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<DIV><FONT face=Arial size=2>Electrical enclosures in flammable / explosive
vapor areas are often maintained at positive pressure with nitrogen (and
this system alarmed) to ensure that there is no fuel for ignition (nor oxygen to
support combustion) in the enclosure.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>While safety cans and / or vented storage cabinets
are a good idea for liquid fuels - their cost generally prevents home
use (most won't pay $85 for a gas can or hundreds for a cabinet). Careful
practice (and often luck) seems to work OK in home use.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The same is true for LiPo's - most folks won't pay
big bucks for some sort of vault and probably don't need to. We do need to
understand that there is a potential for fire (and disbursement of burning
material) if all goes wrong, and provide reasonable containment / location to
accommodate such an occurrence. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>With the cost of the big packs being what it is, I
really want to make sure practice / equipment doesn't allow catastrophic failure
in the first place.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Earl</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=brian_w_young@yahoo.com href="mailto:brian_w_young@yahoo.com">brian
young</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, May 25, 2006 10:11
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Some more
lipo fire videos - Explosion Proofvault</DIV>
<DIV><BR></DIV>
<DIV>Yeah a fuel-air bomb isnt among the most potent explosive?</DIV>
<DIV> </DIV>
<DIV>I worked in petrochem design for awhile, doing projects in areas where we
had electrical sources in explosive areas. The explosion proof electrical
service we placed actually could contain gas and ignite within the box, and
the box would vent but the seal of the box was controlled so the flame was
extinguished as it exited the box and would not ignite a source outside the
box. </DIV>
<DIV> </DIV>
<DIV>I was an ME design coordinator so only know the basics of this from the
EE guys explanation. Im sure others follow this list that know more than
me ;-)</DIV>
<DIV> </DIV>
<DIV> I have wondered since the lipo technology and the fears came
whether there was any market for something like this. If someone ever screws
up and sets a pattern pack off in a garage/car/trailer something
like this might help contain better than sand bags, cinder blocks, crocks,
etc....just a thought. </DIV>
<DIV> </DIV>
<DIV>Price might be high but cheaper than a lot of other things and if all the
safe gaurds go wrong this might offer one last hope. </DIV>
<DIV><B><I></I></B> </DIV>
<DIV><B><I>Earl Haury <ehaury@houston.rr.com></I></B> wrote:</DIV>
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<DIV><FONT face=Arial size=2>All energy sources present a potential risk and
must be handled accordingly. The LiPo fire videos demonstrate the potential
for this source. Anyone have a video of a gallon of glow fuel or gasoline or
Jet-A being ignited - say by a 12v gel cell shorting against a can? I
guarantee it will be even more spectacular than the LiPo!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My point is that we tend to become complacent
with things we are familiar with. Gasoline is an extremely dangerous
material - yet most of us are comfortable in using it and often get by with
potentially fatal practice. Only the narrow flammability range of gasoline
saves us. (And no - the lubricant added for model engines doesn't make it
more safe.)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>How many have gallons of glow fuel stored in
their home or garage? Not a wise thing - but again we get complacent after a
period of good luck. (Then there were my trap shooting days when I bought
gunpowder in multiple 12# containers - guess where that was
stored.)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The LiPo simply presents a new set of risks and
failure modes. Overcharge the things or short them (dents can do this
internally) and things get nasty. Care in handling / charging / using these
things is mandatory - and yet we all make mistakes. Shorting them will get
your attention immediately (extreme care is required when attaching leads).
Crash damage has a high likelihood of shorting them internally / externally
- so extreme caution is need here also (think gasoline dripping on sparking
battery leads). The overcharge issue can be a matter of carelessness or of
charger failure. Containment during charging is a really good idea, as well
as a charge system that prevents overvoltage in individual cells (sets).
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I suspect that most charging errors occur with
folks using a variety of size packs. The other (well discussed) issue is
charger mis-identification of cell count due to trying to charge a charged
pack. A little less risk if pattern equipment only is used. (I choose to use
separate chargers for the large power batteries and the radio power battery
to limit the error factor.) The inclusion of cell "taps" for monitoring cell
(set) voltage and balancing also go a long way toward ensuring that a pack
is healthy and behaving normally during charge. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Bottom line - LiPo's present risk in the same
range as other "fuels" - the safety procedures are no more or less important
- but they are different!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Earl</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=tretas513@yahoo.com href="mailto:tretas513@yahoo.com">Tommy
Scarmardo</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, May 25, 2006 10:09
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Some
more lipo fire videos</DIV>
<DIV><BR></DIV>
<DIV>I saw some pictures on a Japanese web site of an electric Impact
which caught on</DIV>
<DIV>fire and was completely destroyed while in the air flying presumably
from too much</DIV>
<DIV>load on the batteries or maybe a short. I wish I could read Japanese
to find out exactly</DIV>
<DIV>what happened.</DIV>
<DIV> </DIV>
<DIV>tommy s<BR><BR><B><I>Larry <<A
href="mailto:ledunn@centurytel.net">ledunn@centurytel.net</A>></I></B>
wrote:</DIV>
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<DIV><FONT face=Arial size=2>Maybe this is a good time to share these
videos - if you haven't seen them they are well worth watching. Look on
the left side of the bottom of the main page.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Lipos fires 1,2 & 3</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://www.utahflyers.org/">http://www.utahflyers.org/</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have become a bit of a lipo safety nazi
lately - ever since I had my first lipo fire a couple of months
ago.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>
<DIV><FONT face=Arial size=2>I have been using lipos since the early
days. I'm a smart guy with a background in electronics and all things
electrical. I am known as "Electric Larry" at our field. I teach other
people how to do electrics and what NOT to do. I'm the go-to guy in our
club. In spite of all that - I had a major lipo fire a couple of months
ago that destroyed almost all my RC gear and planes and came very close
to burning down my house. It was 100% my fault. I was doing too many
things at once and had become casual/careless in my care of
lipos. I had gone YEARS with no issues at all and had gotten
complacent.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My equipment and charging routines are now
100% improved.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Be careful guys.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>Larry</FONT></DIV></DIV>_______________________________________________<BR>NSRCA-discussion
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