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<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008>About 28 years ago I read a study, by either Niehoff
or Prestolite, on the pros and cons of soldering or crimping, heavy duty
starter cables, for over the road trucks. </SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008>The finding was, that a properly crimped lug made a
solid (molecular) connection while solder did not make as good a connection
because solder was not as good a conductor as copper. They concluded that the
crimped connection carried more amperage and did so over the long haul.
</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008>We use an air over hydraulic crimper on all our
cables with a hydraulic gauge reading of 10,000 lbs PSI. I have done a pull
test with this connection by pulling a truck behind another with this
connection</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008>Tom Duffy</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=156073117-03122008>The Solar Biz</SPAN></FONT></DIV></BLOCKQUOTE>
<DIV><FONT face=Tahoma><FONT size=2><STRONG>From:</STRONG>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>North
Texas Renewable Energy Inc<BR><B>Sent:</B> Wednesday, December 03, 2008 10:08
AM<BR><B>To:</B> RE Wrenches<BR><B>Subject:</B> [RE-wrenches] Soldering
electrical conductors<BR></FONT></FONT><BR></DIV>
<DIV></DIV>
<DIV><FONT face=Arial>Wrenches</FONT></DIV>
<DIV><FONT face=Arial>Over the years I have heard almost nothing about soldering
of electrical connections in PV circuits, AC or DC. The only reference I recall
is from the recommendation that one should crimp AND solder larger compression
fittings to assure a permanent connection. There were references to
factory made battery cable crimps not holding after installation
and during the final "pull-test". </FONT></DIV>
<DIV><FONT face=Arial>I can't find any reference to the practice in the NEC,
either pro or con. It seems that any technique so susceptible to poor results
would be at least addressed. </FONT></DIV>
<DIV><FONT face=Arial>The reason I want to definitively address this
practice, by the Wrenches community, is this.</FONT></DIV>
<DIV><FONT face=Arial>A group of PV industry specialists were invited to
help develop a curriculum for a state funded technical college with 4
separate campuses. The Waco Campus, with the fuel cell and
wind degree programs, is now creating a solar
installer technician degree program. </FONT></DIV>
<DIV><FONT face=Arial>A group of experts spent two days picking our
brains to help create an overview plus detailed duties,
tasks and the separate steps involved in the design/installation
process.</FONT></DIV>
<DIV><FONT face=Arial>So now that the initial draft is finished we are
asked to critique it. </FONT><FONT face=Arial>One of the "General Knowledge"
items is <U>soldering techniques</U>. </FONT></DIV>
<DIV><FONT face=Arial>I need to mention that the degree will cover
both PV and thermal installs. Of course some soldering is necessary in the
thermal installation process, less since the introduction of compression
connections, but I'm interested in addressing the electrical side. </FONT></DIV>
<DIV><FONT face=Arial>If any negative long-term effects from solder
joints have been discovered I would like to hear about them. If they
seem serious enough, I would consider recommending that the
staff include a clarification that electrical soldering should be avoided.
</FONT><FONT face=Arial>If the long-term effect is negligible, it is still
possible to do an electrically poor job even using top quality equipment.
</FONT></DIV>
<DIV><FONT face=Arial>I'll defer to the collective knowledge of this
organization.</FONT></DIV>
<DIV><FONT face=Arial>Thanks as always</FONT></DIV>
<DIV><FONT face=Arial>Jim Duncan<BR>North Texas Renewable Energy
Inc<BR>817.917.0527<BR><A
href="mailto:ntrei@earthlink.net">ntrei@earthlink.net</A><BR><A
href="http://www.ntrei.com">www.ntrei.com</A> </FONT></DIV></BODY></HTML>