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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Kirk Herander,
VSE [mailto:kirk@vtsolar.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Sunday, April 10, 2011 10:02
PM<br>
<b><span style='font-weight:bold'>To:</span></b> 'William Miller'<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [RE-wrenches] 690.4
(B) ???</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks William,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>IMO you are right on in your
interpretation. I can see no wiggle room for the inspector because of the
definitions in 690.2. So we will see what happens. BTW, I hope your local
inspector reversed themselves when presented the same “evidence”.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>That said, 690.4(B) tin the 2008 NEC is
ridiculously vague. PV inputs/outputs are not spelled out as DC (which by
definition they are). Does “unless connected” mean unless the pv
inputs and outputs are tied together (and why woudn’t they be in a jbox
or fused array combiner), or that the pv inputs and outputs are tied to the
“separate” system conductors in the same raceway?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Is this the most poorly worded paragraph
in 690? It seems so right now. Just got my new 2011 NEC (comments version) but
I am without it traveling and can only hope it’s been clarified.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'>Kirk Herander</span></font><font color=navy><span
style='color:navy'> <br>
</span></font><st1:place w:st="on"><st1:State w:st="on"><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>Vermont</span></font></st1:State></st1:place><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'> Solar Engineering</span></font><font color=navy><span
style='color:navy'> <br>
</span></font><font size=2 color=navy face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:navy'>802.863.1202</span></font><font color=navy><span
style='color:navy'> <br>
</span></font><font size=2 color=navy face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:navy'>NABCEP(tm) Certified Solar Installer</span></font><font
color=navy><span style='color:navy'> <br>
</span></font><font size=2 color=navy face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:navy'>NYSERDA-eligible Installer</span></font><font
color=navy><span style='color:navy'> <br>
</span></font><font size=2 color=navy face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:navy'>VT Solar Incentive Program Partner</span></font><font
color=navy><span style='color:navy'> </span></font><o:p></o:p></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> William Miller
[mailto:william@millersolar.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Sunday, April 10, 2011 2:19
AM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">kirk@vtsolar.com</st1:PersonName>;
<st1:PersonName w:st="on">RE-wrenches</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [<st1:PersonName
w:st="on">RE-wrenches</st1:PersonName>] 690.4 (B) ???</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Kirk:<br>
<br>
When you say inverter combiner, I am confident you mean the device combining
the AC output conductors of multiple inverters.<br>
<br>
I got the same jive from an over zealous inspector once, but he and your
inspector are just plain wrong. Examine and show them the diagram
in the code book of PV source and output conductors (690.2). These are
all DC PV conductors, not AC conductors, and, assuming the statement in the
paragraph above is correct, the passage has no application here.
This is a rookie inspector mistake.<br>
<br>
Good luck,<br>
<br>
William<br>
<br>
PS: By saying the source and output connectors are connected together,
this is an oblique way of describing the PV combiner, the one point where PV
source and output circuits are connected together.<br>
<br>
WM<br>
<br>
<br>
<br>
At 06:10 PM 4/9/2011, Kirk Herander, VSE wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>2008 NEC states that:<br>
<br>
(B) Conductors of Different Systems. Photovoltaic<br>
source circuits and photovoltaic output circuits shall not be<br>
contained in the same raceway, cable tray, cable, outlet box,<br>
junction box, or similar fitting as feeders or branch circuits<br>
of other systems, unless the conductors of the different systems<br>
are separated by a partition or are connected together.<br>
<br>
Can anyone describe and give an example of what "connected together"
means<br>
to inverter PV circuits in the same conduit as a branch (load) circuit?<br>
<br>
I have a single existing PVC conduit to a barn with an AC load subpanel. I<br>
want to run the output conductors of an inverter combiner panel in the barn<br>
through the same conduit to get to be main building. The fill / derating<br>
calcs work to do this. The inspector says I have to run a new conduit for<br>
the AC inverter combiner because the subpanel feeder and the combiner output<br>
conductors are "not connected". But they are both connected to the
main<br>
building panel. Any insight will be appreciated. Thanks. I've also been told<br>
that the NEC 2011 comments on 690.4 (B) clarify this. Can anyone comment?<br>
Obviously I am not mixing DC and AC conductors.<br>
<br>
<br>
<br>
Kirk Herander<o:p></o:p></span></font></p>
<p></x-sigsep><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><x-sigsep>William
Miller <br>
Miller Solar<br>
Voice :805-438-5600<br>
email: william@millersolar.com<br>
<a href="http://millersolar.com/" eudora=autourl>http://millersolar.com<br>
</a>License No. C-10-773985<o:p></o:p></span></font></p>
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