ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
nec 110.3 (B)
by gfretwell - 09/22/21 11:11 PM
Grounding electrodes
by gfretwell - 09/07/21 03:41 PM
Looking For Electricians in the Midlands
by Alex247 - 09/06/21 05:26 AM
New in the Gallery:
Now you know.
Now you know.
by Tom_Horne, September 7
February, North East Indiana
February, North East Indiana
by timmp, July 25
Who's Online Now
0 members (), 26 guests, and 16 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 3 1 2 3
Joined: Jul 2004
Posts: 9,663
Likes: 4
G
Member
Is there a violation if you used a cable with another conductor or two in a raceway system?
(example a 12-3 w/g Romex and an additional THHN for the 4th ungrounded conductor in a 3/4" raceway).
It didn't sound right when I heard it but I am not sure what you would cite.


Greg Fretwell
2017 / 2014 NEC & Related Books and Study Guides
Joined: Apr 2002
Posts: 7,279
Likes: 3
Member
That's interesting...
I must say none of the rocket scientists here thought that up....yet!
Time to ponder what (if anything) to cite.

FYI: another reason to add common sense to the NEC?



John
Joined: Aug 2006
Posts: 356
Member
can you install NM cable in a complete raceway system? Or only in a piece of raceway just for physical protection?


Be kind to your neighbor, he knows where you live

Joined: Jul 2004
Posts: 9,663
Likes: 4
G
Member
I can't cite any rule that says you can't have NM cable in a raceway system. Since all circuit conductors come through the same connector there are no inductive heating problems. I know this is ugly but I am stumped to come up with a violation.


Greg Fretwell
Joined: Jun 2004
Posts: 1,273
T
Member
It's not a violation.

However, due to economics you'd not expect to see it.

It's generally impractical.


Tesla
Joined: Nov 2007
Posts: 763
K
Member
Iím wondering if 300.3[B] and 300.3[B],1 might apply if the conductors are all part of the same circuit, since both also state the same "cable or cord" as well.
Something else maybe, is that 334.15[B] is for exposed work, so not sure if this would preclude the NM from being run in a conduit that is concealed or partially concealed.

Joined: Jul 2004
Posts: 9,663
Likes: 4
G
Member
I suspect the RX was there first and the THHN was added.

KJay, this was all exposed in a garage/shop. A 240 2 pole was converted to 120/240 3 pole from what I could assume.
I see RX in pipe quite a bit, just because that is what resi guys have on the truck or what homeowners buy at the HD. I bet 99% of it is fed into the pipe as they build the system just because of how hard it is to pull RX in pipe.
I think part of it is you can buy RX cheaper than THHN if you don't want 500 feet.

I was not AHJ, just asked if it was legal as "gee whiz" info.


Greg Fretwell
Joined: Nov 2007
Posts: 763
K
Member
I guess technically you might be able to say that EMT fittings are not designed or listed for use with NM cables, since I see where 300.15 says that fittings and connectors shall be used only with the specific wiring method for which they are designed and listed.

IMO, I donít think the NEC allowing NM to be sleeved for protection was intended to allow unlimited use like that, but Iím also not sure exactly where to find a specific rule prohibiting it.

Joined: Apr 2002
Posts: 7,279
Likes: 3
Member
Kjay:
The fittings you reference above are EMT, and used on the EMT, not the NM as I understand Gregs description. 300.15 would be a bad cite.

I tend to say there is nothing to directly cite, unless at the begining of the circuit, there is no 'from-to' connector.



John
Joined: Nov 2007
Posts: 763
K
Member
Originally Posted by HotLine1
Kjay:
The fittings you reference above are EMT, and used on the EMT, not the NM as I understand Gregs description. 300.15 would be a bad cite.

I tend to say there is nothing to directly cite, unless at the begining of the circuit, there is no 'from-to' connector.



True. It was just something to mull over. My thought was that NM is a separate wiring method with its own installation requirements and listed connectors, etc.

Page 1 of 3 1 2 3

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
timmp
timmp
Leo, IN, USA
Posts: 27
Joined: June 2004
Top Posters(30 Days)
timmp 3
Popular Topics(Views)
283,076 Are you busy
216,813 Re: Forum
203,189 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5