UL 44:2010 pdf download – Thermoset-lnsulated Wires and Cables
UL 44:2010 pdf download – Thermoset-lnsulated Wires and Cables.
F.1 .1 A covering applied over the outer surface of the Insulation of a single-conductor wire or cable, and each conductor of any 2-conductor flat parallel wire or cable, and of any cabled multiple-conductor cable shall be in accordance with Table 19. See Clause 4.3.2 for a list of materials known to comply with these requirements.
F.1.2 A fibrous covering when used shall be applied to the insulated conductor either before or after the process of vulcanizing, curing, or cross-linking the insulating compound. A separator, when used, shall be applied between the insulation and the fibrous covering.
F.1 .3 If a wire or conductor assembly is intended, and tagged or otherwise marked for further processing, the second fibrous covering required for a single-conductor wire, and the overall fibrous covering required for a multiple-conductor assembly in Table 19 are not required or, if provided, need not comply with the requirements for braids or wraps in Clauses F.3 — F.9 inclusive.
F,2,l Tapes employed as fibrous coverings shall not be the final outer covering of a single- or muttiple-conductor wire or cable,
F.2.2 Tapes over multiple-conductor assemblies shall be applied helically without any creases or folds and with an overlap of at least 3 mm (1(8 inch) on 0.8235 mm2 (8 AWG) and smaller conductors and at least 6 mm or 1/4 inch on larger conductors. Tapes on single conductors shall be applied either helically or longitudinally, with the specified overlap, under a braid or wrap covering On an individual insulated conductor, (Such tape shall be required under the braid on 6 AWG — 2000 kcmil Type SA or SF cable.)
F.2.3 The thickness of a tape shall be determined by removing the tape from the insulation and measuring its thickness by means of a dead-weight dial micrometer having a presser foot 6.4 ±0.1 mm (0.250 ±0.010 inch) in diameter and exerting 85 ±3 gf (0.83 ±0.02 N or 3.0 ±01 ozf) on the tape, the load being applied by means of a weight.
F.3 Cotton braids
F.3. 1.1 A cotton braid employed as a covering on an individual conductor or as an outer covering over two or more individual conductors shall be of a close weave, shall cover the insulated conductor or conductors over which it is applied, and shall be fabricated on a machine having the same number of ends per camer throughout. Each end shall consist of the same kind (soft or glazed), size, and ply of yarn. The braid shall be applied to make the tangent of the lay angle (the angle of weave with reference to the axis of the wire or cable) not less than indicated in Table F. 1. A cotton braid shall employ yam in accordance with Table F.2,
F.3.2.6 If two braids are used to comply with the requirement for two txous coverings in F.3.2.1. the lay angle, yarn size, and coverage (including picks per centimeter or picks per inch Or) of each braid shall be determined on the basis of the diameter under that braid and the number of carriers on the machine applying that braid. For the outer braid, the diameter under that braid shall be taken as the diameter over the Inner braid. It is acceptable for the number of carners for the inner braid to be less than the number of carriers employed for the outer braid, but the size and ply of the cotton yarn used shall comply with these requirements, and the number of ends per carrier in the inner braid shall not be less than the number of ends per carrier In the outer braid.
F.32.7 Tables F.4 and F.5 have been computed on the basis of Clauses F.3.li — F.3.2.6 and give the minimum acceptable number of picks per centimeter (Table F3) and the minimum acceplable number of picks per inch (Table F.4) for the braids most commonly used The ranges of diameter given in the first column are for calculated diameter based on normal values of conductor diameter and insulation thickness. The nominal conductor dianieler as measured shall be used. A braid complying with Table F.3 or F.5 has at least the minimum acceptable angle of lay and coverage. Braids are not limited to those covered in Tables F.4 or F5 as long as they comply with the requirements in Clauses F.3,1i — F.3.2.6.