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On 11/19/2010 5:22 PM, Glenn Burt wrote:
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<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);">It has been my experience that if Sunpower
modules are installed contrary to their manufacturer
recommended positive ground configuration, that in a short
time you will only be generating a few watts. I have seen
this in more than one instance when the array was mis-wired
and the negative was the grounded conductor.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);">Fortunately reversing the wiring allows the
static charge to bleed of in a couple of weeks, and the
strings returned to their expected production values.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);">I would recommend against trying to use them
intentionally in this fashion.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);">-Glenn</span></p>
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<br>
<br>
<br>
<br>
If you have Sunpower modules that are raised up in the air, what if
you put a conductive<br>
plate on the back side of the PV module and tie that to positive
?? (like a Faraday shield)<br>
<br>
Does that accomplish the same thing ? If not, and if you take it
literally that the<br>
positive must be attached to "earth ground", then I guess this would
keep Sun Power out<br>
of the solar powered airplane (or space) business.<br>
<br>
I asked Sun Power this question at SPI a couple of years ago and
nobody could<br>
give me any kind of answer.<br>
<br>
boB<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
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<p class="MsoNormal"><span style="font-size: 11pt; font-family:
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73, 125);"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family:
"Calibri","sans-serif"; color: rgb(31,
73, 125);"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size: 10pt;
font-family:
"Tahoma","sans-serif"; color:
windowtext;">From:</span></b><span style="font-size:
10pt; font-family:
"Tahoma","sans-serif"; color:
windowtext;"> <a class="moz-txt-link-abbreviated" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>
[<a class="moz-txt-link-freetext" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On
Behalf Of </b>Allan Sindelar<br>
<b>Sent:</b> Friday, November 19, 2010 10:08 AM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> [RE-wrenches] Positive-ground question
re Sunpower<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 12pt;">Wrenches:<br>
This has been addressed before in a slightly different
context, so a short answer is enough. Can a Sunpower module be
used successfully in a negative-grounded low-voltage system?<br>
<br>
The situation: Mark in our Taos office sent me the following:
<span style="color: rgb(31, 73, 125);">"We have an old time
friend and customer. [John] and his wife used to help us on
various installations years ago. They're both retired now
and living on fixed limited income. About two months ago, we
sold them a replacement battery bank of golf carts. They
have a small off grid system with a few hundred watts of
PV. Recently, [John's wife] was put on an oxygen machine for
a heart condition. The machine consumes somewhere around 800
Watt-hours per day. Their system can't keep up now without
running the generator most every day. I was wondering about
a couple blem/cosmetic damaged panels that PosE has at their
shop in Santa Fe. I'm not sure yet whether the best solution
would be to upgrade their existing system, or perhaps a
separate system for the O2 machine. Either way, if there is
a way to help them with the equipment, then I'd be happy to
donate my time to help [John] do an upgrade. If there is
some way we can help them out, it would be a good thing.
They're just a couple of really good people who've helped a
lot of others out in their lifetime. Now they're the ones in
need, and I'm just trying to find a way to help them."<br>
<br>
We have two Sunpower 215s with cosmetic damage that can't be
sold. </span>I think that one or both can be used here, but
are just somewhat less efficient if negative grounded. <br>
<br>
What's the straight scoop here, please?<br>
Thanks,<br>
Allan<o:p></o:p></p>
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<p class="MsoNormal" style=""><span style="font-size: 10pt;"><a
moz-do-not-send="true"
href="mailto:Allan@positiveenergysolar.com"
target="_blank"><span class="il">Allan</span>@positiveenergysolar.com</a><br>
NABCEP Certified Photovoltaic Installer<br>
EE98J Journeyman Electrician<br>
<b>Positive Energy, Inc.</b><br>
3201 Calle Marie<br>
Santa Fe, New Mexico 87507<br>
<b>505 424-1112</b><br>
<a moz-do-not-send="true"
href="http://www.positiveenergysolar.com/"
target="_blank">www.positiveenergysolar.com</a></span><o:p></o:p></p>
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