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The other option is Midnite Solar's remote controlled breakers or
combiner boxes. They make up to a 250 amp breaker, but I found on
large battery systems that we need some thing larger. Colorado is
now requiring Rapid Disconnect for the batteries as well, which is
NOT the original intent of that article. Is the Gigavac UL listed?<br>
<pre class="moz-signature" cols="72">R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760</pre>
<div class="moz-cite-prefix">On 9/24/2015 10:45 AM, Starlight Solar
Power Systems wrote:<br>
</div>
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cite="mid:87FCA53C-2D7A-4957-B7AB-EAD9812656E1@starlightsolar.com"
type="cite">
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William and Wrenches,
<div class=""><br class="">
</div>
<div class="">I have pondered situations like this one and wonder
the following: If a high voltage DC solenoid were placed at the
PV array and the coil was controlled by an arc fault detector
along with a means of manually disconnecting, would that not
work to satisfy shut down requirements and safety concerns? </div>
<div class=""><br class="">
</div>
<div class="">We have been using 350A, 800 volt solenoids from
Gigavac in our lithium battery system on both the positive and
negative terminals (controlled by a CPU) to provide 100%
disconnect if case of any battery fault.
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class="">
Larry<br class="">
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class="">
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<div>
<div class="">On Sep 23, 2015, at 2:26 PM, William Miller <<a
moz-do-not-send="true"
href="mailto:william@millersolar.com" class=""><a class="moz-txt-link-abbreviated" href="mailto:william@millersolar.com">william@millersolar.com</a></a>>
wrote:</div>
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<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">Dear Fellow Wrenches</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">Below is a design conundrum that may
resonate with some of you:</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">We are finalizing a design for an off-grid
residential system. The customer insist the PV
should be on the roof and pre-installed a 1-1/4” PVC
conduit from his roof to a crawl space, in
anticipation of a solar install. This created real
problems, because we all know we can’t pull PV
source or output circuits in (or now, on) the
envelopes of habitable buildings.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">There was no practical way to replace the
PVC. We contrived a method to sleeve ¾”
liquid-tight through the 1-1/4” PVC to the crawl
space, continuing on with EMT. This is the largest
metallic conduit we could fit. The distance was
greater than 10 feet so we couldn’t use EMT. Due to
the conduit size restriction, we upgraded to
Morningstar 600 volt charge controllers, allowing us
to reduce conductor size.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">(As a sidebar, although the Morningstar is
listed as a 600 volt charge controller, we have
found no circumstance were we could take advantage
of that high a voltage. With the currently
available high wattage modules, by the time we added
enough in series to get to 600 volts, we were well
beyond the wattage capabilities of the controller.
For sake of design considerations, I suggest one
regard these units as ~300 volt charge controllers.)</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">We now have plans for 300 volt PV feeders
running down an interior wall and under the house,
with no roof-top disconnecting means. It is my
understanding none are required. I am not
comfortable with this. In this scenario, there is
no safe way to replace either of the two Morningstar
controllers. Should someone drill through or damage
the EMT in the wall or under the floor, there would
be no way to turn off the feeder.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">I don’t like putting HU361RBs on a roof.
They must remain vertical and so they stick up too
high and are hard to provide mounting for.
Sola-deck units are another option, but they require
integrating with shingles, not practical on this job
or many others. I finally settled on a DC-Sunvolt
PV-X16A-4X-RG disconnect as a possible solution. At
$216 it is not out of range. The unit will provide
means to turn off the feeders for service. I will
report back on my impressions of the unit.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">To distill this scenario, I don’t believe
the code requires a disconnect, but I feel morally
obligated to install one. I’d be interested in
verification of the code interpretation and others
response to similar situations.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">I found no other options for rooftop
disconnecting means that would be small, reasonably
priced and not present a high profile. If there are
products I don’t know about, I would be most
grateful to receive your input.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">While researching the hardware I stumbled
upon this article, linked below. It seems to
present a real dilemma, but I am not convinced.
Please remain skeptical as you read. It appears all
of the links direct you to the same source.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""><a moz-do-not-send="true"
href="https://www.linkedin.com/pulse/greatest-debacle-solar-pv-australias-rooftop-dc-isolator-lucas-sadler"
class="">https://www.linkedin.com/pulse/greatest-debacle-solar-pv-australias-rooftop-dc-isolator-lucas-sadler</a></span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">Thanks again to all of you for helpful
advice and expertise. I learned about Sunvolt here,
just one of many great suggestions.</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">Sincerely,</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class="">William Miller</span></div>
<div class=""><span
style="font-size:12.0pt;font-family:"Arial","sans-serif""
class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class=""><span
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class=""> </span><br
class="webkit-block-placeholder">
</div>
<div class="MsoNormal"><span style="font-size: 10pt;
font-family: Arial, sans-serif;" class=""><image002.jpg></span><span
style="font-size: 10pt; font-family: Arial,
sans-serif;" class=""><br class="">
Lic 773985<br class="">
<a moz-do-not-send="true"
href="http://www.millersolar.com/" class="">millersolar.com</a><br
class="">
805-438-5600</span></div>
<div class=""><br class="">
</div>
</div>
</div>
<br class="">
</div>
</div>
<br class="">
</div>
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