• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

rigid conduit fittings.

ICE

MODERATOR
Staff member
Joined
Jun 23, 2011
Messages
13,875
Location
California
The rigid conduit has a tapered thread. The coupling does not. The offset fitting does not have tapered threads. The hub has tapered threads. I wrote a correction that said that the conduit must thread into the hub. Do you agree with me?


 
@ * @ * @

ICE,

Does the installation as shown in your picture, provide a
"continuous, effective ground fault path" [ RE: `08 NEC,
Article 344.46, ..." unless the design of the box, fitting,

or enclosure is such that affords equivalent
protection " ] ? Also, Art. 300.10.


I respectfully disagree with your interpretation sir !

@ * @ * @
 
If a contractor in my area did that work I would be happy with it. I don't think I'm skilled enough to catch the different threads entering a hub like you did.

ICE, I think I would have pass it due to my ignorance of the code, along as it's water tight and the grounding path meets code.

Could it become dislodged somehow, is the conduit strapped to the structure?

Is the hub a water type hub? Gasket?
 
I would be more concerned with the liquid resistance. I would be inclined to reject it on that alone, than that it probably violates any listings, to not mate it with the appropriate fitting. JMHO
 
I put it to the test and water gets through when the offset fitting is screwed into the hub. The conduit screwed into the coupling as tight as I can get it with just my hands lets water get through. The conduit screwed into the coupling as tight as I can get it with channel-lock pliers did not leak. The conduit screwed into the hub with just my hands did not leak. I used 2" conduit etc.

CDA, an ohm tester will not give a meaningful result. To my knowledge, the hardware has not been evaluated with mismatched threads and such use contradicts the listing. I have been told that the coupling is shipped with the conduit but the threads do not match and I wonder how it became a common practice.
 
= + = + =

If \ when using the offset, or other hub fittings to couplings,

some electricians have used Teflon tape and wrapped it
around the threads several times, or even used Pipe Dope
on the threads......This in an effort to "seal out" moisture.
Not saying it is compliant [ by the Letter of the Code ], but
it has been done.


Also, a Listed type of "sealing locknut" on the Hub fitting
could be used......One that provides electrical grounding
continuity.


cch_cp_myers_220.jpg



+ = + = +
 
Would have passed it! must have been a local contractor you have history with... But I see your point. Here in North MS, we call that redneck engineering and I've seen a lot worse.
 
Back
Top