Electrical Forum - NM, NMC, NMS Art 334

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Subject - NM, NMC, NMS Art 334
YukonRay	Where in the code Art 334 does it state that Romex is not allowed to be installed in buildings above 3 stories above grade? The 2002 edition calls out types of construction where NM cable is allowed, but who knows what they are. It even directs your inquiries to appenix E for further clarification of building ratings. But It is not clear to me. What can you tell me? Thanks PS. I am a newbe so be patient if this topic is covered in an active post.
Ryan_J	It doesn't. You can use it in higfh rise if the type of construction allows it. Doing the math based on type of construction, you will not be able to use it over 5 stories, and that would take some unusual circumstances.
Electricman	Previous codes including 99 prohibited the use of NM cables above 3 stories 336-5 99 code, but this has been changed in the 2002 code so now it depends upon the type of construction.
Electricmanscott	The good news, no three floor limitaion. The bad news no use in dropped ceilings. More good news, or bad depending if you are the consumer or the manufacturer, you can buy mc cable or conduit! Sure it will run you far more in material and installation costs but think of how much safer you will be! Got to love special interest lobbyists.
YukonRay	Gentlemen, Thanks for the information. The part about this subject that makes it interesting, is this information is not known by qualified and licsensed EE. I asked an associated of mine (who, by the way refered me to this forum) and he said - "no matter if you can find it in there or not, you cannot install romex in structures over three stories above grade." Another interesing sideline; There are other articles in Chapter 3 of the code that clearly state the product is not to be installed in structures that exceed 3 stories above grade. Why does the code not use similar buiding types to limit its use? Why not refer to the same appendix? Anyway, thanks again for the clarification. Yukon
Ryan_J	quote: Originally posted by YukonRay Another interesing sideline; There are other articles in Chapter 3 of the code that clearly state the product is not to be installed in structures that exceed 3 stories above grade. Why does the code not use similar buiding types to limit its use? Why not refer to the same appendix? Where?
YukonRay	Article 362 Art 362 ENT ": (1) In any building not exceeding three floors above grade." The article then goes on to describe the permissions and restrictions for the three floor qualification. The question really is, why use structures to define the acceptance of NM and not use the same type of qualifiers to describe the use and restrictions on ENT?
Ryan_J	I didn't realize you had shifted gears to ENT. I would assume you could use ENT because it is a raceway. Notice also that there must be a full-blown NFPA 13 fire sprinkler system installed.
YukonRay	Sorry Ryan, I just reread my text and it seemed like I was still refering to Romex. I am just wondering why the NEC has changed the refernce for building type for some items and not others. I guess I am just looking for logic in the code - :-)