Al/Cu listing

[mjf]

When aluminum branch circuit conductors were introduced, were the devices used with them supposed to be listed for use with AL, or did that develop at a later date?

Asking because I was replacing some devices (AL wiring) and the old devices appeared to be the origional installs, yet I found no markings pertaining to Cu or Al/Cu.


BTW, anyone know if a GFCI receptacle listed for AL conductors is manufactured?

 

[al hildenbrand]

When aluminum branch circuit conductors were introduced, were the devices used with them supposed to be listed for use with AL, or did that develop at a later date?

#12 and #10 Al solid conductors used on 15A and 20A branch circuits were installed in buildings for several years before the NEC caught up with it. In that time period, terminal screws and stab-ins of 15A and 20A devices did not have to have a specific capability to handle Al conductors. CO/ALR rated devices didn't appear until 210-7(g) was added to the 1978 NEC. #12 and #10 Al had been installed for over a decade by the 1978 NEC.

BTW, anyone know if a GFCI receptacle listed for AL conductors is manufactured?

GFCIs have to be pigtailed. To my knowledge a CO/ALR GFCI does not exist.

 

[mjf]

#12 and #10 Al solid conductors used on 15A and 20A branch circuits were installed in buildings for several years before the NEC caught up with it. In that time period, terminal screws and stab-ins of 15A and 20A devices did not have to have a specific capability to handle Al conductors. CO/ALR rated devices didn't appear until 210-7(g) was added to the 1978 NEC. #12 and #10 Al had been installed for over a decade by the 1978 NEC.

GFCIs have to be pigtailed. To my knowledge a CO/ALR GFCI does not exist.

I haven't seen them either. Just wondered since GFCI rect. already don't like to fit in some switch boxes...add pigtails.... Maybe throw a GFI breaker in instead.


Thanks for the info

 

[don_resqcapt19]

.. CO/ALR rated devices didn't appear until 210-7(g) was added to the 1978 NEC. #12 and #10 Al had been installed for over a decade by the 1978 NEC.GFCIs have to be pigtailed. To my knowledge a CO/ALR GFCI does not exist.

CO/ALR devices were available in early 1974 as I installed many of them. That was the same time that they changed the alloy used in #12 and 10 aluminum conductors.

 

[al hildenbrand]

CO/ALR devices were available in early 1974 as I installed many of them. That was the same time that they changed the alloy used in #12 and 10 aluminum conductors.

I understand. But, except for local ordinance, CO/ALR devices weren't required by NEC until the '78 went into effect for a given jurisdiction. An installer could do more than the minimum required by the NEC, but many didn't. Many a contractor would have resisted adding more devices on the truck, and would have tried to keep using the lower cost non-CO/ALR devices as long as possible.

And it is interesting to note that the NEC requirement for the installation of the improved aluminum alloy didn't get into the Code until 310-14 of the 1987. I'll type it again. . . 1987. Which meant, for much of the country, actually being required to stop using any of the remaining old stock of bad aluminum #8, #10 or #12 solid came only when the local jurisdiction began enforcing the 1987 NEC.

Of course, the historical reason that so much "small gage" aluminum branch circuit wiring was installed was because of the very high price of copper wire, at that time. Copper prices had soared while aluminum hadn't. The additional costs of larger boxes and bigger wirenuts plus the cost of the aluminum #10 or #12 was still less than the cost of the copper assembly, so many a shrewd business person went to aluminum to stay competitive or to win the bid.

When the copper price came down again, most every one went back to copper #12 or #14.

I, for one, hated using the #10 aluminum in the kitchen and other 20 Amp circuits. It was miserable to land on the devices.

 

[don_resqcapt19]

...
And it is interesting to note that the NEC requirement for the installation of the improved aluminum alloy didn't get into the Code until 310-14 of the 1987. I'll type it again. . . 1987. Which meant, for much of the country, actually being required to stop using any of the remaining old stock of bad aluminum #8, #10 or #12 solid came only when the local jurisdiction began enforcing the 1987 NEC.

I thought that they stopped making the old alloy #10 and #12 in 1974.

Of course, the historical reason that so much "small gage" aluminum branch circuit wiring was installed was because of the very high price of copper wire, at that time. Copper prices had soared while aluminum hadn't. The additional costs of larger boxes and bigger wirenuts plus the cost of the aluminum #10 or #12 was still less than the cost of the copper assembly, so many a shrewd business person went to aluminum to stay competitive or to win the bid.

That was exactly the reason we were installing it. This was a conduit job with 4" square boxes and plaster rings, so box fill wasn't a real issue.

When the copper price came down again, most every one went back to copper #12 or #14.

Yes that did happen.

I, for one, hated using the #10 aluminum in the kitchen and other 20 Amp circuits. It was miserable to land on the devices.

I didn't see it that way. The #10 aluminum is easier to bend and terminate than #12 copper, in my opinion....but I that last time I installed any small aluminum was in 1975.

 

[al hildenbrand]

I thought that they stopped making the old alloy #10 and #12 in 1974.

That may well be. In 1974 I was heading "back to the land" and was not paying a lot of attention to the electrical industry.

While the new wire was made with the improved alloy, and an informed person of good conscience would immediately seek it out and start installing it, there was still an existing stock of old-alloy wire already in the supply stream, in warehouses and in the excess stock of contractors. This old stock could legally be installed until the 1987 NEC went into effect for a given jurisdiction (or local ordinance, if that came first).

. . . last time I installed any small aluminum was in 1975.

My experience with small gage Al ended in 1970. At that time I moved on from the company I apprenticed with.

All my experience with installing #8, #10 and #12 aluminum was NM jobs with Allied nonmetallic wall cases. My Master wasn't really careful with the box volume calcs and routinely had us over stuff them. So I had to work really carefully, but very quickly, and pushing that new device in and getting the cover plate smooth to the wall was just plain miserable.