UL 444-2021 pdf download

UL 444-2021 pdf download.Communications Cables.
5.5.3 Cables that contain 200 or more pairs may contain acceptable defective pairs in a quantity that shall not exceed 0.5 percent of the number of pairs marked on the tag, reel, or carton for the cable. Both ends of a cable in which there are one or more acceptable defective pairs shall be marked to warn of the presence of the defective pair(s). A notice such as a defective-pair tag shall be attached to each end of a cable in which there are factory-located defects. The notices shall identify the factory counting system (establish a direction for counting multiunits) and shall also identify each of the factory-found acceptable defective pairs according to layer (if pertinent to the counting system), multiunit number, unit colors, and pair color. 5.6 Spare pairs Cables that contain 400 or more pairs may also contain spare pairs to make certain that the number of usable pairs equals or exceeds the number of pairs marked on the tag, reel, or carton. The quantity and position of the spare pairs are not specified. The colors of each spare pair shall be derived from the standard colors and shall be in unique combinations, and it shall not be possible to confuse them with the colors of the regular cable pairs. 5.7 Core binders The core, any group of conductors, or several groups within the core may be bound by a nonmetallic binder. No other details of the core binders are specified. 5.8 Core wrap The core, any group of conductors, or several groups within the core may be enclosed in a nonmetallic core wrap consisting of a serving, wrap, tape, or other construction. A metal shield as described in Clause 5.9.1 may serve as a core wrap. No other details of the core wrap are specified. 5.9 Shields 5.9.1 An electromagnetic shield is optional other than as the outer conductor in a coaxial member. One or more shields may be used in a given cable.
5.10.3 All cables except those with an overall core wrap as described in Clause 5.8 or an overall bonded or unbonded metal shield as described in Clause 5.9 shall comply with the peel test requirements of Clause 7.11. 5.10.4 Minimum point and minimum average jacket thickness shall be in accordance with requirements specified in Table 7 for jacket materials other than fluoropolymers, and Table 8 for fluoropolymer jacket materials. Maximum average thickness requirements shall be determined from the submitted sample. For reference purposes, measurements shall be made by means of an optical instrument that is calibrated to read to at least 0.001 mm (0.0001 in). 5.10.5 Jackets with thicknesses other than indicated in Table 7 and Table 8 are acceptable if the finished cable complies with the requirements of the tests described in this Standard. Evaluation of thinner jackets shall include, but not be limited to, crush, impact, and abrasion tests. 5.10.6 Cables on which a jacket thicker than as indicated in Table 7 or Table 8 is necessary to enable the cable to comply with any applicable flame or other test described in these requirements shall be made with whatever greater thickness of jacket may be needed for this purpose. In this case, the minimum thickness at any point of the thicker jacket shall be not less than 80 percent of the average thickness of the heavier jacket. 5.10.7 Jackets shall be capable of meeting the unaged and heat-aged requirements in accordance with Clause 7.8. 5.10.8 Tensile strength values of jacket materials, as specified in Table 9 and Table 10 shall be determined in accordance with the test, Insulation and Jacket Physical Properties in CSA C22.2 No. 2556 or UL 2556. 5.10.9 A jacket that is damaged to the point that the underlying assembly is exposed or that is opened for the purpose of repairing a conductor shall either be stripped and replaced in its entirety or have a second jacket applied over the first.UL 444-2021 pdf download.