EGC Insulation Rating

[Evan McArthur]

If an insulated copper EGC is running in underground PVC, does the insulation have to be wet location rated? NEC 2023 250.118(A)(1) allows the EGC to be bare copper, my assumption would be that the insulation rating is made irrelevant by that statement since the copper conductor does not require corrosion protection.

 

[LarryFine]

Welcome to the forum.

That's an interesting question. I would say that it must still be W-rated.

 

[Evan McArthur]

Welcome to the forum.

That's an interesting question. I would say that it must still be W-rated.

Thank you!

What would you reference to say that it should still be wet location rated? It seems that the only purpose the insulation serves is identifying the conductor as an EGC.

 

[hbiss]

You guys are saying that if you do use insulated? I would say that it must be W rated, but that's not hard to do.

-Hal

 

[CoolWill]

I would say that it is a technicality, but legalistic types love to point at the code. In reality, since the EGC can be bare, it doesn't really matter from a practical standpoint.

 

[Evan McArthur]

I would say that it is a technicality, but legalistic types love to point at the code. In reality, since the EGC can be bare, it doesn't really matter from a practical standpoint.

That was my understanding, I was hoping to find a reference to back it up.

 

[Elect117]

I read it both ways.

310.1 and 310.10 have the asterisk at the end that says "or elsewhere in this Code" and I would believe that 250.118(1) / 250.119 would be considered elsewhere in code. Though, they are more obviously there for flexible cords and fixture wire sections.

300.5(B) and 310.10(C) are pretty specific with it though. So it is hard to say where an insulated conductor, even if equipment grounding conductor, is used, it would have to be suitable insulation for the location.

 

[Elect117]

If an insulated copper EGC is running in underground PVC, does the insulation have to be wet location rated? NEC 2023 250.118(A)(1) allows the EGC to be bare copper, my assumption would be that the insulation rating is made irrelevant by that statement since the copper conductor does not require corrosion protection.

I reached out to NFPA on the subject as a technical question and the response was:

"Section 310.10(C) applies only if the equipment grounding conductor is required to be insulated elsewhere in the Code such as in 517.13(B) or 680.21(A)(1)."

I would also add that this is a informal response and any AHJ can enforce it differently.

 

[Evan McArthur]

I reached out to NFPA on the subject as a technical question and the response was:

"Section 310.10(C) applies only if the equipment grounding conductor is required to be insulated elsewhere in the Code such as in 517.13(B) or 680.21(A)(1)."

I would also add that this is a informal response and any AHJ can enforce it differently.

This is helpful, thank you!