My son just bought a house in Charlotte, NC which was built in the 1960's. Is Aluminum Wiring and Pig tailing acceptable to Code in Charlotte, NC?

  • You need to look in the code for your answer. However , aluminum forms oxide which is non-conductive, so the mechanical connections may slowly increase in resistance which may cause heating. There are remedies for this but I am not familiar with them. – blacksmith37 Oct 9 '17 at 18:42
  • @blacksmith37 The key thing for people doing minor home improvements is that you need special wire nuts to connect to copper. – JimmyJames Oct 9 '17 at 20:53
  • I originally used Scotchlok wire nuts with antioxidant compound to pigtail my aluminum wiring 35 years ago and I have had no known failures, but if I were going to do it today I would use AlumiConn connection blocks. Don't used the Ideal purple wire nuts (expensive, bulky, failure rate too high). – Jim Stewart Oct 9 '17 at 21:40
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    Why are you asking this? Are you asking about an existing pigtailing job? (If so, we'll need clear photos of the work done to make any judgement about whether it's OK.) Or are you planning to pigtail and want to know if it's legal? – ThreePhaseEel Oct 9 '17 at 22:33

Aluminum is no longer used in house wiring anywhere in the USA where the NFPA Electrical Codes are accepted that I know of, it had been used many years ago and is as far as I know against code (some one might have a guide to the NFPA NEC that states this). Your home might have been built before the new codes were adopted - so it exists as is.

Of course that really depends on state and county and when they adopted the codes; you should talk to the building code department of your state and county to verify when the change took place and when your house was built. Further take note of ANY electrical upgrades that were done, any building modifications or renovations - the reason being is that there are legal remedies you might have against the seller to get the wiring replaced. It might be considered a material issue (as in facts) that is required for disclosure ..for this you would need to consult a real estate attorney in your area.

The problem with aluminum was a thing called Galvanic Corrosion - it created a very high potential for electrical fires corrosion would occur and the connection would break loose and then you would get sparks etc and create flames, which is why it was removed from use, although I think in some cases they allowed it to continue to be used for ground wire - but DON'T quote me on that.

Now on to your questions: Pig Tailing seems to be allowed and is one method to fix the issue with Aluminum wiring with out replacing all of the wiring in the home .

See this link for more details: Charlotte NC Aluminum Wiring Repair

  • DVing as AA-8k (new alloy) aluminum wire was and still is Code-legal, and may be found in heavy feeders and branch circuits in houses built to this day in most parts of the USA. – ThreePhaseEel Oct 9 '17 at 23:47
  • @ThreePhaseEel - I was not referring to heavy feeders but residential home usage (branch circuits) as the ops question pertained to housing branch circuits. Just for my info: Could you post the Code Reference where it is acceptable to use aluminum wire in the residence for branch circuits. – Ken Oct 10 '17 at 9:23
  • See NEC 310.106(B) – ThreePhaseEel Oct 10 '17 at 11:39
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    While NEC may permit pigtails with anti-oxidant jelly, it ignores that the two metals expand at different rates when heated, and thus pose a fire hazard. Get an aluminum approved splice (like Alumiconn) and do it properly. If you're bound and determined to pigtail, install an AFCI breaker – Machavity Oct 10 '17 at 12:44
  • @ThreePhaseEel reading up; if the op has the original wiring for that house it is probably AA1350 and not used anymore as it is a hazard. AA-8K as you specified is acceptable but at 2AWG sizes larger. 14AWG copper = 12 AWG aluminum . Machavity's advice seems very sound to me. Replacing the home wiring with copper is more expensive; however, a house of that age though would be worth the upgrade , just for the safety factor and I am not just talking about the wiring conductors AL vs CU but other updates as well. – Ken Oct 11 '17 at 18:13

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