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<DIV><FONT face="Lucida Sans">Wrenches,</FONT></DIV>
<DIV><FONT face="Lucida Sans"></FONT> </DIV>
<DIV><FONT face="Lucida Sans"> I installed
a grid tied system 6 years ago consisting of 24, Shell 110 watt, 12V PVs ( Vmp =
17.5V, 6.9 amps short circuit), running through an SMA2500U inverter, one
string, very short DC run ala 10 ga. USE-2 wire. </FONT></DIV>
<DIV><FONT face="Lucida Sans"></FONT> </DIV>
<DIV><FONT face="Lucida Sans"> At
installation I documented a solar noon output of 1900 watts, a hair low of SMA's
estimated inverter output for that temp. However, over the years, the customer
and myself have seen the output gradually drop to lately about 1250 watts under
the same conditions, panels clean. It's kinda a long story, but let's just
say I know the inverter is not the problem (recently changed-out to a factory
rebuilt job with no change in output....different issue).</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face="Lucida Sans"> I clamped
the DC pos before the inverter and got 4.7 amps (about 11AM, array
faces 180 degrees, 6:12 pitch, clean PVs, 80 degrees, F.), DC neg was about
4.3 amps (hmmm). SMA display and my meter reading for Vmp for the
array about 300 volts, pretty low it seems (Green light steady on the inverter,
GFI fuse not failing, SMA display power about 1250 watts. I guess I should
have clamped the inverter output... I didn't. It looked to me like a
failed PV.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face="Lucida Sans"> So, I
removed (as in unbolted, unwired, removed) all 24 PVs to find that all Voc
and Isc with a Fluke 87 were "good", meaning 6.2 amps short circuit (I never
seem to get the full rated output on any new or old PV for Isc). That
was fun. Before I finish here a note, the panels have the Procharger, J
box, which means 2 Jboxes (pos and neg) per panel, SS screws to secure your
USE-2 wire. So, PVs check out, it's the wiring?? I saw no chaffing,
wearing, cracks, etc in the wiring. I will remount the PVs and diligently
resecure the wiring.</FONT></DIV>
<DIV><FONT face="Lucida Sans"></FONT> </DIV>
<DIV><FONT face="Lucida Sans"> I'm looking
for comments about these PVs (I tried calling Arco-Siemens-Shell- now Solarworld
today, after 4 tries got a human being who told me the guy that may know about
any issues with these PVs is on vacation till next week). Or,
anything else that may help me find the loss of power here. Should I spray
on some contact cleaner then use silicone grease on the wire/terminal
connection?</FONT></DIV>
<DIV><FONT face="Lucida Sans"></FONT> </DIV>
<DIV><FONT face="Lucida Sans"> Thanks in
advance,</FONT></DIV>
<DIV><FONT face="Lucida Sans"></FONT> </DIV>
<DIV><FONT face="Lucida Sans">Bill Battagin</FONT></DIV>
<DIV><FONT face="Lucida Sans">Feather River Solar Electric<BR>4291 Nelson
St.<BR>Taylorsville, CA 95983<BR>530-284-7849/6544
fax</FONT></DIV></BODY></HTML>