Duravolt Modules [RE-wrenches]

Sat Jun 24 17:58:24 PDT 2000

Gang,

Anybody had any experience with Duravolt modules?  My understanding is that
they are actually Kyocera modules with the glass removed and tedlar added to
the front and a sheet of aluminum to the back and then are marketed as
"bullet proof".  I saw my first set on two different systems (both less than
two years old) for the Forrest Service the other day and both system were
not performing as expected.  The best I can tell I am looking at a ground
fault problem.  I am looking forward to hearing from you all with any ideas.

System one is a battery less 90 volt water pumping system that has never
pumped much water to speak of.  The pump had burned up several times or
maybe its the motor but everything was a little confusing as I spoke to
about 7 different Forrest service people the whole day who all had there own
ideas.  The well is even a little questionable.  I took all sorts of
measurements and all of them seemed to be in line except the 30-40 volts
from the neg. to ground?  I shorted the panels through my Fluke 87 and had
what I would have expected for short circuit current (~3 amps) and OC
voltage was something like 17-19 but these quality modules had no sort of
info on the back nor could anyone provide me with any.  I unhooked all the
grounds and still had this 30-40 volts from neg to ground.  I then took a
module off the tracker and measured 1.6 volts from the + to the metal
backing of the module.  The - measured 2.1 volts to the metal backing.  What
do you think?  Are the modules screwed up?

Next system has the same modules and is used at the shower house for lights.
 It has 300 watts of solar along with 450 amphours of battery and won't run
40 watts of lights more than a couple of hours.  Batteries are pretty much
new.  I suspected a ground fault on these as well.  Here is where my theory
is a little shakey.  Suspecting a ground fault I had them disconnect the
array at sunset and the lights ran all night long for the first time!  The
charge controller is a ProStar30 and I am pretty sure that they have "night
time disconnect" feature but of course that would only be on the positive. 
If the fault was on the negative then could the system leak enough current
at night to initiate the LVD within a few hours?

If anyone has any ideas or needs I'd love to hear from you.  If you need
some more details don't hesitate to ask for them.  They want to put a new
pump in the hole but I am having them hold off until I can figure out this
voltage to ground issue. Of course the campground is closed until I get the
problem fixed.  I didn't put the system in and this was the first time I
ever even heard of it.  Some electrician put it in and did he do a number. 
Between him and Kyocera  (they won't return calls to the Forrest Service),
solar in my neck of the woods sure has a bad name.  He is refusing to come
back so now they call a solar guy.  I bet I'm not the first one of us to
ever experience this!   What strikes me is that I have seen a whole bunch of
screwed up systems put in terribly but they always seem to work albeit not
safely.  But these two systems should be pretty simple and they don't work
and both of them have these metal backed Duravolt Modules.

Thanks
Travis Creswell
Ozark Solar
Neosho, Missouri
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