NM cable, uses permitted (334.10), commercial. Questions.

[sw_ross]

I'm trying to get a better understanding of when NM cable is allowed in a commercial application.

I'm not an expert at understanding Types III, IV, and V construction. I can't specifically look at a building and know whether a finished wall type has at least a 15-minute fire rating. Does a partition wall with 1/2" Sheetrock fall into this category?

Additionally, is NM cable allowed in an attic space, or crawlspace? It wouldn't be "concealed" if it's in a crawl space and visible would it?

I've looked at Annex E which describes the types of construction. If I walk into a commercial space that needs some circuits run/altered I'm trying to understand if NM cable is allowed...

Thanks for your input!

 

[Dennis Alwon]

The type of construction is probably defined in the building but I would contact the building inspector and have them classify the building for me.

 

[petersonra]

I'm trying to get a better understanding of when NM cable is allowed in a commercial application.

I'm not an expert at understanding Types III, IV, and V construction. I can't specifically look at a building and know whether a finished wall type has at least a 15-minute fire rating. Does a partition wall with 1/2" Sheetrock fall into this category?

Additionally, is NM cable allowed in an attic space, or crawlspace? It wouldn't be "concealed" if it's in a crawl space and visible would it?

I've looked at Annex E which describes the types of construction. If I walk into a commercial space that needs some circuits run/altered I'm trying to understand if NM cable is allowed...

Thanks for your input!

I might be mistaken about this so take with a grain a salt. it is not the type of construction that matters so much as whether the types of construction where NM is allowed would be allowed, even if that type of construction is not being used.

 

[GoldDigger]

I might be mistaken about this so take with a grain a salt. it is not the type of construction that matters so much as whether the types of construction where NM is allowed would be allowed, even if that type of construction is not being used.

Sent from my XT1585 using Tapatalk

 

[sw_ross]

The reason I'm asking about this (and trying to better understand the uses allowed) is that a customer has asked me to add/change/alter branch circuits in an older building that has always been used commercially. The customer is a new tenant for this space and is converting it to meet their needs.

The building was maybe constructed in the 70's to 80's. It appears that it was originally wired with NM cable. There's a crawlspace where you can see older NM cable along with newer looking NM cable. There's also a little bit of conduit in the crawlspace, but not very much.

When I look at the changes requested the crawlspace is going to be my best option. I'm just trying to understand what my options are in terms of NM cable vs MC cable vs EMT.

Thanks!