Aluminum Conductors

[kwired]

The NEC does not now, nor has it ever, had a prohibition on using aluminum circuit conductors of any size.

Agree, the trade in general sort of just abandoned using it in small sizes , particularly 10 and 12 solid.

Now it sounds like copper clad aluminum might be coming back though.

 

[don_resqcapt19]

Agree, the trade in general sort of just abandoned using it in small sizes , particularly 10 and 12 solid.

Now it sounds like copper clad aluminum might be coming back though.

Only because it has not been available in those sizes since the mid 70s.

 

[kwired]

Only because it has not been available in those sizes since the mid 70s.

Yes because the trade in general kind of just stopped using it. Had there been demand for it it probably would have remained more readily available.

If you wanted to order a large enough supply to make it worthwhile for them to produce it they likely would make it for you.

 

[SparkyBirdman]

The NEC does not now, nor has it ever, had a prohibition on using aluminum circuit conductors of any size.

I stand corrected-partially. Thats not entirely true. While I was wrong about not allowing 10 and under for NM cable, amp table and 240.4(D) doesnt allow for less than #12 in AL or copper clad and in 334.104 it mentions specifically the allowed wire sizes for NM and it cant be smaller than 12.

Not sure where I came up with no AL NM less than 10. Maybe a combination of the amp table and some local jurisdiction. I know plenty of AHJs that dont allow AL cable on anything less than 40A in resi or comm applications, except for inside a piece of labeled equipment.

Even with all of this, I think we can all agree that AL/copper clad for a circuit 30A or less is not a great idea, not industry practice and would be hard to source either way.

 

[kwired]

I stand corrected-partially. Thats not entirely true. While I was wrong about not allowing 10 and under for NM cable, amp table and 240.4(D) doesnt allow for less than #12 in AL or copper clad and in 334.104 it mentions specifically the allowed wire sizes for NM and it cant be smaller than 12.

Not sure where I came up with no AL NM less than 10. Maybe a combination of the amp table and some local jurisdiction. I know plenty of AHJs that dont allow AL cable on anything less than 40A in resi or comm applications, except for inside a piece of labeled equipment.

Even with all of this, I think we can all agree that AL/copper clad for a circuit 30A or less is not a great idea, not industry practice and would be hard to source either way.

I mentioned a few posts ago - sounds like copper clad aluminum might be coming back mostly because of high copper prices, and a possibility they may be going higher in the future. Heard they might be up to 25% higher in the future, how soon IDK or how reliable that source was IDK. Did come from my supply house general manager but I don't know what his sources were. Think it is somewhat political driven assumption at this point some of it involving the President getting a copper mine operation shut down but I don't know enough details to say anymore than it is out there but don't know how it will unfold.

 

[don_resqcapt19]

I stand corrected-partially. Thats not entirely true. While I was wrong about not allowing 10 and under for NM cable, amp table and 240.4(D) doesnt allow for less than #12 in AL or copper clad and in 334.104 it mentions specifically the allowed wire sizes for NM and it cant be smaller than 12.

Not sure where I came up with no AL NM less than 10. Maybe a combination of the amp table and some local jurisdiction. I know plenty of AHJs that dont allow AL cable on anything less than 40A in resi or comm applications, except for inside a piece of labeled equipment.

Even with all of this, I think we can all agree that AL/copper clad for a circuit 30A or less is not a great idea, not industry practice and would be hard to source either way.

As far as the sizes, because of the ampacity difference between copper and aluminum, the aluminum was never available as a branch circuit conductor smaller than 12 AWG.

Not something I would agree with, but very few people have had the experience of installing those sizes of aluminum made of the new alloy.

If the new alloy aluminum that was on the market in 75-76 in the 10 and 12 AWG sizes, I would not hesitate to use it. We did an 125 unit apartment complex in that time frame when I was an apprentice. It was single conductor aluminum in 10 and 12 AWG. After I topped out, I ran the service truck for the contractor for a number of years. There were no more problems with that project than with the same types projects that we had done using copper conductors.

 

[SparkyBirdman]

I mentioned a few posts ago - sounds like copper clad aluminum might be coming back mostly because of high copper prices, and a possibility they may be going higher in the future. Heard they might be up to 25% higher in the future, how soon IDK or how reliable that source was IDK. Did come from my supply house general manager but I don't know what his sources were. Think it is somewhat political driven assumption at this point some of it involving the President getting a copper mine operation shut down but I don't know enough details to say anymore than it is out there but don't know how it will unfold.

I am not sure of all the reasons why, but at this point EVERY part for electrical is up, let alone copper, and with all the stories Im hearing it could be supply chain, but in my opinion its just manufactures are raising prices cuz everyone else is. Ive never seen every component of electrical increase all at once to such a degree. Copper wire pricing has been mostly volatile for 20 years, but Aluminum has shot up drastically along with all steel. Have you seen pvc prices these days? Im paying as much for a stick of 2in sch40 now what I was paying for the same stick of IMC 7 years ago

 

[SparkyBirdman]

As far as the sizes, because of the ampacity difference between copper and aluminum, the aluminum was never available as a branch circuit conductor smaller than 12 AWG.

Not something I would agree with, but very few people have had the experience of installing those sizes of aluminum made of the new alloy.

If the new alloy aluminum that was on the market in 75-76 in the 10 and 12 AWG sizes, I would not hesitate to use it. We did an 125 unit apartment complex in that time frame when I was an apprentice. It was single conductor aluminum in 10 and 12 AWG. After I topped out, I ran the service truck for the contractor for a number of years. There were no more problems with that project than with the same types projects that we had done using copper conductors.

I personally wouldnt worry about clad or AA in those sizes for devices and fixtures except for what has been mentioned previously: installation. I wouldnt trust any of my guys to properly term to a switch or plug; make sure they use a rated device; or be able to mate copper and alum wires that size properly. Thats just because not enough experience with it and it is so uncommon.

We only use AL for our larger feeders-mainly 70A and above. I still have to watch them on stripping, torquing, when to use nolox and what size they use depending on ampacity. I can only imagine the phone calls from customers if we wired all 20A circuits in a house with AL/clad after we were done. Ill be the first in line to buy more economical NM at this point, but there has to be in depth and comprehensive training on its use and installation.

 

[ggunn]

What is the point of copper clad aluminum? It doesn't increase ampacity; can you use copper clad aluminum in copper only terminals?

 

[ActionDave]

You can use it with normal devices.

 

[mtnelect]

I would like to ask for information, experiences, recommendations, and whatever I can get on the issue of the use of aluminum (AL) conductors. The NEC has allowed AL conductors for a very long time. The Department of Defense (my present employer) publishes its own “building codes” in the form of “Unified Facility Criteria (UFCs).” The relevant UFC allows AL conductors above a certain AWG size. I am dealing with a military base that has adopted an even more stringent requirement: “copper only.” I would like to get them to reconsider that requirement. But it would help if I could present some supporting technical substantiation.

Questions:

• Am I right in believing that AL conductors had a bad reputation in decades past, and that the technical issues included poor electrical connections, special requirements for making those connections, corrosion, and overheating to the point of creating a fire hazard?
• Am I right in believing that those issues have long since been resolved, and there is no longer any reason to be concerned over the safety of using AL?
• If use of AL conductors is safer now than in decades past, what has changed? Is it something to do with manufacturing (i.e., materials science)? Is it related to installation techniques?
• If AL is used for, say, service or feeder conductors, will that require periodic maintenance to ensure that the connections remain tight?
• Do you use AL conductors when you are given the option?
• Are you aware of any recent failures (e.g., fires) for which the cause was traced to AL conductors?
• What else should I know about AL conductors?

Only reason we have aluminum wiring is because HUD wanted to build cheap housing !

 

[don_resqcapt19]

What is the point of copper clad aluminum? It doesn't increase ampacity; can you use copper clad aluminum in copper only terminals?

All listed wiring devices that are marked for use with copper conductors can be used with CCA per the listing. The same is not true for wire connectors, so that is still an issue for widespread use of CCA.

 

[mtnelect]

The Los Angeles Electrical Code didn't allow aluminum wiring for many years. Then HUD made it mandatory to get federal money.

 

[letgomywago]

All listed wiring devices that are marked for use with copper conductors can be used with CCA per the listing. The same is not true for wire connectors, so that is still an issue for widespread use of CCA.

Copper Clad Aluminum Terminations

iaeimagazine.org

 

[letgomywago]

I will add one other thing to this. UL does not have a wire connector listing for CCA vs al-cu this is discussed in the document that is referenced in the iaei article.

Separate note. Wago makes a paste for aluminum wire that is not ul listed for the US market but is used internationally and is but still available for purchase. This paste would make the CCA ok if it were tested but I feel but maybe a new listing standard would be needed to be able to identify it that way. I also trust a pressure connector more than a twist connector with this specific material because it won't cut the copper layer.

 

[don_resqcapt19]

I will add one other thing to this. UL does not have a wire connector listing for CCA vs al-cu this is discussed in the document that is referenced in the iaei article.

Separate note. Wago makes a paste for aluminum wire that is not ul listed for the US market but is used internationally and is but still available for purchase. This paste would make the CCA ok if it were tested but I feel but maybe a new listing standard would be needed to be able to identify it that way. I also trust a pressure connector more than a twist connector with this specific material because it won't cut the copper layer.

A twist on wirenut is a pressure connector. That is the purpose of the spring and tapered shape of the inside of the wirenut.
As far as cutting through the copper, I have been at a couple of trade shows where that had hundreds of people apply wirenuts to CCA, and when the wirenuts were removed, there was never any cuts through the copper layer. The copper is at least 10% of the total cross sectional area of the conductor per the product standard.

 

[don_resqcapt19]

What is the point of copper clad aluminum? It doesn't increase ampacity; can you use copper clad aluminum in copper only terminals?

Cost