ECN Forum Forums Code Related Discussion NEC & other Code issues 250.96 (A)

Thanks Roger- You beat me to the punch. I was looking it up when your post came through.

Thanks George and Roger.


The removal of paint is required by 250.12 if it is inhibiting the connection.

So IMO if reducing washers or chase nipples are used the paint would have to be removed to ensure grounding continuity.

Hello George and Iwire, I know one of you would have posted the UL info if I hadn't.

This is one situation where I would not argue with an inspector if he did not accept it even though UL says it is safe.

As a matter of fact, it wouldn't be an issue because I wouldn't do it or let an employee do it.

Roger

Thanks for all the insight guys. Seems to me that it's in fact a code-worthy installation, but not a preferred method. It's good to know the difference.

Hello all, just curious as to what earlydean said in the above. I'm clear with replacing the chase nip' with a close nip' and locknuts, but, what method would you use to if you were to leave the install as is, and just bond the LB?

One way I can see is run a seperate EGC from the panel to the first pull box or enclosure from the LB, and bond there. How else could it be done? Or am I thinking to much into this??

Luke

I can see no reason why a chase nipple 'wrench tight' into an LB would not provide a good bond to an enclosure with the paint removed.

If it made the inspector happy I would put a locknut backward on the chase before installing it into the enclosure.

Many a chase nipple I have installed wrenchtight into an LB still rattles against the enclosure. There is no way this is providing the "effective ground fault current path" as required by 250.4(A)(5).

The UL listing of reducing washers as a proper ground, sticks in my craw. I will have to digest this for awhile. UL does add: "where installed in accordance with" the NEC.

250.96(A) requires: Metal parts are to be "effectively bonded where necessary to ensure electrical continuity and the capacity to conduct safely any fault current likely to be imposed on them. Any nonconductive paint, enamel or similiar coating shall be removed" or replaced with grounding fittings.

I have to agree with Earlydean.....
I'm OK with a chase nip with locknuts.
Some chase nips around here have nice rounded shoulders, so there's no way they would be acceptable.

Still thinking on the derating thing....???

John

It just isn't that much work to put a locknut between the enclosure and the LB, LL, LR. Once that is wrench tight against the outside of the enclosure I'd call it good.