Aluminum NM

[David Rogers]

After 40 yrs in the industry and not seeing aluminum romex in forever i've been asked to renovate an existing motel that was built in the late 50's, and most of the wire is 12/2 and 10/3 al. The owner is looking for savings and expects me to use the existing conductors as much as possible. I can't find or am not looking in the correct place to determine if doing that is legal. It's been safe and operational for years, but i want to be capable of showing a doubting inspector or give the correct answer to the owner about using the existing al nm cable.

 

[augie47]

You may want to run the job by your insurance underwriter. Mine would not cover AL NM work in multi-family or commercial structures.
Secondly, what does your renovating include ? If you are installing devices, you may have difficulty finding one rated for AL
and lastly, there are limited "approved" methods of pig-tailing cu.
It is definitely a sticky situation.

 

[Dennis Alwon]

12 alum and up is still in the NEC so I have no doubt that it is legal, however his insurance company may have an issue with it. If you terminate the aluminum correctly then I see no reason why an inspector will turn it down esp. if it is existing.

 

[David Rogers]

Thanks

Thanks

You may want to run the job by your insurance underwriter. Mine would not cover AL NM work in multi-family or commercial structures.
Secondly, what does your renovating include ? If you are installing devices, you may have difficulty finding one rated for AL
and lastly, there are limited "approved" methods of pig-tailing cu.
It is definitely a sticky situation.

Sound advice and thanks

 

[David Rogers]

12 alum and up is still in the NEC so I have no doubt that it is legal, however his insurance company may have an issue with it. If you terminate the aluminum correctly then I see no reason why an inspector will turn it down esp. if it is existing.

Thanks, I'll be passing that along.

 

[Cavie]

Do yourself a favor. Tell your custormer your a better electrician than that and walk away.

 

[curt swartz]

I have a hard time believing the AL NM wiring was original from the 50's. I have never see AL NM with cloth sheathing and NM didn't have plastic sheathing until the mid 60's. I didn't think they started making small AL conductors until the early 70's but I could be wrong.

 

[480sparky]

.......... I didn't think they started making small AL conductors until the early 70's but I could be wrong.

My 1901 NEC addresses aluminum conductors' ampacity (Rule 16), it being 84% of a copper conductor of the same size. The table in Rule 16 lists Brown & Sharp gauges (now AWG) from 18 through 2,000,000

 

[hurk27]

I have a hard time believing the AL NM wiring was original from the 50's. I have never see AL NM with cloth sheathing and NM didn't have plastic sheathing until the mid 60's. I didn't think they started making small AL conductors until the early 70's but I could be wrong.

I think it was around 1976 give or take a year or two, we have a whole neighborhood of houses with this stuff that was built around 1976, and it's been a great service call place, keeps me busy:grin: I use the Ideal twister tails to terminate any new receptacles as they go bad, most problems are at terminations, such as at breakers, neutral bars, and receptacles, some times at switches but not too often.

Once in a while I'll find a 20 amp breaker on #12 where someone didn't know it was supposed to only be on a 15 amp breaker.

If I remember right wasn't it a copper shortage cause by striking miners in South America, that prompted the rise in the AL use?

 

[David Rogers]

I have a hard time believing the AL NM wiring was original from the 50's. I have never see AL NM with cloth sheathing and NM didn't have plastic sheathing until the mid 60's. I didn't think they started making small AL conductors until the early 70's but I could be wrong.

You might be right, obviously I'm not sure. I'm going by the owners information. The NM cable is a woven with 12/2 AL marked on it, and it's white.

Thanks for the input.

 

[480sparky]

Use of aluminum soared during WWII when copper was needed for the war effort.

 

[hurk27]

You might be right, obviously I'm not sure. I'm going by the owners information. The NM cable is a woven with 12/2 AL marked on it, and it's white.

Thanks for the input.

I have seen a few older homes wired back in 1944 when copper was being used for war efforts (WW2) but it was mostly tin coated steel or tin coated copper wires, and I have seen both wrongly identified as AL, but as you said, it does say AL on the jacket, maybe they also used AL back then for the same reason, to free up copper for the war effort?

 

[renosteinke]

If it has cloth insulation and silver wires, it's probably tinned copper - and it almost certainly lacks a ground wire.

If it is aluminum, the ground wire is almost sure to be undersized. This will cause you no end of grief, as the stuff is usually crimped in the bottom of the box, and breaks as soon as you disturb the device.

Splicing / pigtailing to aluminum isn't as bad as folks fear. T&B has their CSA-approved marettes (wire nuts), and King connectors has their little insulated terminal blocks. What WILL bite you is a lack of room in the boxes. Tyco is, for all intents, out of the crimp business.

Aluminum-rated switches and receptacles are not a problem ... but Al-rated GFCI's simply don't exist.

If you're at the point where a remodel requires a complete re-wire, you'll have to bring everything up to current code. This will mean adding plenty of circuits, maybe even panels, egress lighting, interconnected smokes, etc. The customer wanting to shave a few dollars needs to understand that doing 'the least he can get away with' will cost more than 'doing it right.' At some point you simply can't add a patch to a bandage to a make-do .... and it's cheapest to just start over.

 

[MarkyMarkNC]

Aluminum NM was first approved for use in 1964. The major manufacturers quit selling it in 1973, but many homes built a year or two after that can still be found with aluminum wiring. WWII era homes with aluminum looking wiring is probably tinned copper, or new circuits added in the 60's or 70's.

There are lots of threads on the subject here on MH forum, so if you are unfamiliar with aluminum wiring, do plenty of research before proceeding.

 

[Jim W in Tampa]

It would be flat out stupid to keep that aluminum if this is a real renovation. It has been working but i question safe.
He should check with his insurance coverage and you yours. This is one time i hope the inspector finds a way to reject it. Might not be able to force it on existing that not being replaced but i would not allow you to add anything to it.