UL 13

The requirements in UL 13 cover 60 – 250°C (140 – 482°F) single- and multiple-conductor power-limited circuit cables for use as fixed wiring within buildings (some are also marked for direct burial) principally for Class 3 and Class 2 circuits as described in Article 725 and other applicable parts of the National Electrical Code (NEC). Cables covered by these requirements are:

• Types CL3P and CL2P (plenum cables),
• Types CL3R and CL2R (riser cables),
• Types CL3 and CL2 (commercial cables for other than plenum, riser, or tray uses),
• Types CL3X and CL2X (cables for limited use), and
• Type PLTC (cable for non-plenum and non-riser Class 3 and Class 2 circuits in general and in trays).

Cables for Class 3 circuits are rated for 300 volts but are not so marked. Cables for Class 2 circuits do not have a voltage rating. See 47.1(h).

A cable that contains one or more electromagnetic shields may be surface marked or have a marker tape to indicate that it is “shielded”. A cable that contains one or more optical-fiber members has “-OF” supplementing the type letters and is marked in accordance with 48.1(d). A cable may consist of or contain one or more coaxial members.

The overall jacket on a cable that has “sun res” or “sunlight resistant” in a surface marking or on a marker tape complies with a 720-h sunlight-resistance test. The overall jacket on all Type PLTC cable is required to comply with this 720-h test, so Type PLTC cable may be marked “sun res” or “sunlight resistant” but is not required to be so marked.

A cable that has “dir bur”, “direct burial”, or “for direct burial” in a surface marking or on a marker tape complies with a 1000-lbf crushing test. Direct-burial cable with wire armor, a metal braid, interlocked metal armor, or a smooth or corrugated metal sheath has a jacket over the metal covering.

Smoke and fire considerations are as follows for the cables covered in these requirements:

• TYPE CL3P and CL2P CABLES – Cables that are intended for installation in accordance with section 725.82 (A) of the National Electrical Code, ANSI/NFPA 70, in a duct, plenum, or other space used to transport environmental air without the cables being enclosed in a raceway in that space are to be tested for smoke and flame characteristics in accordance with the National Fire Protection Association Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces, ANSI/NFPA 262. A cable that complies exhibits a maximum flame-propagation distance that is not greater than 5 ft, 0 in or 152 cm, a peak optical density of smoke produced of 0.50 or less (32 percent light transmission), and an average optical density of smoke produced of 0.15 or less.
• TYPE CL3R and CL2R CABLES – Cables that are intended for use in vertical runs in a shaft, or for installations in which the cables penetrate more than one floor, as specified in Section 725.82 (B) of the National Electrical Code, ANSI/NFPA 70, are to be tested for flame-propagation characteristics in accordance with the Standard for Test for Flame-Propagation Height of Electrical and Optical-Fiber Cables Installed Vertically in Shafts, UL 1666. A cable that complies has a flame-propagation height less than 12 ft, 0 in or 366 cm and temperatures are 850.0°F (454.4°C) or less at a height of 12 ft, 0 in or 366 cm.
• TYPE CL3 and CL2 CABLES – Type CL3 and CL2 general-use cables comply with a 70,000 Btu/h (20.5 kW) vertical-tray flame test.

The cable manufacturer chooses one of the following tests:

• THE UL TEST REFERENCED IN 28.2.1 – This paragraph applies the test method described as the UL Flame Exposure (smoke measurements are not applicable) in the Standard for Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables, UL 1685, to cable that is surface marked or designated by a marker tape as “CL3” or “CL2”. For compliance, this test damages less than 8 feet (244 cm) of cable.
• THE FT4/IEEE 1202 TEST REFERENCED IN 28.3.1 – This paragraph applies the test method described as the FT4/IEEE 1202 Type of Flame Exposure (smoke measurements are not applicable) in the Standard for Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables, UL 1685. This test differs from the UL test in loading (more cables are used, with small cables bundled, and the spacing between cables is limited), burner angle, and failure criterion. For compliance, this test damages less than 150 cm (59 in) of cable. A cable that complies either is not marked or it bears the designation “FT4/IEEE 1202” or “FT4” legible on or through the outer surface or on a marker tape [see marking in 47.1(i)].
• TYPE CL3X and CL2X CABLES – Type CL3X and CL2X cables comply with the VW-1 vertical-specimen flame test. The cable is not marked “VW-1”.
• TYPE PLTC CABLE – Type PLTC tray cable complies with a 70,000 Btu/h (20.5 kW) vertical-tray flame test. The cable manufacturer chooses the test in (c)(1) or (c)(2). This test is applied to cable that is surface marked or designated by a marker tape as “PLTC”.

The overall jacket on Type PLTC cable is a “gas/vapor-tight continuous sheath” in the sense discussed in sections 501.15 (D) and 501.15 (E) of the National Electrical Code, ANSI/NFPA 70. Cables that are surface marked “-ER” are for use as exposed runs between a cable tray and utilization equipment where the cables are continuously supported and protected against physical damage using mechanical protection such as struts, angles, or channel.

With certain exceptions, as noted in 1.9, Type CL3X and CL2X cables are required by the NEC to be used with protection such as raceway. The Type CL3 and CL2 and other cables covered in these requirements that are not required by the NEC to be used in raceway are capable of use without the physical protection of raceway but may be pulled into conduit or installed in other raceway.

Type CL3X and CL2X cables are limited by the NEC to use in unconcealed spaces in which the exposed length of cable does not exceed 10 ft or 3.05 m, and in raceway. These NEC limitations do not apply to Type CL3X and CL2X cables that are smaller in diameter than 0.25 in or 6.35 mm and are used in a one-, two-, or multi-family dwelling.

These requirements do not cover cables that contain conductors for electric-light, power, or Class 1 circuits. These requirements do not cover optical-fiber cables that do not contain any electrical conductors. These requirements do not cover communication cables (see the Standard for Communications Cables, UL 444) or cables for power-limited fire-alarm circuits (see the Standard for Cables for Power-Limited Fire-Alarm Circuits, UL 1424). These requirements do not cover vault-lacing cable, which is for use in concrete as part of a theft-alarm system.

These requirements do not cover the optical or other performance of any optical-fiber member or group of such members. See 8.3.