[Nut-upsuser] Smart-UPS staying in OB after power return

John Morris john at zultron.com
Sun Sep 22 01:19:39 UTC 2013

Hi Kris,

On 09/21/2013 05:11 PM, Kris Jordan wrote:
> John Morris wrote, On 9/21/2013 11:28 AM:
>> The most distressing problem is the UPS stays OB after removing and
>> reapplying utility power.  When power is removed, the UPS goes OB and
>> upsmon detects the power failure no problem, reporting
>> 's0-ups0 at localhost is on battery'.  But when power is restored, there is
>> no clicking of contactors, no switch back to OL, and no detection by
>> upsmon that power is restored.  The UPS can be manually put back OL with
>> 'upscmd load.on'.  I would expect the UPS go back OL automatically,
>> though; am I wrong about this?  (APC forums folk are thus-far silent on
>> this question.)
> Pull the batteries and unplug the UPS and press the buttons to fully 
> discharge the UPS. Disconnect the serial/computer interface connection. 
> Re-connect the batteries, plug into utility. Do not re-connect the 
> computer interface. Now that we have rebooted the UPS, see that it works 
> like it should.

I've done this a few times already after reading a 'braindeading'
procedure.  With cable installed or not, removing utility power switches
to battery; restoring power remains on battery.

Is that how it should work, or not?

>> - The on-line LED flashes continually; other LEDs look normal; I think I
>> read the on-line LED flashes during a self-test initiated through the
>> 'on/test' button.
>> - The 'on/test' button does not initiate a self-test, or otherwise
>> change the pattern of front-panel LEDs.
> Normally you would press and hold until it beeps, then it will do a 
> manual self-test. That's if it was already turned on. Otherwise a quick 
> press should turn it on and do a self-test. The on-line LED does flash 
> during the self-test.

When the UPS is on, the on-line LED is always flashing.  Pushing the
on/test button has no apparent effect.  Does that mean it's stuck in
self-test mode?

>> - While on utility power, the 'off' button acts as a momentary switch,
>> and the loads are powered down only as long as the button is being
>> pressed; also, 'upscmd -u admin -p $passwd s0-ups0 load.off' (twice, 5
>> secs apart) does not shut down the loads.  While on battery power,
>> 'upscmd [...] load.off' works as expected.
> I think a quick press is all that's needed for it to turn off.

A quick press of the 'off' button would turn it off and back on very
quickly.  :)

> In your upsc output, I see 0 load. When the issues where happening, was 
> there a load present?

Since we got the UPS, it has only been under testing without any load (I
just plugged a 200W lamp in for fun).  These issues have been persistent
since the first time the new batteries were installed and the unit was
powered up two days ago.

My question remains:  The on-line LED should not flash incessantly, and
removing and restoring mains power should cause the UPS to switch to OB
and then back to OL without intervention, correct?



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