Copper Clad Aluminum

[Dennis Alwon]

It appears Copperweld has come out with copper clad aluminum. It was around years ago but these guys seem to be the only ones selling it. Everything is 90C just like other nm cable but this stuff is 1/2 the price. The 10/2 nm can still be used for 4500 watt water heaters if installed on a 25 amp breaker. The stuff has a solid clad of copper

They also have copper clad steel but I have no idea what that is used for.

Here is their site which lacks info. Everything basically says contact an agent

 

[infinity]

I guess that you would need to check the equipment you're connecting it to to make sure that it doesn't required copper only conductors. Can this stuff be pig-tailed with normal wire nuts?

 

[Dennis Alwon]

I guess that you would need to check the equipment you're connecting it to make sure that it doesn't required copper only conductors. Can this stuff be pig-tailed with normal wire nuts?

As far as I can tell it works just like copper since the connection to copper is with the copper clad. Should not be an issue.

 

[JFletcher]

Copper clad Steel is used for the center conductor of coaxial cable, nothing else I know of

 

[don_resqcapt19]

There are a large number of PIs for the 2020 code on the use of copper weld aluminum conductors. It will be interesting to see the panel comments and action. There was a lot of technical information that was submitted that you can view if you download the "raw PIs" (the PIs as submitted without any panel action or comment).

 

[LarryFine]

Copper clad Steel is used for the center conductor of coaxial cable, nothing else I know of

It was used for long-wire antennas when solid copper wasn't strong enough to support its own weight.

 

[Dennis Alwon]

I have seen it back in the early 80's or late 70's but we were never told it was copper clad aluminum so I bet it got used the same as copper.

 

[K8MHZ]

It was used for long-wire antennas when solid copper wasn't strong enough to support its own weight.

Copper clad steel is still available for antennas.


It's not that the copper can't support it's own weight, it's that copper creeps (stretches) over time which will lengthen and eventually de-tune the antenna.

 

[LarryFine]

I have seen it back in the early 80's or late 70's but we were never told it was copper clad aluminum so I bet it got used the same as copper.

I believe the intent is that it could be treated like copper as long as it's sized as aluminum.

 

[LarryFine]

It's not that the copper can't support it's own weight, it's that copper creeps (stretches) over time which will lengthen and eventually de-tune the antenna.

Wouldn't breaking be the end result?

 

[Dennis Alwon]

I believe the intent is that it could be treated like copper as long as it's sized as aluminum.

That is correct... The NEC tables has copper clad & aluminum on the same part of the table

 

[K8MHZ]

Wouldn't breaking be the end result?

Not always. They will just sag more if the copper is large enough. A 66' dipole made from 12 AWG stranded copper will stay in the air practically forever, but you can be certain it will stretch over time. A 4" stretch on 66' isn't much structurally, but it will adversely affect antenna performance. Dipoles are usually trimmed to +/- fractions of an inch when they are installed and tuned.

 

[don_resqcapt19]

I guess that you would need to check the equipment you're connecting it to to make sure that it doesn't required copper only conductors. Can this stuff be pig-tailed with normal wire nuts?

From the substantiation for a PI that would change 110.14 to make it clear copper and copper clad conductors can be directly connected.

Copper-clad aluminum with the outer covering of copper does not have contact as a dissimilar metal when installed in
pressure wire or pressure splicing connectors. The metal to metal contact is copper to copper. It should be noted that
by its design the copper cladding on copper clad aluminum is metallurgically bonded to the aluminum core. Testing
completed to UL 486C has shown that there is no issue with copper-clad aluminum being connected to copper in
pressure wire and pressure splicing connectors. The prohibition for direct connection of copper to aluminum and
aluminum to copper-clad aluminum as dissimilar metals is correct except where the device is listed and identified for
that application. ...

 

[GoldDigger]

On the other hand the thermal coefficient of expansion is clearly very close to that of straight aluminum of the same alloy.
That will definitely affect the suitability of any pressure type joint or connector.
A connector which is subject to creep and loosening during thermal cycling with straight aluminum wire(s) may well not fare any better with a thin copper cladding.

Sent from my XT1585 using Tapatalk

 

[LPS]

Three years since this thread was posted. Is it being used anywhere?

 

[LarryFine]

Three years since this thread was posted. Is it being used anywhere?

It was recently discussed here as a response to the recent copper-wire "shortage" and price increases.

 

[yesterlectric]

When I was young I had been taught that copper clad aluminum was something they tried during the shortages during World War II and that it led to a lot of fires due to dis-similar metals. I was taught that the theory behind its original design was that since most of the current travels on the exterior of the wire due to skin effect loss (and of course due to copper not having the same surface corrosion/oxidation problems) having copper on the outside might allow for the ampacity advantages of copper at a much lower cost.

Perhaps technology has changed to allow this now; or perhaps the electrician mentor who taught me this was totally wrong?

 

[GoldDigger]

When I was young I had been taught that copper clad aluminum was something they tried during the shortages during World War II and that it led to a lot of fires due to dis-similar metals. I was taught that the theory behind its original design was that since most of the current travels on the exterior of the wire due to skin effect loss (and of course due to copper not having the same surface corrosion/oxidation problems) having copper on the outside might allow for the ampacity advantages of copper at a much lower cost.

Perhaps technology has changed to allow this now; or perhaps the electrician mentor who taught me this was totally wrong?

At power frequencies (50 or 60 Hz.) and common sizes (less than 500 MCM?) the skin depth is large compared to the wire size. You can see this in the small change in resistive AC impedance for wire compared to DC.

 

[LPS]

I saw Mike Holt discuss it in a video a while back. He was saying that NM with a white outer jacket wasn’t actually an indication for 14 AWG, but indicated a 15 amp circuit. Therefore a copper-clad aluminum cable that’s 12 AWG would also have a white outer jacket. Similarly, 10 AWG copper-clad aluminum would have a yellow outer jacket indicating a 20 amp circuit. It makes sense. This way the inspectors will still be able to see where the 20 amp circuits are going.

Perhaps the reason it’s not being used is because when you’re talking about building a $300,000.00 home or a multi million dollar building saving a percent on wire just doesn’t make much difference. And even if it is perfectly reliable, all it takes is for one person to tell the customer the electrician installed cheap and potentially dangerous wire…

 

[don_resqcapt19]

I saw Mike Holt discuss it in a video a while back. He was saying that NM with a white outer jacket wasn’t actually an indication for 14 AWG, but indicated a 15 amp circuit. Therefore a copper-clad aluminum cable that’s 12 AWG would also have a white outer jacket. Similarly, 10 AWG copper-clad aluminum would have a yellow outer jacket indicating a 20 amp circuit. It makes sense. This way the inspectors will still be able to see where the 20 amp circuits are going.

Perhaps the reason it’s not being used is because when you’re talking about building a $300,000.00 home or a multi million dollar building saving a percent on wire just doesn’t make much difference. And even if it is perfectly reliable, all it takes is for one person to tell the customer the electrician installed cheap and potentially dangerous wire…

There is no requirement in the product standards or in the NEC that the jacket colors actually mean something. It is just something that the manufacturers have done on their own. You can order custom colors and I expect that you could find a manufacture somewhere that would put a yellow jacket on 15 amp conductors.