# Noalax on copper to aluminum?



## joe-nwt (Mar 28, 2019)

You know, I'll bet if you searched Noalox you would find a recent thread on that very subject.


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## Funkadelicfred (Jan 30, 2019)

joe-nwt said:


> You know, I'll bet if you searched Noalox you would find a recent thread on that very subject.


Thats a good idea


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## HackWork (Oct 2, 2009)

I have never heard of or seen someone use Noalox when terminating copper conductors on aluminum lugs. 

And that’s the question I always ask people when they say that you need to use it when terminating aluminum conductors. Why do you need it on aluminum conductors but not aluminum lugs?


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## Bird dog (Oct 27, 2015)

HackWork said:


> I have never heard of or seen someone use Noalox when terminating copper conductors on aluminum lugs.
> 
> And that’s the question I always ask people when they say that you need to use it when terminating aluminum conductors. *Why do you need it on aluminum conductors but not aluminum lugs?*


 My understanding is to stop the oxidation of the aluminum wire. Lugs are made from alloys & don't need it.


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## HackWork (Oct 2, 2009)

Bird dog said:


> My understanding is to stop the oxidation of the aluminum wire. Lugs are made from alloys & don't need it.


Aluminum conductors are made from aluminum alloy as well.


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## Bird dog (Oct 27, 2015)

HackWork said:


> Aluminum conductors are made from aluminum alloy as well.


True.


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## Bird dog (Oct 27, 2015)

From EC&M halfway down the page...
*Copper or Aluminum Lugs: How Should You Decide?*


"This research turns up some other surprising findings, too. Manufacturers today do not make aluminum-bodied lugs of pure aluminum. Instead, they produce them with a continuous copper or nickel flashing or coating, that they cover with tin or silver. The flashing is necessary because the tin coating will not adhere to the aluminum. You can see this copper coating on lugs you use today by erasing the thin plating from the lug with a pencil eraser, revealing the copper underlayer.


When manufacturers don't provide these coatings, the formation of a high-resistance aluminum oxide powder occurs soon after installation and even sooner in moist conditions. However, the coatings impede aluminum oxide formation for a long time - even in moisture-laden conditions.


When installers use an oxide-inhibiting compound while inserting an aluminum wire (not needed for copper wires) into the lug, and at the lug area where it's connected to the bus bar, the survey shows galvanic action and oxide formation almost ceases to be a problem. When an aluminum lug surrounds the wire (instead of a copper lug surrounding an aluminum wire), it can expand and contract with current flow (and the corresponding temperature change) without causing deformation of the wire, regardless of whether the wire is copper or aluminum."


https://www.ecmweb.com/content/article/20892533/copper-or-aluminum-lugs-how-should-you-decide


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## Forge Boyz (Nov 7, 2014)

HackWork said:


> I have never heard of or seen someone use Noalox when terminating copper conductors on aluminum lugs.


I watched a guy from the power company do it already in a transformer vault. His logic was it couldn't hurt with as damp as it can be in there.

Sent from my SM-G970U using Tapatalk


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## JoeSparky (Mar 25, 2010)

I repair/replace lots of services on the seacoast. The aluminum wire, lugs and buss bars oxidize in the salt air. I grease all of my outdoor aluminum connections near the beach and aluminum wire almost everywhere else. Fixed lots of services with oxidized lugs or burned up main breakers due to oxidized stabs.


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## Navyguy (Mar 15, 2010)

Funkadelicfred said:


> Argument with coworker. As far as I know, every time copper touches aluminum, wether it's copper lugs to aluminum wire or vice versa. You use noalax, am I right or wrong?


Rule 12-118, your answer is in there.

Although I am sure they exist, I have never seen an AL ONLY rated lug (I am sure they would be too soft). Every lug I have seen is CU/AL rated (splitters, disco, panel, breakers, etc). I know there is some AL/AL crimps (compression connectors).

I tend to use Noalox or NO-OX-ID on a lot of connections regardless if it is required or not.

Cheers
John


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