Power gets cut on power restore

[BillP]

To test my new BackUPS 700, I disconnected the power, and happily saw that my machines were still running and my PC automatically go into hibernate. Great I thought, it works!!!

Then I plugged the UPS back to power. It kept beeping for a minute, and then switched to online mode, however when it went online, it first CUT the power to the "Battery back-up" outlets for a split second (with a strong click sound from the UPS). Well, obviously I wasn't expecting that my other machine and equipment on the "battery back-up" outlets would lose power just to restore power. Is something wrong with the UPS, or is this how it works?

BTW, I have charged the UPS for 24 hours before using it. The battery indicator was showing full charge, and was showing 7 minutes of power when it restored. I had the UPS unplugged from power for about 30 seconds, and the UPS kept beeping for about a minute after I re-plugged it back to power.

I am sure that the UPS did not exhaust the battery since it was working only for 30 seconds, and the LCD showed 7 minutes available, and the power spike happened exactly with the "Click" sound when it went from battery mode to online mode.

So, is this expected?

Thanks,
-Ozer.

[BillP]

I repeated my test couple times, and this issue repros about 2-3 times out of 10 tries. Most of the time, the UPS switches back to online mode without any issues (as soon as I plug it back to power), and everything works just fine, but some times when I plug it to power, it does not switch to online, and keeps beeping (once every 10-15 seconds). Then after a minute it "resets" the UPS power (like it reboots), with a loud click, causing the power failure on the attached devices. When this happens all lights on the UPS go off for a second.

BTW, when this happens, the attached devices drain about 320W of power. Is that too much for the device to handle? The LCD shows about 4-5 minutes at least of available power.

This is the BackUPS RS BR700G.

[BillP]

Hi ozer,

You are performing what is know as a 'wall test' when you un-plug and go 'on battery'. Your UPS should not exhibit inconsistent behavior and should not interrupt power when going 'on AC utility power' from an 'on battery' condition. I would perform the 'self-test' with the PowerChute software and see how that performs. If you lose power during the self-test during either transition to 'on battery' or 'on AC power', something is wrong with your UPS.

FYI, the unit periodically performs a self-test automatically (I have a XS1200 and it is every ~2 weeks). This is not dependent on powerchute software and is internal in the UPS unit itself.

Then Contact APC technical support. APC has pretty good customer service and support. http://www.apc.com/support/index.cfm the US tech support # is 800.800.4272

good luck with it!

[BillP]

Clarkson, You are right... I just gave it a try and it is doing exactly what you described... I left the UPS unplugged this time. When it detects the machine go to hibernate, it gives it an extra minute and then goes to sleep mode, cutting down the power on all outlets.

That was not the behavior I was expecting, but hey, at least I know that my UPS is not defective.

Why did I not catch this while doing my tests (and thinking that it was reproing only few times), because I didn't really think this was a "feature", and I manually cancelled most of the hibernation processes on my machine, therefore the UPS did not go into sleep mode most of the time. Now it makes perfect sense...

I'm an APC customer for just a couple days, and already are quite happy and impressed. What a difference a user forum makes in the customer experience.

Thanks clarkson and stellablue for your answers.
-Ozer.

[Anonymous user]

The reason for this is as follows - imagine:

1) You cut power
2) After some time, Powerchute sends a signal to Windows to shutdown or hibernate - windows is now shuttting down - it can't be stopped (otherwise you'd end up with a 1/2 up 1/2 down system)
3) Your OS shuts down and powers off your pc
4) Note (important) - UPS is still providing power to the PC from its battery

At this point, your PC is just like if you'd shut it down w/o a UPS. Think, you told Windows to shutdown; when it was finished shutting down, it told your PC to power off; at all times though, your PC was being supplied power. Now you wouldn't expect your PC to turn around and power on because it had electricity being supplied to it; you would want to have to push the power button to start your PC, right?

So imagine if at this point, you plug the UPS back in. UPS's batteries start charging, but that's about it. Your PC has never lost power, so it stays powered off.

While some people want a UPS to cleanly shutdown if a power outage occurs, some of us ALSO want the PC to power back on when the power returns. Most (all) PC's can be set in their BIOS to power on (boot) when power is RESTORED. This implies that the power has to be cut!!!!!!

So what happens is this:

1) Once Powerchute decides its time from your settings, it sends a command to the UPS telling it to power off in (I think it is 3 minutes?)
2) Powerchute tells Windows to shut down
3) Windows shuts down and tells the PC to power off (hopefully within the allotted 3 minutes)
4) PC power's off
5) 3 minutes (?) after Windows was told to shutdown, the UPS removes power from the PC (batter outlets)
6) UPS then detects that power is restored
7) UPS again provides power to the PC
8) PC detects that it has LOST power and now power has been RESTORED, so it power's on (reboots)

While it is BETTER to have a clean shutdown, it is a real pain to travel maybe hours in the middle of the night, just to press a button to tell a computer to power on.

This is why it works this way.

Linux (I love Windows, but I must admit, this is one of those exceptions) is a bit different. In the above, Windows has a timing issue. Powerchute sends a "power off in ?3? minutes" command to the UPS, then it sends a shutdown command to Windows - Windows MUST shutdown within this time frame, because in 3 minutes, the UPS will cut power to the PC, so there is an opportunity that Windows takes too long to shutdown and the plug is pulled on it, resulting in a dirty shutdown. Linux does a shutdown without sending a command to the UPS; the difference is that after Linux has 99% shutdown (i.e. closed all of its file systems - the reason we want to do a clean shutdown after all), it opens its file system READ ONLY (can't have data corruption if the file system is READ ONLY) and runs a small script. This script sends a command to the UPS saying "power off now". This is much better than how Windows gambles on shutting down before the UPS.

Sorry for the long winded explanation, but many people don't realize that what most of us want is a clean shutdown, FOLLOWED BY A REBOOT WHEN POWER IS RESTORED.

Hope this makes sense. The important point is that if you tell your BIOS to power on upon RESTORATION OF POWER, the power must but cut to be restored. Otherwise, every time you powered off your PC normally, the BIOS would say "hey, the power is there, lets boot" and you'd never be able to power off your PC.

Older versions of Powerchute or older versions of some of the firmware in the UPS did NOT power off the UPS, resulting in graceful shutdowns, but no reboots, and people who were mistaken explained to users that this was because their BIOS settings weren't right - it was because of a bug in the UPS/UPS software. Today it is working correctly.

[Anonymous user]

Yes it would be great if it worked but it does not - APC does not work at all and what you describe can not be achieved.

If power returns before UPS sleeps the PC senses that and starts then UPS cuts the power and switches it back on while the PC was restoring.

Absolute crap - I hate this unit. I paid a bucket of $$$ for it and even if I want to replace it with another brand I doubt that there will be an idiot that will want to buy it.

[voidstar_apc · Accepted solution]

Jack, I would contact APC tech support to figure out what's going wrong. Especially if it's a new UPS you've paid good money for!

You might try "(1) disconnect all USB devices, (2) unplug the UPS, (3) shut down windows (4) plug the UPS back in" to see if the computer can still "sense" power being restored. That would at least tell you if it's the power supply or if it's USB communication.