Can someone explain this?
 

To start with, aluminum
is not that great of a conductor.

aluminum is in fact a pretty good conductor. Not as good as copper or gold,
but still pretty good. Cheap car jumper cables are often aluminum.

Can someone explain this?
 

On 19 Feb 2004 20:23:18 GMT, (JAXAshby) wrote:

To start with, aluminum
is not that great of a conductor.

aluminum is in fact a pretty good conductor. Not as good as copper or gold,
but still pretty good. Cheap car jumper cables are often aluminum.

Yeah, they used to use it in house wiring also until the CPSC reported
that houses with aluminum wiring were 55 times more likely to have an
electrical fire than copper wired houses.

Bye bye aluminum wiring (in most home applications). It has only a
little more than half the conductivity of copper and really is not that
great of a conductor. It's ok, but I wouldn't use it for anything
important.

Steve

Can someone explain this?
 

"Steven Shelikoff" wrote in message
...
On 19 Feb 2004 20:23:18 GMT, (JAXAshby) wrote:

To start with, aluminum
is not that great of a conductor.

aluminum is in fact a pretty good conductor. Not as good as copper or
gold,
but still pretty good. Cheap car jumper cables are often aluminum.

Yeah, they used to use it in house wiring also until the CPSC reported
that houses with aluminum wiring were 55 times more likely to have an
electrical fire than copper wired houses.

Bye bye aluminum wiring (in most home applications). It has only a
little more than half the conductivity of copper and really is not that
great of a conductor. It's ok, but I wouldn't use it for anything
important.

Steve

Was cheap, was lightweight and caused fires as the aluminum flattens out
under presure from the connection screws. Then a loose connection and fire.
Is still used in high voltage power lines e.g. 500KV, as you can go longer
distances between towers. Still sucks as a conductor, but those bigger
wires can still carry the current and span a longer distance.
Bill

Can someone explain this?
 

On Fri, 20 Feb 2004 00:09:41 GMT, wrote:

On Thu, 19 Feb 2004 23:30:40 GMT, (Steven Shelikoff) wrote:

On 19 Feb 2004 20:23:18 GMT, (JAXAshby) wrote:

To start with, aluminum
is not that great of a conductor.

aluminum is in fact a pretty good conductor. Not as good as copper or gold,
but still pretty good. Cheap car jumper cables are often aluminum.

Yeah, they used to use it in house wiring also until the CPSC reported
that houses with aluminum wiring were 55 times more likely to have an
electrical fire than copper wired houses.

Bye bye aluminum wiring (in most home applications). It has only a
little more than half the conductivity of copper and really is not that
great of a conductor. It's ok, but I wouldn't use it for anything
important.


Apparently you don't have any idea why aluminum wiring in homes was a fire
hazard?

Yeah, I do. It was mostly due to the connections. But the ability to
make good connections is something that I would expect a great conductor
to be able to do. If you can't connect to it, it's not so great.

Steve

Can someone explain this?
 

"Calif Bill" wrote in message
k.net...

"Steven Shelikoff" wrote in message
...
On 19 Feb 2004 20:23:18 GMT, (JAXAshby) wrote:

To start with, aluminum
is not that great of a conductor.

aluminum is in fact a pretty good conductor. Not as good as copper
or
gold,
but still pretty good. Cheap car jumper cables are often aluminum.

Yeah, they used to use it in house wiring also until the CPSC
reported
that houses with aluminum wiring were 55 times more likely to have
an
electrical fire than copper wired houses.

Bye bye aluminum wiring (in most home applications). It has only a
little more than half the conductivity of copper and really is not
that
great of a conductor. It's ok, but I wouldn't use it for anything
important.

Steve

Was cheap, was lightweight and caused fires as the aluminum flattens
out
under presure from the connection screws. Then a loose connection and
fire.
Is still used in high voltage power lines e.g. 500KV, as you can go
longer
distances between towers. Still sucks as a conductor, but those
bigger
wires can still carry the current and span a longer distance.
Bill

It is still widely used, now that the proper connectors have been
developed. The newly installed line from the transformer on the pole to
my house for my upgraded service is Aluminum, as was the old one.
Aluminum has far better conductivity per pound than does copper. It is
also stronger per pound. And it is cheaper.

The problem with Aluminum house wiring was that it oxidizes, and it was
being used with devices designed for copper. It is fine when used with
properly designed devices.

del cecchi

Can someone explain this?
 

Hell, I owned a house that was wired with aluminum. With the right outlets
and switches, it was perfectly fine. With the wrong ones. it was a fire
waiting to happen. The subdivision that I lived in is a few blocks away from
this one and I haven't heard of an electrical fire since it was built in
'75. My buddy is a fireman and he hadn't heard of one either. Lots of
press. Some bad problems, but not as bad as most would make it out to
be...RichG

Can someone explain this?
 

If you do a Google search on "metal + conductivity chart" you will see that
aluminum is one of the better conductors of electricity. The reason they
stopped using it in houses is because of heat cycle failure in circuits that
are switched off and on. In this type of application they will become loose
which will cause even more heat and can pose a serious fire threat. In
applications where the electricity is constantly on it is perfectly suitable
and used in many high voltage applications.

Ask at alt.engineering.electrical if you have any doubts. ;)

Can someone explain this?
 

Damn, now I'm posting off topic!!!!!

Can someone explain this?
 

On 20 Feb 2004 04:55:30 GMT, obull (CCred68046)
wrote:

If you do a Google search on "metal + conductivity chart" you will see that
aluminum is one of the better conductors of electricity. The reason they
stopped using it in houses is because of heat cycle failure in circuits that
are switched off and on. In this type of application they will become loose
which will cause even more heat and can pose a serious fire threat. In

And there's more heat in the first place to cause the heat cycle failure
since aluminum has almost twice the resistance as copper. Thus, it's
not such a great conductor.

applications where the electricity is constantly on it is perfectly suitable
and used in many high voltage applications.

That's because it's a "good" conductor, not a great one. And it's other
properties besides conductivity (light weight) make it more ideal than
copper for high voltage applications. You can rest assured that if
copper were as light as aluminum, they would be using that instead.
Utilities don't like loosing all that energy to wasted heat if they
don't have to.

Ask at alt.engineering.electrical if you have any doubts. ;)

No doubts here.

Steve

Can someone explain this?
 

On Thu, 19 Feb 2004 21:47:41 -0600, "del cecchi"
wrote:

It is still widely used, now that the proper connectors have been
developed. The newly installed line from the transformer on the pole to
my house for my upgraded service is Aluminum, as was the old one.
Aluminum has far better conductivity per pound than does copper. It is
also stronger per pound. And it is cheaper.

That's only because it's so light, not because it's such a great
conductor. In applications where it has to be suspended, like high
voltage lines or the feeder line to your house, it's fine. But if you
don't have to suspend it, like boat, house or car wiring, you're better
off with the higher conductivity of copper.

Even in applications where weight is critical, such as spacecraft,
aircraft, etc., they use copper instead of aluminum. For instance, the
international space station has many miles of electrical wire. Think of
all the weight savings and cost savings that could have been had by
using aluminum. The structural components are aluminum but the wiring
is copper despite Al's better conductivity per pound. There's a reason
for that... because it's not a great conductor.

Steve