george t. everett
Senior Member
- Location
- New York
There have been several threads on installing NM cable in EMT. The January issue of EC magazine (page 150 ) has a interesting article on this subject.
NM in EMT
- Thread starter george t. everett
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electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: NM in EMT
Good article. Looks like they are saying anything over 10ft. is a violation. As the article pointed out it is widely done.
Good article. Looks like they are saying anything over 10ft. is a violation. As the article pointed out it is widely done.
charlie
Senior Member
- Location
- Indianapolis
Re: NM in EMT
Where does the "10 foot rule" come from?
Where does the "10 foot rule" come from?
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: NM in EMT
They are quoting the exception to 312.5(C). It has 7 conditions to be met. Read it and give us your take.
They are quoting the exception to 312.5(C). It has 7 conditions to be met. Read it and give us your take.
charlie
Senior Member
- Location
- Indianapolis
Re: NM in EMT
This is from the NEC Handbook, "The exception, which was added for the 1999 NEC, spells out the requirements that allow multiple nonmetallic cables such as Type NM, NMC, NMS, UF, SE, and USE to enter the top of a surface-mounted enclosure through a nonflexible raceway sleeve or nipple. These sleeves or nipples are permitted to be 18 in. to 10 ft in length. However, if the nipple length exceeds 24 in., ampacity adjustment factors as specified in 310.15(B)(2) apply."
IMO, this has no bearing on the NM cable installed in EMT for physical protection. If I wanted to enter a run of EMT an go 50 feet before the NM cable emerged, it would not be a Code violation. I fail to see the difference between a three foot sleeve and a 50 foot sleeve.
This is from the NEC Handbook, "The exception, which was added for the 1999 NEC, spells out the requirements that allow multiple nonmetallic cables such as Type NM, NMC, NMS, UF, SE, and USE to enter the top of a surface-mounted enclosure through a nonflexible raceway sleeve or nipple. These sleeves or nipples are permitted to be 18 in. to 10 ft in length. However, if the nipple length exceeds 24 in., ampacity adjustment factors as specified in 310.15(B)(2) apply."
IMO, this has no bearing on the NM cable installed in EMT for physical protection. If I wanted to enter a run of EMT an go 50 feet before the NM cable emerged, it would not be a Code violation. I fail to see the difference between a three foot sleeve and a 50 foot sleeve.
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: NM in EMT
Earlier in the article it also refers to 314.17(B) noting that since it is impossible to secure the NM at the box if it is enclosed in EMT, therefore such an installation is not code-compliant. I guess I'm as guilty as anyone, having done the same thing many times.
Earlier in the article it also refers to 314.17(B) noting that since it is impossible to secure the NM at the box if it is enclosed in EMT, therefore such an installation is not code-compliant. I guess I'm as guilty as anyone, having done the same thing many times.
- Location
- Massachusetts
Re: NM in EMT
Just got my Mike Holt newsletter and it looks like NM will be allowed in EMT for 2005.
It is not a done deal, it can still change, but I can not imagine the argument to keep it prohibited.
Newsletter
[ February 17, 2004, 08:48 PM: Message edited by: iwire ]
Just got my Mike Holt newsletter and it looks like NM will be allowed in EMT for 2005.
It is not a done deal, it can still change, but I can not imagine the argument to keep it prohibited.
Newsletter
[ February 17, 2004, 08:48 PM: Message edited by: iwire ]
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
Re: NM in EMT
...Earlier in the article it also refers to 314.17(B) noting that since it is impossible to secure the NM at the box if it is enclosed in EMT,
Normally the EMT "sleeve" ends just before the box and the cable is secured with a suitable connector. This does present the problem of grounding the EMT. Perhaps this is the concern for extended runs?
...Earlier in the article it also refers to 314.17(B) noting that since it is impossible to secure the NM at the box if it is enclosed in EMT,
Normally the EMT "sleeve" ends just before the box and the cable is secured with a suitable connector. This does present the problem of grounding the EMT. Perhaps this is the concern for extended runs?
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: NM in EMT
One of the guys on the CMP of the "cable wiring methods" articles is on the IAEI board with me. He has also confirmed this.
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