<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix">Jeff,<br>
<br>
Is there any surge protection in the combiner boxes? Any damage
visible in the combiner boxes? Any fuses or breakers open in the
combiner boxes? Is each pole a single string of modules or
multiple strings of modules?<br>
<br>
While there where undoubtedly ground currents flowing they
probably didn't cause the damage in the module junction boxes. The
PV module and wiring to it form a loop - often a loop with a large
area in the vicinity of the module. The current from the lightning
strike has a tremendous dI/dt and the changing magnetic field from
it will induce voltages in any wire loop. <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 9/7/2012 7:40 AM, Jeff Irish wrote:<br>
</div>
<blockquote
cite="mid:3F29743641444D499E478C7E358A5F046BEB578B@HVCE1.hvce.local"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<meta name="Generator" content="Microsoft Word 14 (filtered
medium)">
<style><!--
/* Font Definitions */
@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:11.0pt;
font-family:"Calibri","sans-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.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Arial","sans-serif";
color:windowtext;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">A
customer of ours has recently suffered lightning damage to
31 out of 160 top of pole mounted modules. This is the
first time in 10 years that I’ve seen modules damaged by
lightning. Lots of inverter GF fuses and a few inverters,
but never modules. We’re trying to determine if it was
caused by the lightning flash irradiating the modules or
ground currents.
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">The
array consists of 16 DP&W top of pole mounts with 10
modules each, arranged in a square of 4 poles E-W and 4 rows
N-S. The poles are 13 feet center to center E-W and the N-S
row spacing is about 50 feet. The poles are 6 inch
galvanized Technoposts, augured 5 – 7 feet into the firm
ground, connected with a network of about 160 feet of bare
#6 copper and at least 8 copper plated ground rods.
Altogether we have about 130 square feet of bare metal
surface area connected and buried in the ground at and
around the array.
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">The
customer saw lightning strike just after dawn a few weeks
ago a couple hundred feet to the southwest where it also
destroyed two utility pole mount distribution transformers
and ran along the utility wires 100 feet south of the
array. The inverters are 200 feet NW and suffered no
damage. The array and modules look totally fine, except
some of the J-boxes are deformed from heat. Opening the
J-boxes shows varying levels of damage to one or more
diodes, from discoloration to being broken and cracked
open. <o:p>
</o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">The
odd thing is the pattern of damage (we’ve tested all the
modules individually for Voc and Isc). Only modules in the
south row of 4 poles are damaged, and the damage is
concentrated on the modules closest to the ground; modules
higher up in the air appear OK. Also, damage is less
frequent as you move east, away from the direction of the
strike.
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">If
it was caused by ground currents, why would the current want
to go up the poles, why only the southern row of poles, and
why damage more modules closer to the ground and not those
at the top? Is it possible a flash near the ground
irradiated the modules causing a current spike and the
southern row shielded the other rows from most of the
flash? Anyone have experience with this?<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">Jeff
Irish, PE</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">President</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">Hudson
Solar</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">13
Hook Road</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">Rhinebeck,
NY 12572</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">T.845.876.3767x110</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">F.845.876.3912</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><a
moz-do-not-send="true" href="mailto:jeff@hudsonsolar.com"><span
style="color:blue">jeff@hudsonsolar.com</span></a></span><o:p></o:p></p>
<p class="MsoNormal"><i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">Solar
Electric Systems</span></i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p></o:p></span></p>
<p class="MsoNormal"><i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">NYSERDA
Eligible PV Installer</span></i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p></o:p></span></p>
<p class="MsoNormal"><i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">NABCEP
Certified Solar PV Installer</span></i><i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif";color:purple"></span></i><i><span
style="color:purple"><o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span
style="font-size:10.0pt;font-family:"Arial","sans-serif"">NABCEP
Certified PV Technical Sales</span></i><o:p></o:p></p>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="color:#919191"><a moz-do-not-send="true"
href="applewebdata://B5F2562A-2B67-4161-84E4-42F12DC28720/www.hudsonsolar.com"><span
style="color:blue">HudsonSolar.com</span></a></span><span
style="font-size:10.5pt;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-size:9.0pt;color:#6D6D6D">2011 NYSERDA
Excellence in Quality Award | 2011 NYSEIA Award Winner |
2009 Best of the Hudson Valley | 2008 SunPower Dealer of the
Year | EDC Business Excellence Award for Innovation</span><span
style="font-size:10.5pt;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
List sponsored by Home Power magazine
List Address: <a class="moz-txt-link-abbreviated" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>
Options & settings:
<a class="moz-txt-link-freetext" 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>
List-Archive: <a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a>
List rules & etiquette:
<a class="moz-txt-link-abbreviated" href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a>
Check out participant bios:
<a class="moz-txt-link-abbreviated" href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a>
</pre>
</blockquote>
<br>
</body>
</html>