UPS question.

[Deezy]

I'll try to make this short:
I have a 750 watt power supply. To protect my PC, I have some cheap USP. On the specs. for the UPS where it says the wattage, is that the constant wattage that it delivers or the wattage it delivers when the power is out?
I don't want to be hooked up to something that gives 450 watts when I need 750 watts.
Thanks in advance.

[mjc]

The power of the two doesn't quite match up that way...

Your power supply, in your computer is providing 750W of DC power. It gets this power by converting AC to DC. If you are in the US, then most likely, you are providing it 110 V. So what you need to find is the input rating of the power supply...how many amps it consumes. Then you multiply that number by 110 to figure out how many Watts it needs/uses.

[jlreich]

If you want to have 750W of true power from a UPS then you need to go with a 1300VA UPS.

If you want to know why the difference in VA and Watts have a look here (http://en.wikipedia.org/wiki/Volt-ampere).

[mjc]

Right...but a 750W power supply doesn't need 750W or 1300 VA...you still need to find the input rating on the power supply...how many amps it will draw.

Granted all that it does is provide a certain amount of run-time, once the main power goes. A 1300VA UPS will run an average computer for quite a while.

[Deezy]

Thanks for the replies, kind of helped, but what I really want to know is say that a UPS has a rating of 650 watts (random number), is that gunna limit it to 650 watts even when the power is on? Or is that only what it's giving out when the power goes out?

Haha, sorry if I'm being naggy, but if this would be easier than finding that answer, could someone recommend me a UPS for a 750? I just don't want to be under-powering my beloved components. Maybe I worry too much, but it never hurt. :)

[PrntRhd]

Actually it won't underpower the components:
1) It will be running on line AC current most of the time.
2) The voltage will still be at specs on little UPSes or bigger UPSes while running on the battery, it just affects how long the stuff runs before the battery runs of of juice.

I have a APC 900VA UPS on my main PC, also the cable modem, router, monitor are on the same unit. It says the power load is 97W right now. It can run the stuff on battery for 45 minutes at that power level. Even if your new PC draws double that of mine, it would run 20-25 minutes.
The big thing is it cleans up the power so everything lasts longer. The last 4 events when it kicked onto battery were due to electrical noise.