UPS not giving backup

[IshraQTaskin]

so I bought a 1250VA(Kstar brand) ups to go with my gtx 970 and CM v750 but everytime my pc is on heavy load like playing games and there's a brownout my ups just won't give backup (pc turns off and restarts)...sometimes it gives me 15 seconds sometimes no time at all to turn off my pc properly...what could be the problem here?

[Benergy]

1 minute ago, IshraQTaskin said:

so I bought a 1250VA(Kstar brand) ups to go with my gtx 970 and CM v750 but everytime my pc is on heavy load like playing games and there's a brownout my ups just won't give backup (pc turns off and restarts)...sometimes it gives me 15 seconds sometimes no time at all to turn off my pc properly...what could be the problem here?

If you're gaming when the power goes out, you'd be lucky to get even 15 seconds 

 

That being said, did you get a UPS with a Pure Sine Wave? This is required for modern PSUs that have Active PFC, and if you don't have it I'm surprised your PC runs at all on battery.

[IshraQTaskin]

1 minute ago, Benergy said:

If you're gaming when the power goes out, you'd be lucky to get even 15 seconds 

 

That being said, did you get a UPS with a Pure Sine Wave? This is required for modern PSUs that have Active PFC, and if you don't have it I'm surprised your PC runs at all on battery.

in the box it says simulated sine wave......do I need to get ups with more VA?

[Benergy]

2 minutes ago, IshraQTaskin said:

in the box it says simulated sine wave......do I need to get ups with more VA?

I'm sorry but simulated sine wave just won't work properly with that PSU (or any PSU with active PFC) - the VA is inconsequential.

 

You'll need to get a UPS with a pure sinewave, which are usually more expensive.

Here's an example of one: http://www.amazon.com/CyberPower-CP1000PFCLCD-Sinewave-Compatible-Mini-Tower/dp/B00429N192/

[IshraQTaskin]

1 minute ago, Benergy said:

I'm sorry but simulated sine wave just won't work properly with that PSU (or any PSU with active PFC) - the VA is inconsequential.

 

You'll need to get a UPS with a pure sinewave, which are usually more expensive.

Here's an example of one: http://www.amazon.com/CyberPower-CP1000PFCLCD-Sinewave-Compatible-Mini-Tower/dp/B00429N192/

oh ok thanks alot mate!...this problem has been bugging me for days!

[HrutkayMods]

yeah I've had the same issue, though UPSes are not measured in Watts, my UPS theoretically only gives 500W, and my PC is at full bore 24/7 folding... I have a 1000W PSU and my PC probably pulls around 700W+, so the UPS shuts off, buzzes, then the PC comes back on. You need to look for a UPS that can supply I think 20%? more power than you actually need to keep your PC running

[W-L]

16 hours ago, IshraQTaskin said:

-SNIP-

16 hours ago, Benergy said:

-SNP-

Stepped Simulated sinewave UPS's don't necessarily cause it to not work with active PFC but my guess is the quality of that unit is really poor as that isn't a brand I've heard of. 

 

[Benergy]

21 minutes ago, W-L said:

Stepped Simulated sinewave UPS's don't necessarily cause it to not work with active PFC but my guess is the quality of that unit is really poor as that isn't a brand I've heard of. 

Yeah I've never heard of the brand either, here's an explanation from http://www.jonnyguru.com/forums/showthread.php?t=3964

 

APC was pretty clear -- they strongly felt that PFC power supplies should use true sine wave UPSs. They told me that the reason for this was because PFC power supplies require a much faster changeover time when the battery kicks in, and that due to the design of stepped sine wave UPSs, they were not always fast enough to satisfy the power supply. This could lead to the PSU shutting down when the battery tried to kick in. The guy I spoke with said that the stepped sine wave wouldn't "damage" the PSU, but that it simply might not work, and that if it DID work, it might not "always" work. Apparently it depends on the specific power supply.

 

There's a lot of 'could's and 'might's but in this situation I believe it's the most likely problem 

[W-L]

2 minutes ago, Benergy said:

-SNIP-

Yeah it's a bit of a trial and error, I've never had issues with the stepped simulated ones from APC before other than some extra electrical noise when on battery backup.

[Benergy]

10 minutes ago, W-L said:

Yeah it's a bit of a trial and error, I've never had issues with the stepped simulated ones from APC before other than some extra electrical noise when on battery backup.

At work I never worry about it for generic workstations for which the average APC unit works great and keeps running for several minutes (long enough for the diesel generator to kick in if the power's out), but I'm paranoid about damaging components in my expensive personal builds