Will 1200VA UPS will be able to support a 600w PSU


May 23, 2009
My system configuration is:

AMD PhenmonII X4 955
ATI Radeon 6950 1gb
4x2GB DDR3 Ram
PSU: Thermaltake toughpower 600w
Monitor: AOC 23' I2353 Monitor

My problem is I have a backup power solution for my desktop{130ahx2 (unit maybe wrong). But I have 2 Battery + a device to convert electricity from them. It is a 1200 VA IPS or converter}. I would like add a UPS so that MY desktop won't restart when electricity gone. But I get a funny factor for UPS from a seller. He mention to me a 1000 VA UPS can provide 490W. So will 1200va UPS will provide me 600w power.

My question and situation a bit awkward but a good advice is very much welcome.


Is your battery to mains converter a UPS designed for Computers ?
if so there should be no problem
(not all converters produce a sine wave output suitable for electronic equipment or switched-mode PSU)

I once had a PC power supply start sparking & smoking when the mains failed and the UPS started up.

You would have to look up the 'power factor' of the Thermaltake toughpower 600w
which gives you some indication of relationship of Watts and Volts X Amps

It is unlikely that a PC ATX power supply would have a power factor as low as 50%
good ones should be much higher nearer to 80% or 95%

see wiki for expalation


Mike Barnes
Thermaltake claims a Power Factor > 0.99 for the Toughpower 600W (W0103) since it has Active PFC (Power Factor Correction).

There is no guarantee of compatibility of a power supply having Active PFC with a UPS that outputs a stepped approximation to a sine wave while on battery power.

The only way to find out if it works is to test your system with the UPS you are planning to purchase.

Your other more expensive option is to get a UPS that outputs a pure sine wave while operating on battery power.

A 600 Watt power supply can draw more than 730 Watts at the AC wall outlet. The 600 Watt rating of the power supply is referring to its DC Output capacity only. I highly doubt that you are drawing anywhere near the power supply's maximum capacity. Based on your system configuration you should be drawing less than 300 Watts including the monitor.

A 1200 VA UPS should give you more than ample time for the system to perform a graceful shutdown.


May 23, 2009

I think you are assuming my pc draw less than 300w in idle. In load it is not the case. From outerversion PSU calculator from this configuration I get that it will draw 441w at 100% load. Monitor takes 34w. AOC says that. It may come 480w+ . So So will 1200va will be enough?


1200 VA should give the system enough time to automatically properly shut itself down.


the 1200va rating is how long the batteries will last and nothing to do with how much power the UPS Inverters can deliver. You need to contact the manufacturers for these specs if they are omitted.
Here are some cyberpower pure sinewave outputs UPS's that would meet your needs I beleive.
4-5minutes of operation from : http://www.newegg.com/Product/Product.aspx?Item=N82E16842102132
6-8 minutes: http://www.newegg.com/Product/Product.aspx?Item=N82E16842102133
about 12 minutes: http://www.newegg.com/Product/Product.aspx?Item=N82E16842102134


Dec 7, 2011

1200 VA is kinda the same then 1200W. Well technicaly their is a difference betwin VA and W but its something too complicated to explain for nothing. Just count 1200 VA = 1200W

Edit I just explained how VA are related to Watt I have no idea about your particular question.