UL-13:2011 pdf free download – Underwriters Laboratories Inc. Standard for Safety Power-Limited Circuit Cables.
10 Electromagnetic Shield(s)
10.1 An electromagnetic shield is not required other than as the outer conductor in a coaxial member but is acceptable over an individual insulated conductor, over a pair of insulated conductors, over one or several groups of insulated conductors with or without one or more optical-fiber members in any group, or over the entire cable assembly. Several shields may be used in a given cable. Insulating material as indicated in Table 7.1 or referenced in note a to Table 7.1 may be provided in any thickness between shields. The electrostatic/electromagnetic performance of a shield is not specified. When provided, the shield shall be electrically continuous throughout the entire length of the finished cable (see Continuity Test of Conductors, Section 16).
10.2 An electromagnetic shield shall be of metal and shall consist of one or more of the following but otherwise is not specified:
a) A laminated shield tape of polymeric material and metal(s) with or without a bare metal- coated or uncoated (uncoated not acceptable with an aluminum-faced tape) copper or copper alloy drain wire in contact with the metal(s) part of the tape. The tape may be applied with the metal(s) side in or out. The size of a drain wire is not specified. A drain wire may be solid or stranded.
b) A corrugated or smooth single-metal or bi-metal tape applied longitudinally, helically, or interlocked with or without a bare metal-coated or uncoated (uncoated not acceptable with an aluminum tape) copper or copper alloy drain wire in contact with the metal tape (a specific version of this shield is described in 10.3). The tape may be polymer-coated on one side if there is a drain wire or on both sides if a drain wire is not used. Any inward-facing coating may bond to the insulation in the case of a coaxial member but, where the metal tape is applied over more than one conductor or member, any inward-facing coating shall not bond to the conductors or coaxial members or optical-fiber members in the cable. The size of a drain wire is not specified. A drain wire may be solid or stranded. Interlocked aluminum tape shall comply with the requirements for a metal covering but, if the cable has an overall cable jacket, the strip thickness and width are not specified. Interlocked zinc-coated steel tape shall comply with the requirements for a metal covering (see Metal Covering, Section 14), with the following modifications for cable that has an overall cable jacket:
1) NOT SPECIFIED for DIRECT-BURIAL CABLE — Strip thickness and strip width.
2) NOT SPECIFIED for OTHER CABLE — Edge coating, strip thickness, and strip width.
C) A serving, wrap, or braid of aluminum wires or of metal-coated or uncoated (uncoated not acceptable in contact with aluminum wires) copper wires. See 6.4. If the overall cable jacket is thinner in average thickness than 0.013 in or 0.33 mm and is thinner at any point than 0.010 in or 0.25 mm, a wrap or other protective covering shall be provided over the wire serving, wrap, or braid (see note b to Table 13.1). The construction of the protective covering is not specified but the covering shall keep bobbin ends and other wire projections from penetrating the overall cable jacket during and after application of the overall jacket.
d) An investigated equivalent of any of the above.