UPS Sizing

Noyu · May 2, 2016

Good Day!

Since it's gonna be payday a few days from now, I am now planning to (yet again) buy unnecessary stuff for my PC. hahaha

So I'm either going with a HyperX Cloud or a UPS (if the Clouds I want aren't available).

So, how do we size a UPS vs our PC??

From what I've read so far, if you have a PSU rating of 520W, and your PSU has some sort of power factor correction (99% thingy), you're safest bet is getting a 520VA UPS too.

Source

Is this correct?

Moonzy · May 2, 2016

normally the box of the UPS will write how many watts will give you how many minutes uptime, rough estimation

and normally your desktop wont use your PSU's full wattage, but dont forget to factor in the monitor's wattage and networking gear if you're powering it from the ups too

just factor in everything you want to power and find their wattage (normally a desktop's wattage is way lower than your psu's rated wattage)

and then find the ups that can power that wattage for the time you want

my desktop consumes about 300W~ + my monitor about 70W~ + my networking gears for about 30W~

so its about 400~500W, and i bought a UPS thats 1100VA because it'll last for 15 minutes or so (written on the box)

also, APC is the brand to go for UPS

TrigrH · May 2, 2016

if you have a little headroom on your PSU:

PSU wattage = UPS wattage is enough.

VA IS NOT THE WATTAGE

Noyu · May 2, 2016

1 minute ago, Moonzy said:

"just factor in everything you want to power and find their wattage (normally a desktop's wattage is way lower than your psu's rated wattage)

and then find the ups that can power that wattage for the time you want

I plan on factoring the full "520W" rating of the PSU since that will, IMO, cover for the other low-wattage devices to be connected (monitor, ext HDD, etc).

Thanks this comment, I found a chart by APC: http://www.apc.com/products/runtime_for_extendedruntime.cfm?upsfamily=29

I think this will be enough for my purposes.

SOLVED i guess

TheMorphinator · May 2, 2016

The wattage is the max that the UPS can handle. Usually on the spec sheet they'll show how long it will run at max load, and good manufacturers will even show a chart of runtime vs load, so you can get an idea of how long it would run.

You can also use this tool:

http://www.apc.com/tools/ups_selector/US/en/home/load