<html><body><span style="font-family:Verdana; color:#000000; font-size:10pt;"><div><br></div><div>Hey
Charles, Thanks for your reply. First off I'd like to suggest that
anyone truly interested in Fire Ground Activities and serving their
community, should join their local fire department if possible. I'm sure
the community would appreciate it and the fire dept. could most likely
use the help.</div><div><br></div><div>I did read that section of the UL
document outlining the test they performed using class A foam as well
as much of the other resources you suggested and I do appreciate your
advice. I do however have several observations I'd like to explore. But
first, I'd like to share a perspective from a rural Volunteer Fire
Fighters point of view (who just happens to have been installing PV
since 1991). Although each fire is unique, Fire ground activities can
generally be broken down into two distinct categories: Initial attack
(Scene Size up, Ventilation / Knock down) and Overhaul (clean up).<br></div><div><br></div><div>Initial
attack happens very quickly. Ideally within the first half hour or
less. Scene Size up (The first step in Initial Attack) usually happens
within the first five minutes. During that time the IC (Incident
Commander) needs to quickly and accurately determine the scope of
involvement and formulate a safe and effective plan based on the
circumstances and resources available. Ventilation and fire suppression
tactics (Knock Down or Fire Control) go hand in hand. Toxic smoke, heat
and even flames can be controlled using ventilation. In some cases,
applying water to a fire without proper ventilation can actually
exacerbate the situation because water turns to scalding steam and
expands rapidly. It's primarily during the ventilation / knock down
phase when folks cut hasty holes in roofs and walls and find themselves
crawling around in attics and such.. many times in poor visibility or by
feel alone. While using foam is not a perfect solution, it's during
this Initial Attack / Ventilation phase I propose the use of properly
applied foam on a PV array can quickly and effectively help mitigate a
potentially lethal situation.. using equipment already familiar to most
departments. </div><div><br></div><div>Again, I did read through the UL
document outlining the tests they conducted using class A foam to reduce
Voltage in a PV array. I found it interesting that they conducted the
test in less than ideal conditions (approaching darkness and changing
weather conditions). They eventually pulled the plug because of these
conditions and stated "More research needed to be done". The second chin
scratcher for me was that they only tested with a 1% mix (Very wet) and
applied only 2-3". While a wet mix is appropriate for extinguishing a
wood fire (basically it's a wetting agent at that point), as they noted,
it did not stick well to the glass panels. They did say however it did
stick better to the laminates and was effective in reducing that output
voltage. The more troubling point for me is that they seemed to only
apply 2-3" of wet runny foam, watched it run off, gave up and packed
out.. and concluded that Class A foam was not effective in significantly
reducing voltage in a PV array.<br></div><div><br></div><div>Obviously,
if a dept. has the resources (and the proper training) to quickly and
safely apply black plastic sheeting to an array during the Initial
Attack phase, that should be their first choice. (Assuming it's an older install without rapid shutdown). But if they're anything
like our average rural Dept. (where we're lucky to get 6 people to show
up), a sticky / dry (5%+) mix applied at least 6-10" thick might be a
good temporary option in an emergency situation.. certainly better than
no protection at all.</div><div><br></div><div>During the mop up phase,
yes, a more permanent method of disabling an array may be necessary. I
also like to suggest sending a team in with yellow spray paint to
identify all DC home runs if possible.</div><div><br></div><div> Also I
feel worth mentioning here, I was involved with one commercial project
where we were required to short all strings and home runs prior to final
termination. The logic was that by shorting, it reduced the voltage to
zero (Eliminating a potential shock hazard) and made it easier to
identify current carrying conductors and connections with a thermal
imaging camera.<br></div><div><br></div><div>In conclusion, I could not
find in any of these resources any statement the read "Foam should not
be used". Agreed, it's not perfect and should not be relied upon, but
neither should black plastic or even some connection strategies. Wind
can blow tarps around, or they can be torn. Wires can get jostled around
and open or make contact. In my view, a thick layer of sticky, heavy /
dry foam piled up on an array can be quickly and safely applied by one
person (and a pump operator) and can temporarily reduce array voltage in
a short term emergency situation.<br></div><div><br></div><div>Certainly if you
could refer me to information that suggests this is not the case or is
dangerous and "Should not be used", I would appreciate it.</div><div><br></div><div>Thank You. db</div><div></div><div><br>Dan Brown<br>Foxfire Energy Corp.<br>Renewable Energy Systems<br>(802)-483-2564<br><a href="http://www.Foxfire-Energy.com">www.Foxfire-Energy.com</a><br>NABCEP #092907-44</div><div></div><div><br><br></div>
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-------- Original Message --------<br>
Subject: Re: [RE-wrenches] Fire fighters safety class<br>
From: Charles Picard <<a href="mailto:cpicard@solarcity.com">cpicard@solarcity.com</a>><br>
Date: Wed, September 21, 2016 9:39 am<br>
To: "<a href="mailto:dan@foxfire-energy.com">dan@foxfire-energy.com</a>" <<a href="mailto:dan@foxfire-energy.com">dan@foxfire-energy.com</a>><br>
Cc: "<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>"<br>
<<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br>
<br>
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</style> <div class="WordSection1"> <div class="MsoNormal" style="font-size:12pt;">Hi Dan,<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">I’ll try to stop short of playing armchair firefighter here, and stick to what legitimate data is available. I follow most of the prominent Firefighter trade rags, and while there is some good technical content, there are also a fair amount of opinion pieces.<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">The UL study linked earlier is typically the basis for any credible guidance on tactics or strategies, largely because there has been very little research done in the U.S.. In section 9 of that document you’ll find the analysis of the de-energizing experiments conducted. These quotes stand out to me:<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoListParagraph" style="margin-left:38.25pt;text-indent:-.25in;mso-list:l0 level1 lfo1"> <!--[if !supportLists]--><span style="color:black"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman""> </span></span></span><!--[endif]-->“<span style="color:black">It was the consensus of those witnessing this experiment that this Class A foam was generally ineffective in blocking what little illumination the sun was providing that day.”<o:p></o:p></span></div> <div class="MsoListParagraph" style="margin-left:38.25pt;text-indent:-.25in;mso-list:l0 level1 lfo1"> <!--[if !supportLists]--><span style="color:black"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman""> </span></span></span><!--[endif]--><span style="color:black">“The application of ordinary Class A foam with a compressed air foam system did not prove to be effective or reliable in blocking sun to an array of PV modules.” (Note: VT is likely to have much steeper roofs than used in these tests.)<o:p></o:p></span></div> <div class="MsoListParagraph" style="margin-left:38.25pt;text-indent:-.25in;mso-list:l0 level1 lfo1"> <!--[if !supportLists]--><span style="color:black"><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman""> </span></span></span><!--[endif]--><span style="color:black">“…firefighting foam should not be relied upon to block light.” – Section 14<o:p></o:p></span></div> <div class="MsoNormal" style="font-size:12pt;"><span style="color:black"><o:p> </o:p></span></div> <div class="MsoNormal" style="font-size:12pt;">You bring up a great point about the rank-and-file firefighter needing something quick and effective. Foam may be quick, but we would never say with confidence it is safe and effective. (How does an “average Fire Fighter” confirm that hypothetical 20Vdc?) I’d also ask that we start first by examining the need…Why would the firefighters need to de-energize the array during active fireground operations? Are those scenarios both plausible and likely?<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">As a practical matter, de-energizing the array itself is going to be most important post-incident. This is admittedly a gap in coverage in this country. “Board-up”, or salvage companies may not be trained to make these systems 100% safe, so each Fire Department is left to seek out a local PV professional to offer guidance.<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">Another document that may serve as a blueprint for developing standard procedures is here: <a target="_blank" href="http://www.nfpa.org/news-and-research/fire-statistics-and-reports/research-reports/for-emergency-responders/fireground-operations/fire-fighter-safety-and-response-for-solar-power-systems"> http://www.nfpa.org/news-and-research/fire-statistics-and-reports/research-reports/for-emergency-responders/fireground-operations/fire-fighter-safety-and-response-for-solar-power-systems</a> <o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;">The bibliography is quite extensive.<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;">Happy Reading!<o:p></o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div class="MsoNormal" style="font-size:12pt;"><o:p> </o:p></div> <div> <div class="MsoNormal" style="font-size:12pt;"><b><span style="font-family:"Arial","sans-serif";color:#00833F">Charles Picard</span></b><span style="font-size:9.0pt;font-family:"Arial","sans-serif""> <br> <span style="color:#777777">Sr. Compliance Engineer |</span><span style="color:#00833F"> </span><a target="_blank" href="http://www.solarcity.com"><span style="color:#00833F;text-decoration:none">SolarCity</span></a> <br> <span style="color:#00833F">-----------------------------------------------------------------------</span><br> <span style="color:#777777">t: 518.380.6628</span><br> <span style="color:#777777">m: 508.965.0144</span><br> <br> </span><span style="font-size:6.0pt;font-family:"Arial","sans-serif";color:#777777">RI A-004714 REPC-119, CA CSLB 888104, MA HIC 168572/EL-1136MR. </span><span style="font-size:9.0pt;font-family:"Arial","sans-serif""><a target="_blank" href="http://www.solarcity.com/company/contractor-licenses"><span style="font-size:6.0pt;color:#777777">Click here</span></a> </span><span style="font-size:6.0pt;font-family:"Arial","sans-serif";color:#777777">to view our complete list of license numbers by state.</span><span style="font-size:9.0pt;font-family:"Arial","sans-serif""> <o:p></o:p></span></div> </div> <div class="MsoNormal" style="font-size:12pt;"><span style="font-size:9.0pt;font-family:"Arial","sans-serif""> </span><o:p></o:p></div> </div>
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