Backing up the others, if you look at electrical outlets designed for Al wiring, the part that accepts house wiring has a sort of "scaled" surface rather than smooth, to grab the Al wire securely and also likely punch through oxide.
The above is fact. I conjecture that the reason for the difference between the quoted AL wire resistance and copper vs. 1.5 is that they wouldn't be using pure Al, but some alloy. Finally, I seem to dimly remember that Al wire gauges were different than for Cu wire, to at least partially make up for the difference in conductivity. Ken Javor Phone: (256) 650-5261 > From: Richard Nute <[email protected]> > Reply-To: <[email protected]> > Date: Mon, 12 Dec 2016 15:34:56 -0800 > To: <[email protected]> > Subject: Re: [PSES] aluminum vs copper wiring > > The coefficients of expansion are sufficiently > different between aluminum and traditional wiring > devices that connections would go loose over time, > yielding a resistive connection and fire. > > The outer surface of aluminum is aluminum oxide, a > non-conductor. To make a low-resistance > electrical connection, the termination must break > through the oxide. (Oxidation is almost > instantaneous; welding of aluminum must be done in > an inert atmosphere.) > > Best wishes for the holiday season, > Rich > >> -----Original Message----- >> From: Ralph McDiarmid >> [mailto:Ralph.McDiarmid@SCHNEIDER- >> ELECTRIC.COM] >> Sent: Monday, December 12, 2016 11:50 AM >> To: [email protected] >> Subject: Re: [PSES] aluminum vs copper wiring >> >> I've just come across this statement in a user > manual for a >> small inverter product: >> >> "Do not use aluminum. It has about 1/3 more > resistance >> than copper cable of the same size, and it is > difficult to >> make good, >> low-resistance connections to aluminum wire" >> >> I think both statements are wrong. Science Data > Book by >> Oliver&Boyd, lists resistivity of aluminum at > about 1.5X >> that of copper. And, I don't see why electrical > connections >> would be less reliable using aluminum, although, > I do >> remember household wiring in the USA was done > with Al >> some years ago with questionable success. >> >> Thoughts? >> >> Ralph McDiarmid >> Product Compliance >> Engineering >> Solar Business >> Schneider Electric >> >> >> >> ________________________________ >> This message was scanned by Exchange Online > Protection >> Services. >> ________________________________ >> >> - >> > -------------------------------------------------- > -------------- >> This message is from the IEEE Product Safety > Engineering >> Society emc-pstc discussion list. To post a > message to the >> list, send your e-mail to <[email protected]> >> >> All emc-pstc postings are archived and > searchable on the >> web at: >> http://www.ieee-pses.org/emc-pstc.html >> >> Attachments are not permitted but the IEEE PSES > Online >> Communities site at > http://product-compliance.oc.ieee.org/ >> can be used for graphics (in well-used formats), > large files, >> etc. >> >> Website: http://www.ieee-pses.org/ >> Instructions: > http://www.ieee-pses.org/list.html (including >> how to unsubscribe) >> List rules: > http://www.ieee-pses.org/listrules.html >> >> For help, send mail to the list administrators: >> Scott Douglas <[email protected]> >> Mike Cantwell <[email protected]> >> >> For policy questions, send mail to: >> Jim Bacher: <[email protected]> >> David Heald: <[email protected]> > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
