[Nut-upsuser] Tripp-Lite SMART1500LCD: powers off with /etc/killpower...then powers back on...

Roger Price roger at rogerprice.org
Tue Apr 28 19:27:07 BST 2020

On Tue, 28 Apr 2020, Tom Velozo wrote:

> Hi Everyone,
> I recently bought a Tripp-Lite SMART1500LCD for my Linux Mint 19.3 machine, connected via a USB cable. I installed Nut 2.7.4 from the Mint
> package repository via sudo apt update && sudo apt install nut. Everything works great: NUT issues low battery warning when it reaches the
> set low battery point and then issues shutdown commands...computer shuts down..then the UPS shuts down a few seconds after that (i hear a
> 'clunk' noise from the outlets)...BUT...after the UPS has shut down, I hear another clunk noise and the computer starts to power back on.
> Since the UPS battery is about dead at this point, the computer starts to boot up only till the UPS completely dies since its batteries
> are depleted.  This is what is happening:
> - Low Battery setpoint reached --> issue computer shutdown
> - Shutdown commands sent --> computer starts shutting down
> - At some point, /etc/killpower is sent before computer fully shuts down
> - Computer shuts down
> - A few seconds later, I hear a clunk in the UPS (UPS powers off... I used a multimeter to verify no AC voltage on the UPS output outlets)
> - Another few seconds later, I hear another clunk in the UPS --> computer starts to power on --> AC voltage is present on the UPS output
> outlets
> - A few seconds later the battery in the UPS depletes --> computer dies while booting up
> The computer BIOS is obviously set to turn back on when AC is restored. What could be causing the UPS to turn back on after a few seconds
> of being off ?? As testing, I grabbed my Linux laptop (a separate machine) and installed Nut 2.7.4 via sudo apt install nut. I then
> manually issued the command "sudo upsdrvctl shutdown". There is a big clunk noise and the UPS immediately turns off its outlets...and
> after a few seconds there is a clunk and the ups outlets are back on. I don't understand why the UPS is not staying off when issuing the
> command /etc/killpower or via sudo upsdrvctl shutdown. 
> ups.conf:
> [Tripp_Lite]
> driver = usbhid-ups
> port = auto
> pollinterval = 10
> desc = "Tripp-Lite SMART1500LCD"
> vendorid = 09ae
> ignorelb
> override.battery.charge.low = 10
> ----------------------------------------------------------------------------
> ------------------------------------------------------------------------
> Here is the output from "upsc Tripp_Lite"
> ...
> ups.delay.shutdown: 20

It's just a shot in the dark, but a report for the TrippLite SMART1500LCD at 
had parameters offdelay and ondelay set in ups.conf. Your upsc does not report a 
ups.delay.start and you have no "offdelay = xx" or "ondelay = yy". I wondered if 
setting them had any effect?


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