romex vs. conduit

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evileddy

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I believe the code says that if a building has an occupency of 100 or more it has to be wired in conduit and/or mc cable. Is this correct and if so how do I determine the occpency rating of the structure?
 
The occupancy rating, use and classification of a building are all determined and regulated by the building code in effect within the jurisdiction you're working in. Also, if it's a Place of Assembly as classified by Article 518.2 in the NEC, then the wiring methods are determined by 518.4. :smile:
 
The occupancy does not affect the wiring method in the NEC that I remember, the construction type does.(type I-IV) 334.10.
The oppupancy would be figured by building code and or fire marshal.
 
Legal Romex

Legal Romex

I went into a shopping/Business center recently to do a pool hall. All existing wire was romex. Work was only about ten years old. Glad I called AHJ before starting. They said no to romex, yes to MC and/or pipe.
 
ashtrak said:
They said no to romex, yes to MC and/or pipe.
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Did they give an actual code to back this up, or just a generic "no romex allowed" answer?

As the others have said, Romex may be allowed depending on the building type. It is restricted from installation above suspended ceilings, but it can still be used inside wall and above hard ceilings.

If the pool hall is indeed classified as a place of assembly, then no NM cable would be allowed, even in the walls. But just because 100 or more people are in a building at once does not qualify it as a place of assembly.
 
peter d said:
just because 100 or more people are in a building at once does not qualify it as a place of assembly.
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I agree and that is an important point.

In addition parts of a building may be a place of assembly while other parts of the same building are not.
 
quogueelectric said:
I was taught occupancy of 50 or more almost 20 yrs ago I have no reference tho
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Your in New York, there is apparently a change from 100 down to 50. Pierre has mentioned this a couple of times. :)
 
Keep in mind that the requirement that a place of assembly as defined in the NEC must be wired by certain wiring methods only applies if the building is constructed of fire resistant construction. (off the top of my head) For example a wood framed restaurant can be wired in romex. I'm generalizing, but just trying to give some insight.

Also, some of the confusion of the 50 vs. 100 occupancy limit may stem from the building code. In MA, an assembly use group with a capacity of 50 or more is classified as an A3 use group, and it falls into a certain set of regulations.
 
j_erickson said:
Keep in mind that the requirement that a place of assembly as defined in the NEC must be wired by certain wiring methods only applies if the building is constructed of fire resistant construction. (off the top of my head) For example a wood framed restaurant can be wired in romex. I'm generalizing, but just trying to give some insight.
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That wouldn't fly where I work, mc or conduit for a resturant holding 100 seats, regardless of building construction type.
 
macmikeman said:
That wouldn't fly where I work, mc or conduit for a resturant holding 100 seats, regardless of building construction type.
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Is that their interpretation, or do they modify the NEC?
 
iwire said:
Your in New York, there is apparently a change from 100 down to 50. Pierre has mentioned this a couple of times. :)
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Just generally speaking, and this area can be quite confusing, a building or tenant space used for assembly purposes by less than 50 persons is considered a Group B occupancy. Our (NY State) Group B occupancies are (B)usiness occupancies like banks, educational occupancies above 12th grade, post offices, radio stations, etc.
Section 303 of our building code has the details.:smile:
 
ashtrak said:
I went into a shopping/Business center recently to do a pool hall. All existing wire was romex. Work was only about ten years old. Glad I called AHJ before starting. They said no to romex, yes to MC and/or pipe.
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Pool and billiard halls are regulated as Assembly Uses in NY. As such, they're subject to Article 518 for wiring methods. :smile:
 
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