ECN Forum Forums Code Related Discussion NEC & other Code issues Connection between panels

Bob,
I just don't see any applications listed that don't involve the use of a locknut. I would expect that UL only tests to the manufacturer's intended installation methods and that the method described here is not one of those methods. Lacking a statement from either UL or the manufacturer that this is an intended use of chase nipples, I would redtag this installation if I was the AHJ.
Don

Don


What code article would you cite?

To each their own, I would fight it.

Good talking with you.

Bob

Why not use a rigid metal nipple with locknuts & bushing instead of the coupling?

Al

Bob,
250.4(A)(3).
Don

You know, circumstances have dictated that I try this sort of connection a few times. I've hhad instances where the sheetmetal was so thin, or the receiving female threads were so shallow, that it was not possible to tighten the chase nipple enough to clamp down on the enclosure.
(In those cases, I instead used 'running thread.')

I usually go with a chase into an LB. I think it is much more sanitary inside the box than a nipple, locknut, and bushing. When I tighten the assembly up, it is mechanically very solid and the chase is in solid contact with the edge of the usually hole sawed hole.