pc turning off due to power failure.

[sandeephoro]

I have a 650w smps running a i3 3220 and a gtx 750ti. Voltage fluctuation is a big problem here. Sometimes because of voltage fluctuation, the pc turns off suddenly as the ups itself turns off. The ups works normally on other occasions and also gives decent backup during power failures. Will buying a new ups help? Or all the ups can have the same problem?

 

[Onus]

How old is the UPS? If more than four years old, especially if it gets a lot of use, its SLA battery probably needs to be replaced. Do you have anything else plugged into the UPS, like a printer?
Does the UPS provide a true sine wave output, a simple square wave, or a stepped square wave?
What is the brand and model of the "650W" PSU? Some are more sensitive to input waveform than others.

 

[geofelt]

Not all ups devices work the same.
It sounds like you might want a ups that always works off of the battery first with a constant recharge from the wall.
Some ups units are better at running through power fluctuations.
What exactly is your UPS?
FWIW, I have been pleased with APC; they have been in the business a long time.

 

[sandeephoro]

That is the surge protection kicking in and doing its job. If it was a simple brown out, then you should have uninterrupted power (as long as the battery holds out). But, you are saying the voltage fluctuates which would cause the breaker in the UPS to trip.[/quotemsg]

This does not always happen. Sometimes ups performs normally during fluctuations and sometimes it just restarts or turns off and the pc along with it. So will other ups will have the same problem. My previous ups also behaved similarly. I am asking maybe a better brand or higher capacity may hold up better?

 

[sandeephoro]

The ups is intex 3 years old. Smps is antec 650 watt. Ups is not a big brand product. Only the monitor and cpu are connected to it. As i said my previous ups also had the exact same problem.

 

[Onus]

The Antec is most likely a [very] good PSU, but may be sensitive to waveform, especially if it was built by Delta. My Delta-built SG-650 will not run on a typical APC UPS which provides a stepped square-wave, but will run happily on a true sinewave APC or on a clipped-triangle (iirc) Cyberpower APFC-series UPS. A true sine UPS will be fairly expensive; the Cyberpower models are not. I've bought two of them, and they work quite well for me.

 

[ko888]

It's most likely an Antec VP650P.

If the UPS is turning off then of course any of the devices plugged into it will also turn off. It could be due to overloading of the UPS or the UPS' batteries haven't reached sufficient charge due to a previous recent power outage..

 

[Onus]

The UPS could indeed be overloaded. What is its VA rating, or even just watts?
Three years is a little short, but if it has a low capacity anyway, its battery may be due for replacement.