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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>William,<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'>I would strongly disagree that conduit is tried and true on rooftops. I have rarely seen good conduit runs on rooftops. Most electricians have no clue how to work with expansion joints. Conduit on rooftops is a bad idea in general. Most conduit runs in big buildings are all done indoors for good reason. We are the crazy people doing things on the roof. <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 sooner we get away from conduit—particularly for long feeder runs—the better.<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'>In Europe they don’t have problems with their rooftop wiring systems because everything is in tray.<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'>For those that don’t allow cable tray for anything less than 1/0, just remember that if it isn’t called cable tray, then 392 doesn’t apply. The NEC would allow us to use treated lumber in place of cable tray. This makes no sense.<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'>We did some research on the origin of the 1/0 requirement, and it is ancient and no longer relevant. Just because it is in the code, does not mean it is correct. That’s why we try to fix it every three years.<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><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";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"'>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, March 25, 2013 9:30 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Cable tray<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>David:<br><br>Of course, I understand that you are not saying we can willfully disregard the Code in anticipation of future clarification. I was just extrapolating on your idea. <br><br>If we want an exception based on a predicted update in the code, we are at the mercy of the AHJ who may or may not be convinced. I think most AHJs are willing to diverge from the Code in a more strict interpretation, but not the reverse. Right now, as I read it, unless the leads are 1/0 or larger, we are forbade.<br><br>I treat PV systems like rooftop AC units. The voltages and currents are similar, if not more severe. I don't believe you could or should run power to a rooftop AC unit in cable tray. Conduit is a tried and true practice and I recommend it.<br><br>William Miller<br><br><br>At 06:01 PM 3/25/2013, you wrote:<br><br><o:p></o:p></p><p class=MsoNormal>Ouch. I promise I'm not advocating for anything like that. What I may be missing is the Code reference that says "no cable tray on roofs" or similar. <br><br>There is so much room for improvement in wire management practices, that being able to use cable tray seems like a step forward. I understand some jurisdictions do not allow it, but it appears as though Code changes were made specifically to address this. It's boring stuff, but you can read the explanation of the Code changes in the ROP and ROC documents. <br><br>The Code changes a lot with regards to PV system, and Article 690 is more fluid than other articles. Some of this is the Code trying to keep up with technology. In other cases the Code evolves based on new applications for existing products. Often it changes because some areas of the Code are confusing for electricians and inspectors alike. If the new Code language is more clear in its intent than previous versions, some inspectors are willing to let installers build to the most current standard.<br><br>That's all I'm advocating for: Trying to understand how the minimum requirements outlined in Code evolve over time so that you can have a friendly and informed conversation with your AHJ over a donut. <br><br><br><br> <br>On Mar 25, 2013, at 6:26 PM, William Miller wrote:<br><br><br><o:p></o:p></p><p class=MsoNormal>David:<br><br>This is great news. Now, whenever I want to do something that is prohibited by code, I can just say that the Code Making Panel is gonna correct that pesky code section (<i>insert your problem citation here</i>) any day now, so I might as well be allowed to do whatever it was I was fixin' to do anyway. Unless I am missing something...<br><br>Thanks!<br><br>William Miller<br><br>PS: Just kidding. Hope no offense is taken.<br><br>wm<br><br><br>At 03:46 PM 3/25/2013, you wrote:<br><br><br><o:p></o:p></p><p class=MsoNormal>So if you ever get called on 392.10(B)(2), I think you can point out that the Code Making Panels have been busy clarifying that cable tray is okay for source circuit conductors. Unless I'm missing something....<o:p></o:p></p><p class=MsoNormal>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Change email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a href="http://www.members.re-wrenches.org/">www.members.re-wrenches.org</a><o:p></o:p></p><p class=MsoNormal><br>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Change email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a href="http://www.members.re-wrenches.org/">www.members.re-wrenches.org</a><o:p></o:p></p><p>Miller Solar<br>Voice :805-438-5600<br>email: <a href="mailto:william@millersolar.com">william@millersolar.com</a><br><a href="http://millersolar.com/">http://millersolar.com<br></a>License No. C-10-773985<o:p></o:p></p></div></body></html>