Copper Clad Aluminum NM vs Copper NM for Small Scale Multifamily

[bearthebuilder3000]

Hello Everyone,

I'm an Architect / GC and we're working on a small scale multifamily community made up of single story duplex and quadplex buildings. The largest unit is approximately 1,350 SF. The basis of design for the electrical wiring is standard copper NM, however our EC is proposing that we substitute CCA NM as it represents a "substantial" savings across the project. Unfortunately, I have no experience with CCA. From what I am finding online, its much softer and breaks more easily than copper, but it can carry more current.

What are your thoughts on CCA NM? Are there any safety concerns that might offset the potential cost benefit? Is it something you would be willing to specify for small scale residential? Would you put it in your own home?

 

[infinity]

Unfortunately, I have no experience with CCA. From what I am finding online, its much softer and breaks more easily than copper, but it can carry more current.

It carries less current for the same size copper conductors. Typically you need to use conductors one size larger than the standard #14 and #12 copper conductors for 15 and 20 amp circuits. I've never used it and since it's only become popular recently I wouldn't use it it my own home.

 

[electrofelon]

Personally I would not use it until it has a longer established positive track record. In the grand scheme of things, the cost savings seem pretty small.

 

[don_resqcapt19]

The biggest issue right now is the wire connectors...as far as I know, the only wire connectors that have the "CC" rating that is required for copper-clad aluminum conductors is the one sold by the manufacturer of copper-clad aluminum wire.
The product guide information for switches and receptacles both say that those 15 and 20 amp wiring devices marked for use with copper conductors are also suitable for use with copper-clad aluminum.

 

[petersonra]

I think it only comes in #12 and 10 either 2-g or 3-g. So it can only be used on 15 and 20 Amp circuits.

I would not be worried about using it.

 

[electrofelon]

anyone know what the price difference is between a roll of 10-2 CCA VS 12-2 CU?

 

[Birken Vogt]

At the moment, it appears they only sell direct to approved contractors. So there is no internet pricing available.

I too would not be afraid of it. But whether it makes economic sense is another question.

Also one of their marketing topics is the fact that it is worthless for scrap. So depending on job site location this may be a factor.

 

[VirutalElectrician]

What;s this gonna save, a couple hundred bucks a house?

 

[qcroanoke]

Substantial savings for who?
I would not use it in my home or anyone else's.
Hasn't been out long enough to see if a problem will arise.
Plus as Infinity said you have to use 10 awg on 20 amp circuits and 12 awg on 15 amp circuits

 

[ron]

It is aluminum conductors with a copper coating, so they get sized based on aluminum. If the copper is scraped off during termination or insulation striping, you essentially have AL conductors.

 

[LarryFine]

It is aluminum conductors with a copper coating, so they get sized based on aluminum. If the copper is scraped off during termination or insulation striping, you essentially have AL conductors.

Is it apt to oxidize wherever exposed?

 

[petersonra]

Substantial savings for who?

Contractors will cheapen up light fixtures or combine circuits to save a few bucks. If this product is actually more cost effective than regular NM, I see no reason not to use it. The problem is that there seems to be a sole supplier. I'd be a little nervous that they might get into a production issue and I can't actually get it.

I would not use it in my home or anyone else's.
Hasn't been out long enough to see if a problem will arise.

How many decades will "long enough" be?

Plus as Infinity said you have to use 10 awg on 20 amp circuits and 12 awg on 15 amp circuits

This would be my issue as much as anything. I don't think it actually matters much for the specific circuits it is intended for, but it might be an issue if someone grabs #10 AL and uses it on a 30 A circuit.

 

[hbiss]

Hasn't been out long enough to see if a problem will arise.

What's the difference between this stuff and what was banned in the late 60's because of fires? Copper cladding? I really don't think that that's enough to instill confidence. Is it electrically better or mechanically better? Is it safer than copper? Its only excuse for existence is to save some contractor a few dollars. That's really not a good argument for a home buyer to want it or feel comfortable with it.

-Hal

 

[junkhound]

copper coated aluminum was popular back in the late 1960s. I used a few rolls back then, harder to pull and strip, difficult to get good contact under screw heads, stripped a few outlet screws and threw the outlet away.

savings might be eaten up by more hours on the job due to larger wires.

 

[petersonra]

What's the difference between this stuff and what was banned in the late 60's because of fires? Copper cladding? I really don't think that that's enough to instill confidence. Is it electrically better or mechanically better? Is it safer than copper? Its only excuse for existence is to save some contractor a few dollars. That's really not a good argument for a home buyer to want it or feel comfortable with it.

-Hal

the wire was not the cause of the fires.

 

[don_resqcapt19]

Contractors will cheapen up light fixtures or combine circuits to save a few bucks. If this product is actually more cost effective than regular NM, I see no reason not to use it. The problem is that there seems to be a sole supplier. I'd be a little nervous that they might get into a production issue and I can't actually get it.



How many decades will "long enough" be?

This would be my issue as much as anything. I don't think it actually matters much for the specific circuits it is intended for, but it might be an issue if someone grabs #10 AL and uses it on a 30 A circuit.

The jacket on 10 AWG NM is yellow to indicate a 20 amp conductor, however, just like with copper NM, the jacket colors are not required by the product standards or the code. Just a voluntary industry standard that all of the manufacturers have complied with...at least so far.

 

[don_resqcapt19]

What's the difference between this stuff and what was banned in the late 60's because of fires? Copper cladding? I really don't think that that's enough to instill confidence. Is it electrically better or mechanically better? Is it safer than copper? Its only excuse for existence is to save some contractor a few dollars. That's really not a good argument for a home buyer to want it or feel comfortable with it.

-Hal

It was never banned by the NEC...it just was removed from the market by the manufactures.
The biggest issue with the old aluminum was the huge difference in the thermal expansion between the aluminum conductor and the wiring device screws. The new alloy aluminum has a thermal expansion much closer to that of copper, and the copper-clad aluminum even closer.
For a few years in the early 70s there was 10 and 12 AWG aluminum on the market. I worked on an apartment complex that was in EMT because of the local code and we used the single conductor new aluminum alloy. I ran the shop service truck for a number of years after than, and there were no more trouble calls to that project as compared to similar projects that were done using single conductor copper.

 

[LarryFine]

I have seen aluminum-related issues, primarily loose terminals, on regularly-cycled-loaded circuits.

The usual ones are kitchen-appliance receptacle circuits and master-bedroom receptacle circuits.

 

[norcal]

Local contractor used 10/3 AL for the dryer feeds, far as I know still there.

 

[Speedskater]

The aluminum alloy in 1960 wires was very different than the aluminum alloy in current wires.