What testing method is used by the CPSC? Who designed the test
procedure, and how was it derived? Was an electrical engineer
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.
On 11/6/2013 3:01 PM, firstname.lastname@example.org wrote:
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
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.
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
On 11/7/2013 3:49 PM, email@example.com wrote:
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.
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.
Well, the USA definitely moved to aluminum a lot quicker than Canada
did - took longer for CSA to approve the stuff than it took UL - so in
Canada there is a LOT less OT than NT aluminum wiring. My dad was an
electrician, and he only installed a very small amount of the OT
aluminum - and he hated the stuff. The NT aluminum was "like working
with copper, but thicker" - #12 bent about like #14 copper, but took
up more space.. He never stripped aluminum wire 'till he was ready to
make the connections - while in the insulation it didn't oxidize - and
he was always carefull not to nick the conductor - but unlike the OT
wire you COULD bend it twice. Make an eye, straighten it, and make the
eye again, without snapping the wire. The OT stuff was like working
with iron wire.
Depends on your definition of "harder" The new wire is less stiff, and
less likely to crack when bent.
There is actually more of the "revised" wire in use (at least in
Canada) than the "original" wire.
Used "as" a "consumer product" aluminum wiring is a lot more dangerous
than when used, as designed, as a professionally installed product.
Same with the ideal 65 wirenut. (not impressed with the wirenut in any
event, but "properly installed" they have never failed under testing.)
Proper installation involves disruption of the oxide layer and sealing
with the antioxide paste.
If not properly installed, and then disturbed (by moving the wires to
replace the outlet or switch) failure is pretty well guaranteed.
Been in my 40 year old house 32 years now - all aluminum wiring - and
never a connection problem. Had a couple non-co/alr outlets overheat -
but not at the wiring connection. Just cheap-ass low-buck outlets that
got a lot of use.
Just switched everything over to co-alr over the last 2 months. Pricy
little buggers, but a lot simpler than pigtailing which just stuffs
YOu never know about the wiring problems. In the area I lived in there were
14 houses built arund the same time in 1965 and very similar to each other.
Two of them caught on fire. One several years before we moved in and one
about 10 years after we moved in.
1965 was the old hard fragile aluminum , and there were NO wiring
devices available specifically for aluminum in 1965 - not to mention
most electricians had never worked with the stuff and didn't have a
clue about the possible problems. By the late '60s and early
seventies, the better wire came on stream, and in the mid seventies
CO-ALR devices were developed and listed for use with both copper and
aluminum wiring. The cu-al devices were a stopgap measure that were
never actually tested and listed for Aluminum wiring, and in many
cases were IDENTICAL to the cu-only devices except for the marking.
CO-ALR became REQUIRED by the end of the seventies, and when properly
installed on the second generation wire are perfectly safe. A lot
safer than pigtailing with Ideal Purple twist connectors - and about
the same price but less labour than pigtailing with AlumiConn
connectors. Both are much less expensive than the AMP connectors,
which are virtually impossible to get installed in most of Canada and
the USA today. Special tool, leased from AMP for very high price to
electricians who spent lots of money to be trained and certified in
their application, and generally wanted to cover the training costs on
every job. - didn't go very far....
On 11/04/2013 03:05 PM, firstname.lastname@example.org wrote:
that's correct, it would also need to be a 50A receptacle. You actually
*could* connect a 15A recep to 8AWG wire though - but only if the
circuit were protected by a 15A breaker. You couldn't physically do it
though, you'd have to pigtail the 8AWG to 12AWG or 14AWG in the box.
You might even want to do this in certain circumstances, e.g. wanting to
provide a receptacle in a very far away outbuilding but not wanting to
pay for another service, panel, meter, etc.
replace "roosters" with "cox" to reply.
Used panels and disconnects are so cheap it doesn't make sense to do
it that way in the real world though. Heck, even a 2 circuit
disconnect NEW is cheap enough to run the heavy wire to the
disconnect, properly protected for the 15 or 20 amp circuit you want
to connect to it, making a code compliant installation. Run the cable
off a double 30 amp breaker or fuse block in the main panel to protect
the cable, and then fuse or breaker the disconnect for the POU load..
Other than a "lug" connector it is pretty difficult to make a good
connection between a 8AWG and a 14 AWG connector. Dad used to use
Burndy connectors for that. (split copper bolt and nut) KS15 or
ks17/ks17-3 wrapped with tape when he needed to connect widely
disparate wires. ALso work good to extend service wires when
installing a new panel where the old wire is too short. (different
sizes for different cables, of course)
On Sunday, November 3, 2013 6:35:56 PM UTC-5, Pete C. wrote:
No but there can be requirements as to the max allowed breaker size.
Take a central air conditioning unit. Look at the install instructions
and/or rating plate on the unit and it will typically spec both a
min breaker size and maximum, like min 30A, max 50A. If that
is part of the manufacturers install instructions I believe it would
be a code violation to use a breaker exceeding 50A, no matter
what size wire you use.
Also, I don't think it's kosher to change the cord and plug on
any listed appliance to accomodate being able to be plugged into
a higher amp receptacle. I think that is the point gfre was
making with his citation of the code.
A #18 cord on a 20A circuit can carry enough current to trip a breaker
on a fault, and is not likely to be damaged by the fault current (if the
supply breaker trips). That is why #18 wire is allowed.
A #18 cord on a 50A circuit will get 6x the heat from a fault if the
breaker trips as fast (and it won't trip as fast).
The size of the wire goes up as the circuit capacity increases.
UL regulations cover the air conditioner cordset and plug that are allowed.
UL will not allow a 50A plug on your 15A air conditioner. If you replace
the plug with a 50A one the air conditioner is no longer UL listed.
If you read the instructions for the air conditioner it will, in all
probability, give you the maximum rating for the circuit the air
conditioner can be connected to. (May also be on the label on the air
conditioner.) For a 15A air condtioner that will not be 50A.
UL sizes the cord and internal components based on the circuit amp
capacity. If the air conditioner was intended for a 50A circuit it would
not have the cord that is installed on a 15A air conditioner.
It is a violation of the UL listing. The air conditioner is no longer UL
That means it is a code violation.
240.5 Protection of flexible cords...
"(1) Supply Cord of a Listed Appliance....
Where flexible cord... is approved for and used with a specific listed
appliance..., it shall be considered to be protected when applied within
the appliance... listing requirements."
UL and the NEC work together.
The branch circuit device also protects the air conditioner.
Don't confuse overload protection with overcurrent protection.
A fault will trip a breaker with smaller wire than is safe for a load.
This assumes you are dealing with a known load that has an acceptable
ampacity on the wire
Fixture wires are regulated in the NEC article 402.5(2)
(2) Fixture Wire. Fixture wire shall be permitted to be tapped to the
branch-circuit conductor of a branch circuit in accordance with the
(1) 20-ampere circuits — 18 AWG, up to 15 m (50 ft) of run length
(2) 20-ampere circuits — 16 AWG, up to 30 m (100 ft) of run length
(3) 20-ampere circuits — 14 AWG and larger
(4) 30-ampere circuits — 14 AWG and larger
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