UPS not good anymore?

[Imago]

I have a question to the "heavy UPS users" here, I hope someone can help me figure out what's happening...

In my living area there are some work-in-progress in the electrical net and dome times there are few, short power outages. Very short but enough to turn off my PC and lose all my ongoing works...

So I decided to bring back my old Keor SP 800 to work with a brand new battery. I thought it could be enough since it's a 800VA/480W UPS and my whole system (PC, two monitors, various keyboard, one mouse, one 10 inch tablet connected and one DAS) never go above 300W total under heavy load (I did the measurements with a smart plug with power consumption functions) and even giving it a 20% error margin, it would be max 366W of max consumption, way under the 480W of the UPS.

BUT, even if it seems to be enough, as soon as the power goes off, the UPS screams in pain(literally!) and turns off along with the rest of the system.

I checked it and the UPS works fine with any other kind of device but it seems to deeply hate my PC.

What's wrong with it? Could be the PSU? It's an Itek BD700 DC-to-DC.

Shall I change UPS or PSU?

[Average Nerd]

A constant beep is either an overload, or a unspecified fault (according to the manual).

You said that the UPS works fine unless the PC is connected, so I'd suspect the PSU to be the issue. Do you have another PSU to test with?

[Imago]

3 hours ago, Average Nerd said:

A constant beep is either an overload, or a unspecified fault (according to the manual).

You said that the UPS works fine unless the PC is connected, so I'd suspect the PSU to be the issue. Do you have another PSU to test with?

Yes but that one is 600VA/350W so it's a bit weak for my use case. I tried it some time ago, the PC stays on for a few seconds then it shuts down everything.

When you said that it could be an overload, I checked the manual and I see it's a "pseoudo wave type". Perhaps the active PFC of the PSU isn't too happy to see that kind of wave?

[Average Nerd]

6 minutes ago, Imago said:

Yes but that one is 600VA/350W so it's a bit weak for my use case.

I actually meant another PC power supply, since I doubt the UPS is faulty.

The active PFC is not supposed to cause issues for other devices as far as I am aware, though I could be wrong.

[Imago]

16 minutes ago, Average Nerd said:

I actually meant another PC power supply, since I doubt the UPS is faulty.

The active PFC is not supposed to cause issues for other devices as far as I am aware, though I could be wrong.

Sorry, I misreaded. No, I have no other PSU available to make a test. The one that was in my PC before the Itek one is long dead.

But I can try the UPS on another PC to see if it behaves the same way, thanks for the "collateral" suggestion!

[ewitte]

5 hours ago, Imago said:

Yes but that one is 600VA/350W so it's a bit weak for my use case. I tried it some time ago, the PC stays on for a few seconds then it shuts down everything.

When you said that it could be an overload, I checked the manual and I see it's a "pseoudo wave type". Perhaps the active PFC of the PSU isn't too happy to see that kind of wave?

At this point I look at all UPS systems as weak typically only have 100-200w and highly inefficient lead acid.  I've been converting over to power stations but the ones with super-fast transfer times have only started coming out, so I haven't done the main PC yet though I have 14KW battery/inverter on a 20a outlet in the office.  I only have 1 monitor and the Synology on that.  For the machine I work on its a USBC converted NUC that runs about 20-30 hours on 560W

[Imago]

13 hours ago, ewitte said:

At this point I look at all UPS systems as weak typically only have 100-200w and highly inefficient lead acid.  I've been converting over to power stations but the ones with super-fast transfer times have only started coming out, so I haven't done the main PC yet though I have 14KW battery/inverter on a 20a outlet in the office.  I only have 1 monitor and the Synology on that.  For the machine I work on its a USBC converted NUC that runs about 20-30 hours on 560W

My Keor SP 800 is super fast response, when I used it with my previous PC it helped me a lot of times. I stopped using that because the power outages stopped completely a few years ago, I need this now only for the short while the works on the power lines are done.

I don't have the space, also luckily I'm not in a such desperate situation (30 hours without power is truly problematic!), to build such a monster of power source!

Reading you guys comments, though, made me look for more info about my UPS and found out it came with a 9Ah battery, while I replaced it with a 7Ah unit... Could it be the reason it can't keep up? Perhaps the new battery has not enough "kickstart" to bear the initial surge and the UPS surrenders?

I thought it was just matter of "how long it lasts".