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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-size:13.5pt'><a href="http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CEoQFjAC&url=http%3A%2F%2Fwww.slideshare.net%2Fsolpowerpeople%2Finterconnection-rule&ei=FZcYU5e_LsSi0QH5yICQCQ&usg=AFQjCNGypW0SbS6-POHt4d82Sxc--kZ0ig&sig2=Kz2661LzDghXtx9GwuhOfw&bvm=bv.62577051,d.dmQ">Changes to <i>2014 NEC</i> Interconnection Rule 705.12</a><o:p></o:p></span></b></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Here’s a link to a powerpoint (slideshare.net) by Richard Stovall which clarifies 705.12 using some excellent illustrations. Maybe some have seen it already. Works for me.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Contact me off-list if you’d like a pdf version.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kirk Herander<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT Solar, LLC<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>dba Vermont Solar Engineering<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NABCEP<sup>TM </sup>Certified Inaugural Certificant<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NYSERDA-eligible Installer<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT RE Incentive Program Partner<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>802.863.1202<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><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>Brian Mehalic<br><b>Sent:</b> Wednesday, March 05, 2014 10:02 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] conductors and the 120% rule<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>A very clarifying change is what I'd call it! <o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>First off, rather than being based on the actual breaker size on the inverter output circuit, calcs are instead based on 125% of the inverter rated output current.<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>705.12(D)(2)(1) addresses "Feeders" - but only applies when the inverter output circuit connection is made somewhere other than the opposite end of the feeder from the utility supply. This addresses concerns about whether the feeder conductor needs to be larger due to the presence of the additional source of supply, and so long as the inverter isn't connected to the feeder in the middle of it then the existing conductor size should be okay (because if it is at the opposite end of the feeder than there is nowhere where the utility and inverter current will be additive).<o:p></o:p></p></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>705.12(D)(2)(3) addresses "Busbars" and allows several options, including the familiar "120% rule" as you stated in your original post. Also check out 705.12(D)(2)(3)(c) - depending on the load breakers in the subpanel, the 120% rule may not even need to be used (if the sum of the inverter and load breakers is less than or equal to the busbar rating).<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>And remember, even if your AHJ hasn't adopted 2014 yet it is worth having a conversation with them to see if they'll allow you to design the system based on the new Code - after all, in a certain sense, the 2014 NEC is what "they" meant the 2011 NEC to say!<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Cheers,<o:p></o:p></p></div></div><div><p class=MsoNormal><br clear=all><o:p></o:p></p><div><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Brian Mehalic <br>NABCEP Certified Solar PV Installation Professional™ R031508-59<o:p></o:p></p><div><p class=MsoNormal>IREC ISPQ Certified Affiliated Instructor/PV US-0132<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>PV Curriculum Developer and Instructor<o:p></o:p></p><div><p class=MsoNormal>Solar Energy International<br><a href="http://www.solarenergy.org" target="_blank">http://www.solarenergy.org</a><o:p></o:p></p></div></div></div></div></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div><p class=MsoNormal>On Tue, Mar 4, 2014 at 5:21 PM, Kirk <<a href="mailto:kirk@vtsolar.com" target="_blank">kirk@vtsolar.com</a>> wrote:<o:p></o:p></p><div><div><p class=MsoNormal>Is this a code change in 2014 vs 2011 or merely a clarification? Vt has not adopted 2014 yet. What was the original rationale for the 120% rule to apply to conductors in addition to a panel bus? <span style='color:#888888'><br><br><span class=hoenzb>Kirk Herander<o:p></o:p></span></span></p><div><p class=MsoNormal><span style='color:#888888'>VSE</span><o:p></o:p></p></div></div><div><div><div><p class=MsoNormal style='margin-bottom:12.0pt'><br>On Mar 4, 2014, at 6:20 PM, Brian Mehalic <<a href="mailto:brian@solarenergy.org" target="_blank">brian@solarenergy.org</a>> wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal>If the subpanel is at the end if the feeder, and there are no taps in between the main and the sub then I don't see any reason that the conductors need to be any larger than 200 A as there is no where on the feeder conductors where grid and PV current will be additive. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The changes in 705.12 in 2014 address this in large part. <br><br>Brian<o:p></o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><br>On Mar 4, 2014, at 2:41 PM, "Kirk Herander" <<a href="mailto:kirk@vtsolar.com" target="_blank">kirk@vtsolar.com</a>> wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Solaredge 20 kw, 480 3-phase. Good point, but that may be irrelevant. The feed-in subpanel is also powering unrelated loads, which use the neutral as a conductor from the main panel. So 4 conductors from the main.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kirk Herander</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT Solar, LLC</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>dba Vermont Solar Engineering</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NABCEP<sup>TM </sup>Certified Inaugural Certificant</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NYSERDA-eligible Installer</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT RE Incentive Program Partner</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="tel:802.863.1202" target="_blank">802.863.1202</a></span><o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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"'> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Allen Frishman<br><b>Sent:</b> Tuesday, March 04, 2014 4:32 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] conductors and the 120% rule</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>what inverter(s) are you using? In many cases the Neutral is not considered a Current Carying Conductor by the Manufacturer and therefore you only have 3 CCC.<o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><i><span style='font-size:10.5pt'>Al Frishman</span></i><span style='font-size:13.5pt'><br><span style='color:#030100'>Aeon</span><span style='color:#FF9700'>Solar</span></span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><i><span style='font-size:10.5pt'><a href="tel:%28917%29%20699-6641" target="_blank">(917) 699-6641</a> - cell</span></i><span style='font-size:10.5pt'><br><i><a href="tel:%28888%29%20460-2867" target="_blank">(888) 460-2867</a></i><br><i><a href="http://www.aeonsolar.com/" target="_blank">www.aeonsolar.com</a></i></span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On Mar 4, 2014, at 4:20 PM, Kirk Herander wrote:<o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><o:p> </o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Approx.. 50 – 60ft.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p></div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kirk Herander</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT Solar, LLC</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>dba Vermont Solar Engineering</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NABCEP<sup>TM </sup>Certified Inaugural Certificant</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NYSERDA-eligible Installer</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT RE Incentive Program Partner</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="tel:802.863.1202" target="_blank">802.863.1202</a></span><o:p></o:p></p></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p></div><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in;border-width:initial;border-color:initial'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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"'> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a> <a href="mailto:[mailto:re-wrenches-bounces@lists.re-wrenches.org]" target="_blank">[mailto:re-wrenches-bounces@lists.re-wrenches.org]</a> <b>On Behalf Of </b>Ray Walters<br><b>Sent:</b> Tuesday, March 04, 2014 4:05 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] conductors and the 120% rule</span><o:p></o:p></p></div></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'>What is the length of the conduit to the subpanel? That will determine whether to apply the derates.<br><br><o:p></o:p></p></div><pre>R.Ray Walters<o:p></o:p></pre><pre>CTO, Solarray, Inc<o:p></o:p></pre><pre>Nabcep Certified PV Installer, <o:p></o:p></pre><pre>Licensed Master Electrician<o:p></o:p></pre><pre>Solar Design Engineer<o:p></o:p></pre><pre><a href="tel:303%20505-8760" target="_blank">303 505-8760</a><o:p></o:p></pre><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On 3/4/2014 1:34 PM, Kirk Herander wrote:<o:p></o:p></p></div></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Whether or not a further derate has to be applied is the killer here, as I am working with existing panels and conductors. In an old Code Corner(HP140) J. Wiles goes through a similar scenario and calls out the allowable current rating and conductor in 310.15, but makes no mention of applying additional derate factors. The .8 derate for 4-6 conductors(l1,l2,l3, & n) will put the existing 4/0 cable between feed-in and main panel at 208 amps, less than the allowable 217. I’d hate to need to upsize the wire to 250 mcm.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kirk Herander</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT Solar, LLC</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>dba Vermont Solar Engineering</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NABCEP<sup>TM </sup>Certified Inaugural Certificant</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>NYSERDA-eligible Installer</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>VT RE Incentive Program Partner</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="tel:802.863.1202" target="_blank">802.863.1202</a></span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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"'> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Jason Szumlanski<br><b>Sent:</b> Tuesday, March 04, 2014 2:57 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] conductors and the 120% rule</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-family:"Verdana","sans-serif"'>Both the bus and conductors need to be rated for 217 amps minimum. As you mentioned, the bus is not a problem. The way I interpret it, the conductor size required would be after derate factors are applied. The rating of the conductor is ultimately dependent on the derate factors.</span><o:p></o:p></p></div></div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-family:"Verdana","sans-serif"'> </span><o:p></o:p></p></div></div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-family:"Verdana","sans-serif"'>If you can locate your subpanel adjacent to the main distribution panel, you may be able to use Exception #3 to 310.15(B)(2) by connecting the panels with a short nipple. I assume you are just looking at a number of conductor derate and not an ambient temperature derate.</span><o:p></o:p></p></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><div><div style='margin-bottom:6.0pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'>Jason Szumlanski</span><o:p></o:p></p></div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'>Fafco Solar</span><o:p></o:p></p></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'><br> </span><o:p></o:p></p></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";border:solid windowtext 1.0pt;padding:0in'><image001.jpg></span><o:p></o:p></p></div></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'> <o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On Tue, Mar 4, 2014 at 12:05 PM, Kirk Herander <<a href="mailto:kirk@vtsolar.com" target="_blank">kirk@vtsolar.com</a>> wrote:<o:p></o:p></p></div><div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>Hello,</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>I have a 225 amp 3-phase main lug sub-panel protected by a 200 amp breaker. My inverter breaker feeding the sub panel is 60 amps. So 225 a bus x 1.2 = 270 amps. That’s less than the sum of the two breakers of 260 amps, so no issue there. The conductors between sub and main panel have to be rated for at least 260/1.2 = 217 amps, correct? Is this 217 amps before or after derating the conductor?</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>Kirk Herander</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>VT Solar, LLC</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>dba Vermont Solar Engineering</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>NABCEP<sup>TM </sup>Certified Inaugural Certificant</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>NYSERDA-eligible Installer</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'>VT RE Incentive Program Partner</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:14.0pt'><a href="tel:802.863.1202" target="_blank">802.863.1202</a></span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div></div><div><p class=MsoNormal 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