dmulhol925
Member
Where does the NEC require using two lock nuts, 1 inside, 1 outside on rigid conduit?
Where does the NEC require using two lock nuts, 1 inside, 1 outside on rigid conduit?
I will add that I have never seen RMC run without a locknut on both sides unless a threadless connector was used.
Well you say it is a violation but I have not seen an article other than the few mentioned that requires 2 locknuts. I thought it was a violation but I don't see the art.I have. It is a violation, but some people will use a locknut and a metal bushing.
Well you say it is a violation but I have not seen an article other than the few mentioned that requires 2 locknuts. I thought it was a violation but I don't see the art.
The violation is using a bushing where a locknut is required. The bushing is not listed as a fitting to secure the RMC.
http://www.emersonindustrial.com/en...tting/conduit-bush-rmc-imc/Pages/default.aspx
Is that more clear as to what I was trying to say?
I can't imagine why a locknut is only required on one side. Just does not seem right. :thumbsdown:
In don't read it that way. Unless otherwise specified a metal bushing on the inside and a locknut on the outside of the enclosure is an acceptable means.
I discussed it with a UL rep and he is in agreement. To me, the wording on the referenced Appleton cut sheet can indicate a locknut on the outside and a metal bushing on the inside.
We my end up agreeing to disagree.
Until the conductors are 4AWG or larger, then the bushing must be "insulating" according to 300.4(G).
I think it is what is addressed. A metal bushing can be on inside of enclosure and locknut on outside to secure the raceway to the enclosure, then we have 300.4(G) to comply with on top of securing the raceway. I did not quote the entire section, but yes a metal bushing with insulated throat should fulfill the requirements of that section.True but that is not what Gus is addressing. Besides you could have a metal bushing with an insulated throat
I think it is what is addressed. A metal bushing can be on inside of enclosure and locknut on outside to secure the raceway to the enclosure, then we have 300.4(G) to comply with on top of securing the raceway. I did not quote the entire section, but yes a metal bushing with insulated throat should fulfill the requirements of that section.
That never happens hereI understand that but the insulated throat or bushing was not what this thread is about. That is all I am saying. You just added another dimension to the question.
:?:?So now the question is why is a locknut needed on the rmc with the bushing but not the locknut.
So now the question is why is a locknut needed on the rmc with the bushing but not the locknut.
That never happens here