With the price of copper so high, many contractors have been submitting on aluminum conductor feeders for panelboards and HVAC equipment. I understand that the AL wire has less ampacity so they actual size of the conductor would need to be reviewed, but are there any reasons not to accept AL wiring in lieu of copper? This typically comes up in the VE process.
Aluminum vs Copper
- Thread starter bwyllie
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bkludecke
Senior Member
- Location
- Big Bear Lake, CA
- Occupation
- Retired Electrical Contractor
Aluminum wire is a safe and proven alternative to copper. It is not at all difficult to make reliable terminations and splices. We do them hundreds, if not thousands of times per year, and have had virtually no problems for decades.rattus said:
johnny watt
Member
?round these parts you would be hard pressed to find a residential service
entrance or circuit higher then 30 amps that is not aluminum...inum.
entrance or circuit higher then 30 amps that is not aluminum...inum.
davidr43229
Senior Member
- Location
- Columbus, Oh
I can't remember the last time that a mobile home caught fire....
- Location
- Massachusetts
davidr43229 said:
I can't remember what that has to do with the question.
davidr43229
Senior Member
- Location
- Columbus, Oh
Loose terminations, or ionization bewteen dis-simular metals. People use to use "no-ox" on those connections to prevent oxygen from entering into them.
davidr43229
Senior Member
- Location
- Columbus, Oh
I know on our Fuseblocks & Power DIstribution blocks we rate them for Copper seperately than alunimum.
As an example, on a standard 30 amp fuseblock is printed " Will accept copper 2-14CU or 2-12 AU. Some Breakers and fuseblocks say "terminate with Copper only"
http://www.bussmann.com/library/bifs/1112.PDF
Aluminum does NOT conduct the same as Copper.
Conclusion, before using Alunimum in place of Copper:
1. Check with the AHJ.
2. Check components, Switchboards, Panelboards to see if the UL Listing will accept Alunimum.
3. In boarder line applications, Alunimum may have too much heat-rise.
Just my $.02
As an example, on a standard 30 amp fuseblock is printed " Will accept copper 2-14CU or 2-12 AU. Some Breakers and fuseblocks say "terminate with Copper only"
http://www.bussmann.com/library/bifs/1112.PDF
Aluminum does NOT conduct the same as Copper.
Conclusion, before using Alunimum in place of Copper:
1. Check with the AHJ.
2. Check components, Switchboards, Panelboards to see if the UL Listing will accept Alunimum.
3. In boarder line applications, Alunimum may have too much heat-rise.
Just my $.02
- Location
- Massachusetts
davidr43229 said:
They have to be diffrent, there is no such thing as 14 AWG AL to the NEC.
Agreed and we must follow that info.
But in general AL is used in larger sizes without any problems.
electricmanscott
Senior Member
- Location
- Boston, MA
rattus said:
Absolute nonsense. :roll:
This debate is right up there with ground up or down.
Properly installed aluminum is just as good as copper these days.
electricmanscott
Senior Member
- Location
- Boston, MA
davidr43229 said:
Why? Does this AHJ have a special little book they use in place of the NEC?
davidr43229
Senior Member
- Location
- Columbus, Oh
Because the AHJ may know more than the contractor quoting the Alunimum over Copper :grin: Oh I would like to think so.
kingpb
Senior Member
- Location
- SE USA as far as you can go
- Occupation
- Engineer, Registered
If you look around on the internet, there were some articles written having to do with the cost savings on large projects whereby the copper feeders were replaced with Aluminium (as the Brit's would say it). The cost savings was quite substantial as I remember.
As far as safe, well, I guess if the NEC says it's OK, then why should we question it.:-?
As far as safe, well, I guess if the NEC says it's OK, then why should we question it.:-?
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
rattus said:
The primary installation problem was fixed was with "circuit" size conductors which is why the NEC no longer allows and manufacturers no longer make these small sizes.
Except on small gauge conductors, one major problem with alumium was its increased size, but even this went away when "compact stranding" came out in the 80's. I know that Square D's circuit breaker mechanical lugs have been dual rated for AL/CU for at least 30yrs.
Every supply house I have known has always inventoried aluminum for residential use.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
jim dungar said:
I don't believe that there is a _market_ for these small size aluminium conductors (12ga and 10ga), and thus one doesn't see them sold. Furthermore Cu/Al rated devices are much more expensive than Cu rated devices.
But if you can get the stuff, and if your customers would accept the stuff, I am pretty sure that it is still perfectly code compliant to use Aluminium for branch circuit wiring.
Personally, as a customer: I would not want Aluminium for any circuit smaller than 6ga, and I would not want it in any direct bury situation. I would want anti-oxidant even if not required, and I would want all lugs tightened with a torque wrench or torque screwdriver.
-Jon
brian john
Senior Member
- Location
- Leesburg, VA
rattus said:
We perform IR scans and see as many thermal issues with a copper installations as we do aluminum (AL). When AL is properly installed and terminated IMO there are no problems with one exception, the MAC ADAPT type temination adaptors, Time after time we see these adaptors with thermal issues, not sure if it is the product, the method of termination or the improper hypress tool.
Oh and I my discussing feeders not branch circuit 15-30 amp.
Having said all this I used CU at my house.
- Location
- Illinois
- Occupation
- retired electrician
Jim,
Don
There is no NEC restriction on the use of 15 and 20 amp aluminum branch circuit conductors. It is only a marketplace issue based on the problems that resulted from the older small aluminum conductors.
Don
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
jim dungar said:
I stand corrected - my bad.
Electechgeek
Member
The only problem I can see is that the average homeowner has NO idea what they are doing while taking on home improvement jobs. Electrical Especially... If a home was originally built with AL, and a homeowner was replacing some form of Electrical equipment, light fixtures, rcpts etc. and replaced the equipment with anything that had Copper terms, they could easily burn down the home. I attended a presentation that was put on by a research rep for ALCAN, a large aluminum producer and distributer, his recomendation was that aluminun should be primarily used in Commercial/Industrial applications. As for the wire itself with new processes they were able to produce a wire called STABILOY, which is a wire that is so flexible and also sturdy, that I had a tough time bending it to its breaking point. It took substantially longer than that of the same size solid copper conducter. Though the wire sizes maybe larger due to lower ampacitys, a 200 kcmil stabiloy conducter is in fact easier to terminate than a 100 kcmil copper conducter...
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