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<div class=Section1>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>Walt,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>I would also offer that in a hot climate,
MPPT in general is only useful in a case where odd cell counts take the Vmp
away from 24V nominal specs. That is, MPPT was originally developed to harvest
the voltage headroom between Voc and Vmp, which was greatest in cold ambient
temperatures. There is little benefit to MPPT in a tropical climate, unless it’s
being used (incorrectly in this case) to adapt a particular module with odd
cell count.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>Walt, I would suggest that you consider
pursuing replacing the Sharps with any 12Vnom or 24Vnom module commonly in use
there, and then either keep the SB50 because it’s already there, or replace it
with the most reliable non-MPPT PWM controller you can bring in or find in
country. This maximizes the likelihood that the system can be kept in operation
even if the SB50s fail (and experience says that some will in time) and the
locals can’t get service or replacement product. It seems to me that the SB50
is an unnecessarily complex component for this application, and a standard PWM
replacement controller will match poorly and inefficiently to the Sharps.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>FYI, I called Earthwalk and spoke with “Joey”
there. I copied him on Rick’s email, and got a read response. So Earthwalk is
aware of this situation, although Joey was a computer tech, not one of the “solar
experts”. If they have integrity, they’ll contact you and start making
arrangements to get this resolved. Perhaps they can wire you the funds to
purchase compatible modules locally? <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>I have copied Joey on this message as
well.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>Allan Sindelar<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Times New Roman"><span
style='font-size:10.0pt;color:black'><a
href="mailto:Allan@positiveenergysolar.com">Allan@positiveenergysolar.com</a></span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Times New Roman"><span
style='font-size:10.0pt;color:black'>NABCEP Certified Photovoltaic Installer</span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face="Times New Roman"><span
style='font-size:10.0pt;color:black'>EE98J Journeyman Electrician</span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>Positive Energy, Inc.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>3201 Calle Marie<o:p></o:p></span></font></p>
<p class=MsoNormal><st1:place w:st="on"><st1:City w:st="on"><font size=3
color=black face="Times New Roman"><span style='font-size:12.0pt;color:black'>Santa
Fe</span></font></st1:City><font color=black><span style='color:black'>, <st1:State
w:st="on">New Mexico</st1:State> <st1:PostalCode w:st="on">87507</st1:PostalCode></span></font></st1:place><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'>505 424-1112<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'><a
href="http://www.positiveenergysolar.com">www.positiveenergysolar.com</a></span></font><o:p></o:p></p>
</div>
<div>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org]
<b><span style='font-weight:bold'>On Behalf Of </span></b>Bob-O Schultze<br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, June 30, 2009 8:14
AM<br>
<b><span style='font-weight:bold'>To:</span></b> wratterman@sunenergypower.com;
RE-wrenches<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [RE-wrenches] Solar
Boost Controller in <st1:country-region w:st="on"><st1:place w:st="on">Senegal</st1:place></st1:country-region></span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>alt,<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>In addition to those possible replacement controllers you mentioned,
you might add the BZ MPPT 500 to the list. I've had a few issues with them but
that seems to have mostly sorted itself out. Very reasonably priced for a MPPT
controller, 100 Voc input. The catch is you've got a 500W output limit.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Bob-O<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Jun 30, 2009, at 1:26 AM, Walt Ratterman wrote:<o:p></o:p></span></font></p>
</div>
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</span></font><span class=apple-style-span><font size=4 color=black
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<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Hello all,<u1:p></u1:p></span></font><font
size=2 face=Calibri><span style='font-size:11.0pt;font-family:Calibri'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Thanks to all of
your responses, and particularly Rick’s confirmation of the appropriate ranges
for the SB50, it has become clear that these panels can not be made to work
with the SB50, and that the SB50 was the wrong choice for these pre-fabricated
systems, or perhaps better phrased, the panels were the wrong choice for the
controller. Actually, it is probably more accurate that the panels were
the wrong choice because their characteristics severely limit the possible
options of what to do next.<u1:p></u1:p></span></font><font size=2 color=black
face=Calibri><span style='font-size:11.0pt;font-family:Calibri;color:black'><o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>I would like your
input on what you think should be done here.<u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Nine systems were
purchased from Earthwalk. One has been deployed for four months. A
second unit is being deployed now. This leaves seven in the
warehouse. (And we wont even get into the fact that we have AGM batteries
here instead of the advertised GEL batteries, and the voltage is so low they
might not even work……I will deal with that separately…..)<u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>While it is clear
that the panels do not match up with the controller, it is not clear why they
are still working (other than the heat and dirt) and if they will continue to
work. <u1:p></u1:p></span></font><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>One solution would
be to just leave everything alone and tell them what they should do if the
system(s) fail. In some cases, this might be the right action to
take. But in this case, I think the folks who sold the prefabricated unit
should be held accountable, and provide a system that is designed to work
properly. The schools paid good money for this equipment and they should
at least have a running start at success, which is difficult to come by in this
part of the world on a good day.<u1:p></u1:p></span></font><font size=2
color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>So – when we tell
the schools to insist that the system be fixed, what do you think we should
tell them?<u1:p></u1:p></span></font><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Due to the
characteristics of the panel (not being either 12V or 24V nominal) they need a
MPPT controller. I suppose we could tell them to change to a controller
that will accept the output of the panel. This would be either Outback,
Midnite Solar, or possibly the new Morningstar 15A controller. Any
suggestions?<u1:p></u1:p></span></font><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>The other route
would be to have them change the panels, and keep the prefabricated system as
it is. Rick: what would you recommend the best voltage / current
combination to replicate the need for a 440 to 500 watt peak array output with
the SB50? <u1:p></u1:p></span></font><font size=2 color=black
face=Calibri><span style='font-size:11.0pt;font-family:Calibri;color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Given the relative
cost of the panels versus the controller, the manufacturer may likely decide to
switch the controllers, but it is not as easy as it sounds. If either the
Outback or Midnite controllers are used, they will not fit into the small space
the cabinet allowed for the SB50. But I will deal with that another
way. (We will just build an all new cabinet here in <st1:country-region
w:st="on"><st1:place w:st="on">Senegal</st1:place></st1:country-region>).<u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>So – any ideas or
thoughts I have missed are welcome!!<u1:p></u1:p></span></font><font size=2
color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Thanks so much for
all of the great feedback. I think, like most of us, every day is a
learning experience, even if we think we have done this 100 times before. <u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Take care,<u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Walt<u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in;
border-width:initial;border-color:initial'>
<div>
<p class=MsoNormal><b><font size=2 color=black face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;color:black;font-weight:bold'>From:</span></font></b><span
class=apple-converted-space><font size=2 color=black face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;color:black'> </span></font></span><font
size=2 color=black face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
color:black'>Rick Cullen - Blue Sky Energy, Inc. [<a
href="mailto:rick@blueskyenergyinc.com">mailto:rick@blueskyenergyinc.com</a>]<span
class=apple-converted-space> </span><br>
<b><span style='font-weight:bold'>Sent:</span></b><span
class=apple-converted-space> </span>Monday, June 29, 2009 10:14 AM<br>
<b><span style='font-weight:bold'>To:</span></b><span
class=apple-converted-space> </span><a
href="mailto:wratterman@sunenergypower.com">wratterman@sunenergypower.com</a>;
'RE-wrenches'<br>
<b><span style='font-weight:bold'>Subject:</span></b><span
class=apple-converted-space> </span>RE: [RE-wrenches] Solar Boost
Controller in <st1:country-region w:st="on"><st1:place w:st="on">Senegal<u1:p></u1:p></st1:place></st1:country-region></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
</div>
</div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>Hello Everyone,</span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'> <u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>The SB50's maximum input voltage spec it
57VDC. This should be considered an absolute maximum above which the controller
will be damaged in a manner not covered by warranty. Our recommendation is
to not apply a total Voc at STC of more than 57V/1.25= 45.6V. There are
transient voltage protection diodes on both battery and PV inputs on
ALL Solar Boost charge controllers. These are not "tell tail" indicators
but real protection devices designed/selected to protect down stream
electronics from transient voltage damage resulting from ESD, lightning, etc.
On the PV side of the SB50 the protection diodes will begin to clip at about
58-60V. They can eat a 1 millisecond 3000W transient without damage, but will
burn up if they receive more than about 10W continuously. These two diodes are
located right behind the PV terminals.</span></font><font size=2 color=black
face=Calibri><span style='font-size:11.0pt;font-family:Calibri;color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'> <u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>In the application described below I
would expect the SB50 to be damaged. What typically happens with excess over
voltage is the diodes fail short, and then clamp PV voltage low and
protect the down stream electronics. If PV current is sufficiently high the
diodes will burn open and the SB50 may continue to operate since down
stream devices have somewhat higher voltage withstand capability, or it may
suffer catastrophic damage.</span></font><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'> <u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>Why these systems continue to operate
must be due to actual Voc not getting high enough long enough to cause
catastrophic damage. If the controllers were to not switch to Float
(unloading the PV's), the brief Voc sample as part of MPPT may not have burned
up the diodes and they are successfully eating the excess voltage transients
which would seem to occur during the Voc sample. It may also be that the
modules are so hot that their actual Voc & Vmp are low enough that
when PV voltage is clamped to 60V by the SB50's protection diodes
insufficient power is delivered at 60V to burn up the diodes...</span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'> <u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>Needless to say, this is a
situation that need to be corrected. Technical Bulletin #100214 available
on our web site describes proper voltage, current and power sizing for all
Solar Boost charge controllers.</span></font><font size=2 color=black
face=Calibri><span style='font-size:11.0pt;font-family:Calibri;color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'> <u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>Regards,</span></font><span
class=apple-converted-space><font color=black><span style='color:black'> </span></font></span><font
color=black><span style='color:black'><br>
</span></font><font size=2 color=black face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:black'>Richard A. Cullen</span></font><span
class=apple-converted-space><font color=black><span style='color:black'> </span></font></span><font
color=black><span style='color:black'><br>
</span></font><font size=2 color=black face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:black'>Blue Sky Energy, Inc.</span></font><span
class=apple-converted-space><font color=black><span style='color:black'> </span></font></span><font
color=black><span style='color:black'><br>
</span></font><font size=2 color=black face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:black'>760-597-1642 x102</span></font><span
class=apple-converted-space><font color=black><span style='color:black'> </span></font></span><font
color=black><span style='color:black'><br>
</span></font><font size=2 color=black face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:black'>fax 760-597-1731</span></font><span
class=apple-converted-space><font color=black><span style='color:black'> </span></font></span><font
color=black><span style='color:black'><br>
<a href="mailto:rick@blueskyenergyinc.com"><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>rick@blueskyenergyinc.com</span></font></a><span
class=apple-converted-space> </span><br>
<a href="http://www.blueskyenergyinc.com/"><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>www.blueskyenergyinc.com</span></font></a><span
class=apple-converted-space> </span><br>
</span></font><font color=black face=Arial><span style='font-family:Arial;
color:black'> </span></font><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><u1:p> </u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
color=black face="Times New Roman"><span style='font-size:12.0pt;color:black'>
<hr size=2 width="100%" align=center>
</span></font></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 color=black
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;color:black;
font-weight:bold'>From:</span></font></b><span class=apple-converted-space><font
size=2 color=black face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
color:black'> </span></font></span><font size=2 color=black face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;color:black'><a
href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a><span
class=apple-converted-space> </span>[<a
href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>]<span
class=apple-converted-space> </span><b><span style='font-weight:bold'>On
Behalf Of<span class=apple-converted-space> </span></span></b>Walt
Ratterman<br>
<b><span style='font-weight:bold'>Sent:</span></b><span
class=apple-converted-space> </span>Friday, June 26, 2009 3:22 PM<br>
<b><span style='font-weight:bold'>To:</span></b><span
class=apple-converted-space> </span>'RE-wrenches'<br>
<b><span style='font-weight:bold'>Subject:</span></b><span
class=apple-converted-space> </span>[RE-wrenches] Solar Boost Controller
in <st1:country-region w:st="on"><st1:place w:st="on">Senegal</st1:place></st1:country-region></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Hello,<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>I am in a very remote
part of Senegal, (near the Guinea and Mali borders…) and I have come
across some prefabricated “plug and play” American made systems installed for
educational institutions.<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>The systems use two
Sharp panels that are 220Watts, 33.6 Voc, 29.2 Vmp, wired in series, using
#10AWG home run wire from the panels back to the charge controller.<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Charge Controller is a
Solar Boost 50. <o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Batteries are Dekka
AGM – two strings of 250AH, 12V batteries. (four batteries total).<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>My specific question
is about the controller. This is a 24V in / 24V out charge controller
with MPPT. I have not used this before, so I am not familiar with the
details of operation.<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>The data sheet that I
downloaded says that the maximum open circuit voltage is 57 VDC. But,
this system is hitting the charge controller with two panels of 33.6 VDC wired
in series for 73.2VDC. So, why is the controller not fried, or what am I
seeing wrong here. I suppose with the panel temperature being elevated
maybe 35 degrees above 25 degrees and a resulting 17.5% loss, coupled with some
voltage drop, the system may actually be seeing less than the 57 volts. <o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>But…..isnt this a
dangerous way to design a system? (it will get cooler here ….)<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Or am I missing
something?<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>What would be the
appropriate application here….<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Sorry, I cant do a lot
of internet research from here – limited download capability on the satellite….<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Thanks!!<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'>Walt<o:p></o:p></span></font></p>
<u1:p></u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><b><font size=2 color=black face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:black;font-weight:bold'>Walt
Ratterman<u1:p></u1:p></span></font></b><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 color=black face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:black;font-weight:bold'>SunEnergy
Power International</span></font></b><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'><u1:p></u1:p><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 color=black face="Times New Roman"><span
style='font-size:10.0pt;color:black;font-weight:bold'><u1:p> </u1:p></span></font></b><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><st1:address w:st="on"><st1:Street w:st="on"><font size=1
color=black face=Arial><span style='font-size:8.0pt;font-family:Arial;
color:black'>11 Laurel Lane South</span></font></st1:Street><font size=1
color=black face=Arial><span style='font-size:8.0pt;font-family:Arial;
color:black'> <st1:City w:st="on">Washougal</st1:City>,
<st1:State w:st="on">WA</st1:State> <st1:PostalCode w:st="on">98671<u1:p></u1:p></st1:PostalCode></span></font></st1:address><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Arial><span style='font-size:
8.0pt;font-family:Arial;color:black'>(360)-837-3680 ▪
fax (360)-837-1315 ▪ Skype Walt-Mobile<u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Arial><span style='font-size:
8.0pt;font-family:Arial;color:black'><a href="mailto:wratterman@SunEPI.org">wratterman@SunEPI.org</a> <span
class=apple-converted-space> </span></span></font><font size=2
color=black face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:black'> </span></font><font size=1 color=black face=Arial><span
style='font-size:8.0pt;font-family:Arial;color:black'>▪ <span
class=apple-converted-space> </span><a href="http://www.sunepi.org/">www.SunEPI.org</a><u1:p></u1:p></span></font><font
size=2 color=black face=Calibri><span style='font-size:11.0pt;font-family:Calibri;
color:black'><o:p></o:p></span></font></p>
</div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div><u1:p>
<p class=MsoNormal><font size=2 color=black face=Calibri><span
style='font-size:11.0pt;font-family:Calibri;color:black'> <o:p></o:p></span></font></p>
</u1:p></div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt;color:black'><br>
<br>
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The message was checked by ESET NOD32 Antivirus.<br>
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