Aluminum antioxidant paste on copper

Why would sparky put Aluminum antioxidant paste on Copper ?

Would you call this out? He has this in all the panels on a commercial building.






This from UL might help.

Conductor Termination Compounds

The red phase lower lug looks overheated.

Did you take an IR pic?

There’s nothing wrong with using it. In fact many meter enclosures come with some paste already in the lug which can be used with copper or aluminum conductors. I would wonder why there are black, white and bare conductors terminated on the same bar in the last photo.

Just don’t forget something. They make the paste for use with specific conductor types. This is how the NEC deals with the use…the NEC does not mandate it (manufactures have to do that if they want it used) but it clearly says that if you use it…it has to be the correct type for the correct conductor material. In otherwords, you don’t use a type made for aluminum conductors on copper conductors…

A link to some good info on AL…again

A link to some good info on AL…again

Is there actually aluminum only and copper only anti oxidants?

Yep…they do make it.

Does copper oxidize? NO, alloys do. I have never seen copper cond. coated with anything.
But I do question what little I can see of the panel. Has the Main been adapted to the panel? If so, that would be a ul / code violation. I am looking at the (3) phase conductors and they appear to be field installed, which seems unusual to me.
The nuetral conductor is usually I.D. with more white tape.:roll:
Did anyone notice the feed-thru connections? Someone noticed the discolored lug making me think that the main smoked due to overload which also fried the phase conductors. Could the repair person be trying to “fix” temp. instead of splitting the load.
Sound logical to anyone else?

interesting…do you REALLY believe that copper does not oxidize…I would beg to differ.

Take the time to read this article if you will :

Aluminum widely use as an antioxidant paste on Copper

Forgive me as I have no idea what you just tried to convey. If the Paste is designed for AL only it can’t be used on CU conductors…Period.

If you are looking for a universal oxide inhibitor then they make them but manufacturers also make conductor specific inhibitors also…so no you can’t use an AL specific oxide inhibitor on CU conductors.

Is it recommended to use oxide inhibitors on both AL and CU - YES

Who knows Paul, this is a zombie thread from 6 years ago they added to.

Are you sure it is aluminum antioxidant? If there is such a thing, I’ve never heard of it.

When I was an electrical contractor, we put antioxidant on all terminations in all panels.

Sounds contradictory. You used it on every connection , but have never heard of Penetrox or No-Alox .

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