lighted switches & aluminum wiring

[Yumpin.Yimminie]

Our home has aluminum wiring. In the past, a couple of light switches went bad and I replaced them with lighted switches.

A couple more switches went bad. This time they control the same light. I went out to Lowe's to buy lighted switches. But this time the lighted switches they had specified "not to be used with aluminum wiring."

Now the previous lighted switches that I installed I honestly don't remember reading anything about not installing them if you have aluminum wiring.

We are concerned about safety. So what is the actual guidelines now for lighted switches and aluminum wiring. Is it that lighted switches should not be used with aluminum wiring at all - or - does the vendor that supplies Lowe's lighted switches just being very conservative.

I'm kind of perplexed as why this is a concern at all. It seems like the little bit of electricity being used by a lighted switch is miniscule in comparison to what a light fixture would use.

Would appreciate any insight anybody could provide.

Thank you, Jim

[RBM]

I doubt it has anything to do with the light in the switch, but rather the screw terminals were made for copper wire only. Find a switch that says on the terminals cu-al these are rated for either copper or aluminum

[bowgus]

The aluminum is the problem ... banned up here because the average person can install incorrect switches etc :-)

The main problem with aluminum wiring is a phenomenon known as "cold creep". When aluminum wiring warms up, it expands. When it cools down, it contracts. Unlike copper, when aluminum goes through a number of warm/cool cycles it loses a bit of tightness each time. To make the problem worse, aluminum oxidises, or corrodes when in contact with certain types of metal, so the resistance of the connection goes up. Which causes it to heat up and corrode/ oxidize still more. Eventually the wire may start getting very hot, melt the insulation or fixture it's attached to, and possibly even cause a fire.

Read on at the site (or Google a few sites) for appropriate fixtures, switches etc ...

[Joseph Meehan]

Or you can pigtail copper wire using an approved connection device.

[RayV]

Depends on what you mean by approved and who approved it. The purple wire nuts are UL approved but the CPSC does not approve.

[Bud--]

Research done for the CPSC showed the purple wirenuts were generally not any beter that other wirenuts and were worse than some others. As far as I know they are the only ones UL listed for aluminum wire.

I believe the marking on devices that are UL listed for aluminum wire is CO/ALR.

The original aluminum wire, which started to be used often for 15 and

20A branch circuits about 1965, had problems with expansion, as in the post by bowgus. This was essentially fixed about 1972 with changes in UL standards requiring a new aluminum alloy and the CO/ALR device rating. It still could be a problem for old technology wire.

Pre and post 1972 wire has a problem with aluminum oxide, which is an invisible clear insulator and forms rapidly on the very reactive aluminum.

Good information on working with 15 and 20 amp aluminum wire branch circuts is at:

is written by a professional engineer and has a wide range of fixes based on the extensive research done for the CPSC. [The CPSC appears to have attempted to force a recall on aluminum wire.] It includes recomendations on wire nuts. A technique common to many fixes is to put antioxide paste on the wire and abrade it to remove the oxide.

If I had aluminum wire I would probably pigtail to copper for any device on circuit with a high amp load using the techniques in the paper. Also redo wirenuts back to the breaker and pigtail the breaker connection as described in the paper.

bud--

[RayV]

Inspect-ny.com reccomends a 3M scotchlok wirenut instead of the purple Ideal 65 wirenut found at the Borg. These are about $4.00 for two in NJ. I couldn't find CPSC approval for the 3M wirenut.

Here is how they reccomend pigtailing

best thing to do is hire an electrician knowledgeable in aluminum wiring repair.

[Bud--]

$2/wirenut????

The only fix recommended by the CPSC is the COPALUM high pressure crimp which is very expensive to have done if you can even find the required trained electrician with the necessary crimp tool.

The recommendation to use one of the 3M wirenuts is the from the engineer who did extensive tests for the CPSC, as is the wirenut process in your link below. None of this has been endorsed by the CPSC, but it is based on the only extensive testing of aluminum branch circuit connections I am aware of.

(It is the same as the wirenut process in the paper at

You may have a lot of trouble finding one. There are likely very-few-to-none familiar with the wirenut process at your link above. And using the recommended 3M wirenut instead of the UL listed purple wirenut may be a problem for an electrician or inspector.

bud--