Pc restarting on it's own

[Ultra_]

First my PC specs:
Motherboard: MSI Z SERIES
GC: ZOTAC GTX 970
Processor : INTEL I5 4690
PSU: CORSAIR VS 650
RAM: VENGEANCE 8gb
HDD: 2X WDD 1TB
UPS: MICROTEK 1000V
MONITOR: AOC 24INCH

My PC shuts down then restarts several times during the day with a loud clicking noise from the ups.
I have already changed 3 ups starting from a small one to a big 1000v one.

Also, when I connect my CPU directly to mains it works fine but I am afraid it may damage my CPU because of power fluctuations in the home.

Now some people are saying it might be PSU but that is working fine with no issues that I can see.

There is one more PC in home that's an old dual core home desktop with very low specs and no GC. It also had same company ups and that works fine, so I don't know if ups manufacturer is the issue.

Please, any suggestions will be appreciated.

 

[Darkbreeze]

After doing a bit more research, it turns out that your Corsair VS650 as well as your new CXm650, both have active PFC (Power factor correction) and should only be used with UPS devices which are pure sine wave. I would highly recommend, even though I know it is an additional cost, that you purchase one that IS pure sine wave. Otherwise, you are likely to continue to have issues with both your UPS and your PSU.

 

[Ultra_]

So, first of all really sorry for such a late reply. I was busy with my new job.
PC works fine now, no restarts or anything such. Though, the UPS still clicks sometimes but i just ignore it for the time being.
Thank you all for helping me out and i guess admin's answer is the winner here. So now you can close the post brother if you want.
Thanks again

PS: Even if my new PSU doesnt go good with modified sinewave, i still cant do anything cause i dont have money right now. Once i have it ill definitely buy a pure sinewave UPS

 

[Darkbreeze]

Sounds good my man, just glad we got most of it worked out ok for you. Good luck to you and if you have more problems sometime just give us a shout. One of us will surely be glad to help you out.