Would any of you consider using a chase nipple as a primary means to bonding a threaded 1-1/4" LB if the chase nipple was attached to an enclosure through an eccentric knockout?

So the chase nipple is going though an eccentric knockout in a panel and attached to a threaded LB. In your opinion, does this wiring method meet NEC requirements?

Thanks!

--Ron

Ron if this is a circuit over 250v. to ground then it might be a violation. 250.97 If this is a Service raceway and this is the method of bonding then it might be a violation. 250.92 Your not giving us much information. I don't think it's a good installations but I've seen it done and can't really argue that it's not "effectively bonded" based on my understanding of the term. In technical terms it's "pig work". You only have to bond one end of a raceway sometimes, even on Service raceways. Now what brings up this question?

Thanks George. I bring this up because I was on a job where this was done and I was concerned that the pipe was not properly bonded. IMO it's not. The guy who did it is one of these guys that can do no wrong no matter what you tell him and I've just given up trying. In my opinion it's a poor bond. I'm very concerned about the installation because the pipe feeds numerous pieces of commerical kitchen equipment (28 current-carrying conductors in all) and I'd hate to to later find out that someone died there because a ground fault did not clear when it should have. And because this job had no permits, there is no paper trail, and therefore no responsibility if a fatality occurs.

Shock it may be a violation if over 250 volt but I have very little doubt it is bonded well enough if you have 28 current carrying conductors.

When you have multiple conductors you base the grounding on the single largest OCPD protecting the circuits. Not the collective total.

So what would that be.....a 20 amp breaker vs a 1 1/4" LB and chase?

One last thing is that if the fittings don't bit into the paint the paint should be removed.

OK, now let's dig a little deeper.....
1-1/4" raceway.....comm kitchen equip....28 current carrying conductors.....

45% derated, for 28ccc; ambient in comm kitchen?? site discussion for sure, or plan review reject/clarification........OH, I FORGOT, no permit, no inspection....

No paper trail??? DO NOT BET your life, or $1; you may be surprized how quick the client 'fesses' up who did the work. It's not really that hard for an AHJ, cop, insurance adjuster, etc., to get info.

That said, the chase nip debate cannot get a firm answer from me. More info needed.

John

NEVER assume there's no paper trail.
Just wait till something goes wrong and see how fast the owner comes up with the cancelled check that the contractor deposited into his business account. Not to mention anything the contractor wrote down on company letterhead. Put somebody in a hot enough seat and they come up with all kinds of interesting paperwork in order to save their own butt.
You failed to mention whether a full size grounding conductor was installed in the conduit in question.

Chase nipples cannot provide proper bonding, as there is no way to "bite" into the enclosure (same reason why reducing washers cannot provide a bond). The threaded connection into the LB would be sufficient (if wrenchtight) for bonding the locknut to the LB, but not to bond the nipple or the LB to the enclosure. Locknuts do "bite". Sounds like either a green wire EGC bond would be required in this installation or replace the chase nipple with a close nipple and use two locknuts (and maybe a bushing).

BTW removing paint may lead to rust problems in the future. Always repaint over the bonded connection after it's all terminated and tightened.

Earlydean- While I support you professionalism and if I were installing the job I would not use chase nipples as this thread discribed them being used nor would I use reducing washers except where I had to for some unknown reason. While there are code reasons to not use these items for Service raceway bonding or over 250v. to ground, etc. the use of reducing washers and chase nipples is a code compliant installation and as an inspector we usually accept them when installed correctly.

Unfortunatly, reducing washers are suitable for grounding per UL. (not that I agree they should be)

From the White Book:


Roger

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.