Romex in commercial and/or a firehouse application

[don_resqcapt19]

Yes, cable is a small load compared to carpets, drapes and couches, but you dont have carpet, drapes, and couches in air return spaces.

http://www.ecmag.com/section/systems/dont-gamble-abandoned-cable

https://www.chemours.com/Cabling_Solutions/en_US/assets/downloads/buildings_article.pdf

http://www.abrconsulting.com/Standards/Toxics In Cable.htm

Wiring methods in return air have to meet strict rules....open cables are required to be "plenum rated". If fire and smoke were the real issues, you would not just require the removal of abandoned cables, you would not permit cable to be installed there in the first place.

These rules are just an extension of the ongoing fight between cable manufacturers and the metal conduit manufacturers.

 

[GoldDigger]

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.

:thumbsup::thumbsup:

I.E. the same conditions that require steel and concrete construction also require other than NM for wiring.

Not everyone agrees with this interpretation, although the wording seems clear to me.

 

[Carultch]

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.

Interesting distinction.

Looking at a finished building, how would an inspector or a contractor doing additions know that the steel and concrete is overkill, such that the building really could otherwise have been built out of wood and still meet code?

 

[iwire]

Interesting distinction.

Looking at a finished building, how would an inspector or a contractor doing additions know that the steel and concrete is overkill, such that the building really could otherwise have been built out of wood and still meet code?

I do not know, but here is an example you will see all over Mass.

Almost all stop and shops built in MA from the 1980s till early 2000 per building codes could have been built with wood. Stop & Shop chose to use steel to get the spans and deck strength for pallet jacks etc. They are wired with NM as are many similar retail stores.

 

[GoldDigger]

Interesting distinction.

Looking at a finished building, how would an inspector or a contractor doing additions know that the steel and concrete is overkill, such that the building really could otherwise have been built out of wood and still meet code?

The building documents should indicate the planned usage and that will determine the allowed construction. In some cases zoning will indicate, for example, single family residential.
Just looking at the building itself will not do the job unless the use/occupancy is clear at the time of inspection.
The FD inspection, if there is one, should also document that info.

 

[mgookin]

A full set of drawings to build a building typically includes a building code analysis on the cover page or very close to the cover page.
It's a matrix which indicates Required and Provided code provisions.
Part of that is a Table 500 analysis from the building code and that will include Construction Type.
If the required construction type allows NM, you're good to go as long as job specs don't dictate otherwise.