Romex in commercial and/or a firehouse application

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wrobotronic

wrobotronic

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Colorado
Hi All,
As an electrician I was "taught" Romex is not to be used in a commercial application. However, as an inspector, a green one mind you, I cannot find in the code where this is prohibited.

I have a project at a firehouse remodel and the EC has used some 12/4 #12 Romex in a common area for switching some fancy LEDs the customer requested. I asked him why he used Romex and not MC as he did throughout the rest of the remodel. The price was twice the cost.

While my gut tells me this is wrong to use Romex, I simply cannot find a code section to cite. Am I wrong in my assessment and Romex is actually allowed in a firehouse and/or commercial projects?

Thank you as always....
 
It has more to do with the type of building structure rather than the old thinking of Commercial vs. Residential.


JAP>
 
wrobotronic said:
Hi All,
As an electrician I was "taught" Romex is not to be used in a commercial application. However, as an inspector, a green one mind you, I cannot find in the code where this is prohibited.

I have a project at a firehouse remodel and the EC has used some 12/4 #12 Romex in a common area for switching some fancy LEDs the customer requested. I asked him why he used Romex and not MC as he did throughout the rest of the remodel. The price was twice the cost.

While my gut tells me this is wrong to use Romex, I simply cannot find a code section to cite. Am I wrong in my assessment and Romex is actually allowed in a firehouse and/or commercial projects?

Thank you as always....
Click to expand...

Look at 334.10 and 334.12 (2014). If you have Type III, IV, or V construction you're OK as long as you meet the requirements. I'm guessing that the usual tripping point is under 334.12(A)(2) where it's forbidden in drop ceilings except for one- and two- and multifamily dwellings.
 
wrobotronic said:
Hi All,
As an electrician I was "taught" Romex is not to be used in a commercial application. However, as an inspector, a green one mind you, I cannot find in the code where this is prohibited.

I have a project at a firehouse remodel and the EC has used some 12/4 #12 Romex in a common area for switching some fancy LEDs the customer requested. I asked him why he used Romex and not MC as he did throughout the rest of the remodel. The price was twice the cost.

While my gut tells me this is wrong to use Romex, I simply cannot find a code section to cite. Am I wrong in my assessment and Romex is actually allowed in a firehouse and/or commercial projects?

Thank you as always....
Click to expand...

Ive seen many a new 3 and 4 story hotels wired with NM, as late as 2010. I *thought* there used to be a code that prohibited it in commercial buildings over 4 floors and/or did not have a sprinkler and FA system,but that may go to the type construction mentioned in post #2. There is no article that blanket prohibits NM in most commercial applications.
 
dionysius said:
Let us think about this logically. There is NO good technical reason to outlaw it.
Click to expand...
I thought the reasoning was to reduce smoke loading in a fire? That said, unless there are tight restrictions on many other building materials, I agree, Romex would be a very small part of the problem.
 
JFletcher said:
Ive seen many a new 3 and 4 story hotels wired with NM, as late as 2010. I *thought* there used to be a code that prohibited it in commercial buildings over 4 floors and/or did not have a sprinkler and FA system,but that may go to the type construction mentioned in post #2. There is no article that blanket prohibits NM in most commercial applications.
Click to expand...

That code for over three floors went away I'm thinking 2 code cycles ago


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gadfly56 said:
Look at 334.10 and 334.12 (2014). If you have Type III, IV, or V construction you're OK as long as you meet the requirements. I'm guessing that the usual tripping point is under 334.12(A)(2) where it's forbidden in drop ceilings except for one- and two- and multifamily dwellings.
Click to expand...

This is the correct answer. I'm an AHJ in Oregon and this is how it's done.


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big john said:
I thought the reasoning was to reduce smoke loading in a fire? That said, unless there are tight restrictions on many other building materials, I agree, Romex would be a very small part of the problem.
Click to expand...

Comm cables have ratings from CMX (residential grade) to CMR (riser) and CMP (plenum). The last two are all we used to stock for commercial even tho only about half the jobs involved riser installs; accidentally installing CM rated cable that penetrates more than one floor would be a costly mistake. None of the ratings on that are for smoke load but smoke type (CMP -less toxic than PVC, thus permitted in air returns/plenums) and burn characteristics (the rest).
 
Like others said, it is completely dependent on the structure type. As an example, 10 years ago we designed two different suite style college dormitories for a building developer. For one project, the structure was wood, and therefore, we were allowed to use NM cable. For the second project, the structure was concrete. Code research indicated that we had to design around MC cable, even though it was a residential project.

I believe it really has to do with fire spread. If the structure is wood, installing plastic sheathed cable like NM cable isn't going to matter that much in a fire, as the wood is going to cause the fire to spread through the building rather quickly, and thus, adding plastic cabling into the mix isn't going to cause the fire to spread any faster. If the structure is steel or concrete, the structure itself is not going burn as fast as a wood structure obviously. If you install plastic cable then it can cause the fire to spread rather quickly relative to the structure, and thus compromise one of the reasons for the non flammable structure, which is to reduce fire spread so that the occupants have enough time to get out of the building.
 
ElectricPersonality said:
I believe it really has to do with fire spread. If the structure is wood, installing plastic sheathed cable like NM cable isn't going to matter that much in a fire, as the wood is going to cause the fire to spread through the building rather quickly, and thus, adding plastic cabling into the mix isn't going to cause the fire to spread any faster. If the structure is steel or concrete, the structure itself is not going burn as fast as a wood structure obviously. If you install plastic cable then it can cause the fire to spread rather quickly relative to the structure, and thus compromise one of the reasons for the non flammable structure, which is to reduce fire spread so that the occupants have enough time to get out of the building.
Click to expand...

This just does not satisfy my logic. I applaud your reasoning but if this is the correct explanation there is some flawed thinking in the code creation folks. No offence meant. I would like to hear other thoughts.
 
dionysius said:
This just does not satisfy my logic. I applaud your reasoning but if this is the correct explanation there is some flawed thinking in the code creation folks. No offence meant. I would like to hear other thoughts.
Click to expand...

Regardless of your personal thoughts it is about smoke loading.
 
ElectricPersonality said:
Like others said, it is completely dependent on the structure type. As an example, 10 years ago we designed two different suite style college dormitories for a building developer. For one project, the structure was wood, and therefore, we were allowed to use NM cable. For the second project, the structure was concrete. Code research indicated that we had to design around MC cable, even though it was a residential project.
Click to expand...

Let me clear one thing up.

It has nothing to do with what the structure is built out of and everything to do with what the structure could be built out of.

In other words you can run NM in a streel and concrete structure if the buiding code would have allowed wood construction.
 
ElectricPersonality said:
Like others said, it is completely dependent on the structure type. As an example, 10 years ago we designed two different suite style college dormitories for a building developer. For one project, the structure was wood, and therefore, we were allowed to use NM cable. For the second project, the structure was concrete. Code research indicated that we had to design around MC cable, even though it was a residential project.

I believe it really has to do with fire spread. If the structure is wood, installing plastic sheathed cable like NM cable isn't going to matter that much in a fire, as the wood is going to cause the fire to spread through the building rather quickly, and thus, adding plastic cabling into the mix isn't going to cause the fire to spread any faster. If the structure is steel or concrete, the structure itself is not going burn as fast as a wood structure obviously. If you install plastic cable then it can cause the fire to spread rather quickly relative to the structure, and thus compromise one of the reasons for the non flammable structure, which is to reduce fire spread so that the occupants have enough time to get out of the building.
Click to expand...
In both fire spread and smoke production, the amount of plastic materials used as wiring methods is extremely small when you compare it to the building finishes and furnishings. In my opinion, small enough in comparison, that it doesn't make any real difference.
 
don_resqcapt19 said:
In both fire spread and smoke production, the amount of plastic materials used as wiring methods is extremely small when you compare it to the building finishes and furnishings. In my opinion, small enough in comparison, that it doesn't make any real difference.
Click to expand...

I agree.
 
don_resqcapt19 said:
In both fire spread and smoke production, the amount of plastic materials used as wiring methods is extremely small when you compare it to the building finishes and furnishings. In my opinion, small enough in comparison, that it doesn't make any real difference.
Click to expand...

If this were true then the chapter 7 and 8 articles (xx0.25) would not require removal of abandoned wiring
 
For clarification on nomenclature, there is fireload and then there's flamespread & smoke development (ASTM E84).

Fireload is calculated to determine how much water is needed to put a fire out. The basis of the process is the crib test.

The flamespread & smoke development ratings have to do with interior finishes (Class A, B, C) and plenums where you don't want burning materials to accelerate fire or produce excess levels of products of combustion.

As to why sheathed NM cable is restricted to more stringent construction types, it's my opinion it has to do with flamespread & smoke development and less to do with fireload. When NM is barred from the project, wires are in EMT and FMC which will somewhat contain both flame & smoke and discharge smoke at the raceway terminations where it will be seen instead of being retained in a building cavity where it could accelerate undetected.

Although the principle occupancy classification of a fire station is Group B (Business) if I were fire chief I would not want NM used in the fire station. OP may want to read job specs and/ or consult with the customer even if code does allow NM. Accessory occupancy classifications in a fire station can include Group S (Storage) for the apparatus bay, Group R (Residential) for sleeping rooms and Group A (Assembly) for meeting rooms > 750sf.

As ironic as it is, fire stations actually do have lots of fires. You have guys cooking en masse and they're not cooks. You also have them doing that when they run out the door on a hot call and forget to turn off the kitchen appliances. I've known of several. They are always embarrassed!
 
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