Another Aluminum Wiring Question

ron schenker

I've been doing an interior painting job in a house built in the mid 70's. While removing switchplates and receptacle covers, I noticed aluminum wiring everywhere. Went downstairs to the panel and saw romex with "aluminum" printed on it, so I know that it is not copper with a tin coat on it. The home owner knows this and said that she was told to just tighten up all the connections every 2 years. I've seen many aluminum connections work their way loose and even evidence of arcing. Residential aluminum wiring was very common here in Toronto in the 70's and thanks to some threads here I know of a number of fixes, but "tightening every 2 years" is probably not wise. I suggested that she get an electrician in. What do you guys think?

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Don't worry, the baseboard will hide it!

mdshunk

A home with aluminium branch circuit wiring can be maintained in a safe manner.

The steps are simple. First, a person with aluminium branch circuit wiring needs to make sure they have switches and receptacles with screw terminals rated to accept aluminium wiring. These switches and receptacles are readily available, but are "special". They are marked "AL/Cu". The terminal screws appear dull in color, as they are tin-lead plated.

Second, a person with aluminium branch circuit wiring needs to make sure they have no direct copper to aluminium connections on those aluminium circuits. Examples of such connections would be at light fixtures and dimmer switches, where the aluminium would connect to copper pigtails on the fixtures and devices. Also, be on the lookout for more modern non-compliant copper extensions from the aluminium circuits, where copper condutors may have be in contact with the aluminium conductor. There are splicing devices designed for the express purpose of connecting aluminium to copper, and these should be used. A normal wire nut won't suffice.

Third, semi-annual torqueing of the terminals with a torque screwdriver is the recommended PM procedure. The older alloys of aluminium used in building wiring expanded and contracted dramatically, leaving some connections loose over time. Because aluminium has a property called "cold flow" (it actually will continue to "squish" when under the pressure of the terminal screw), I also recommend cutting off the stripped portion of the conductor about every 10 years and re-terminating a fresh portion around the screw.

In homes with aluminium wiring, some circuits are easily and inexpensively rewired with modern copper. One simple example is the electric clothes dryer, which is normally easy to get a new cable to in all but the most highly finished homes. Any areas of a home wired with aluminium wiring that are undergoing rennovations would be well served to be re-wired with copper while the room is torn up. Rarely is there an aluminium wiring installation that is in such bad shape that it should be considered for imediate replacement with copper. I certainly don't hold it against a person who wants a aluminium wired home re-wired, as I'm sure they'll sleep easier.

ron schenker

MD...the Al/Cu swithes and receptacles here in Toronto cost around 5 bucks each. I'm guessing there are about 50 that should be changed in this house. Being the handy guy that I am, (not an electrician) I would like to this job for them for a fee. Any reason why I shouldn't in your opinion.
BTW..I've changed hundreds of receptacles and switches in my life however never aluminum and I have $2 million insurance

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Don't worry, the baseboard will hide it!

mdshunk

I'm not qualified to answer that, as I'm not famaliar with your skills or the legal licensing requirements of doing so in your area.

GregS

Does that $2M insurance cover you even if you are not an electrician and mucking around with someones electrical?

Why not just sub it out to a licensed electrician?

ron schenker

Will do...better safe than sorry

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Don't worry, the baseboard will hide it!

Magnettica

I'm not doubting you in the least, but I know I have done this practice in the past, and if I'm not mistaken IDEAL specifically makes a wirenut for this purpose.

By the way, aluminum wire has 3 valence electrons, copper just one. Does this have anything to do with why the aluminum terminations become loose over time?

mdshunk

You're absolutely right, which is why I said:

The Ideal purples are special wire nuts, listed for that purpose, but failures in the field have been evidenced.

Magnettica

D'oh!

Capt2

There's interesting info on purple wire nuts:
www.alwirerepair.com/burned_purples.htm

And another new AL to CU at:
www.alumiconn.com

Sparky Joe

It doesn't have anything to do with the valent electrons, although everything is related.

Kinda funny though that the characteristics of a good conductor is 1 valent electron, and aluminum is a good conductor but is closer to the classification of a semi-conductor of 4 to 5 valent electrons.

Aluminum, because it is so light weight expands and contracts with heat a lot more than other conductors. And if you've ever left a can of soda in the freezer you've noticed there's not much to stop an expanding material. Not even a screw cranked down on an aluminum conductor.

Magnettica

Valence, valent... what the hell was I thinking? LOL. Shows how much I know! I don't normally use aluminum wires with the exception of the el Cheapo service upgrade.

Sparky Joe

The other thing that is needed to know when working with aluminum conductors is that aluminum oxidizes ,as all metals do, but aluminum oxide is a very poor conductor. So alumnum terminations need to be coated with an anti-oxidizer such as Noalox.

I just looked the word up in the dictionary and 'valence' is the proper word...my apologies....I guess

Magnettica

You mean I was right?



Good, now I don't have to dig up the old Mike Holt book where I originally learned about that. Nonetheless, it's good to know the difference between copper and aluminum. The best conductor out there is silver.

The other thing that should be noted about aluminum wire is that aluminum wire is always bigger than a copper conductor. For instance, with copper conductors, #12 AWG is good for 20 AMPS under normal conditions. For aluminum conductors, #12 is only good for 15 AMPS. Aluminum wire is so crappy that they don't even list the amperage rating for #14 aluminum in NEC article 310.16.

Sparky Joe

I was looking at electrical propertiets of elements on a table yesterday, copper is a close second to silver and gold is actually in the middle of the large gap between copper and aluminum.
Ag .630
Cu .596
Au .452
Al .377

Then also very close is beryllium then calcium
Calcium being what your bones are made of ranks at .298
No wonder why high voltage shocks find your bones and make them explode

Magnettica

Very cool.

I'm fascinated by the movement of electrons through a conductor too.

RobertWilber

There is only one product, made by AMP I believe, which meets the standard recommended by the Consumer Product Safety Commission.
I have a pdf on my FAQ page of the CPSC document.
http://www.wilberelectrical.com/down...tion%20516.pdf

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Philadelphia electrician

mickeyco

Aluminum has a lower melting point as well.

I agree with mdshunk, that a home with aluminum branch circuit wiring can be maintained in a safe manner. The problems start when adding devices, appliances, etc. to the system. I have seen 3 situations were there were problems, 2 involving hooking up new hard-wired appliances using the ideal purple wire nuts and one where a house burned down because of a loose connection on aluminum wire. I personally would replace aluminum with copper where it's feasible on branch circuits (not bad out here with emt) or run the wires were the connection can be made on a AL/CU device, or use the Tyco (Amp) connectors (Amp crimper can only be rented (never purchased) by trained person, quite expensive). I would NEVER use the Ideal purple wire nuts. The King Innovation AlumiConn connectors mentioned by Capt2 are newer and are UL approved under UL 486C but only time and independent real world testing will tell. I sent a picture I took of a melted Ideal 30-265 (Purple AL/CU wire nut) I ran across along with a letter to UL and haven't heard back. UL is and has been aware of the problems with the purple wire nuts for some time and hasn't done anything about it.

Here's some info about Ideals Purple AL/CU wire nut:

IEEE (Institute of Electrical and Electronics Engineers, Inc) Publication Date: 20-22 Oct 1997
A new type of twist-on splicing connector for use with aluminum and copper wire combinations is tested to determine initial resistance, performance in a zero-current environmental test, performance in a heat-cycle test, and portion of current carried by the connector's steel spring. The splices tested consist of two aluminum wires and one copper wire. The aluminum wire samples used for the test are of the types actually installed in aluminum-wired homes. Initial resistance is found to be relatively high, and there is a significant sample-to-sample variation. This reflects failure to consistently establish low-resistance wire-to-wire contact through the insulating oxide film on the wire. Results of the environmental and heat-cycle tests show deterioration of a significant portion of the samples. The splices made with this connector are also found to be sensitive to mechanical disturbance, such as applied in normal installation when the completed splice is pushed back into the junction box. Based on the test results, it is concluded that this connector has not overcome the fundamental deficiency of twist-on connectors for use with aluminum wire, and is not considered to be suitable for permanent splices in residential aluminum wire applications.


CPSC (U.S. Consumer Product Safety Commission) believes that "twist-on" connectors, receptacles and switches and other devices that connect directly to aluminum wires, are an inadequate solution. The COPALUM crimp connector system provides a safe, permanent fix.



REPORT of the ELECTRICAL COUNCIL MEETING of UNDERWRITERS LABORATORIES INC. May 2 - 4, 2005
ALUMINUM WIRE CONNECTORS
Ted Olechna
Are aluminum wire connectors that are listed, acceptable as a retrofit foraluminum to copper? Background: The following is information about aluminum wire connectors and the fact that they are being approved for use on AL/CUapplications but CPSC has identified that there are potential problems (see attached PDF document from CPSC). There has been a lot of discussion as to the use or wire connectors that are approved for aluminum and copper. ESA as well as other in Canada are recommending the approved twist-on wire connectors as a fix for existing systems to make it compatible with today's copper world. In addition, the insurance companies are pressuring clients to inspect their aluminum wiring. In addition, the links below provide information about problems and fixes, interesting reading. From the web sites it is evident that the twist on wire connectors are a problem.
http://www.cpsc.gov/CPSCPUB/PREREL/prhtml03/03120.html
http://www.inspect-ny.com/aluminum.htm.
Clarification is needed so that some of the concerns raised by customers and installers can be addressed. If it is identified that in fact the problems do exist, then the products should not be used, and alternatives should be recommended. This issue might be covered in the study that UL is involved with in assessing older installations.

UL COMMENTS
John Kovacik, Ext. 42972
This is a topic that had been addressed in several past Electrical Council meetings. The following provides an update on the status of the issues. The CPSC press release is merely an acknowledgment that the Listed COPALUM system manufactured by Tyco Electronics will continue to be offered. Without it, the connector endorsed by the CPSC in their publication would be unavailable. The CPSC publication and their press release state that twist-ons for pigtailing and CO/ALR rated Switches and Receptacles are not recommended or are inadequate for repairing existing aluminum wire circuits. It should be noted that the CPSC publication is the only one of its kind that specifically recommends a single specific product. Note that this is a recommendation and not necessarily a required wiring practice. The NEC is the most appropriate document pertaining to installation practices for wiring terminations. UL has Listed twist-on Wire Connectors and CO/ALR devices that perform in accordance with their respective standards and which are viable alternatives to the recommended CPSC practice. The CO/ALR devices have been in use for
many years and UL has not received any Field Reports. The first such device was Listed in 1972. The Ideal 65 Listed twist-on Wire Connector rated for copper to aluminum was first Listed in 1995 as an alternative to the COPALUM device. Since the Tyco Copalum, Ideal 65, and CO/ALR devices are UL Listed, their continued use would be NEC compliant. Ideal Industries, UL and the CPSC have been monitoring all field related reports related to the Ideal 65 connector since its
original Listing in 1995. To date, there have only been two UL field reports and both of these have been analyzed and the failures have been attributed to installation error. UL has determined there have been no occurrences where the connector was solely at cause. The number of field reports for this product are no more than the number of field reports for all copper only rated twist-ons. Many of these failures for copper wire only rated twist-ons have also been attributed to
installation error. The second internet link is to an individual?s website that portends to be a site for home inspectors. The validity of the information presented in this site has not been confirmed. It also supports the CPSC position as the only fix to the aluminum wiring issue. Much of the substantiation is based on the work of a single individual contracted by CPSC. It should be noted that the figures of the alleged ?failed twist-on connectors? are from that individual?s lab tests rather than from any field failures. It should also be noted that the bulleted point regarding field failures in actual service now being reported was one of the previously mentioned two field reports that were attributed to installation error. Yet the presentation in the website implies failure was due to the design of the connector. UL has elected not to lend any credibility to this site by not commenting on its content. The information contained on this site needs to be considered with a critical eye toward its source. Unfortunately, too much credibility is being rendered to this site, the issues with aluminum wiring and the alleged field reports (failures) of this connector. The Tyco COPALUM system, CO/ALR Wiring devices and the Ideal 65 Twist-On Wire Connector are all UL Listed for the connection of aluminum conductors. All three products have been subjected to rigorous testing and found to comply with UL?s Nationally Recognized


It's funny how everyone sees the problem but UL.

Sparky Joe

Hey Mickey, just a tip to stop bugging everyone....
Try posting links instead of the entire 10 page article.

Or better yet, if you have something good to say, then just say that thing.
You're not helping anyone other than those who have too much time to read something that may or not be helpful.