
:-)

Thanks for reminding me, though; my UPS at home is coming up for renewal, 
too.

Cheers... Dop.

!DSPAM:43a6b3f313731149128258!




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