System turns off even with UPS

[Anonymous user]

Hello, I have APC BACK-UPS ES 650VA 230V INDIA Offline UPS with software, Cooler Master eXtreme Power Plus 700W PSU both under warranty. My computer runs for 20+ hours per day.

UPS Output Power Capacity : 390W

Typical recharge time : 5 hours

Situation #1 (Works fine)

Load on Battery Backup : 100-130W

UPS switches to battery backup and provides the given mins of uptime without any problem.

Tested in random over-voltage/blackouts/fluctuation events as well as in manual blackout testing.

Situation #2 (Problem)

Load on Battery Backup : 300+W but < 390W

UPS switches to battery backup but sometimes computer turns off immediately in any event like there was no ups installed.

Now the reasons can be

1) Battery is exhausting in split second.

2) Battery was not charged completely.

3) My power supply is faulty and its loosing the charge before the switching occurs / UPS is switching after my power supply looses its charge on load.

I am using APC Powerchute software. The software has High voltage sensitivity selected, it shuts down the computer when battery backup has <=5 mins remaining (all default values).

Now this software shows that i have 100% charged batteries, battery passed its self test showing batteries are working normally.

But sometimes when the load is more than 300W, even a small fluctuation restarts my computer.

So now -

If batteries are getting exhausted in split second then the software should show the changed battery value on next restart but it shows 80-90% charged.

If battery wasn't charged completely then their software should reflect that low charge value OR computer should turn off in few mins in manual test (turning main switch off and let my computer run on battery backup).

If my power supply is faulty then it should turn off my computer in any case on any load, but it works without problem when load is low (<300W) and sometimes gives problems on high load (300w+). However i am not sure about capacitors charge holding time on load in my PSU.

I told my problem to APC Service Executive since these problems started to happen after connecting UPS (wasn't happening before this ups). The dude says to turn off your equipment and UPS and let the UPS charge from ac power source for 5 hours, many software shows wrong values (including their own apc powerchute).

Its an offline UPS, my computer runs for 20+ hours , software shows 100% battery time as well.

So where is the problem? PSU or UPS or something else?

[BillP]

What does the UPS report the runtime as during situation #2 before you initiate the test? Do you ever hear any tones or see any LEDs during situation #2? I assumed you would've noted it but just checking.

[Anonymous user]

I cant see the runtime because system immediately restarts if any power related problems occur in that time, but at 310-320W runtime is 10mins. As system turns off and on, ups goes on battery mode till ac power source comes back on. Idle usage is 97-130W.

This has happened before but on rapid fluctuations and every time it was on high load. But while testing with manual blackout on high load, computer turned off as soon as i switched off the main source and ups went on battery mode.

[Anonymous user]

Its not exactly reboot as well, it literally cuts the power then starts it, there is a small delay in between which is higher than normal reboot. This has happened before few times but on rapid fluctuations and every time it was on high load. But while testing with manual blackout on high load, computer turned off as soon as i switched off the main source and ups went on battery mode. Sorry i edited that post as well. Is it possible that switching is taking more time on high load?

I will try to brain dead it and perform a second test by plugging random electrical items so that load goes above 350w.

[BillP]

Oh ok - yes I was just looking for you to check at very high load assuming a power problem did not occur all of the time.

I don't suppose it is possible to put another high load on it besides your computer and see what happens with no data cable attached and maybe with it attached? Just to see if you can narrow it down to the computer or UPS? I can't really tell either what's happening.

My gut tells me that the runtime is close to 5 minutes (assuming you've chosen to keep your computer as long as possible and selected the lowest value of 5 minutes) and this it starts shutting down but it does not necessarily explain the reboots which I think basically what you're thinking - there is no one single symptom that confirms the UPS is at fault or the PSU in your PC is either.

[Anonymous user]

Ok i have tested ups with random electric equipment but i wasn't able to get load that high. I tested with a desk fan on high speed, a netbook, a dual emergency rechargeable light. After switching the main power off, fan changed its speed but netbook & light didnt loose power. Ran my computer without ups on high load, no problem as well.

[BillP]

I consulted with a few folks here and they suggested this could be an issue with a Power Factor Corrected PSU or the transfer time causing this. It was suggested that I have you review knowledge base article FA158939 @ http://www.apc.com/site/support/index.cfm/faq/ and see what your feedback is on after reading that.

[Anonymous user]

This can be the cause, here is a link to my PSU http://www.coolermaster-usa.com/product.php?product_id=2991

So my options are :

1) Replace my PSU with lower one.

2) Replace my UPS with higher one.

3) Reduce the load on my current PSU.

Currently i have removed my monitor from battery backup to surge protection slot to reduce the load. Which option would you suggest?

[BillP · Accepted solution]

We'd recommend a larger VA UPS (option 2) - something like a 1500VA unit. If nothing else prevails, keep in mind you can trade that one in if you'd like towards a discount on a newer one.

[Anonymous user]

1500VA is extremely costly and way out of my budget, will 1000VA be sufficient? its a home desktop system and my highest power usage will be like 450W, 150w for future expansion.

There are 2 products available for 1000VA:

APC Back-UPS RS, 1000VA, 230V, INDIA

APC Power-Saving Back-UPS Pro 1000 with LCD, 230V, India

[BillP]

I asked our Back UPS support specialist and he suggested 1500VA. As the knowledge base article suggests, your 700W power supply is capable of requiring 875W since it is Power Factor Corrected. Something like the BR1000G-IN only gives 600W still. You could still run into a problem under certain operating conditions I imagine - maybe not as often. We'd still recommend 1500VA for your best chance of no issues.