Chapter 3 Wiring Methods and Materials

324.60 ARTICLE 326 - INTEGRATED GAS SPACER CABLE: lYPE lOS
conductors, and for electrically connecting the assembly to the
metal cable shields and to equipment grounding conductors.
324.60 Grounding. All metal shields, boxes, receptacle
housings, and self-contained devices shall be electrically
continuous to the equipment grounding conductor of the
supplying branch circuit. All such electrical connections
shall be made with connectors identified for this use. The
electrical resistivity of such shield system shall not be more
than that of one conductor of the 'Jype FCC cable used in
the installation.
DI. Construction
324.100 Construction.
(A) Type FCC Cable. Type FCC cable shall be listed for
use with the FCC system and shall consist of three, four, or
five flat copper conductors, one of which shall be an equipment
grounding conductor.
(B) Shields.
(1) Materials and Dimensions. All top and bottom shields
shall be of designs and materials identified for their use.
Top shields shall be metal. Both metallic and nonmetallic
materials shall be permitted for bottom shields.
(2) Resistivity. Metal shields shall have cross-sectional areas
that provide for electrical resistivity of not more than
that of one conductor of the Type FCC cable used in the
installation.
324.101 Corrosion Resistance. Metal components of the
system shall be either corrosion resistant, coated with
corrosion-resistant materials, or insulated from contact with
corrosive substances.
324.112 Insulation. The insulating material of the cable
shall be moisture resistant and flame retardant. All insulating
materials in the FCC systems shall be identified for
their use.
324.120 Markings.
(A) Cable Marking. Type FCC cable shall be clearly and
durably marked on both sides at intervals of not more than
610 mm (24 in.) with the information required by
310.11 (A) and with the following additional information:
(1) Material of conductors
(2) Maximum temperature rating
(3) Ampacity
(B) Conductor Identification. Conductors shall be clearly
and durably identified on both sides throughout their length
as specified in 310.12.
I. General
326.1 Scope. This article covers the use, installation, and
construction specifications for integrated gas spacer cable,
Type IGS.
326.2 Definition.
Integrated Gas Spacer Cable, Type IGS. A factory assembly
of one or more conductors, each individually insulated and
enclosed in a loose fit, nonmetallic flexible conduit as an integrated
gas spacer cable rated 0 through 600 volts.
II. Installation
326.10 Uses Permitted. Type IGS cable shall be permitted
for use under ground, including direct burial in the earth, as
the following:
(1) Service-entrance conductors
(2) Feeder or branch-circuit conductors
326.12 Uses Not Permitted. Type IGS cable shall not be
used as interior wiring or be exposed in contact with buildings.
326.24 Bending Radius. Where the coilable nonmetallic
conduit and cable is bent for installation purposes or is
flexed or bent during shipment or installation, the radii of
bends measured to the inside of the bend shall not be less
than specified in Table 326.24.
Table 326.24 Minimum Radii of Bends
Conduit Size
Minimum Radii
Metric Designator Trade Size mm in.
53 2 600 24
78 3 900 35
103 4 1150 45
326.26 Bends. A run of Type IGS cable between pull
boxes or terminations shall not contain more than the
equivalent of four quarter bends (360 degrees total), including
those bends located immediately at the pull box or
terminations.
326.40 Fittings. Terminations and splices for Type IGS
cable shall be identified as a type that is suitable for maintaining
the gas pressure within the conduit. A valve and cap
shall be provided for each length of the cable and conduit
to check the gas pressure or to inject gas into the conduit.
70--180
NATIONAL ELECTRICAL CODE
2008 Edition