I just finished looking at a wiring job on one of our new buildings. It is a steel building and it will have a suspended ceiling. I remember well Mike Holt's recent Newsletter about the fact that open runs of NM cable is not allowed in that area. Article 334.12. On this building, however, the contractor has routed the nm cable on the top of the partitions. I would assume that it would be permissible to do this as the NM cable is then in the area but it is "not" an open run in the suspended ceiling area?
NM Cable in suspended ceilings
- Thread starter dan316
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hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Re: NM Cable in suspended ceilings
Unless the ceiling grid and tiles are run uninterrupted over the top of the partitions with the NM below I can't see how this would be legal. Just because the NM runs on top of the partition does not mean it is not in the plenum or ceiling space.
Unless the ceiling grid and tiles are run uninterrupted over the top of the partitions with the NM below I can't see how this would be legal. Just because the NM runs on top of the partition does not mean it is not in the plenum or ceiling space.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: NM Cable in suspended ceilings
I think the term "open run" refers to it not being encased (open as opposed to concealed). I would red-tag this installation.
Just my opinion though
I think the term "open run" refers to it not being encased (open as opposed to concealed). I would red-tag this installation.
Just my opinion though
Re: NM Cable in suspended ceilings
Just my Opinion,
But if the NM cable runs or passes over the ceiling grid area. I would also Red Tag it unless it is a Dwelling unit.
And also note. Art.334.10(3) it must also be concealed within walls ,ceilings or floors that have at least a 15 min finish rating.
Just my Opinion,
But if the NM cable runs or passes over the ceiling grid area. I would also Red Tag it unless it is a Dwelling unit.
And also note. Art.334.10(3) it must also be concealed within walls ,ceilings or floors that have at least a 15 min finish rating.
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: NM Cable in suspended ceilings
Seems like the code is pretty explicit here."Open runs" are prohibited. Open to me means not enclosed.
Seems like the code is pretty explicit here."Open runs" are prohibited. Open to me means not enclosed.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: NM Cable in suspended ceilings
I'm assuming it to be in an "other than dwelling unit". With that in mind, and for reasons already discussed, I think 334.12 (A)(1) applies.
You disagree, Roger?
I'm assuming it to be in an "other than dwelling unit". With that in mind, and for reasons already discussed, I think 334.12 (A)(1) applies.
You disagree, Roger?
Re: NM Cable in suspended ceilings
Hey Ryan, I worded my post poorly. I'm not contesting that 334.12 prohibits it, I'm looking for oppinions as to why the NEC prohibits it.
If properly supported what is the danger? I think it was a trade off to the metalic cable and conduit manufacturers when the three story limit went out the window.
Roger
Hey Ryan, I worded my post poorly. I'm not contesting that 334.12 prohibits it, I'm looking for oppinions as to why the NEC prohibits it.
If properly supported what is the danger? I think it was a trade off to the metalic cable and conduit manufacturers when the three story limit went out the window.
Roger
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: NM Cable in suspended ceilings
When I read the ROP's that was exactly what it looked like to me... :roll:
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: NM Cable in suspended ceilings
Just my opinion;
Maybe it has to do with the smoke producing characteristics of the jacket and adds to the fire load?
Just my opinion;
Maybe it has to do with the smoke producing characteristics of the jacket and adds to the fire load?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: NM Cable in suspended ceilings
I guess that persons in a commercial building are more important than persons in a dwelling. or they can't handle the smoke that the romex would give off in a fire, and the people in the house can?
Ok Ok just trying to be funny But I do agree with Roger as I remember this point comming up in the old forum. and I think it was a trade off with the removal of the 3 floors rule.
But why couldn't somone put 5/8" sheetrock on top and sides of it and be done with it? it would now be part of the wall and inside of it.
I guess that persons in a commercial building are more important than persons in a dwelling. or they can't handle the smoke that the romex would give off in a fire, and the people in the house can?
Ok Ok just trying to be funny But I do agree with Roger as I remember this point comming up in the old forum. and I think it was a trade off with the removal of the 3 floors rule.
But why couldn't somone put 5/8" sheetrock on top and sides of it and be done with it? it would now be part of the wall and inside of it.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: NM Cable in suspended ceilings
You could be right though. It would be interesting to see the conversations that take place in some of the CMP's. I think Charlie is lucky being involved with article 240...I don't think it would be as subject to outside influence as chapter 3 is.
I have a hard time buying that. Not when I see NM cable stapled next to a piece of WOOD!!
You could be right though. It would be interesting to see the conversations that take place in some of the CMP's. I think Charlie is lucky being involved with article 240...I don't think it would be as subject to outside influence as chapter 3 is.
Re: NM Cable in suspended ceilings
I thought this had something to do with the NEC not considering a grid ceiling to be permanent. (Thus if it were to be removed the NM would become exposed.) It was this same reason that we are no longer allowed to attache hardware to the grid.
I thought this had something to do with the NEC not considering a grid ceiling to be permanent. (Thus if it were to be removed the NM would become exposed.) It was this same reason that we are no longer allowed to attache hardware to the grid.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: NM Cable in suspended ceilings
Wolfman
The NEC allows N/M to be run exposed.
334.10 Uses Permitted.
(A) Type NM. Type NM cable shall be permitted as follows:
(1) For both exposed and concealed work in normally dry locations except as prohibited in 334.10(3).
We attach lay in's to the grid. I'm not sure what kind of hardware your refering too. But there are many types of clip's made to attach componits to the grid and I don't know of any code in the NEC that prevents it. It could be a local code in your area?
Wolfman
The NEC allows N/M to be run exposed.
334.10 Uses Permitted.
(A) Type NM. Type NM cable shall be permitted as follows:
(1) For both exposed and concealed work in normally dry locations except as prohibited in 334.10(3).
We attach lay in's to the grid. I'm not sure what kind of hardware your refering too. But there are many types of clip's made to attach componits to the grid and I don't know of any code in the NEC that prevents it. It could be a local code in your area?
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