<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Cambria;
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
span.apple-style-span
{mso-style-name:apple-style-span;}
span.EmailStyle20
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
span.EmailStyle22
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.EmailStyle23
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:1197887676;
mso-list-template-ids:152499698;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1
{mso-list-id:2111197968;
mso-list-template-ids:-905522018;}
@list l1:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1:level2
{mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level3
{mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level4
{mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level5
{mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level6
{mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level7
{mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level8
{mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;}
@list l1:level9
{mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
--></style></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">Wrenches,</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I wrote back to Bill with the person at SMA who gave the talk and it is possible that I may have been mistaken about the ship date for AFCI-enabled Sunny Boys. Transformerless Sunny Boy US-series units are on the way soon too and I may have gotten mixed up. To be sure, don't take my word for it and check in with your supplier. </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Anyway, I'm looking forward to trying the AFCI enabled inverters when we can get them and suspect that they will be industry standard well before CA adopts the 2011 NEC in 2014. </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Best, August</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </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""> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Bill Brooks<br>
<b>Sent:</b> Sunday, October 14, 2012 9:44 AM<br><b>To:</b> 'RE-wrenches'<br><b>Subject:</b> Re: [RE-wrenches] Two NEC questions</span></p></div></div><p class="MsoNormal"> </p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">August,</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Who at SMA said that they won’t be shipping AFCI inverters? I know they have been manufacturing. I have two of the AFCI inverters in operation at my office and they are very impressive. Three months of operation since startup without a single nuisance trip and it trips every time I simulate a fault. I would press SMA on delivery since I believe they are available. It may be either an internal hold on the product or bad information.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Eaton has released their AFCI component but it is not a listed component so it has to be incorporated into a listed product like a combiner box or inverter. </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Although the AFCI technology will have some issues in implementation, I believe that it is going to solve a lot of safety issues, particularly with residential systems. We have been seeing more and more series arc fault failures in the field, so the timing could not be better. Even if you are in a region that does not enforce the 2011 NEC yet, I would recommend seriously looking at products in this area.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">One word of caution. I believe AFCI products incorporated into inverters will be more successful in the short term than products that are independent of the inverter. The reason for this is simple. When the product developer has the defined noise signature of the inverter, they can build a product that accounts for the that noise signature (transistor switching). Without that key piece of data, there will be stand-alone AFCI products that have problems with particular inverters and other components (dc-dc converters). These interactions are difficult to predict without product by product testing. </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Over the next few years, products like the one from Eaton will create lists of inverters that they know work well with their products. Until you get some good data on that issue, be careful.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Lastly, it is way cool to be able to walk up to a combiner box or plug connector and open it under load and see the inverter trip on the detected arc-fault. These products will become common retrofit items as modules, connectors, combiner boxes, and inverters have connection defects that start fires. Often, the only cost-effective way to fix these connection problems is with detection since replacing PV arrays and other products may be far more costly than installing an AFCI detector.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Bill.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </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""> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>August Goers<br>
<b>Sent:</b> Sunday, October 14, 2012 9:11 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Two NEC questions</span></p></div></div><p class="MsoNormal"> </p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">Hi David and Rebecca -</span></p>
<p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black"> </span></p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">We're still in the 2008 code cycle here in California so AFCI hasn't become an issue yet. I just listened to a webinar by SMA last week and I believe that their AFCI Sunny Boys wont' be shipping for at least a couple of months.</span></p>
<p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black"> </span></p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">Rebecca, have you already installed this system? What type of inverter do you want to use? NEC 90.4 (Enforcement) states this:</span></p>
<p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black"> </span></p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">"This<span class="apple-converted-space"> </span><i>Code</i><span class="apple-converted-space"> </span>may require new products, constructions, or materials that may not yet be available at the time the<span class="apple-converted-space"> </span><i>Code</i><span class="apple-converted-space"> </span>is adopted. In such event, the authority having jurisdiction may permit the use of the products, constructions, or materials that comply with the most recent previous edition of this<span class="apple-converted-space"> </span><i>Code</i><span class="apple-converted-space"> </span>adopted by the jurisdiction."</span></p>
<p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black"> </span></p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">So, you might be able to convince the AHJ to enforce the 2008 NEC which doesn't require AFCI. Or, use microinverters or ACPV as David mentioned below.</span></p>
<p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black"> </span></p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">Good luck out there!</span></p>
<p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black"> </span></p><p class="MsoNormal"><span style="font-family:"Calibri","sans-serif";color:black">-August </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </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""> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>David Brearley<br>
<b>Sent:</b> Saturday, October 13, 2012 9:02 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Two NEC questions</span></p></div></div><p class="MsoNormal"> </p><p class="MsoNormal">RE Question #2: </p><div>
<p class="MsoNormal"> </p></div><div><p class="MsoNormal">Article 100 defines a service as:</p><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"><b>Service.</b> The conductors and equipment for delivering electric energy <i>from</i> the serving utility to the wiring system of the premises served. (<i>emphasis added</i>)</p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">PV system wiring simply does not fit that definition. The PV system is not part of the serving utility. And inverters are not service equipment. </p></div>
<div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">You need to refers them to this definition in Article 705.2 (added in NEC 2011):</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"><b>Power Production Equipment.</b> The generating source, and <i>all</i> distribution equipment associated with it, that generates electricity from a source <i>other than</i> a utility supplied service. (<i>emphasis added</i>)</p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">FWIW: Mike Holt has written for SP about the Code requirements for interconnecting PV systems, as well as some additional recommendations for making supply side connections:</p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"><a href="http://solarprofessional.com/article/?file=SP5_1_pg14_QA&search=">http://solarprofessional.com/article/?file=SP5_1_pg14_QA&search=</a></p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">RE Question #1: I had a local inspector ask me about this in late-August & there were relatively few listed products at that time:</p>
</div><div><p class="MsoNormal"> </p></div><div><ul style="margin-top:0in" type="disc"><li class="MsoNormal" style>SMA America has dc AFCI in their standard SunnyBoy US-series inverters (SB 3000-US, SB 3800-US, SB 4000-US, SB 5000-US, SB 6000-US, SB7000-US, SB 8000-US): <a href="http://www.sma-america.com/en_US/news-information/current-news/news/news/1487.html">http://www.sma-america.com/en_US/news-information/current-news/news/news/1487.html</a></li>
<li class="MsoNormal" style>Microinverter systems (Enphase, Enecsys, etc.) typically do not operate above 80 Vdc and are therefore exempt from 690.11</li><li class="MsoNormal" style>AC module systems (powered by SolarBridge, Exeltech, etc.) typically do not operate above 80 Vdc and are therefore exempt from 690.11</li>
<li class="MsoNormal" style>SolarBOS reportedly has a dc AFDI and GFI combiner box: <a href="http://www.solarbos.com/news/solarbos-puts-out-the-fire-in-pv-systems">http://www.solarbos.com/news/solarbos-puts-out-the-fire-in-pv-systems</a> (However, I don't see this product on their website under their regular lists of products.)</li>
<li class="MsoNormal" style>While module-level dc-to-dc converters—like those from SolarEdge and Tigo Energy—presumably have the ability to provide dc AFCI capabilities, last I checked it didn't look like any of them were formally listed to do so.</li>
</ul></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">I suspect that most manufacturers are trying to avoid spending additional money on testing until the market requires this. </p></div><div><p class="MsoNormal">
</p></div><div><p class="MsoNormal">Have any wrenches here actually had an inspector required dc AFCI? Also, is the dc AFCI test standard actually finalized and adopted at this point or are companies testing to a draft standard? </p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"><span class="apple-style-span"><span style="font-family:"Cambria","serif"">David Brearley, Senior Technical Editor</span></span></p>
</div><div><div><p class="MsoNormal" style="margin-bottom:12.0pt"><span class="apple-style-span"><span style="font-size:13.5pt;font-family:"Cambria","serif";color:black">SolarPro magazine </span></span><span style="font-size:13.5pt;font-family:"Cambria","serif";color:black"><br>
<span class="apple-style-span">NABCEP Certified PV Installer ™</span><br><span class="apple-style-span"><a href="mailto:david.brearley@solarprofessional.com">david.brearley@solarprofessional.com</a></span><br><span class="apple-style-span">Direct: 541.261.6545</span></span></p>
</div><p class="MsoNormal"> </p><div><div><p class="MsoNormal">On Oct 13, 2012, at 10:12 AM, Rebecca Lundberg wrote:</p></div><p class="MsoNormal" style="margin-bottom:12.0pt"> </p><p class="MsoNormal" style="margin-bottom:12.0pt">
Dear fellow wrenches,<br><br>Does anyone have suggestions for the 'best' way to keep up with product availability for meeting 690.11 on DC AFCI? I understand that when this code section was written there was no available device, and know that at least several companies are working on devices. How will I know (before the AHJ knows :-) that residential-scale products are available for purchase, and at what point would you say now should be required over every other option?<br>
<br>Second question: I have an inspector insisting that the solar PV system is the same as a utility service, and is requiring all of the required service code references to apply. Anybody have a concise reference that might convince him otherwise? This same inspector has decided that the electrical permit will have adders for each inverter as service equipment, and each module as an electrical device. It would sure be nice if there was more consistency...we're still in the early adopter phase here in Minnesota.<br>
<br>Thanks in advance for your input.<br clear="all"><br>Keep Shining!<br><span style="font-family:"Arial","sans-serif"">Rebecca Lundberg<br>NABCEP Certified Solar PV Installer ®<br>Owner/CEO, Powerfully Green<br>
<a href="mailto:Rebecca.Lundberg@PowerfullyGreen.com">Rebecca.Lundberg@PowerfullyGreen.com</a><br>763-438-1976</span><br><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>Options & 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></p></div><p class="MsoNormal"> </p></div></div></div></body></html>