[Hallicrafters] Line voltage and other sundry topics

[Glen Zook]

Actually, aluminum is used in most "high tension"
lines (i.e. 69KV, 138KV, and 276KV lines) these days. 
Also, in the 7200 to 7800 volt and 14,200 to 15,600
volt distribution lines.  In addition, most of the
"drop" lines (240 volt) to most houses are now
aluminum.  This is done to increase the current
handling abilities of the lines while reducing the
weight of the copper lines.  The slight difference in
the fact that copper is a slightly better conductor of
electricity is offset by the fact that aluminum with a
larger diameter can be used at a considerable
reduction in weight.  Also, there is a considerable
difference in cost with aluminum being much cheaper.

Now for house wiring aluminum is a definite "no no"! 
It was found that the common "Romex" type of wire
became brittle after a relatively short period of time
and was easily broken.  Also, when going from the
aluminum wire to the brass or copper used in switches,
outlets, etc., corrosion was rampant.  The "fix" was
to add "pigtails" to the aluminum wire which allowed a
transistion between the aluminum and copper based
materials.  However, this still does not alleviate the
problem with the aluminum wire becoming brittle.

My house was wired with copper from the "get go"
(built in 1969).  However, the houses on either side
of me got aluminum wire.  When both houses were sold
to new owners in the mid 1970s the wiring had to be
"pigtailed" before the sale could become final (City
of Richardson requirement).  When both houses were
sold again in the 1990s they had to be completely
rewired.  That is all aluminum wiring removed and
replaced with copper wire.  The houses in my
neighborhood are "custom built", not tract.

Now both the actual alloy of the aluminum wire used by
the power companies and the actual installation are
much different than those used in home and business
120/240 VAC wiring.  Thus, there are no problems with
using aluminum by the electric company.  However,
aluminum wire used in residential and business wiring
is a definite "no no".

Glen, K9STH


 
--- jeremy-ca <km1h at jeremy.mv.com> wrote:

----- Original Message ----- 
From: "Joe Bob Brunson" <yowje at yahoo.com>

Regarding the price of copper...

In the wind power industry (and probably elsewhere as
well) I have seen a shift toward aluminum cables
instead of copper cables...I've also seen transformers
wound with aluminum rather than copper.  Wonder how
long before aluminum wire becomes the standard?

WB6FQL
 
Never unless you want to relive the late 60's when it
was used in many homes; usually cheap tract style.
Created a bit of a ruckus with fire departments.
Banned by NEC shortly after that.









Glen, K9STH

Website:  http://k9sth.com


       
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