Unfortunately where I live I do not have 24/7 electricity.

My new PC rig which is considered to be a high-end(gaming) system is connected to a brand new APS/UPS that have these specs:

DC-AC Inverter-Pure Sine wave
Charge 20A
97% peak efficiency with power factor correction.

According to the company's technical support, they say it can provide stable 800 watt on 12V and even non-stable 1000 watt.

Of course I have a brand new Car battery (more-like truck battery) "N200 12v 200ah" connected to the inverter.

And I'm using a tier 1 PSU considered-among-enthuasiats that is Corsair AX860i — 860 Watt 80 PLUS® Platinum Certified Fully-Modular PSU with over current and undercurrent protection.

While I'm gaming, my computer restarts when a main power cut occurs, the UPS does take over but while it does the computer restarts.

Though, if I'm not gaming(low power consumption) it doesn't restart. And the UPS would take over without any interruption.

Taking into consideration that my GPU is MSI 980 gtx GAMING 4g.

I calculated my RIG power consumption online and under load it doesn't exceed 550 watt.

The only "non-high-quality" parts in this case I would think of, is the surge protector (or surge suppressor) that connects everything to everything! And there are two of them, one for UPS < main power and the other for UPS output < RIG.

What may be causing the restart when power cuts off while gaming? And is it going to shorten the life-span of my components or possibly cause damage? Also would you think it boils down to large switchover time?


  • Consider getting an online UPS if what you have is either an offline or line interactive model. – Karan Apr 20 '15 at 11:07
  • 2
    What's the wattage rating of the UPS? Are you sure they said 800 watt? What's the make/model? – David Schwartz Apr 20 '15 at 11:39
  • Yes and the technician tested it live on 8 lamps (800watt). – Alex Apr 20 '15 at 12:14

Power, simply put, is volt times current. So the 800 Watt output should match the current rating. Unfortunately, it doesn't. The specified output current of 5 Amp doesn't lead to 800 Watt - nobody uses 160 Volt.

Instead, you'd be looking at either a 550 Watt UPS (110 V * 5A) or a 1150 Watt UPS (230 V * 5A). Considering the observed failures under load, I'm assuming it's the first. So, you are probably looking at a somewhat underdimensioned UPS.

I'm also surprised by your use of two surge protectors. A UPS never, never ever should produce a surge. Hence, remove the surge protector between your PC and the UPS.

  • Do you mean the AC output socket on the UPS? Because it mentions 220V AC output, and in-regards to the surge protectors, they are used for the distance between the ups and the rig. – Alex Apr 20 '15 at 11:05
  • Yeah - if that's a 220V output, 5A, then it is possibly old. Europe moved from 220V to 230V,except for the UK which moved down from 240V to 230 V. But most hardware doesn't care about that. The point is that 220V, 5A should give you 1100W (or 1150), not 800. There's some nitpicking about "power factor", but in your case that factor is 0.99 so you should still get 1089W. – MSalters Apr 20 '15 at 12:47
  • 1
    Thanks, I read somewhere that it could be from the Motherboard "Asus anti-surge protection". Now in this scenario do you think disabling it from Bios to give it a try would have any issues or risk of damaging my components? – Alex Apr 20 '15 at 15:56
  • I don't believe that such a surge protection is really reliable anyway, so the risk doesn't really change. – MSalters Apr 20 '15 at 19:08
  • Meh, didn't work. Weird thing tho if I switched off the main power manually, I wouldn't have an issue, although if the power cuts off automatically, the issue occurs. At this point I believe it's just the large switchover time – Alex Apr 20 '15 at 23:50

UPS battery backups don't output 'clean' power. When the UPS switches from wall power to battery power, there's a switch in the waveform of the power being supplied.

PSUs that utilize Active Power Switching will see this changeover as unclean power, and restart or shutdown. I had the exact same issue with my servers for over a year until I troubleshooted and found out what it was.

You can read another article about it here:



Since your PC restarts when you switch off the mains, the UPS does provide enough power. Otherwise your PC would simply shut down and you wouldn't be able to start it while on UPS.

This means the switchover time is most probably the root cause. You'll need a Line-Interactive UPS, which has no switchover at all.

Obviously, such abrupt restarts are no good for both your UPS and your PC, so besides the inconvenience of sudden restarts your current setup does shorten the lifetime of the electronics.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.