[Nut-upsuser] Info on Cyber Power CP1500AVRLCDa

Phil Chadwick phil.chadwick at claremont.farm
Tue Jun 7 02:12:29 BST 2022

stefanos at karandreas.gr wrote:

> Can you share a link to where the manual describes ups.delay.start? I 
> found
> some information but not the complete description you mention here.
> For ondelay=0 what happens? The load instantly returns on UPS shutdown
> or the bug doesn't trigger?

Hi Stefanos,

For "ondelay=0", the load returns immediately the wall power returns.

I should mention for clarity that "ups.delay.start" is set, by nut at
startup, from the value of "ondelay" in ups.conf.

However, I'm in the embarrassing situation of having to retract what I
said about "ups.delay.start".

Your question prompted me to verify my assertions, and I found this:


which says of ondelay:

    "Set the timer for the UPS to switch on in case the power returns
    after the kill power command had been sent, but before the actual
    switch off.  This ensures the machines connected to the UPS are,
    in all cases, rebooted after a power failure.

    "The default value is 30 (in seconds).  Usually this must be greater
    than offdelay, but the driver will not warn you upon startup if it
    isn't.  Some UPSes will restart no matter what, even if the power is
    (still) out at the moment this timer elapses.  In that case, you could
    see whether setting ondelay = -1 in ups.conf helps.

    "Note that many CPS models tend to divide this delay by 60 and round
    down, so the minimum advisable value is 120 to allow a short delay
    between when the UPS shuts down, and when the power returns."

So my interpretation of "ups.delay.start" (as being applied after the
return of wall power) was coloured by a lot of research that all turned
out to be wrong.  In my defense, I was led astray by many others who
have trod the same path.  Sorry...

My next step will be to set offdelay=90, ondelay=120, and see how the
UPS behaves.
I still don't have any clear idea of how to delay restarting the load
while the batteries re-charge after an outage, so shutting down on a
"battery low" condition (and avoiding an infinite shutdown loop) remains
a challenge.



Blessed are the young, for they shall inherit the national debt.
	-- Herbert Hoover

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