334-Nonmetallic-Sheathed Cable

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I. General

334.1 Scope. This article covers the use, installation, and construction specifications of nonmetallic-sheathed cable.

334.2 Definitions.

Nonmetallic-Sheathed Cable. A factory assembly of two or more insulated conductors enclosed within an overall nonmetallic jacket.

Type NM. Insulated conductors enclosed within an overall nonmetallic jacket.

Type NMC. Insulated conductors enclosed within an overall, corrosion resistant, nonmetallic jacket.

Type NMS. Insulated power or control conductors with signaling, data, and communications conductors within an overall nonmetallic jacket.

334.6 Listed. Type NM, Type NMC, and Type NMS

cables shall be listed.

II. Installation

334.10 Uses Permitted. Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following:

(1) One- and two-family dwellings.

(2) Multifamily dwellings permitted to be of Types HI, IV, and V construction except as prohibited in

334.12.

(3) Other structures permitted to be of Types III, IV, and V construction except as prohibited in 334.12. Cables shall be concealed within walls, floors, or ceilings that provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire-rated assemblies.

FPN No. 1: Types of building construction and occupancy classifications are defined in NFPA 220-2006, Standard on Types of Building Construction, or the applicable building code, or both.
FPN No. 2: See Annex E for determination of building types [NFPA 220, Table 3-1].
(4) Cable trays in structures permitted to be Types III, IV,
or V where the cables are identified for the use.
FPN: See 310.10 for temperature limitation of conductors.

(A) Type NM. Type NM cable shall be permitted as follows:

(1) For both exposed and concealed work in normally dry locations except as prohibited in 334.10(3)

(2) To be installed or fished in air voids in masonry block or tile walls

(B) Type NMC. Type NMC cable shall be permitted as follows:

(1) For both exposed and concealed work in dry, moist, damp, or corrosive locations, except as prohibited by 334.10(3)

(2) In outside and inside walls of masonry block or tile In a shallow chase in masonry, concrete, or adobe pro- tected against nails or screws by a steel plate at least

1.59 mm (!/i6 in.) thick and covered with plaster, adobe, or similar finish

(C) Type NMS. Type NMS cable shall be permitted as follows:

(1) For both exposed and concealed work in normally dry locations except as prohibited by 334.10(3)

(2) To be installed or fished in air voids in masonry block or tile walls

334.12 Uses Not Permitted.

(A) Tjpes NM, NMC, and NMS. Types NM, NMC, and

NMS cables shall not be permitted as follows:
(1) In any dwelling or structure not specifically permitted
in 334.10(1), (2), and (3)

Exception: Type NM, NMC, and NMS cable shall be per- mitted in Type I and II construction when installed within raceways permitted to be installed in Type I and II construction.

(2) Exposed in dropped or suspended ceilings in other than one- and two-family and multifamily dwellings

(3) As service-entrance cable

(4) In commercial garages having hazardous

(classified) locations as defined in 511.3

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