Need a little help

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Tulsa Electrician

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Location
Tulsa
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Electrician
Oklahoma has adopted the 2017 NEC, Tulsa is still on 2104 NEC. In preparation for an code update to 2107 I have been reading through the New parts of 2017. I ran across one I am just not clear on.
"use non-threaded fittings"
How does this apply to an Installation method and can some one give me a real world example. I'm having a hard time visualizing the situation. I do a lot of roof installations and I want to be up to speed.


New for 2017
"440.9 Grounding and Bonding. Where multimotor and
combination-load equipment is installed outdoors on a roof, an
equipment grounding conductor of the wire type shall be
installed in outdoor portions of metallic raceway systems that
use non-threaded fittings."

About all I can come up with is an EMT to FMC one piece fitting.

This is why I follow hhsting post. He always looking for 2107 ansawers.
 
I interpret it this way: If you're using RMC or IMC with threaded fittings for these types of installations, then you don't need a wire-type EGC. Otherwise, you will need to have a wire-type EGC.
 
OK I think I get it.
So if i run outdoor on roof using EMT ( EMT as an example) and compression fitting than a wire type EGC Shall be used. We do roof work where this is common place. As a rule we run a wire type EGC anyway. What I do find interesting is this is one time EMT can not be used as an EGC.
I will give an example we have a roof top Panel and run feeders to RTU,s using EMT and rain tight compression fitting. A wire type EGC shall be installed.
Comment: I can understand why based on how many times the roofers/ others have damaged the raceways connection(s) using compression fitting.

Thank you
If my comment is correct I will be sure to pass this on to the men.
I'm going back to 250.118 and make note in book by 250.118 (4) * see 440.9 Roof
 
If it's a threaded raceway it cannot easily pull apart at the fitting. Something like EMT or RMC with threadless fittings would require much less force to separate the raceway at a fitting that had no threads holding it together. On a roof raceways are subject to all sorts of stress and potential damage from people walking on them.
 
Thank you,
Also made note on 358.60
Laughed at 358.100
Never seen it or heard of it.
Seen it with factory set screw coupling.
Any one have a pic to share of factory threaded integral coupling send it my way.

Again thanks for helping me clear it up in my head. I was told once to never read past what you don't understand.
 
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