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<DIV><FONT face=Arial size=2>Dan and others, </FONT></DIV>
<DIV><FONT face=Arial size=2>Thanks for the comments. The answer from Dan is
what I was needing: </FONT></DIV>
<DIV><FONT face=Arial size=2>"<FONT face="Times New Roman" size=3>For two
parallel runs of different sized conductors, add the circular mil area for both
conductors, then using a wire table (such as a pocket guide), find the gauge
closest to the total CMA to get the AWG equivalent."</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Perhaps I should have explained that the PV system
voltage is under 50 volts and that all conductors are bonded with terminal
blocks at both ends. The current will distribute itself across the two
conductors.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><FONT face=Arial size=2>Just a side note for those
concerned with the NEC and RV wiring: After years of wire
installations in nearly every recreational vehicle made, I can assure
you that not one RV is in total compliance with NEC. Some of the DC wiring
performed by manufacturers is downright dangerous with long cable runs or
many branch circuits with no circuit protection at all. Very scary.
</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Larry</FONT></DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=exeltech@yahoo.com href="mailto:exeltech@yahoo.com">Exeltech</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=re-wrenches@lists.re-wrenches.org
href="mailto:re-wrenches@lists.re-wrenches.org">RE-wrenches</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, February 02, 2011 10:26
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [RE-wrenches] Parallel wire
runs to increase size</DIV>
<DIV><BR></DIV>
<TABLE cellSpacing=0 cellPadding=0 border=0>
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<TR>
<TD vAlign=top>NEC 310.4 permits parallel conductors of 1/0 or
larger. Conductors smaller than 1/0 are permitted, but with
stipulations.<BR><BR>Nick's assertion "most if not all of the current
will flow on the larger wires" is incorrect. The current will be shared
proportionately between two paralleled conductors commensurate with
their individual resistances.<BR><BR>The original query related to
recreational vehicle PV DC-side installation, and referenced
installation of a "second PV", implying only one existed
initially. This would thus fall outside the bounds of the NEC, but
shouldn't be interpreted to mean some of the common-sense aspects of the
NEC aren't to be considered.<BR><BR>Dan<BR><BR><BR><BR>--- On <B>Wed,
2/2/11, Jason Szumlanski <I><Jason@fafcosolar.com></I></B>
wrote:<BR>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(16,16,255) 2px solid"><BR>From:
Jason Szumlanski <Jason@fafcosolar.com><BR>Subject: Re:
[RE-wrenches] Parallel wire runs to increase size<BR>To: "RE-wrenches"
<re-wrenches@lists.re-wrenches.org><BR>Date: Wednesday, February
2, 2011, 11:15 AM<BR><BR>
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<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'">Nick,</SPAN></P>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'"></SPAN> </P>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'">Can
you cite a code section that supports this. (not challenging you – it
makes sense and I agree)</SPAN></P>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'"></SPAN> </P>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'">I
have been wondering about SMA’s recommendation to parallel two 1/0
cables for a Sunny Island. If the wire sizes and lengths are
identical, is this acceptable?</SPAN></P>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'"></SPAN> </P>
<DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="COLOR: rgb(31,73,125); FONT-FAMILY: 'serif'">Jason
Szumlanski</SPAN></P>
<P class=yiv1123860912MsoNormal><SPAN
style="COLOR: rgb(31,73,125); FONT-FAMILY: 'serif'">Fafco
Solar</SPAN></P></DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 11pt; COLOR: rgb(31,73,125); FONT-FAMILY: 'sans-serif'"></SPAN> </P>
<DIV>
<DIV
style="BORDER-RIGHT: medium none; PADDING-RIGHT: 0in; BORDER-TOP: rgb(181,196,223) 1pt solid; PADDING-LEFT: 0in; PADDING-BOTTOM: 0in; BORDER-LEFT: medium none; PADDING-TOP: 3pt; BORDER-BOTTOM: medium none">
<P class=yiv1123860912MsoNormal><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">From:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of
</B>Nick Soleil<BR><B>Sent:</B> Wednesday, February 02, 2011 12:05
PM<BR><B>To:</B> RE-wrenches<BR><B>Subject:</B> Re: [RE-wrenches]
Parallel wire runs to increase size</SPAN></P></DIV></DIV>
<P class=yiv1123860912MsoNormal> </P>
<DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-FAMILY: 'sans-serif'">You shouldn't parallel wiring that
way. That is not acceptable by code, and it is unnecessary.
If the #10 is not sufficient just replace it. Due to the
fact that the larger wiring has much less resistance, most if not all
of the current will flow on the larger wires.</SPAN></P>
<DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-FAMILY: 'sans-serif'"></SPAN> </P></DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-FAMILY: 'sans-serif'">Nick Soleil<BR>Project
Manager<BR>Advanced Alternative Energy Solutions, LLC<BR>PO Box
657<BR>Petaluma, CA 94953<BR>Cell: 707-321-2937<BR>Office:
707-789-9537<BR>Fax: 707-769-9037</SPAN></P>
<DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-FAMILY: 'sans-serif'"></SPAN> </P></DIV>
<DIV>
<DIV>
<DIV class=yiv1123860912MsoNormal style="TEXT-ALIGN: center"
align=center><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">
<HR align=center width="100%" SIZE=1>
</SPAN></DIV>
<P class=yiv1123860912MsoNormal style="MARGIN-BOTTOM: 12pt"><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">From:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'"> "Starlight Solar,
Larry Crutcher" <larry@starlightsolar.com><BR><B>To:</B>
RE-wrenches <re-wrenches@lists.re-wrenches.org><BR><B>Sent:</B>
Wed, February 2, 2011 8:00:07 AM<BR><B>Subject:</B> [RE-wrenches]
Parallel wire runs to increase size</SPAN></P>
<DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Wrenches,</SPAN></P></DIV>
<DIV>
<P class=yiv1123860912MsoNormal> </P></DIV>
<DIV>
<P class=yiv1123860912MsoNormal><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Some of our
business involves repairing poor PV solar installations on
recreational vehicles. So often we wind up installing a roof junction
box and running a second PV to controller wire and then replacing the
controller to battery wire size. For instance, we may find a 10 gauge
wire run to the controller. We then add #8, #6, #4 or even 2
gauge and parallel to the #10 depending on power and distance of the
run. My question: Is there a calculator or chart that will tell me
what the combination of any two wire sizes equate to? example: #10 +
#4 = X</SPAN></P></DIV>
<DIV><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Thanks.</SPAN></DIV>
<DIV>
<P><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Larry
Crutcher<BR><A href="http://www.starlightsolar.com" target=_blank
rel=nofollow>Starlight Solar Power Systems</A><BR></SPAN><EM><SPAN
style="FONT-SIZE: 7.5pt; COLOR: red; FONT-FAMILY: 'serif'">powered by
</SPAN></EM><EM><B><SPAN
style="FONT-SIZE: 13.5pt; COLOR: red; FONT-FAMILY: 'serif'">S</SPAN></B></EM><EM><B><SPAN
style="FONT-SIZE: 10pt; COLOR: red; FONT-FAMILY: 'serif'">TARLIGHT</SPAN></B></EM><SPAN
style="FONT-SIZE: 10pt; COLOR: red; FONT-FAMILY: 'serif'">™</SPAN><BR></P></DIV></DIV></DIV></DIV></DIV></DIV></BLOCKQUOTE></TD></TR></TBODY></TABLE><BR>
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