着火条件下电缆和光缆的试验第3-25部分:垂直安装的成束电线或电缆的垂直火焰蔓延试验D类

[中文适用范围]： IEC 60332 的这部分内容涵盖了 D 类方法，用于在既定条件下评估垂直安装的捆扎电线或电缆（电气或光缆）的垂直火焰蔓延情况。本文件仅适用于直径不超过 12 毫米、截面不超过 35 平方毫米的小电缆，这些电缆安装在测试梯上，以实现测试样品总非金属材料体积为 0.5 升/米的目标。火焰施加时间为 20 分钟。安装方法仅使用标准梯的前部，采用触接排列形式。该类别旨在用于需要评估非常低非金属材料体积的小电缆。该测试旨在用于型式试验。电缆选型要求见附录 A。火焰蔓延通过电缆样品的受损程度来衡量。该程序可用于证明电缆限制火焰蔓延的能力。附录 B 给出了建议的性能要求。注：就本文件而言，术语“电线或电缆”涵盖所有用于传输能量或信号的多层绝缘金属导体电缆。 [外文原描述]： IEC 60332-2-25:2018 covers category D for methods of test for the assessment of vertical flame spread of vertically mounted bunched wires or cables, electrical or optical, under defined conditions. This document relates only to small cables of overall diameter 12 mm or smaller and cross-section of 35 mm2 or smaller installed on the test ladder to achieve a nominal total volume of non-metallic material of 0,5 l/m of test sample. The flame application time is 20 min. The method of mounting uses the front of the standard ladder in touching formation only. The category is intended for use with small cables where very low volumes of non-metallic material are required to be evaluated. The test is intended for type approval testing. The requirements for the selection of cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the cable sample. This procedure can be used to demonstrate the cable’s ability to limit flame spread. A recommended performance requirement is given in Annex B. This second edition cancels and replaces the first edition published in 2000 and Amendment 1:2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) all pre-existing categories of test have been retained and updated; b) a new category (category D) has been added to cater for testing at very low non-metallic volumes. It has the status of a group safety publication in accordance with IEC Guide 104.