permitted to be installed under carpet.
(7) Industrial Establishments. In industrial establish- ments where the conditions of maintenance and supervision ensure that only qualified persons service the installation, and where the cable is not subject to physical damage, Type PLTC cable that complies with the crush and impact requirements of Type MC cable and is identified for such use shall be permitted to be exposed between the cable tray and the utilization equipment or device. The cable shall be continuously supported and protected against physical damage using mechanical protection such as dedicated struts, angles, or channels. The cable shall be supported and secured at intervals not exceeding 1.8 m (6 ft).
(F) Cross-Connect Arrays. Type CL2 or CL3 conductors or cables shall be used for cross-connect arrays.
(G) Class 2 and Class 3 Cable Substitutions. The substi tutions for Class 2 and Class 3 cables listed in Table
725.154(G) and illustrated in Figure 725.154(G) shall be permitted. Where substitute cables are installed, the wiring requirements of Article 725, Parts I and III, shall apply.
FPN: For information on Types CMP, CMR, CM, and
CMX, see 800.179.
Table 725.154(G) Cable Substitutions
Cable Type Permitted Substitutions
CL3P CMP
CL2P CMP, CL3P
CL3R CMP, CL3P, CMR
CL2R CMP, CL3P, CL2P, CMR, CL3R
PLTC
CL3 CMP, CL3P, CMR, CL3R,
CMG, CM, PLTC
CL2 CMP, CL3P, CL2P, CMR,
CL3R, CL2R, CMG, CM, PLTC, CL3
CL3X CMP, CL3P, CMR, CL3R,
CMG, CM, PLTC, CL3, CMX CL2X CMP, CL3P, CL2P, CMR,
CL3R, CL2R, CMG, CM, PLTC, CL3, CL2, CMX, CL3X
Plenum CMP •■
and Smoke of Wires and Cables for Use in Air-Handling Spaces, to a maximum peak optical density of 0.5 and a maximum average optical density of 0.15. Similarly, one method of defining fire-resistant cables is by establishing a maximum allowable flame travel distance of 1.52 m (5 ft) when tested in accordance with the same test.
(B) Types CL2R and CL3R. Types CL2R and CL3R riser cables shall be marked as Type CL2R or CL3R, respec tively, and be listed as suitable for use in a vertical run
our
^ ' ' '
Riser CMR CL3R CL2R
in a shaft or from floor to floor and shall also be listed as
having fire-resistant characteristics capable of
preventing the car rying of fire from floor to floor.
FPN: One method of defining fire-resistant characteristics capable of preventing the carrying of fire
General purpose CMG
PLTC '
1
from floor to floor is that the cables pass the
requirements of ANSI/UL 1666-2002, Test for Flame
Propagation Height of Electrical and Optical-Fiber Cable
CM CL3 CL2
i ' ' '
Installed Vertically in Shafts.
(C) Types CL2 and CL3. Types CL2 and CL3 cables
Dwelling CMX
UL O \ IsL ^A
shall be marked as Type CL2 or CL3, respectively, and be listed as suitable for general-purpose use, with the
Type CM—Communications wires and cables
Type CL2 and CL3—Class 2 and Class 3 remote-control, signaling, and power-limited cables
Type PLTC—Power-limited tray cable
\K\—*{B! Cable A shall be permitted to be used in place of Cable B.