NM Cable Requirements

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jimdavis

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salt lake city, UT USA
Does anyone know when 334.12(A)(2) first appeared? I looked at a small remodel job at a medical office today. The place is wired with NM cable. It's a multi-occupancy commercial building which I believe to be 15-20 years old.
 
another question on NM cable

another question on NM cable

I’mtrying to understand exactly where you can and can’t install NM cable in a churchesmulti-use building. Metal frame withwood framed Sunday school classes and offices, also the center was left openfor small gym type area, everything is single story. The question I have is the gym area, can itbe used in that area if not in conduit, looking at 334.10 it can be used butnot if it isn’t in walls, floors, or ceiling that provide a 15 min finishrating. Then there’s 334.15 (B) where cable shall be protected from physicaldamage, I don’t see how lighting wires bringing power to the lights would be indanger of physical damage
 
darren12 said:
I’mtrying to understand exactly where you can and can’t install NM cable in a churchesmulti-use building. Metal frame withwood framed Sunday school classes and offices, also the center was left openfor small gym type area, everything is single story. The question I have is the gym area, can itbe used in that area if not in conduit, looking at 334.10 it can be used butnot if it isn’t in walls, floors, or ceiling that provide a 15 min finishrating. Then there’s 334.15 (B) where cable shall be protected from physicaldamage, I don’t see how lighting wires bringing power to the lights would be indanger of physical damage
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Correct in that it must be within at least 15 min finish rating.

It is not specifically prohibited in churches or multi-use buildings, but if you have an occupancy of over 100, now you get into Article 518 and NM cable is not permitted in spaces covered by art 518.
 
kwired said:
Correct in that it must be within at least 15 min finish rating.

It is not specifically prohibited in churches or multi-use buildings, but if you have an occupancy of over 100, now you get into Article 518 and NM cable is not permitted in spaces covered by art 518.
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NM cable can be used in places of assembly where the building is of non-rated construction. See 518.4(B)
 
packersparky said:
NM cable can be used in places of assembly where the building is of non-rated construction. See 518.4(B)
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Not quite what it says.

"...shall be permitted to be installed in those buildings or portions thereof that are not required to be of fire-rated construction by the applicable building code."

In the place of assembly portions of the building the building code will require fire rated construction. You may run into old buildings that don't comply, then it is a judgement call if AHJ will allow something like NM cable for added wiring. Here they generally won't.

But you can have a room classified as place of assembly with fire rating construction around it and the adjacent room is non place of assembly. That adjacent room can possibly be wired in NM cable, it is not a place of assembly.

Example might be main church sanctuary - occupancy of over 100 - 518 applies to this room. Next to it is pastor's office, occupancy under 100 and has 1 hour rating between it and the sanctuary. 518 does not apply to this room. Penetrations in common wall could make for some complexities, but in general the office is not a 518 covered area.
 
kwired said:
Not quite what it says.

"...shall be permitted to be installed in those buildings or portions thereof that are not required to be of fire-rated construction by the applicable building code."

In the place of assembly portions of the building the building code will require fire rated construction. You may run into old buildings that don't comply, then it is a judgement call if AHJ will allow something like NM cable for added wiring. Here they generally won't.

But you can have a room classified as place of assembly with fire rating construction around it and the adjacent room is non place of assembly. That adjacent room can possibly be wired in NM cable, it is not a place of assembly.

Example might be main church sanctuary - occupancy of over 100 - 518 applies to this room. Next to it is pastor's office, occupancy under 100 and has 1 hour rating between it and the sanctuary. 518 does not apply to this room. Penetrations in common wall could make for some complexities, but in general the office is not a 518 covered area.
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In addition to the example you give, many of us would argue that even if the entire building uses high rated construction methods, the basic rules and the specific extension you refer to would still not prohibit use of NM in those non-assembly areas because they are not required to be of rated construction.
 
kwired said:
Not quite what it says.

"...shall be permitted to be installed in those buildings or portions thereof that are not required to be of fire-rated construction by the applicable building code."

In the place of assembly portions of the building the building code will require fire rated construction. You may run into old buildings that don't comply, then it is a judgement call if AHJ will allow something like NM cable for added wiring. Here they generally won't.

But you can have a room classified as place of assembly with fire rating construction around it and the adjacent room is non place of assembly. That adjacent room can possibly be wired in NM cable, it is not a place of assembly.

Example might be main church sanctuary - occupancy of over 100 - 518 applies to this room. Next to it is pastor's office, occupancy under 100 and has 1 hour rating between it and the sanctuary. 518 does not apply to this room. Penetrations in common wall could make for some complexities, but in general the office is not a 518 covered area.
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Many places of assembly are built with non-rated construction. The building code does not require all places of assembly to be built using rated construction. I also agree with GoldDiggers assessment.
 
Guess I’m not familiar with “rated” or “nonrated” construction. I seen construction type II-B/ II(000) on the permit for the building.
 
hbiss said:
You might also want to read Art. 517.13- the requirements for the wiring and receptacles in the exam/ patient care areas.

-Hal
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Yeah anything medical mostly has additional specs/plans that call for EMT, FMC (less than 6' runs) for new construction and or that special "Health Care Facility MC" for new or fished in spaces.
If the job does not come with plans (design/build) that I usually draw them up that way :D.
 
tortuga said:
Yeah anything medical mostly has additional specs/plans that call for EMT, FMC (less than 6' runs) for new construction and or that special "Health Care Facility MC" for new or fished in spaces.
If the job does not come with plans (design/build) that I usually draw them up that way :D.
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NM can't be used in patient care areas because it doesn't meet requirements in 517.13, not because of anything in 334
 
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