NM buried in chase in gypcrete floor

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Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I ran across a piece of Romex installed in a shallow chase of a gypcrete floor on the second story.
With this even covered with a steel plate I think it is not legit.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
(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)

this is a concealed and normally dry chase.

334.10(3) has some restrictions that might apply.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
this is a concealed and normally dry chase.

334.10(3) has some restrictions that might apply.

that is only part of the codes.
Sec 334.12 uses not permited.
(B) Types NM and NMS.​
Types NM and NMS cables
shall not be used under the following conditions or in the
following locations:
(1) Where exposed to corrosive fumes or vapors
(2) Where embedded in masonry, concrete, adobe,
fill, or plaster
(3) In a shallow chase in masonry, concrete, or adobeand covered with plaster, adobe, or similar finish
(4) In wet or damp locations


So if the cable is left exposed and a metal plate is placed along the entire run this is OK. Is a metal plate good for the 15 min. fire rating needing?


 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer


that is only part of the codes.
Sec 334.12 uses not permited.
(B) Types NM and NMS.​
Types NM and NMS cables
shall not be used under the following conditions or in the
following locations:
(1) Where exposed to corrosive fumes or vapors
(2) Where embedded in masonry, concrete, adobe,
fill, or plaster
(3) In a shallow chase in masonry, concrete, or adobeand covered with plaster, adobe, or similar finish
(4) In wet or damp locations


So if the cable is left exposed and a metal plate is placed along the entire run this is OK. Is a metal plate good for the 15 min. fire rating needing?


it is not embedded nor is it covered with one of the banned finishes.

I don't see how a metal plate can't meet the 15 minute fire rating.
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
I ran across a piece of Romex installed in a shallow chase of a gypcrete floor on the second story.
With this even covered with a steel plate I think it is not legit.
Firstly, it is Nonmetallic-Sheathed Cable or Type NM and give a look at 334.12(B)(3) and tell me if you think what you did is compliant?
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
Replace it with Type UF-B Cable and install it under 340.10(4) and then protect it in accordance with 334.15(B) as you would Type NMC.

FYI- We don't even make Type NMC simply because we make Type UF.....
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Firstly, it is Nonmetallic-Sheathed Cable or Type NM and give a look at 334.12(B)(3) and tell me if you think what you did is compliant?

I have not done this work. It was something I observed.
I had thought it was not compliant.
I see now that if the groove is not filled and a proper thickness metal plate covers it then it is ok.
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
I have not done this work. It was something I observed.
I had thought it was not compliant.
I see now that if the groove is not filled and a proper thickness metal plate covers it then it is ok.
I am with ya brother...I was speaking in general terms of what I believe should have been done...No Worries
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
How does 334.15 work into the picture?

Because in my response the use of UF is permitted per 340.10(4) and then it also states that the UF has to be installed in accordance with Art. 334 Part II and III. Is 334.15 not included in Part II of Article 334?

You are using it in the same respect as Type NMC...are you not?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Because in my response the use of UF is permitted per 340.10(4) and then it also states that the UF has to be installed in accordance with Art. 334 Part II and III. Is 334.15 not included in Part II of Article 334?

You are using it in the same respect as Type NMC...are you not?

It appears to me that 334.15 only applies to exposed work, whether it is UF or NM, is not material.
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
I thought you said it was not NMC cable.
No but it is UF being used as Nonmetallic-Sheathed Cable and in doing so has to meet the requirements of part II and III of Article 334. So normal Type NM cant't be installed in shallow grooves of this material [which I will assume is like concrete or masonry as expressed in 334.12(B)(3)]. ...since 340.12(10) also has the same concerns about being subject to physical damage, and the original question depicts the use of what I would consider the installation as depicted in 334.15(B) in the last paragraph...it would stand to reason it is being used as NM cable, as per 340.10(4) then it has to also be a type of NM Cable that can be in the very installation in question...which is Type NMC.
Dude....just say we agree to disagree.....im sticking with my position...:angel:..lol
 
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