plenum wrapping Romex

Status
Not open for further replies.

bwyllie

Senior Member
Location
MA
On a project where Romex was used and then the mechanical engineer decided to use the ceiling space as a plenum. The contractor has proposed using a 3M-Fire Barrier Plenum wrap to wrap around the Romex to make it plenum rated. Is this against code? I can't seem to put my hand on the exact code article. Has anybody used this product?
 

earshavewalls

Senior Member
First, is this a suspended ceiling system? If so, romex is not allowed, period. Wrapping the romex would not change the burning characteristics, but if you enclose all romex in conduit, this would be the only code-compliant method for this condition as you have described it.
 

earshavewalls

Senior Member
Article 300.22 is pretty specific about what you can install in a plenum space, and I don't believe that the 3-M product is listed for this use.
What happened? Did the mechanical engineer make the change after the project was permitted? If there are other combustibles in the area used as a plenum (wood framing, etc.) this area would not be allowed to be used as such. If the area meets all requirements to be used as plenum space, then I see no alternative than to remove the romex, or install it in metal conduit approved for the space. Sounds like a huge extra no matter what.
 

cadpoint

Senior Member
Location
Durham, NC
try this

try this

look at 3M's home page

http://www.3m.com/

I think the product you looking for is 98040054953 (but I might be wrong)

I'm going to go on record as saying No;
Art 100 Conductor. Covered,
note the next listing - Conductor, Insultated.

I thing the real thing is it Identified (as applied to equipment).

Is it Labeled, is it Listed is it UL; Labeled , listed for electrical work,
I couldn't find it ...
 

peter d

Senior Member
Location
New England
earshavewalls said:
First, is this a suspended ceiling system? If so, romex is not allowed, period.

NM cable is permitted in Massachusetts above an suspended ceiling (the OP's location) as long as it closely follows the surface of the building. (Mass. ammendment)
 

iwire

Moderator
Staff member
Location
Massachusetts
If I was the EC in charge of the job this is where I would start.

bwyllie said:
the mechanical engineer decided to use the ceiling space as a plenum.

If this was in fact a change I would send an RFI asking what the GC expects the EC to do about this change.

The options I would present would be change to MC or EMT, I can not even imagine trying to wrap NM and leave a professional looking job assuming that would even be acceptable.
 

dnem

Senior Member
Location
Ohio
earshavewalls said:
First, is this a suspended ceiling system? If so, romex is not allowed, period. Wrapping the romex would not change the burning characteristics, but if you enclose all romex in conduit, this would be the only code-compliant method for this condition as you have described it.

It's going to be able to "breathe" in the conduit and shed some heat. . The wrap would trap the heat. . I imagine the wrap isn't cheap so maybe you're talking about short sections. . But if the sections are long, even if you find that 3M has convinced UL that it's OK, I still wouldn't do it. . If the decision isn't yours, see if they'll go for over-sizing the Romex or putting it on a smaller breaker size.

David
 

bwyllie

Senior Member
Location
MA
response from 3M

response from 3M

This is the response from 3M:

"In regards to being able to use the 3M Plenum wrap with your cables. The
cables will work with our wrap as long as they conform to UL 910 ratings.
(The cable manufacturer should be able to provide a data sheet on the cable
with the UL ratings that it conforms to."
 
Status
Not open for further replies.
Top