Aluminum antioxidant paste on copper

[rbibler]

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.

Best

Ron

[Michael Larson]

This from UL might help.

Conductor Termination Compounds

Conductor termination compounds are for use on splice and termination connections of aluminum, copper-clad aluminum and copper conductors where used to retard oxidation at the conductor/connector interface. These compounds do not have a deleterious effect on the conductor metal, insulation or equipment when used in accordance with the manufacturer's installation instructions.

Reference should be made to the product label located on the smallest unit container for specific instructions as to the proper use of the compound.

The red phase lower lug looks overheated.

Did you take an IR pic?

[Robert Meier]

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.

[Paul W. Abernathy]

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....

[Paul W. Abernathy]

A link to some good info on AL...again

http://www.nachi.org/forum/f19/nice-...s-enjoy-18514/

[Robert Meier]

Originally Posted by pabernathy

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....

Is there actually aluminum only and copper only anti oxidants?

[Paul W. Abernathy]

Yep......they do make it.

[bstenger]

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.
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?

[Paul W. Abernathy]

Originally Posted by bstenger

Does copper oxidize? NO, alloys do.

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 :http://www.whyguides.com/why-does-copper-oxidize.html