[Nut-upsuser] APC SmartUPS powercycles when power returns

[Roger Price]

On Tue, 11 Oct 2022, Andrea Venturoli via Nut-upsuser wrote:

> I've got an APC SmartUPS 1500: it's connected via USB and I'm using the 
> usbhid-ups driver. This used to work properly until recently.
>
> Now, when power goes out it keeps on going on battery potentially for several 
> minutes, but, the moment line returns, I hear a click and power is cycled on 
> the outlets (so every computer is rebooted forcily).
>
> I'm thinking about a hardware issue, but could it be that NUT is instructing 
> it to do so?
>
> All I see in the logs before the nasty event is: "upsmon[89989]: UPS 
> APC at localhost on battery".
> So I don't think a low battery status was reached and/or a shutdown 
> initiated.
>
> # upsc APC
> battery.charge: 100
> battery.charge.low: 10
> battery.charge.warning: 50
...
> ups.beeper.status: enabled
> ups.delay.shutdown: 20

I do not see a line such as « ups.delay.start: 30 » in the upsc output.  Is this 
UPS capable of reacting to an early power-return and cancelling the shutdown?

> ups.firmware: UPS 08.8 / ID=18
> ups.mfr: American Power Conversion
> ups.mfr.date: 2014/06/20

How old is the battery?

> ups.model: Smart-UPS 1500

It's difficult to say more without knowing exactly where you are in the sequence 
of events and the timing as listed in 
https://rogerprice.org/NUT/ConfigExamples.A5.pdf chapter 2.6 The shutdown story 
for a simple server.

Roger