power monitoring

[Ted Roche]

Curtis Sandoval wrote:

Q1:
>   Is there a way, using these or other UPS units, to constantly monitor 
> input line voltage and length of outages? 

Yes. Check out NUT, the Network UPS Tools, at
http://eu1.networkupstools.org/ -- check the compatibility link for your
particular models. Also, I've had a lot of luck with apcupsd, at
http://www.apcupsd.org/ for APC-branded models, which have lots of
brains and reporting capabilities.

In the past I've seen links on these pages to 3rdparty scripts that 
implement monitoring, graphing, email and pager notifications...

Q2:
>   Also, is there a way to monitor the power draw of a set of devices 
> (say, plugged into the same power strip and monitor the total) or 
> individual device for the purposes of capacity planning for UPS units, 
> akin to a Kill-a-watt device but with some sort of ability to report its 
> data to a desktop?

Yes, with the smarter UPSes. Yes, my SmartUPS tells me what it's load 
is. See the status dump at the end of the message.

>   I have been looking at getting some new or larger UPS units, and I've 
> noticed there is a nonlinear relationship between price and capacity, 
> which makes me wonder why a person would not buy two or more smaller 
> units and daisy-chain them to get higher capacity and redundancy.
>  

Daisy-chain is not a good ideas, and most manufacturers will tell you
their warranties won't apply, for good reason. When the units are on
battery power, the UPS circuitry attempts to simulate AC power from DC,
and can only produce a rough approximation. A downstream UPS is likely
to find this unacceptable, and will trip onto battery power itself.

For frugality, I've shopped at a couple of places that sell replacement
batteries and refurbished units that are much more reasonable than the
shiny new units, if you don't mind a scratch or ding or two.
http://www.refurbups has been the source of my last few purchases, and
I've been very happy with them. You really want the higher-end units for 
the circuitry and programmability, but you don't need to pay the premium 
price for more lead-acid batteries.


-- 

Ted Roche
Ted Roche & Associates, LLC
http://www.tedroche.com

[troche at neresus ~]$ /sbin/service apcupsd status
apcupsd (pid 2934) is running...
APC      : 001,053,1336
DATE     : Mon Jun 16 17:43:36 EDT 2008
HOSTNAME : neresus.tedroche.com
RELEASE  : 3.14.3
VERSION  : 3.14.3 (20 January 2008) redhat
UPSNAME  : SmartUPSNumberOne
CABLE    : APC Cable 940-0024C
MODEL    : SMART-UPS 1000
UPSMODE  : Stand Alone
STARTTIME: Sun May 11 10:43:32 EDT 2008
STATUS   : ONLINE
LINEV    : 118.9 Volts
LOADPCT  :  40.5 Percent Load Capacity
BCHARGE  : 100.0 Percent
TIMELEFT :  27.0 Minutes
MBATTCHG : 5 Percent
MINTIMEL : 3 Minutes
MAXTIME  : 0 Seconds
MAXLINEV : 120.2 Volts
MINLINEV : 118.3 Volts
OUTPUTV  : 118.9 Volts
SENSE    : High
DWAKE    : 000 Seconds
DSHUTD   : 020 Seconds
DLOWBATT : 02 Minutes
LOTRANS  : 103.0 Volts
HITRANS  : 132.0 Volts
RETPCT   : 000.0 Percent
ITEMP    : 25.6 C Internal
ALARMDEL : 5 seconds
BATTV    : 27.6 Volts
LINEFREQ : 60.0 Hz
LASTXFER : Automatic or explicit self test
NUMXFERS : 6
XONBATT  : Wed Jun 11 10:30:27 EDT 2008
TONBATT  : 0 seconds
CUMONBATT: 1934 seconds
XOFFBATT : Wed Jun 11 10:56:27 EDT 2008
SELFTEST : NO
STESTI   : 336
STATFLAG : 0x07000008 Status Flag
DIPSW    : 0x00 Dip Switch
REG1     : 0x00 Register 1
REG2     : 0x00 Register 2
REG3     : 0x00 Register 3
MANDATE  : 10/28/98
SERIALNO : ws9844016836
BATTDATE : 28/03/08
NOMOUTV  : 115 Volts
NOMBATTV :  24.0 Volts
EXTBATTS : 0
FIRMWARE : 60.11.D
APCMODEL : IWD
END APC  : Mon Jun 16 17:44:36 EDT 2008