GB/T 24276-2017 in English

《GB/T 24276-2017通过计算进行低压成套开关设备和控制设备温升验证的一种方法》由TC266（全国低压成套开关设备和控制设备标准化技术委员会）归口，主管部门为中国电器工业协会。

Scope

This standard specifies a method for verifying the temperature rise of low-voltage switchgear and controlgear assemblies by calculation. This method is applicable to enclosed switchgear or partitioned cabinet units of switchgear without forced ventilation, but not to situations where the relevant product standard GB/T 7251 explicitly specifies a temperature rise verification method. Note 1: The material and wall thickness of the enclosure can generally have some influence on the steady-state temperature. However, the generalized method used in this standard ensures its applicability to enclosures made of steel, aluminum, cast iron, insulation, and similar materials. The recommended method is intended to determine the temperature rise of the air inside the enclosure. Note 2: The air temperature inside the enclosure is equal to the ambient air temperature outside the enclosure plus the air temperature rise inside the enclosure due to the power losses of the installed equipment. Unless otherwise specified, the ambient air temperature outside the switchgear is the air temperature at the installation location at 35°C (above the 24-hour average). If the ambient air temperature at the location where the switchgear is used exceeds 35°C, this higher temperature is considered the ambient air temperature.