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]： This Technical Report specifies a method of temperature rise verification of low-voltage switchgear and controlgear assemblies by calculation. The method is applicable to enclosed ASSEMBLIES or partitioned sections of ASSEMBLIES without forced ventilation. It is not applicable where temperature rise verification to the relevant product standard of the IEC 61439 series has been established. The proposed method is intended to determine the temperature rise of the air inside the enclosure. Unless otherwise specified, the ambient air temperature outside the ASSEMBLY is the air temperature indicated for the installation (average value over 24 h) of 35°C. If the ambient air temperature outside the assembly at the place of use exceeds 35°C, this higher temperature is deemed to be the ambient air temperature. This document 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. However, some technical guidance to adapt it for the use of forced ventilation is given in this document. The results obtained by using this method are directly influenced by the accuracy of the evaluation of power losses used as inputs to perform the thermal calculations. For the method to be applied, the maximum daily average ambient air temperature outside the assembly at the place of installation is specified between 10°C and 50°C. The maximum daily temperature does not exceed the maximum daily average temperature by more than 5 K. Several annexes in this document provide guidance on how temperature-rise within assemblies can be affected by influences which are not considered in the calculation method included in this document, for example, when the assembly is subject to solar radiation. In such cases, different means of verification to that given in this document can be applied to ensure a definitive result and verification of the design. [外文原描述]： IEC TR 60890:2022 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 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.