[Nut-upsuser] Unexpected shutdown begins for WOW-500U

Sergei V. Dubrov dubrov at inp.nsk.su
Sun Jul 24 05:25:33 UTC 2011


On 23 Jul 2011 at 11:26, Sergei V. Dubrov wrote:

To clarify some points...

> > 
> > What I see after pulling the plug:
> > 
> > ./upsc xen-home battery.charge
> > 72
> > 
> > ./upsc xen-home ups.status
> > 
> > OB status is correct but why is there DISCHRG status?! This flag, as I
> > think, cause immediately begin of shutdown although the battery is not
> > discharged and has 72 percent of charge.
> > 
> > Is DISCHRG exactly from UPS or is it an inaccurate interpretation of
> > obtained status from WOW-500U?
> > 
> > DISCHRG is a normal value:

Yes, it's absolutely true. My mistake was that I  thought that DISCHRG 
status means DISCHARGED (low) battery. But really this mean DISCHARGING, 
that is quite natural immediately after switching to battery.

> Start test of battery:
> ups.status: OB DISCHRG

I used a test battery instead of turning off from the outlet, because the 
behavior of NUT in these cases coincides. After switching UPS to battery 
and obtaining status OB (instead OB+LB) NUT immediately starts shutdown 
(after FINALDELAY - 5 sec by default). My workaround - is significantly to 
increase the delay (FINALDELAY=90 sec for me) but it's not quite right.

Confirmation that the shutdown should not begin on the status OB (instead 
critical OB+LB) I found in manual page:



This forces the low battery flag true. Without it, if you want to test your 
UPS, you will have to unplug it and wait until the battery drops to a 
low/critical voltage level before NUT will respond and power down your 
system. With the flag, NUT should power down the system soon after you pull 
the plug. When you are done testing, you should remove this flag."

And once again want to emphasize - UPS does not go to state 'data stale' 
(loss of communication) after switching to battery since we can immediately 
read its status, for example, with the command 'upsc'.

> > cheers,
> > Arnaud

Sergei Dubrov

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