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<DIV dir=ltr align=left><SPAN class=078255602-30032011><FONT color=#0000ff
size=2 face=Arial>Al,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=078255602-30032011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=078255602-30032011><FONT color=#0000ff
size=2 face=Arial>The sub panel can be rated at 80A.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=078255602-30032011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2 face=Arial>With
no other loads in the subpanel, 80A is the most that could flow out past the 80A
breaker.</FONT></SPAN></DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2 face=Arial>If you
had other loads in the sub-panel, then it would have to be no less than
(50+50+50+80)/1.2 or 200A.</FONT></SPAN></DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2 face=Arial>Note
from 2008 690.64 (B) that the sub-panel is NOT "capable of supplying multipule
branch circuits......" </FONT></SPAN></DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2 face=Arial>Still
this part of the new text for 690.64 in 2008 is not really that well thought
out, since with this understanding we see none of the provisons 1 -7 would apply
to that particular sub-panel at all.</FONT></SPAN></DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2 face=Arial>In the
diagram from the article you could ask, "Where is the point of interconnection
of the PV system?" Effectively, it is at the 80A breaker, not at the individual
50A breakers (so long as the sub-panel is a dedicated PV backfeed panel). The
80A breaker is the boundry below which it could be said all is PV circuit, and
above it, premise wiring.</FONT></SPAN></DIV>
<DIV><SPAN class=078255602-30032011><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><BR><SPAN lang=en-us><FONT size=2 face=Arial>Mark Frye</FONT></SPAN>
<BR><SPAN lang=en-us><FONT size=2 face=Arial>Berkeley Solar Electric
Systems</FONT></SPAN> <BR><SPAN lang=en-us><FONT size=2 face=Arial>303 Redbud
Way</FONT></SPAN> <BR><SPAN lang=en-us><FONT size=2 face=Arial>Nevada
City, CA 95959</FONT></SPAN> <BR><SPAN lang=en-us><FONT size=2
face=Arial>(530) 401-8024</FONT></SPAN> <BR><SPAN lang=en-us></SPAN><A
href="http://www.berkeleysolar.com/"><SPAN lang=en-us><U><FONT color=#0000ff
size=2 face=Arial>www.berkeleysolar.com</FONT></U></SPAN></A><SPAN
lang=en-us><FONT size=2 face=Arial> </FONT></SPAN> </DIV>
<DIV> </DIV><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Al
Frishman<BR><B>Sent:</B> Tuesday, March 29, 2011 7:46 PM<BR><B>To:</B>
re-wrenches@lists.re-wrenches.org<BR><B>Subject:</B> [RE-wrenches] sizing a
sub-panel used to combine multiple inverteroutputs<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV class=WordSection1>
<P class=MsoNormal>Hi Wrenchers,<o:p></o:p></P>
<P class=MsoNormal>When using a sub-panel for the sole purpose of combining the
output of multiple single phase inverters does NEC 690.64 (B) (2) apply? I
know that this topic has been discussed but I am still not clear.<o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>The “Can we Land” Article pg 11 Diagram 2b shows that using a
Subpanel eliminates the problem of exceeding the 120% rule illustrated in
diagram 2a but it does not show the rating of the sub-panel.
In the example it shows 3 Fronius 7500W single phase inverters
landing in a sub-panel and then the 3-phase sub-panel grid connected to a 80A
3-phase breaker in a 400A main panel. What is the minimum Amp
rating required for the 3-phase Sub-panel in diagram 2b? Do we only need
to size it for the OCP for the combined outputs of the 3 inverters (80A) or do
the three 50A two-pole breakers need to be considered? <o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>For easy reference here is a link to the article: <A
href="http://www.spgsolar.com/wp-content/uploads/2010/05/SPGLeBlancYates.pdf">http://www.spgsolar.com/wp-content/uploads/2010/05/SPGLeBlancYates.pdf</A><o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>All feedback is appreciated.<o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal><I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 10.5pt">Al
Frishman</SPAN></I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 13.5pt"><BR></SPAN><SPAN
style="FONT-FAMILY: ''Microsoft Sans Serif''; COLOR: #030100; FONT-SIZE: 13.5pt">Aeon</SPAN><SPAN
style="FONT-FAMILY: ''Microsoft Sans Serif''; COLOR: #ff9700; FONT-SIZE: 13.5pt">Solar</SPAN><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 13.5pt"><o:p></o:p></SPAN></P>
<P class=MsoNormal><I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 10.5pt">(917)
699-6641 - cell</SPAN></I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 10.5pt"><BR></SPAN><I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 10.5pt">(888)
460-2867</SPAN></I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 10.5pt"><BR></SPAN><I><SPAN
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href="http://www.aeonsolar.com/"><SPAN
style="COLOR: blue">www.aeonsolar.com</SPAN></A></SPAN></I><SPAN
style="FONT-FAMILY: 'Helvetica','sans-serif'; COLOR: black; FONT-SIZE: 13.5pt"><o:p></o:p></SPAN></P>
<P style="TEXT-ALIGN: center" class=MsoNormal align=center><I><SPAN
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