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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:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The other thing I could do is downsize the main to 190 amps or less. 190 + 60(pv) = 250 / 1.2 = 208 amps, exactly the 4/0 derate amperage.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Unfortunately I can’t get away with downsizing the 60 amp pv breaker, unless I could find a breaker rated to operate continuously at greater than 80% of its trip rating. I guess they do exist. Then you don’t have to apply the 1.25 multiplier when sizing the breaker. This is a SQD industrial panel the inverter is feeding into. Any SQD gurus out there who know of these types of breakers? <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>Jason Szumlanski<br><b>Sent:</b> Tuesday, March 04, 2014 4:06 PM<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><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'>Yeah, I assumed you meant the four conductors. The exception would solve your problem if it's physically possible.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'>How long of a run are we talking about? The cost difference shouldn't be bad for a short distance.<o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div id="WISESTAMP_SIG_gmail_session"><div><div style='margin-bottom:6.0pt'><p style='margin:0in;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'>Jason Szumlansk<o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'>i<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'>Fafco Solar<o:p></o:p></span></p></div></div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";border:solid windowtext 1.0pt;padding:0in'><img width=1 height=1 id="Picture_x0020_1" src="cid:image001.jpg@01CF37C7.2E5844B0" alt="Description: Image removed by sender."></span><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'><o:p></o:p></span></p></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 3:34 PM, Kirk Herander <<a href="mailto:kirk@vtsolar.com" target="_blank">kirk@vtsolar.com</a>> wrote:<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'>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><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><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><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'><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> [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">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><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;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><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><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><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'><p style='margin:0in;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif"'>Jason Szumlanski</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:10.0pt;font-family:"Verdana","sans-serif"'>Fafco Solar</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:10.0pt;font-family:"Verdana","sans-serif"'><br> </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:10.0pt;font-family:"Verdana","sans-serif";border:solid windowtext 1.0pt;padding:0in'><img border=0 width=1 height=1 id="Picture_x0020_2" src="cid:image003.jpg@01CF37C7.12AC8730" alt="Description: Description: Image removed by sender."></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><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><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><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><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><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><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><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><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><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><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><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><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><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;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div></div></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><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" target="_blank">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" target="_blank">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" target="_blank">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a href="http://www.members.re-wrenches.org" target="_blank">www.members.re-wrenches.org</a><br><br><o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>