家用和类似固定电气装置的电气附件的箱盒及其配件 第21部分：悬挂装置要求特殊的箱盒和封闭件的要求

[中文适用范围]： 此文档适用于带有悬挂装置预留的天花板和墙壁安装的盒子和外壳。 [外文原描述]： IEC 60670-21:2024 applies to boxes, enclosures and parts of enclosures (hereafter called "boxes" and "enclosures") for electrical accessories with a rated voltage not exceeding 1 000 V AC and 1 500 V DC intended for household or similar fixed electrical installations, either indoors or outdoors. Boxes and enclosures complying with this document are suitable for use at ambient temperatures not normally exceeding +40 °C, but their average over a period of 24 h does not exceed +35 °C, with a lower limit of the ambient air temperature of −5 °C. Other temperatures outside the above range can apply according to the classification of the boxes and the enclosures. This document applies to boxes and enclosures for ceiling and wall mounting with provision for suspension means. This second edition cancels and replaces the first edition published in 2004 and Amendment 1:2016. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) Complete revision of the tests and requirements of the suspension means.