On 11/7/2013 3:49 PM, wrote:
On Thu, 07 Nov 2013 12:37:43 -0500, wrote:

On Thu, 07 Nov 2013 10:53:28 -0600, wrote:

On 11/6/2013 3:01 PM, wrote:
On Wed, 06 Nov 2013 12:42:14 -0600, wrote:

On 11/4/2013 12:22 PM, wrote:
On Mon, 4 Nov 2013 10:06:10 -0500, "Ralph Mowery"
wrote:

Probably several code violations. The 14 wire on the 50A breaker for one.
Slipping and mixing the copper and aluminum wire is probably another one.
When dealing with the aluminum wire it is difficult enough to keep from
burning down a house. I lived in a house that had the aluminum wiring and I
did tighten the wires at the fuse box several times. A house down the
street that was built at the same time (aound 1965) did burn down and the
cause was stated to be wiring in and around the fuse box.

Copper and aluminum isn't a problem as long as listed CU-AL
connections are used between.

Extensive testing of aluminum connections for the CPSC found that the
only listed wirenut for aluminum (Ideal 65) can fail even if installed
using the manufacturer's instructions.

Aluminum caused all sorts of grief but
it was eventually sorted out. Some of the problems were labor quality
(AL is less forgiving) and others were metallurgy. AL us still widely
used for large appliances (clothes dryers and ranges) with very few
issues.

Yes, the problems were only for 15 and 20A branch circuits.

Interesting information/question.
What testing method is used by the CPSC? Who designed the test
procedure, and how was it derived? Was an electrical engineer
involved?

The testing was at Wright-Malta Corp and was run by a PE.

He wrote a report with recommendations that has been revised a couple times
http://www.kinginnovation.com/pdfs/R...Fire070706.pdf

There were many thousands of connections under long-term testing.

In addition to expansion, a major problem with aluminum wire is surface
oxidation. A thin oxide layer rapidly forms, and it is an insulator. In
a wire nut connection there may be little actual contact between the
wires because of the oxide. Most of the contact may wind up being the
metal spring in the wire nut, with a couple turns carrying the current.
The spring is not intended to carry the current, and at relatively high
current through the connection the spring can get red hot (probably what
is happening in fig 1 in the report).

The glowing spring will not trip an AFCI because there is no arc.

The author recommends, in general, applying antioxide paste, abrading
the surface to remove the oxide, and making the connection with enough
antioxide paste to protect the wire.

(The last instructions I saw for lugs on large aluminum wire were to
wirebrush the wire and apply antioxide paste. A utility lineman said
they were supposed to wire brush aluminum wire used in mid-span splices
in their wire.)

The report has a couple pages on Ideal 65 wire nuts. They have an
antioxide paste, but that does not fix problems with oxide already on
the wire. Based on information provided I would not use them.

Alumiconn connectors were not in the original testing (they did not
exist then) and initial results have been added to the report. They look
like the best way to splice Al-Al or Al-Cu. Alumiconn uses set screws,
and likely deforms the wire which can break through an oxide layer.
Deforming the wire is likely why connections on large aluminum wire do
not have the same problems as 15 and 20A branch circuits.

The new aluminum wire is harder, and not likely to "extrude" in
heat-cycling at a connection.


The answer, the test method does not adhere to any published or
approved testing method or specification, and no electrical engineer
is involved with the testing, according to all the information I have
been able to find. Kinda says something about their conclusions.

Not to say I have any faith in the Ideal Purple wire nuts - but no
less than the faith I have in the CPSC.

The UL and CSA testing labs test to a standard, which is determined by
electrical engi eers, and the methods are designed by and monitored by
qualified electrical engineers. Do they always get it right??? Nope.
But I think they have more than a fleeting chance of hitting the mark
- being they know what the mark is, what it means, etc etc etc.

Details of testing are not included. There are some details by way of
what testing was not done on the Ideal 65 wirenuts.

One of the complaints that came out of the testing was that the UL tests
used the revised aluminum wire for tests of other components. Most of
the wire actually in use is the original wire. The CPSC asked UL to
revise their tests and UL didn't.

The CPSC appears to have been headed for a recall of aluminum wire,
which would have been enormously expensive. In the inevitable law suit
the court ruled that aluminum wiring was not a consumer product and not
under the purview of the CPSC. (This may have been part of the reason
the CPSC dropped an investigation of FPE breakers. They had some initial
testing done which was not reassuring.)

The only problem with all of this hype is the millions of aluminum
wired houses that are still there showing no problems.
(before CO AL-r and paste).

I always believed this was a workmanship problem as much as an
aluminum problem. Copper is just more forgiving of sloppy
installation.

About 1965 copper prices went up and aluminum wire started to be used
for 15 and 20A branch circuits. UL CU/AL rated devices appear to have
come out in the late 60s because of problems. There were still problems
and about 1971 UL removed the listing for aluminum wire, devices and
wire nuts. New UL standards came out about 1972, with a new aluminum
alloy and CO-ALR devices. Use died out about 1973.

UL responded to problems that went far beyond workmanship. Steel screws
in older devices were a particular problem.

100%. PROPERLY INSTALLED aluminum has proven to be a very reliable
product - particularly the revised wire. Properly installed WITH
proper wiring devices (co-alr) it is as good as copper.

Actual tests have shown that connections made according to manufacturers
instructions can fail.

The vast majority of 15/20A aluminum branch circuits in the US use "old
technology" wire. UL tests of CO-ALR devices and wire nuts are made with
the "new technology" wire, which is not the bulk of what is installed
here. And the "new technology" wire has the same oxide problem that the
old wire has.

(The older CU/AL devices, and those from before that which are not
specifically rated for aluminum are certainly also around.)

I have not seen instructions for devices that include abrading the
wire and using paste.

I doubt Ideal 65 instructions include abrading the wire, or twisting
(another recommendation based on testing). Ideal 65 appears to be rated
only Al-Cu now. They do not have Al-Al combinations.

The CPSC previously recommended only pigtailing with COPALUM splices
(which I think you commented on). They now also recommend AlumiConn
splices, which are easily installed.

Aluminum branch circuits can be safe. But they have a lot more potential
for failure than copper.