How to choose an UPS?

[Nathan Vidican]

a at zeos.net wrote:
> I am going to buy an UPS.
> What should I know and take into account to choose a proper one?
>
> Elisej Babenko
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>   
Aside from the obvious (that it matches the power type you use; ie North 
American vs european, aka 50 vs 60 cycles)... You should look to the 
overall capacity, (to make sure it can operate your hardware), and then 
the runtime... for example, you probably want something larger than 
500va on a dual-cpu server loaded with goodies... however a 500va unit 
is just fine for the average desktop system.

My advice, would be to calculate the maximum draw for everything you 
want on the UPS combined, (ie: 450watt desktop pc, 250watt monitor = 
700watts total), and then find a UPS with a suitable runtime for that 
wattage, ie: decent 1000va should give about 20mins for a 700watt load. 
Bear in mind, that's at maximum draw and maximum charge on the UPS' 
battery... so your runtime will vary and almost never maxes at what the 
box it came in may say ;) Be liberal about it is all, and remember to 
leave monitor (if any) off when you're not around.

Unless of course you're talking about larger (datacenter-oriented) 
UPS'... in which case, if you're asking this generally - it'd be my 
advice to you to seek out an electrician.

--
Nathan Vidican
nvidican at wmptl.com