[Nut-upsuser] choosing a UPS (in the United States)

[Eric S. Johansson]

Charles Lepple wrote:
> On 8/8/06, Eric S. Johansson <esj at harvee.org> wrote:
>> I do a bunch of "kindness of strangers" hosting in my basement and my
>> three kVA apc unit died recently.  In looking around, it looked like
>> Belkin was a reasonable low-end replacement
> 
> IMHO, "low-end" means something to filter power blips less than 10
> seconds long. That's what I would use for a desktop machine, but not
> any sort of hosting (even if it's not mission-critical).

10 seconds?  My experience has been about 10 minutes.  When I had the 
APC three kVA unit running, I would typically get about 40 minutes on of 
a set of new batteries with a full charge.  Unfortunately, the batteries 
would wear out in about a year and a half to two years.  Not exactly 
what I considered a good or reliable unit.  So when it stopped working I 
was not going to spend $3000 give or take to replace it.  It made just 
as much sense to get a small (2) number of 1kva UPS's and plan for 
shutdown in five minutes.  This plan works around here because if the 
power doesn't come back in five minutes, it's not coming back for a while.

I often thought it would be nice to have a small propane powered 
generator come on automatically when the UPS's started working.  the 
double benefit around here is that both my wife and I sleep with CPAP 
machines and I really hate waking up trying to suck air through 
unpowered CPAP. ;-)  but unfortunately, no such beast exists unless 
you're willing to buy something in the 5 kWh range that is the size of a 
basement full body freezer.

>> So the question is what's a good UPS for running for five machines, 12
>> disk drives, and seven CPUs (one being a DEC Alpha)?  No, I haven't
>> figured out the power budget.  When I take things down this weekend, I
>> will be measuring the power consumption of all the devices.
> 
> I don't know your physical setup, but if it were me, I would get a few
> rack-mount UPSes instead of putting everything on one big UPS.

okay, I'm looking at the MGE machines and the nova is obviously the 
desktop system.  For 30 bucks more, you get the same thing in the AVR 
model.  Haven't figured out the difference yet.  But going to a 
rackmount, what's the advantage?  it's really not clear why one spends a 
whole boatload more money ($300mumble) for what appears to be identical 
functionality.  Yes, I know I'm exaggerating.  But for my purposes, all 
I care about is that I can know when to shut down, tell me the health of 
the battery, and let me auto power up after power has been restored for 
some duration of time.

> Obviously, you don't want to go too crazy on splitting things up,
> because the per-unit cost for replacement batteries is generally
> higher than half the cost of a battery twice as large.

understood.  Obviously be nice to hook up some additional batteries via 
Anderson power pole connectors to extend capacity abut this it also 
slows the recharge time given that the charger is current limited.

> 
> This also usually gives you more control over switchable outlets, in
> case you want to remotely power-cycle one particular server.

nah, if I can't get my fat ass out of the chair, walk downstairs and hit 
the power switch, I have more problems than a server needing a power cycle.

> If you can't find an MGE unit that suits your needs and/or wallet, I

I've found an MGE unit that should work.  I'm going to check on eBay as 
well with the assumption that I'm going to need to replace the battery.

thanks to all of you for your great feedback and information.

---eric