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<div class="moz-cite-prefix">Most often it is the negative wire that
is grounded, but not all of the time. Whichever is grounded should
have white or light gray insulation and it should have a
mechanical connector or bus bar connection in the disconnect
switch so that the grounded conductor can be opened for
maintenance. While that is what the code says, I don't feel a
small array is any more dangerous if both conductors are switched.
Quite the opposite: the array is "probably" safer if both
conductors are open. <br>
<br>
For an ungrounded array, which will probably become more common as
equipment is designed to operate that way, both conductors are
supposed to be switched in the disconnect. In that case there
shouldn't be any white wire going to the PV array.<br>
<br>
<pre class="moz-signature" cols="72">Kent Osterberg
Blue Mountain Solar, Inc.
<a class="moz-txt-link-abbreviated" href="http://www.bluemountainsolar.com">www.bluemountainsolar.com</a>
t: 541-568-4882
</pre>
On 9/14/2012 6:46 PM, Bob Clark wrote:<br>
</div>
<blockquote cite="mid:006101cd92e3$e37cf0a0$aa76d1e0$@us"
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<div class="WordSection1">
<p class="MsoNormal"><span style="color:#1F497D">Kent:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">In a normally
grounded array, the grounded conductor is the negative
conductor, right? So, no disconnecting the negative
conductor. It should go straight through the DC disconnect
and on to the inverter. Correct?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">Bob Clark<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><i><span
style="font-family:Papyrus;color:#E36C0A">SolarWind
Energy Systems, LLC<o:p></o:p></span></i></b></p>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">P.O. Box 1234<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">Okanogan, WA
98840<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">(509) 826-1259<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span
style="font-size:6.0pt;font-family:"Lucida
Handwriting";color:#E36C0A"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><i><span style="color:teal">Although no
trees were killed in the sending of this message, a
large number of electrons were terribly inconvenienced.</span></i><i><span
style="color:teal"><o:p></o:p></span></i></p>
<p class="MsoNormal"><span
style="font-size:10.5pt;font-family:"Helvetica","sans-serif""><img
id="_x0000_i1026"
src="cid:part1.07050806.05050808@coveoregon.com"
alt="cid:822514723@19022009-0502" height="50"
width="353"></span><span style="font-family:"Arial
Rounded MT Bold","sans-serif";color:green"><o:p></o:p></span></p>
</div>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #B5C4DF
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
<a class="moz-txt-link-abbreviated" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>
[<a class="moz-txt-link-freetext" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On
Behalf Of </b>Kent Osterberg<br>
<b>Sent:</b> Friday, September 14, 2012 5:00 PM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] Disconnect BOTH
positive and negative conductors from array?!?<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal">See 690.13. There must be a means to
disconnect all conductors of a PV system. If it is a
normally grounded array you are not allowed to put a switch
in the grounded conductor, except .... for circumstances
added in the 2011 code.<br>
<br>
<o:p></o:p></p>
<pre>Kent Osterberg<o:p></o:p></pre>
<pre>Blue Mountain Solar, Inc.<o:p></o:p></pre>
<pre><a moz-do-not-send="true" href="http://www.bluemountainsolar.com">www.bluemountainsolar.com</a><o:p></o:p></pre>
<pre>t: 541-568-4882<o:p></o:p></pre>
<p class="MsoNormal">On 9/14/2012 4:39 PM, Bob Clark wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">Wrenches:<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">A local utility person has suggested that
both the positive and negative conductors from a solar array
should be disconnected.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Disconnect both or not? 2008 NEC
supporting citation please.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Thanks for your response.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">Bob Clark</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><i><span
style="font-family:Papyrus;color:#E36C0A">SolarWind
Energy Systems, LLC</span></i></b><o:p></o:p></p>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">P.O. Box
1234</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">Okanogan, WA
98840</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span
style="font-family:Papyrus;color:#E36C0A">(509)
826-1259</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:6.0pt"> </span></b><o:p></o:p></p>
<p class="MsoNormal"><i><span style="color:teal">Although no
trees were killed in the sending of this message, a
large number of electrons were terribly
inconvenienced.</span></i><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.5pt;font-family:"Helvetica","sans-serif""><img
id="f40d97e9-df88-4267-bf14-46315c1976b9"
src="cid:part1.07050806.05050808@coveoregon.com"
alt="cid:822514723@19022009-0502" border="0"
height="50" width="353"></span><o:p></o:p></p>
</div>
<p class="MsoNormal"><b><i><span
style="font-family:Papyrus;color:#E36C0A"> </span></i></b><o:p></o:p></p>
</blockquote>
</div>
</blockquote>
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