Nut upsuser - Sep 2005 - What are some effective power status solutions?

Greetings NUT users,

I am looking for a solution to monitor the power OUTSIDE my datacenter. 
(The on/blackout status of main building power). 

My small datacenter is covered by a UPS, an older Liebert 18Kva unit with 
no environmental or status monitoring outside of the LCD console and 
audible alarm.  The Liebert UPS is backed by a 35KW diesel generator which 
usually kicks on within 10 seconds of a power outage.   The generator has 
a ~36hour runtime.   (Air conditioning of the datacenter is also generator 
backed).

This solution is great for the needs of the datacenter for most 
conditions, but I still would like to know when power in my building goes 
out so I know if the outage is long enough for me to need to come on site 
shut non-critical systems down or monitor generator fuel levels. 

What I am looking to accomplish is setting up a cheap pollable UPS that 
can report online or no incoming power status.  Which will then be used by 
Nagios to send off an alert. The only load on the UPS will be a clock or 
something very low power like an LED light. 

Yes, it is a hack... but it's a simple hack, and they have saved me more 
times than not. 

What would be the cheapest UPS unit that NUT, or other apps can poll to 
check good vs no power status?   I was looking at the PowerWare 3105, 
though it's a beta driver.  For $40, it seems like it would be a good 
starting point.  If the solution becomes too expensive, Ill just end up 
putting a longlife lightbulb on building power and pointing a webcam at 
it. 

Anyone have any sample output of this or other UPS unit?   Or any other 
ideas for this sort of monitoring?


Thanks,

Jarett Kulm
eMail: jkulm@planalytics.com
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> I am looking for a solution to monitor the power OUTSIDE my datacenter.
> (The on/blackout status of main building power).
[...]
> Anyone have any sample output of this or other UPS unit?   Or any other
> ideas for this sort of monitoring?
Since you only need a status signal and not a full UPS function, I would
hook up to a relay with a 110VAC coil (or 230VAC, whatever you have in
your place of the world) and use that to interface to a serial port. Wire
the contacts such that it mimics one of the many 'dumb' serial interface
UPSes and off you go.

Regards,
Arjen