Products and the 2002 National Electrical Code Changes

362.10(2) Exception. (ENT). The 1999 NEC permits Electrical Nonmetallic Tubing
(ENT) to be used in buildings above three floors when concealed behind a 15 minute
finish rated thermal barrier. 1999 NEC Section 331-3(2)
The 2002 NEC will have an exception to this rule. The 2002 NEC will permit the
installation of ENT in buildings above three floors either EXPOSED or CONCEALED
(without a 15 minute finish rated thermal barrier) when a fire sprinkler system is installed
in accordance with NFPA 13,
Installation of Sprinkler Systems.
Section 362.10(2) of the 2002 NEC will read as follows:
362.10
(2) In any building exceeding three floors above grade, ENT shall be concealed
within walls, floors, and ceilings where the walls, floors, and ceilings provide a
thermal barrier of material that has at least a 15-minute finish rating as identified in
listings of fire-rated assemblies. The 15-minute finish rated thermal barrier shall be
permitted to be used for combustible or noncombustible walls, floors, and ceilings.
Exception: When a fire sprinkler system(s) is installed in accordance with NFPA 13,
Installation of Sprinkler Systems on all floors, ENT is permitted to be used within
walls, floors and ceilings exposed or concealed in buildings exceeding three floors
above grade.
FPN: A finish rating is established for assemblies containing combustible (wood)
supports. The finish rating is defined as the time at which the wood stud or wood joist
reaches an average temperature rise of 121ºC (250ºF) or an individual temperature of
163ºC (325ºF) as measured on the plane of the wood nearest the fire. A finish rating
is not intended to represent a rating for a membrane ceiling.
This exception will also be adopted for suspended ceilings, section 363.10(5) where
currently a 15 minute finish thermal barrier for the ceiling assembly is required. 1999
NEC Section 331-3(5)
One is hard pressed to find a building built today without a fire sprinkler system installed.
NFPA 13 is probably the most recognized system used by architects and approved by
building officials today. This exception will expand the use of ENT in buildings above
three floors by removing a restriction for the installation of the raceway.
Article 378
(1999 NEC Article 362 Part B)
Nonmetallic Wireways
Article 378 Nonmetallic Wireways. This article for Nonmetallic Wireway is now a stand
alone article. In the 1999 NEC this product was Part B of the Metal Wireway article.
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