NM cable

Status
Not open for further replies.
G

guschash

Senior Member
Location
Ohio
Is nm cable permit in commercial buildings? I read through Annex E and 334 but am still not sure if NM can be used, say in small commercial building.
 
Around here the answer is no If the commercial building can handle 100 or more persons. See 518.1.
 
tortuga said:
Around here the answer is no If the commercial building can handle 100 or more persons. See 518.1.
Click to expand...
That would be really pushing the scope of Article 518 without a legally adopted amendment to the NEC.

The occupants of a commercial building are not gathered for the purposes of deliberation, worship, entertainment, eating, drinking, amusement, awaiting transportation, or similar purposes. I do not see shopping as a similar purpose to the listed purposes.
 
don_resqcapt19 said:
The occupants of a commercial building are not gathered for the purposes of deliberation, worship, entertainment, eating, drinking, amusement, awaiting transportation, or similar purposes.
Click to expand...

Not to be snarky but what do call buildings that serve the purposes of:
  • deliberation,
  • worship,
  • entertainment,
  • eating,
  • drinking,
  • amusement,
  • awaiting transportation,
  • or similar purposes
??
They certainly are not residential or industrial.
I am just pointing out people need to check 518 and what your future tenant is.
 
tortuga said:
Not to be snarky but what do call buildings that serve the purposes of:
  • deliberation,
  • worship,
  • entertainment,
  • eating,
  • drinking,
  • amusement,
  • awaiting transportation,
  • or similar purposes
??
They certainly are not residential or industrial.
I am just pointing out people need to check 518 and what your future tenant is.
Click to expand...
we call them assembly occupancies.

it is possible that what the OP is calling a commercial building is also an assembly occupancy. the terms are not mutually exclusive.
 
petersonra said:
we call them assembly occupancies.
Click to expand...
Ahh Ok makes sense, I lump them all into commercial, so i would not give NM a blanket yes without more info on what the space was.

Case in point I went out to a what was described as an commercial office to install a new AC disconnect, turns out it was a small medical clinic, and the HVAC guy ran 14-3 UF with his line sets for a ductless heatpump head into a patient care room.
 
tortuga said:
Ahh Ok makes sense, I lump them all into commercial, so i would not give NM a blanket yes without more info on what the space was.

Case in point I went out to a what was described as an commercial office to install a new AC disconnect, turns out it was a small medical clinic, and the HVAC guy ran 14-3 UF with his line sets for a ductless heatpump head into a patient care room.
Click to expand...
Reason 1001 why HVAC people should not touch electrical.
 
Commercial doesn't automatically mean 518 applies either.

You can have a building with spaces where 518 applies and other spaces where 518 doesn't apply.

A school for example may have classrooms that are too small for 100 persons, yet has an assembly hall that does.
 
kwired said:
A school for example
Click to expand...
Its been over a decade since I did any work on a school, everything had to be EMT back then other than 'where flexibility was required'
I think they way it went is schools here are their own Educational group 'E" occupancy and cannot be of one of the III,IV or V construction types where NM is allowed.
Might have changed now.
 
Last edited:
guschash said:
Is nm cable permit in commercial buildings? I read through Annex E and 334 but am still not sure if NM can be used, say in small commercial building.
Click to expand...
It all depends on the type of the building. NM can be used in Type III, IV and V but never above a hung ceiling in those buildings.

Part II. Installation
334.10 Uses Permitted. Type NM, Type NMC, and Type NMS
cables shall be permitted to be used in the following, except as
prohibited in 334.12:
(1) One- and two-family dwellings and their attached or
detached garages, and their storage buildings.
(2) Multi-family dwellings permitted to be of Types III, IV,
and V construction.
(3) Other structures permitted to be of Types III, IV, and V
construction. Cables shall be concealed within walls,
floors, or ceilings that provide a thermal barrier of material
that has at least a 15-minute finish rating as identified
in listings of fire-rated assemblies.
Click to expand...
 
tortuga said:
Its been over a decade since I did any work on a school, everything had to be EMT back then other than 'where flexibility was required'
I think they way it went is schools here are their own Educational group 'E" occupancy and cannot be of one of the III,IV or V construction types where NM is allowed.
Might have changed now.
Click to expand...
Can't recall ever running NM in a school myself, but at same time have known that only certain areas are 518 areas. NM would be allowed depending on construction type, still can possibly be locations if not covered with right finish still isn't allowed. Might be more likely with older buildings. If not an assembly PVC could still be allowed, it has some of the same limitations in 518 or in air handling spaces but otherwise not same general limitations.
 
Status
Not open for further replies.
Top