<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p><br>
</p>
<p>Eric, this is very interesting that the foil (Faraday shield)
used in this way would help that situation !</p>
<p>A Faraday shield using aluminum foil will only shield electric
fields and not magnetic fields of course</p>
<p>so something interesting is going on here. SO, the foil was not
grounded in any way ?</p>
<p>The mechanism should hopefully become obvious after some thought
and experimentation.<br>
</p>
<p>We will definitely be looking into your fix. <br>
</p>
<p>Than you !</p>
<p>boB<br>
</p>
<p><br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 12/16/2020 3:36 PM, Eric Smiley
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CACtViAFvH8fwW4x7NdNm9ye0DfYq10_S4Pw9D_YC2379h+p63g@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">Season's Greetings Wrenches
<div><br>
</div>
<div>We have been attempting to use MidNite SOB's with Sol-Ark
inverters this year. In Canada we only need one SOB per string
since our Code requires Rapid Shutdown for PV source or output
circuits more than 1 meter from the array.
<div><br>
</div>
<div>However, not all the SOB's were closing the circuit when
we had two strings on one MPPT - both when we combined two
strings on the Sol-Ark PV input terminals or when we used
MC4 Y connectors outside the Sol-Ark to combine two strings.
MidNite had no solution for this back during the summer and
tech support there only suggested that we had configured the
system incorrectly or that we shouldn't combine strings that
way. This array also had a very long underground run between
the array and inverter. So, at that time, not knowing if it
was distance, interference from something else or gremlins,
we just took out all the MidNite equipment and installed a
DC SunVolt Rapid Shutdown box.</div>
<div><br>
</div>
<div>Diagnosing the problem was a challenge since only one of
the parallel strings on each MPPT was not producing power at
any given moment. Also, everything worked fine while I made
voltage and current measurements but when I pushed the coil
and wires into the JB I lost half my solar power.</div>
<div>Anyway, today I solved the problem on a new system I was
commissioning by wrapping the SOB Transmitter coil, with the
positive conductors passing through it, in aluminum foil.<br>
</div>
<div><br>
</div>
<div>I hypothesized that with the coil on the
positive conductors, the negative conductors, which were
very close to the coil, all of which was inside a metal
junction box, were picking up a signal from the coil and
this was interfering with the signal on the positive.</div>
<div><br>
</div>
<div>It's a bit cludgy, but shielding the coil seems to be the
solution.</div>
<div><br>
</div>
<div>I'd love to hear if anyone else has had this problem
and/or solution.</div>
<div>
<div><span style="background-color:transparent;color:rgb(0,0,0);font-family:Arial;font-size:11pt;font-weight:700;white-space:pre-wrap">
</span></div>
<div><span style="background-color:transparent;color:rgb(0,0,0);font-family:Arial;font-size:11pt;font-weight:700;white-space:pre-wrap">Eric Smiley, MASc</span>
<div>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr"><span>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">Project Manager, North Island</span></p>
<br>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">E: </span><a
href="mailto:eric@vecoop.ca"
target="_blank" moz-do-not-send="true"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,255);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">eric@vecoop.ca</span></a></p>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">T: 1-888-386-0116 ext 702 (toll free)</span></p>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">C: 250-703-6004</span></p>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">W: </span><a
href="http://www.viridianenergy.ca"
target="_blank" moz-do-not-send="true"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,255);background-color:transparent;vertical-align:baseline;white-space:pre-wrap">viridianenergy.ca</span></a></p>
<br>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><a
href="http://www.viridianenergy.ca/"
target="_blank" moz-do-not-send="true"><span style="font-size:9.5pt;font-family:Arial;color:rgb(17,85,204);background-color:transparent;font-weight:700;vertical-align:baseline;white-space:pre-wrap"><img src="https://lh5.googleusercontent.com/zI5FY8yVAfvFf7VtaZc6K9cNYSGpE1vmAIDl5TEHFyy3_574vql1uHlYsUcpSw74Lz3hZPreus9KG7QQL9KzP_xhCNrktRiHtHx_FRhdPY4hstzinUT5SuS21R1VxVC8JdQmMFh-" style="border:none" moz-do-not-send="true" width="128" height="45"></span></a></p>
<p dir="ltr"
style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:8pt;font-family:"Trebuchet MS";color:rgb(56,118,29);background-color:transparent;font-weight:700;vertical-align:baseline;white-space:pre-wrap">RENEWABLE </span><span style="font-size:8pt;font-family:"Trebuchet MS";color:rgb(11,83,148);background-color:transparent;font-weight:700;vertical-align:baseline;white-space:pre-wrap">POWER</span><span style="font-size:8pt;font-family:"Trebuchet MS";color:rgb(56,118,29);background-color:transparent;font-weight:700;vertical-align:baseline;white-space:pre-wrap"> NOW</span></p>
</span></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
List sponsored by Redwood Alliance
List Address: <a class="moz-txt-link-abbreviated" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>
Change listserver email address & 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>
There are two list archives for searching. When one doesn't work, try the other:
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a>
<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-freetext" href="http://www.re-wrenches.org/etiquette.htm">http://www.re-wrenches.org/etiquette.htm</a>
Check out or update participant bios:
<a class="moz-txt-link-freetext" href="http://www.members.re-wrenches.org">http://www.members.re-wrenches.org</a>
</pre>
</blockquote>
</body>
</html>