Aluminum Wiring Re: Electrical Properties of Brass

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

 > However, it is still difficult to make a good electrical connection with
 > the aluminum, since oxidation occurs in minutes.  Connections have to be
 > made air tight to prevent the oxidation process, which probably already
 > started before the connection was made air tight (work in an argon-rich
 > atmosphere, perhaps?).
 >
 > So I, too, would agree with Terry's recomendation against using it.
 > Mark Broker
 > Chief Engineer, The Geek Group


Mark, All,

Actually, this isn't true.  Aluminum was widely installed in homes in the
United States in 1960's to 1970's.  And yes, in some homes, fires occurred
within a
few years of construction which is the primary reason aluminum wires for
branch circuits in homes were discontinued.  HOWEVER, the oxidation of the
aluminum
was NOT the cause of these fires.  The problem stemmed from the fact that
aluminum connections had a much greater tendency to become loose (i.e.
circuit breakers,
switches, various fixtures, etc...) and this ultimately led to fires.
Aluminum expands much faster and more than copper, so if aluminum wire is
attached to a copper terminal
screw or connector, it can loosen.  In time, the connection can badly
overheat and fail, leading to arcing and fires.  Actually, one of the
biggest problems today when people find
out they have aluminum wiring in their homes is that they get conned by
electricians stating they need the entire house rewired with copper wire
when instead, a qualified
electrician can simply retrofit the aluminum wiring with safer-type
connections which basically renders the entire home safe.

Aluminum wiring can be very safe and effective.  And almost all the problems
resulting from aluminum wiring were the result of unqualified homeowners
modifying their aluminum-wired
branch circuits such as adding outlets, other circuits, etc...  If a
qualified electrician performs the work, aluminum wiring is as safe as
copper wiring.  The only bad point about it
is that aluminum wiring doesn't perform as well as copper wiring.

Aluminum wiring is still widely used today even in homes as new
installations.  Code prohibits the use of aluminum wiring (new work) for
low-current circuits (branch circuits) such
as outlets, lights, etc..., but it is still used for high-current service
connections such as dryers, air conditioners, stoves, etc...  And
electricians certainly don't make the connections in
an airtight environment as Mark has said above.


The Captain