光缆第4-20部分:分规范沿电力线的架空光缆ADSS（全介质自支撑）光缆系列规范

[中文适用范围]： 本部分IEC 60794-4是系列规范，涵盖光通信电缆，通常使用单模光纤，主要用于架空电力线应用。电缆也可用于其他架空公用事业网络，如电话或电视服务。IEC 60794-4对沿电力线的架空光电缆的要求适用于本文件所涵盖的电缆。 本文件涵盖全介质自承式光纤电缆（ADSS）的结构、机械、电气和光学性能、安装指南、验收标准、测试要求、环境考虑和附件兼容性。本文件提供了结构和性能要求，确保在本文件指南范围内，电缆组件的机械完整性以及光纤机械可靠性和传输参数得到保持。 ADSS电缆由一个或多个保护性介质光纤单元中包含的单模光纤组成，周围或附着于适当的介质强度构件和护套。电缆不含金属部件。ADSS电缆设计用于满足不同安装、操作和环境条件下的光学和机械要求，如附件B所述。 本文件不包括IEC 60794-4中包含的任何“捆绑”或“缠绕”OPAC电缆。图8架空电缆也被排除在外；它们在IEC 60794-3-20中有规定。 [外文原描述]： IEC 60794-4-20:2018 RLV contains both the official IEC International Standard and its Redline version. The Redline version is available in English only and provides you with a quick and easy way to compare all the changes between the official IEC Standard and its previous edition. IEC 60794-4-20:2018 covers optical telecommunication cables, commonly with single-mode fibres used primarily in overhead power lines applications. The cables can also be used in other overhead utility networks, such as for telephony or TV services. Requirements of the sectional specification IEC 60794-4 for aerial optical cables along electrical power lines are applicable to cables covered by this document. This document covers the construction, mechanical, electrical, and optical performance, installation guidelines, acceptance criteria, test requirements, environmental considerations, and accessories compatibility for an all dielectric, self-supporting fibre optic (ADSS) cable. This document provides construction and performance requirements that ensure, within the guidelines of this document, that the required mechanical integrity of the cable components as well as optical fibre mechanical reliability and transmission parameters are maintained. The ADSS cable consists of single mode optical fibres contained in one or more protective dielectric fibre optic units surrounded by or attached to suitable dielectric strength members and sheaths. The cable does not contain metallic components. An ADSS cable is designed to meet the optical and mechanical requirements under different installation, operating and environmental conditions and loadings, as described in Annex B. This document excludes any "lashed" or "wrapped" OPAC cables included in IEC 60794-4. Figure 8 aerial cables are also excluded; they are specified in IEC 60794-3-20. This second edition cancels and replaces the first edition published in 2012 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - this document has been streamlined by cross-referencing IEC 60794-1-1, - IEC 60794-4 (all parts) and IEC 60794-1-2; - reference to the MICE table has been deleted; - the example of test method for particular environment in Annex C has been deleted; - creep test method has been updated in Annex E. Keywords: optical telecommunication cables, single-mode fibres used primarily in overhead power lines