Metal Clad cable in a school

[dhalleron]

I don't do this full time so I am rusty on a lot of stuff.

A friend of mine asked me if I knew any reason not to use MC in an existing school for some new branch circuits. He does a lot of residential and says he is used to piping most commercial. I looked over NEC 2011 article 330 and didn't see any mention of building occupancy. Then I thought maybe a building code might limit its use but not sure where to look. I don't keep anything but Life Safety 101 on my shelf.

Sort of like I remember an article that allowed NM cable in a commercial building if it was not over 3 stories. An old boss of mine lost a bid years ago on an insurance company office building because he bid pipe and someone else bid romex. I don't remember where the rule is that allowed NM in commercial.

 

[kwired]

The place to look is 330.10 and 330.12 for MC cable and 334.10 and 334.12 for NM cable.

Then you need to check if there are local amendments as many places seem to like to add a little extra or even take away from the section on NM especially.

As NEC is written you could use NM in school building with limitations to just where you can use it. Gymnasiums, thearers, or other assembly areas it would not be allowed, many other areas it could be used if conditions of uses permitted are met.

 

[cdslotz]

By code MC would be allowed in a school, however, very few specs I've seen on schools allow MC except for fixture whips no longer than 6'.
Your friend didn't lose a bid if he bid it per specs, which was probably an all conduit spec. If some idiot bid it in romex and was awarded the job, he probably had to rip it all out, or give the owner the difference in money.
Your friend was the winner

 

[GBBOLT]

Specs

Specs

Definitely have your friend check the spec. If he is not bidding the job and is doing it as a service call or remodel, then he should refer to the code as mentioned and uses permitted as mentioned above. I agree that every school I have bid or done has been in conduit with the exception of fixture whips. If it is a service call, he may want to stick his head above the ceiling to see if there are any mc runs, but I'm sure he will find all conduit and that is what he should stick with.

 

[kwired]

By code MC would be allowed in a school, however, very few specs I've seen on schools allow MC except for fixture whips no longer than 6'.
Your friend didn't lose a bid if he bid it per specs, which was probably an all conduit spec. If some idiot bid it in romex and was awarded the job, he probably had to rip it all out, or give the owner the difference in money.
Your friend was the winner

Specifications are one thing NEC is another. You can install anything to NEC and not necessarily meet a designers specifications. Many times inspectors only inspect to codes and don't care what the designer has specified. And why should they? They are supposed to be code people. If designer doesn't like something that is otherwise compliant it is up to the designer to ensure it is done not an inspector that only cares about code.

 

[dhalleron]

Thanks guys.

This is 57 year old private school that just calls my friend for most of their work. There is no real spec on this small job. They call him, tell him what they want, he writes up a contract, pulls a permit and just does the work.

The guy that lost the bid was my former boss from back in the 80's. He somehow missed the part in the code or the specs that allowed romex in that insurance company. It ended up being wiring in romex to the best of my memory.

 

[Strathead]

Thanks guys.

TThe guy that lost the bid was my former boss from back in the 80's. He somehow missed the part in the code or the specs that allowed romex in that insurance company. It ended up being wiring in romex to the best of my memory.

Maybe, maybe not. While Romex is allowed in commercial construction, I rarely see it. First off, it is not allowed above an accoustical drop ceiling. Second, most Coomercial jobs have at least marginal specifications and are designed by an Electrical Engineer and usually they don't allow Romex. Third, I just don't like it and would not do it. When I do a design build for a small Commercial project, the people I work with know that I am not going to install romex, or residential pullout disconnects, or residential grade switches and receptacles. I am just arrogant that way.

 

[Strife]

I don't do this full time so I am rusty on a lot of stuff.

A friend of mine asked me if I knew any reason not to use MC in an existing school for some new branch circuits. He does a lot of residential and says he is used to piping most commercial. I looked over NEC 2011 article 330 and didn't see any mention of building occupancy. Then I thought maybe a building code might limit its use but not sure where to look. I don't keep anything but Life Safety 101 on my shelf.

Sort of like I remember an article that allowed NM cable in a commercial building if it was not over 3 stories. An old boss of mine lost a bid years ago on an insurance company office building because he bid pipe and someone else bid romex. I don't remember where the rule is that allowed NM in commercial.

The NEC doesn't prohibit the use of MC cable.
However the specs on schools (least down here in Broward and Palm Beach County), go WAYY WAYY beyond the NEC. No flex other than lights and equipment, and NOT longer than 6 feet. No more than 3 home runs in a conduit, steel fittings, stamped boxes(not welded), and many many more.