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<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=765193713-12102010>Well yes but, 690.64 (2) is titled and reads "Bus or
Conductor Rating". The "or" is important and the 120% requirement does not apply
to the upstream conductors, in this case.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=765193713-12102010></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=765193713-12102010>In general, if the sudpanel of 225A where backfeed
with the 120A of PV and had a 150A breaker on its feeder from the main
panel, the conductor between the main panel and the sub need be rated only for
the 150A feeder conductor.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><SPAN class=765193713-12102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=765193713-12102010><FONT color=#0000ff
size=2 face=Arial>The size of the feeder tap between the transfer switch lug and
the new sub panel needs to be evaluated differently.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=765193713-12102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=765193713-12102010><FONT color=#0000ff
size=2 face=Arial>I myself am a big fan of 240.21 (B), even when it comes to
feeders with PV on them. I guess some folks are not, but other than the
expression of opinion, I don't see anything to prohibits the use of downsized
feeder taps in PV circuits. I think most folks would go for a downsized
conductor to connect up the new subpanel, so long as it was located right next
to the transfer switch equipment.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><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>
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<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>Jason
Szumlanski<BR><B>Sent:</B> Tuesday, October 12, 2010 4:05 AM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> Re: [RE-wrenches] Supply side connection to a
dedicated panel<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV>That sounds right, which means that the existing wiring between the service
disconnect and the transfer switch may also need to be evaluated since it will
now have sources available at both ends. The rule applies to all bus bars and
conductors "upstream" of the interconnection point as I understand
it.<BR><BR>Jason Szumlanski</DIV>
<DIV>Fafco Solar</DIV></BODY></HTML>