UL 1651

1.1 These requirements cover single and multiple optical-fiber cables for control, signaling, and communications as described in Article 770 and other applicable parts of the National Electrical Code (NEC). Cables complying with these requirements are:Type OFNP - Plenum - A nonconductive cable for use in ducts, plenums, and other spaces used for environmental air. A nonconductive cable contains no metallic members and no other electrically conductive materials.Type OFCP - Plenum - A conductive cable for use in ducts, plenums, and other spaces used for environm0ental air. A conductive cable contains non-current-carrying conductive members such as metal strength members and metallic vapor barriers.Type OFNR - Riser - A nonconductive cable for vertical use in shafts or from floor to floor.Type OFCR - Riser - A conductive cable for vertical use in shafts or from floor to floor.Type OFN and OFNG - General Purpose - Nonconductive cables for general purpose use.Type OFC and OFCG - General Purpose - Conductive cables for general purpose use.

1.2 Smoke and fire considerations are as follows for the cables covered in these requirements:
1.TYPE OFNP and OFCP CABLES - Cables that are intended for installation in accordance with Section 770-53(a) of the National Electrical Code (ANSI/NFPA 70-1999) in a duct, plenum, or other space used to transport environmental air without the cable being enclosed in a raceway in that space are tested for smoke and flame characteristics in accordance with the Standard Test for Flame-Propagation and Smoke-Density Values for Electrical and Optical-Fiber Cables Used in Spaces Transporting Environmental Air (UL 910). A cable that complies exhibits a maximum flame-propagation distance that is not greater than 5 ft, 0 inch 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.