低压开关设备和控制设备组件温升的计算验证方法

[中文适用范围]： 本文件规定了低压开关设备和控制设备组件或类似产品外壳内部空气温升的计算方法，该方法适用于其各自的标准。 该方法主要适用于无强制通风的封闭组件或组件分区。然而，本文件提供了一些技术指导，以使其适用于强制通风的情况。使用该方法获得的结果直接受用于热计算的功率损耗评估的准确性影响。 注：外壳内的空气温度等于外壳外部的环境空气温度加上由于安装设备的功率损耗引起的内部空气温升。 为了应用该方法，安装地点的组件外部最大日平均环境空气温度规定在10°C至50°C之间。最高日温度不超过最高日平均温度5K以上。 本文件的几个附件提供了关于组件内温升如何受到本文件计算方法未考虑的影响因素的指导，例如当组件受到太阳辐射时。在这种情况下，可以应用不同于本文件给出的验证方法，以确保设计结果的确定性和验证。 [外文原描述]： IEC TR 60890:2022 specifies a method of air temperature-rise calculation inside enclosures for low-voltage switchgear and controlgear assemblies or similar products in accordance with their respective standard. The method is primarily applicable to enclosed assemblies or partitioned sections of assemblies without forced ventilation. This third edition cancels and replaces the second edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - alignment with IEC 61439-1:2020; - addition of individual annexes for guidance of technical explanations related to: --- effect of an uneven power distribution; --- additional temperature-rise due to solar radiation; --- effect of different enclosure materials; --- effect of different natural ventilation management; --- forced ventilation management; --- power losses calculation; --- impact of an adjacent wall can have on the assembly cooling surface(s); - maximum internal ambient temperature limit into an assembly; - validity area of the calculation extended from 3 150 A to 3 200 A; - addition of an algebraic equation to the different curves included in the document.