I am doing a renovation project at an apartment housing complex and during my initial fieldwork came across something I've never seen before: copper and aluminum wiring being used on the same circuit. There were copper "pigtails" at the panel and at the device and spliced to these copper "pigtails" was aluminum NM cable for the run. There was some "goop" applied to the CU/AL splice which I am guessing was to prevent interaction of the metals. Is this code compliant? I don't understand why the contractor did this because the electrical panel is within close proximity to all the devices in the apartment. And the other thing is that if the panel had eleven circuits, they only did this CU/AL combination on seven of them, the other four circuits were copper all the way.
AL or CU or BOTH ????
- Thread starter bfletcher
- Start date
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- Location
- Logan, Utah
Were the device terminals listed for use with aluminum conductors? I suspect this is the reason that they pigtailed copper wire onto the aluminum wire to connect to the devices and breakers.
As far as the connections between the copper and the aluminum wire, these splices should be done using a method designed for the purpose, such as using wirenuts listed for the connection. Standard wirenuts are not listed for CU/AL connections even if you use an antioxidant compound.
Chris
As far as the connections between the copper and the aluminum wire, these splices should be done using a method designed for the purpose, such as using wirenuts listed for the connection. Standard wirenuts are not listed for CU/AL connections even if you use an antioxidant compound.
Chris
The devices were listed for AL and the wirenut was a CU/AL type wirenut. I contacted the local electrical inspector and found that this wiring method was used in the 1970's and was used as a cost savings. The aluminum conductor was much cheaper than copper so it was used for the longer runs in residences. Needless to say I will be removing all the aluminum cabling and installing new copper NM cable.
Thanks for the input.
Thanks for the input.
glene77is
Senior Member
- Location
- Memphis, TN
BF,
Good thinking. :smile:
Check this website for very helpful information
on the characteristics of Aluminum Wiring.
http://www.inspect-ny.com/aluminum.htm
I have repaired a good number of aluminum wire fires !!
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
BF,
Good thinking. :smile:
Check this website for very helpful information
on the characteristics of Aluminum Wiring.
http://www.inspect-ny.com/aluminum.htm
I have repaired a good number of aluminum wire fires !!
The above mentioned site is very biased in regards to this topic. If one goes back to 1993 in a search, one will find a very biased and unsubstantiated report, performed by a home inspector.
In regards to aluminum conductors, there is really very little that is wrong with aluminum conductors.
The area of aluminum that there are issues with is the termination points. If one installs according to instructions, the percentage of failures is probably similar to the percentage of failures with copper.
The issue is there is less "wiggle" room in error with aluminum terminations, which means the installer needs to pay close attention to the termination process.
UL stands behind the proper fittings for termination of aluminum conductors. Not just the wirenuts, but other termination points such as split bolts, terminal bars, circuit breakers and devices that are listed as suitable for these terminations.
We have all seem terminations with copper conductor terminations go bad, the same as aluminum. Proper installations and maintenance should be adhered to when one is installing either type of conductor.
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