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

Kris Jordan nut01.kj at sagebrushnetworks.com
Sat Sep 21 22:11:03 UTC 2013

John Morris wrote, On 9/21/2013 11:28 AM:
> Hi list,
> UPS is a Smart-UPS 3000 RM (SU3000RM3U, ups.firmware 92.11.D,
> ups.mfr.date 12/14/99) with brand-new batteries.  NUT is 2.6.5 running
> on SL6 (RHEL6 clone) from EPEL packages.  'upsc' output pasted at bottom.
> I'm not very familiar with UPSs in general or this model in particular,
> and it's doing things I don't expect.  I have done my homework, and read
> UPS user manual, googled much, read most NUT manuals, read up to
> 'queequeg', asked on APC forums, etc.
> 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.

> There are other things I also think odd:
> - 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.

> - 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.

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

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