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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Mark and Rebekah,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The term “continuous” is a requirement for any
circuit and implies electrical continuity and current-carrying capability. Both
the GEC and EGC must be continuous or you don’t got one. It is not
defined in NEC Article 100.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>What most people are referring to when they say that a GEC must
be continuous is “unbroken” or the NEC talks about “irreversibly
spliced.” Splicing of a GEC is usually a last resort because there is no
other option. For instance, multiple bonding jumpers coming off of multiple
inverters would need to be irreversibly spliced to the main GEC that should
proceed unbroken from the farthest inverter from the grounding electrode.
250.66 for ac and 250.166 for dc are consistent in requiring the minimum GEC to
be 8AWG copper. Since the GEC for Enphase starts at the inverter on the roof,
you must have a minimum of 8AWG running among the microinverters and down to
the grounding electrode system. In the 2008 NEC and 2011 NEC, this conductor
can serve the purpose of the ac EGC as well and can be terminated on the
service panel grounding bus.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Bill.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Rebekah
Hren<br>
<b>Sent:</b> Tuesday, September 14, 2010 7:25 AM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] GEC for Enphase inverters<o:p></o:p></span></p>
</div>
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<p class=MsoNormal>The code does require the GEC to be continuous (250.64C),
and I believe that the AC EGC for the Enphase metal inverter cases is in fact
the same as the DC GEC since the point of system bonding on the DC side is
inside the inverter. <o:p></o:p></p>
<div>
<p class=MsoNormal>See art. 100 definitions:<b>Grounding Electrode Conductor.
A conductor used to</b><o:p></o:p></p>
</div>
<p class=p1><b>connect the system grounded conductor...to a point on the
grounding electrode</b><o:p></o:p></p>
<p class=p1><b>system.</b><o:p></o:p></p>
<div>
<p class=MsoNormal><br>
So this means that for Enphase systems the AC EGC (which is also the DC GEC)
should be at minimum 8 awg (250.66) and continuous? Seems like it to
me. <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<p class=MsoNormal>Rebekah Hren<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<p class=MsoNormal><br>
<br>
--- On <b>Tue, 9/14/10, Mark Frye <i><markf@berkeleysolar.com></i></b>
wrote:<o:p></o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><br>
From: Mark Frye <markf@berkeleysolar.com><br>
Subject: Re: [RE-wrenches] GEC for Enphase inverters<br>
To: "'RE-wrenches'" <re-wrenches@lists.re-wrenches.org><br>
Date: Tuesday, September 14, 2010, 10:05 AM<o:p></o:p></p>
<div id=yiv1974489623>
<p class=MsoNormal><span class=yiv1974489623468365813-14092010><span
style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>I
believe the AC GEC runs from; the point where the ungrounded current carrying
conductor is bonded to the enclosure of the service enterance equipment; to
the connection to the ground electrode system. Conductors that run from the
service enterance equipment, thru the premis to the Enphase are bonding
jumpers that are not required to be continuous.</span></span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Mark
Frye</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Berkeley
Solar Electric Systems</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>303 Redbud
Way</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Nevada
City, CA 95959</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>(530)
401-8024</span> <br>
<a href="http://www.berkeleysolar.com/" target="_blank"><span
style='font-size:10.0pt;font-family:"Arial","sans-serif"'>www.berkeleysolar.com</span></a><span
style='font-size:10.0pt;font-family:"Arial","sans-serif"'> </span> <o:p></o:p></p>
<div>
<p class=MsoNormal> <o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:
10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>William
Miller<br>
<b>Sent:</b> Monday, September 13, 2010 9:46 PM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> [RE-wrenches] GEC for Enphase inverters</span><o:p></o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'>Friends:<br>
<br>
According to the 2005 NEC 250.64(C), the GEC for an AC system needs to be
continuous without splices unless they are irreversible. I am not clear
where this conductor starts and ends. Is it from the ground buss in a
sub-panel to the disconnect switch on the roof, or to each inverter?<br>
<br>
Also, non-reversible splices need to be listed for use in grounding
systems. Any suggestions on make and model of splices so listed?<br>
<br>
Any advise from those more experienced is much appreciated.<br>
<br>
William Miller<o:p></o:p></p>
<p><u>Please note new e-mail address and domain:<br>
<br>
</u>William Miller <br>
Miller Solar<br>
Voice :805-438-5600<br>
email: william@millersolar.com<br>
<a href="http://millersolar.com/" target="_blank">http://millersolar.com<br>
</a>License No. C-10-773985<o:p></o:p></p>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'><br>
-----Inline Attachment Follows-----<o:p></o:p></p>
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