UL 13:2021 PDF Download

UL 13:2021 is a standard that applies to power-limited circuit cables used for fixed wiring within buildings. These cables are primarily used for Class 3 and Class 2 circuits, as defined in Article 725 of the National Electrical Code (NEC). The standard covers various types of cables, including plenum cables (Types CL3P and CL2P), riser cables (Types CL3R and CL2R), commercial cables (Types CL3 and CL2), limited-use cables (Types CL3X and CL2X), and non-plenum/non-riser cables for Class 3 and Class 2 circuits (Type PLTC).

The standard specifies that Class 3 circuits are rated for 300 volts but are not marked as such, while Class 2 circuits do not have a voltage rating. Cables with electromagnetic shields may be marked as "shielded," and cables with optical-fiber members have "-OF" as part of their type designation. The overall jacket of cables marked as "sun res" or "sunlight resistant" complies with a 720-hour sunlight resistance test. Cables marked as "dir bur," "direct burial," or "for direct burial" comply with a 1000-pound crushing test.

Additionally, the standard defines the smoke and fire characteristics for different cable types. Plenum cables (Types CL3P and CL2P) are tested for smoke and flame characteristics, while riser cables (Types CL3R and CL2R) are tested for flame propagation height. General-use cables (Types CL3 and CL2) can be tested using either the UL test or the FT4/IEEE 1202 test. Limited-use cables (Types CL3X and CL2X) and PLTC tray cables are also subject to flame tests. Type PLTC cables have a "gas/vapor-tight continuous sheath," and cables marked with "-ER" are used for exposed runs.

It is important to note that the standard does not cover cables for electric-light, power, or Class 1 circuits, optical-fiber cables without electrical conductors, communication cables, cables for power-limited fire-alarm circuits, or vault-lacing cables used in theft-alarm systems. The optical or other performance of optical-fiber members is also not covered by this standard.