1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared and published by Underwriters Laboratories Inc.(UL). It is normative for the a
2、pplicable UL Product Certification Program(s); however, it is currently notpart of the UL Standard(s) referenced below.Product Category (CCN): DUZXStandard Number: UL 444Edition Date: July 11, 2008Edition Number: 4Section / Paragraph Reference: Pars. 5.1.1, 5.1.3, 7.17 Tables 1, 2, 3, and 5Subject:
3、Coaxial Cables - Copper Tube Center ConductorDECISION:5.1.1 The conductors shall be solid or stranded, annealed, bare or metal-coated copper. The centreconductor of coaxial cables is also permitted to be a smooth or corrugated copper tube. The centreconductor of CMP, CMR, CMG, CM, CMH and CMX coaxia
4、l cables made of copper-clad steel shall have21 percent or higher conductivity in accordance with ASTM Standard B 869.5.1.3 If the insulation adjacent to the copper conductor is of a material that corrodes unprotected copperin the test described in Clause 7.1, the conductor shall be covered with a c
5、oating of tin complying withASTM Standard B 33, of lead or lead-alloy complying with ASTM Standard B 189, of nickel complying withASTM Standard B 355, of silver complying with ASTM Standard B 298, or of another metal or alloy.Evaluation of the effectiveness of these coatings shall be required. Metal
6、-coating a conductor on whichthe coating is not required for corrosion protection shall be permitted. When this is done, the 100 per centcoverage requirement of the relevant ASTM Standard shall be waived.The maximum temperature rating of cables relative to the diameter and coating of solid copper co
7、nductorsor copper conductor strands or the thickness and coating of tubular copper conductors shall not be higherthan those shown in Table 1.7.17 Conductor diameter or cross-sectional areaMeasurements of the diameter of a solid conductor or of a wire (strand) from a stranded conductor, thecross-sect
8、ional area of a stranded conductor, or the cross-sectional area of a tubular conductor shall bemade in accordance with the procedure outlined in the test, Conductor Diameter, Cross-sectional Area byMass (Weight) Method, or Cross-sectional Area by Diameter Method, in CSA C22.2 No. 2556 or UL 2556.UL
9、COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 1Maximum temperature rating of cables relative to diameter and coating of the solid copperconductor or of each copper conductor strand or thickness and coating of the tubular copperconductor(S
10、ee Clause 5.1.3.)Diameter of each strand or of the solid conductor or thickness of thetubular conductorMetal coating Smaller than 0.38 mm (0.015 in) At least 0.38 mm (0.015 in)Uncoated, tin or tin/lead alloy coating 150C 200CSilver coating 200C 200CNickel coating over 200C over 200CTable 2Maximum di
11、rect current resistance of copper conductors in ohms per km(See Clauses 5.1.6 and 7.16.3, and 8.3.2.)Conductorsize (AWG)Stranded conductor Solid or tubular conductorUncoated Coated Uncoated Coated20C 25C 20C 25C 20C 25C 20C 25C.Table 3Maximum direct current resistance of copper conductors in ohms pe
12、r 1000 ft(See Clauses 5.1.6, 7.16.3, and 8.3.2.)Conductorsize (AWG)Stranded conductor Solid or tubular conductorUncoated Coated Uncoated Coated20C 25C 20C 25C 20C 25C 20C 25C.Table 5Minimum diameter for solid conductors and cross-sectional area for tubular or strandedconductors(See Clause 5.1.6.)Con
13、ductor size (AWG)Diameter of solid conductorCross-sectional area of tubular or strandedconductormm in mm2cmil30 0.251 0.0099 0.0497 9829 0.284 0.0112 0.0633 12528 0.318 0.0125 0.0790 15627 0.358 0.0141 0.100 19826 0.384a0.0151a0.126 24825 0.432a0.0170a0.159 31424 0.485a0.0191a0.201 39623 0.546a0.021
14、5a0.254 50122 0.610a0.0240a0.318 627STANDARD NUMBER: UL 444 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 5 ContinuedConductor size (AWG)Diameter of solid conductorCross-sectional area of tubular or strandedconductormm in mm2cmil21
15、0.688a0.0271a0.404 79620 0.772a0.0304a0.509 100019 0.866a0.0341a0.641 126418 1.013 0.0399 0.807 158817 1.138 0.0448 1.02 200916 1.278 0.0503 1.28 252815 1.435 0.0565 1.62 319514 1.613 0.0635 2.04 402813 1.81 0.0713 2.58 507612 2.03 0.0800 3.24 639911 2.28 0.0898 4.09 806510 2.56 0.1010 5.16 101729 2
16、.87 0.113 6.50 128288 3.22 0.127 8.20 161807 3.63 0.143 10.34 204046 4.06 0.160 13.03 25715aMinimum acceptable diameter (0.95 x nominal) of a solid conductor of this size.RATIONALE FOR DECISION:Historically, coaxial cables covered under Community- Antenna and Television cables in accordance withUL 1
17、655 have been permitted to employ hollow copper tubes as the center conductor. These cablestypically employ much larger conductors than those used in communications cables and the tubes havebeen permitted since these cables are used in circuits where the RF energy transmits along the outersurface of
18、 the conductor, and a solid conductor is not required provided that the overall cross sectionalarea is suitable. Based on the history and use as CATV cables, the construction should also be permittedfor coaxial communication cables.Copyright 2012 Underwriters Laboratories Inc.UL, in performing its f
19、unctions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certification Requirement Decisions are the opinion of Underwriters Laboratories Inc. inpractically applyi
20、ng the requirements of the standard. They do not represent formal interpretations of thestandard under American National Standards Institute (ANSI) processes. UL shall not be responsible toanyone for the use of or reliance upon Certification Requirement Decisions by anyone. UL shall not incurany obl
21、igation or liability for damages, including consequential damages, arising out of or in connectionwith the use or reliance upon Certification Requirement Decisions. The electronic version of theCertification Requirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 444 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSTANDARD NUMBER: UL 444 -4-No Text on This Page
