Is copper antioxidant paste use for copper wire connections now recommended in USA?

Question

We will be improving/replacing our electrical service's earth ground, currently a galvanized pipe in the ground with a maybe 10 gauge copper conductor leading to 1970ish split bus Square D electrical panel.

New grounding will be three 5/8" x 8' copper-clad grounding rods, set 6' apart with 4 gauge copper conductor running by each and to electrical panel. Our city electrical guide implies that antioxidant paste must be used not just with aluminum, but with all connections including copper/stainless wire mechanical connections or even split bolts.

Should I use the copper antioxidant paste I have (Kopr Shield) at each 4 gauge wire/grounding rod acorn connection? How about on the 4 gauge to electrical box screw connection?

Answer 1

I have been using anti oxide compounds noalox and deox for decades. It is especially helpful on the threads of the screw lugs for your mains.

The anti oxide prevents oxides and is a lubricant so the threads don’t gal most lugs are aluminum so it really should be used anyway.

If you look at the pressure point in many new breakers you will see a little “grease” this is a special anti oxide/ lubricant that the manufacturer puts on.

Most of the newer connectors today including split bolts are aluminum, and all of the larger lugs on breakers and bus bars are aluminum so yes anti oxide should be used.

In the rare cases that you have brass hardware anti oxide compound is not required but it will still protect threads and prevent some corrosion in the connections or on the west coast they can.

So yes it is a good idea to coat wires / threads with a anti oxide compound.