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<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2>Hi Bruce,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2>Unless you are leaving something meaningful out of your
description, the AHJ is wrong. Your description is fine as far as the code goes.
</FONT></SPAN><SPAN class=812130117-31072009><FONT face=Arial color=#0000ff
size=2>I recommend installing a 100A main in the new 200A panel for local
disconnect @ house. </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2>Leave 100A main & feeder as-is (assuming safe, properly
sized feeders, suitable grounding, etc.). There is nothing in the code that says
you have to use identical size breaker to the buss rating. </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2>Try explaining it to the AHJ this way: Take the solar away
from the question. </FONT></SPAN><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2>The 100A main breaker determines the MINIMUM rating of the
feeders and busbars. The busbars and feeders determine the MAXIMUM rating of
overcurrent devices. For example, using the AHJ logic, you would be
prohibited from using a #2 for feeder conductors between the 100A main and the
house because they are rated for up to 130A. Doesn't make any sense,
huh?</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2>The extra ampacity in the bussing is permitted and provides
additional safety.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><FONT face=Arial><FONT size=2><FONT color=#0000ff><SPAN
class=812130117-31072009>Best of luck!</SPAN><SPAN
class=812130117-31072009></SPAN></FONT></FONT></FONT></DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=812130117-31072009></SPAN><FONT
face=Arial><FONT color=#0000ff><FONT size=2>M<SPAN class=812130117-31072009>att
Lafferty</SPAN></FONT></FONT></FONT><BR></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Mendocino
Solar Service<BR><B>Sent:</B> Friday, July 31, 2009 9:57 AM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> [RE-wrenches] down-sizing main
breaker<BR></FONT><BR></DIV>
<DIV></DIV>Hi Folks,
<DIV><BR></DIV>
<DIV>Can anyone provide code reference or advice on this question?</DIV>
<DIV>Our customer has 100 amp service at the meter pedestal, 100 amp main
breaker feeding 200 foot underground run to a 100 amp panel at the house. We
need to land a 40 amp breaker, so are proposing to replace main panel at house
with 200 amp panel. The AHJ says we need a 200 amp main breaker in this panel,
which will work, but says this requires upsizing the feeder, main breaker at
meter, and therefore utility service to 200 amps.</DIV>
<DIV><BR></DIV>
<DIV>I've read on this list and elsewhere about downsizing the main breaker in a
panel to create capacity to make the 120% rule. This AHJ says you can't put in a
breaker smaller than the panel size, and furthermore, everything upstream would
have to be upsized. Is this from the code?<BR><BR>
<DIV><SPAN class=Apple-style-span
style="WORD-SPACING: 0px; FONT: 14px Palatino; TEXT-TRANSFORM: none; COLOR: rgb(0,0,0); TEXT-INDENT: 0px; WHITE-SPACE: normal; LETTER-SPACING: normal; BORDER-COLLAPSE: separate; orphans: 2; widows: 2; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0">
<DIV>Bruce Erickson</DIV>
<DIV>Mendocino Solar Service</DIV>
<DIV>PO Box 1252</DIV>
<DIV>Mendocino, CA 95460</DIV>
<DIV>707-937-1701</DIV>
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