Romex in a class 3 facility.

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kda3310

kda3310

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Dry Prong, Louisiana
I work in a class 3 industrial wood facility. We use rigid for everything. However, there is a part of our facility that are offices that is under the same roof as the factory. EMT is the majority of what is used here in these offices. There is some romex that has been ran in these offices. At what point is romex not allowed. I was told that romex is not allowed in commercial facilities. Later I found out that that was the local code I learned Dallas not the National Electric Code. Here in Louisiana we have no local code to address this in the rural area that I am in. I told my boss I don't think the use of romex in this facility is right. He wants me to show where it is against the code. I can show where romex/NM is not allowed to be used in a class 3 facility but is the offices considered class 3. How do I differ.
 
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kda3310 said:
I work in a class 3 industrial wood facility. We use rigid for everything. However, there is a part of our facility that are offices that is under the same roof as the factory. EMT is the majority of what is used here in these offices. There is some romex that has been ran in these offices. At what point is romex not allowed. I was told that romex is not allowed in commercial facilities. Later I found out that that was the local code I learned Dallas not the National Electric Code. Here in Louisiana we have no local code to address this in the rural area that I am in. I told my boss I don't think the use of romex in this facility is right. He wants me to show where it is against the code. I can show where romance is not allowed to be used in a class 3 facility but is the offices considered class 3. How do I differ.
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What is a 'class 3 facility'?
 
Areicle 500.5 D
(D) Class III Locations. Class III locations are those that
are hazardous because of the presence of easily ignitible
fibers or materials producing combustible flyings are
handled, manufactured, or used, but in which such
fibers/flyings are not likely to be in suspension in the air in
quantities sufficient to produce ignitible mixtures. Class III
locations shall include those specified in 500.5(D)(1) and
(D)(2).
 
kda3310 said:
I work in a class 3 industrial wood facility. We use rigid for everything. However, there is a part of our facility that are offices that is under the same roof as the factory. EMT is the majority of what is used here in these offices. There is some romex that has been ran in these offices. At what point is romex not allowed. I was told that romex is not allowed in commercial facilities. Later I found out that that was the local code I learned Dallas not the National Electric Code. Here in Louisiana we have no local code to address this in the rural area that I am in. I told my boss I don't think the use of romex in this facility is right. He wants me to show where it is against the code. I can show where romex/NM is not allowed to be used in a class 3 facility but is the offices considered class 3. How do I differ.
Click to expand...

It is highly unlikely/improbable that the office areas are Class III areas, use of romex/NM in these areas would depend on the type of construction and local laws.

Engineers usually define the classification of areas.

Annex E in the NEC shows the various types of construction and 334.10 lists the use of romex/NM in the various types.
 
jumper said:
It is highly unlikely/improbable that the office areas are Class III areas, use of romex/NM in these areas would depend on the type of construction and local laws.

Engineers usually define the classification of areas.

Annex E in the NEC shows the various types of construction and 334.10 lists the use of romex/NM in the various types.
Click to expand...

Yes, I think you are right. There are no combustible fibers in these offices coming from the plant. So, they would not be considered a class 3.

I have always thought it was against the code to run non-metallic cable in a commercial building. But, from what I can tell you are not allowed to run non-metallic cable behind a dropped tile ceiling or an exposed rafter ceiling. I have not worked in a commercial building that does not have tiles or an open ceiling. That is why we have never used non-metallic cable in a commercial building. These offices I am talking about use dropped tile ceiling grid. So, if I understand this right there should not be exposed Romex / non-metallic cable above it.
 
kda3310 said:
Yes, I think you are right. There are no combustible fibers in these offices coming from the plant. So, they would not be considered a class 3.

I have always thought it was against the code to run non-metallic cable in a commercial building. But, from what I can tell you are not allowed to run non-metallic cable behind a dropped tile ceiling or an exposed rafter ceiling. I have not worked in a commercial building that does not have tiles or an open ceiling. That is why we have never used non-metallic cable in a commercial building. These offices I am talking about use dropped tile ceiling grid. So, if I understand this right there should not be exposed Romex / non-metallic cable above it.
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It used to be legal to run romex/NM above a dropped tile ceiling in commercial construction, not anymore.
 
Whether or not NM can be used in general in a building depends on what level of fireproofing the construction of the building is required to use.
For example, if the occupancy of the building requires it to be concrete and steel construction then you are not allowed to run NM.

Arguably (and it has been argued both ways here) if a building's occupancy type would be allowed to be in a wood frame building then NM would be OK even if the building happened to be concrete and steel instead.
 
jumper said:
It is highly unlikely/improbable that the office areas are Class III areas, use of romex/NM in these areas would depend on the type of construction and local laws.

Engineers usually define the classification of areas.

Annex E in the NEC shows the various types of construction and 334.10 lists the use of romex/NM in the various types.
Click to expand...
If it's primarily a milling operation, I doubt it's Class III at all. NEC Zone classification doesn't even recognize what would be Class III except as a (very) limited subset of dusts. IEC Zones doesn't recognize it at all. The concernn is a flash fire rather than an explosion.

That doesn't mean that caution can be thrown to the wind, but good housekeeping is about all that's necessary.
 
GoldDigger said:
Whether or not NM can be used in general in a building depends on what level of fireproofing the construction of the building is required to use.
For example, if the occupancy of the building requires it to be concrete and steel construction then you are not allowed to run NM.

Arguably (and it has been argued both ways here) if a building's occupancy type would be allowed to be in a wood frame building then NM would be OK even if the building happened to be concrete and steel instead.
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Our factory is a steel and concrete building. However, the offices that were built inside of it were built out of wood. I guess this was approved.
 
rbalex said:
If it's primarily a milling operation, I doubt it's Class III at all. NEC Zone classification doesn't even recognize what would be Class III except as a (very) limited subset of dusts. IEC Zones doesn't recognize it at all. The concernn is a flash fire rather than an explosion.

That doesn't mean that caution can be thrown to the wind, but good housekeeping is about all that's necessary.
Click to expand...

Yes, we make engineered wood products. There is a lot of sawing involved. Saw dust is everywhere and we are constantly cleaning the plant. We are required to hold to class 3 specifications. But, sawdust does not get into the offices so I can see how they are not considered a class 3 area.
 
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