(ET) Shunt calibration

["SWS" <ssawtelle erols com>]

I took some current vs. shunt mV readings this evening on my E12S. It may 
be
of use to others:

The shunt reads about 0.61 mV / Amp.  This would give about 91mV at 
150Amps.

I read this by using a voltmeter across where Power Use gauge connects to
the shunt and I measured actual current by putting another meter across the
disconnect switch. Since my meter 'only' goes up to 20 Amps I had to limit
my measurements to 20A max. Turns out the mower deck with no load is about
17A. I turned the mower on with the disconnect switch engaged since there 
is
a big current spike when the mower is first switched on. Then I disengaged
the disconnect and took readings.

The E12S (at least mine) has a shunt made of a short (few inches) sheet of
copper ( I assume) with a four point probe setup - current in at one end 
out
the other, with separte meter connections in between. One meter connection
is adjustable, so I guess they are calibrated to some degree.

I can now hook up my data logger and actually be able to convert the shunt
reading into real data. Hopefully I'll do that and get to run it some
tomorrow.

SteveS
E12S