[BBLISA] UPS suggestion

[Edward Ned Harvey]

Yeah, I have some very good info for you on this - 

Every number you ever lookup anywhere will be bloated.  And buying the bloated UPS will cost you.

Buy a kill-a-watt, and measure the actual power draw of the unit.  Measure both VA and W.  Don't exceed 80% of *either* the VA or W rating of your UPS.  While you're making your power measurement, make sure you work the machine as hard as you can.  My measurements on systems such as you've described are approximately:  250W 250VA for the system.  

I've never measured the power draw of a display, because I allow the displays to shut off during power outage.

Another bit of advice - 

I've seen a lot of power outages *caused* by cheap UPS's.  The most common scenarios are two:
*  Can you hot-swap a battery in that model of UPS?  Can you afford planned shutdowns to replace batteries once in a few years?
My guess is that you're ok with a non-hot swap battery.   (APC SmartUPS is hotswappable)
*  What happens if you plug in a device which draws more than the rated VA or W?  For some cheap UPS's, the overload fails the system and all devices lose power.  (Tripp lite).  It can even permanently destroy the UPS (tripp lite).  For some UPS's, when you exceed the rating of the unit, the unit begins to beep, and cannot protect against power failure anymore, but at least it continues supplying power from the wall.  (APC SmartUPS and Belkins such as ... the model that I don't see for sale anymore ... so hopefully their other models are equally good.)



> -----Original Message-----
> From: bblisa-bounces at bblisa.org [mailto:bblisa-bounces at bblisa.org] On
> Behalf Of Eric Smith
> Sent: Sunday, February 01, 2009 3:14 PM
> To: L-bblisa
> Subject: [BBLISA] UPS suggestion
> 
> A friend is looking to get a UPS for his home business system and I
> thought you all might have some suggestions (you'll certainly have
> more experience!)
> 
> I asked him for ideas what the system draws for power and got this
> email:
> --------------------------
> Fair question but a bit hard to answer.  I did some google searches
> and found entries in the 500w range that actually seemed low.
> 
> I also saw a notation that with the RAID hardware card that I have,
> the system does not meet energy star ratings, not a surprise.
> 
> Below is a url to an apple site that for a 2.8 GHz suggests 250 W that
> seems way low.
> 
> http://support.apple.com/kb/HT2836
> 
> I have 2 quad core 3.2 Ghz Processors,
> 8GB memory,
> Standard graphics
> 4 15,000 SAS drives
> Hardware RAID card
> 
> 
> My 30" Cinema display shows up as 150W just by itself.
> 
> I think when you add in the cinema display we have to be pushing 750.
> --------------------------
> Now, that estimate has gotta be the theoretical peak demand (if even
> that) but I thought this was the type of info that you'd be needing to
> me a good suggestion.
> 
> Any tip would be a great help - if you have any more questions I can
> easily find the answers....
> 
> Eric
> 
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