IEC 61857-1:2008规定了电气绝缘系统（EIS）热评估和鉴定的一般试验程序，并建立了一个程序，将候选EIS的性能与参考EIS的性能进行比较。本标准适用于输入电压高达1000 V的电工产品中使用的现有或拟定EIS，其中热因素是主要老化因素。本第三版取消并取代了2004年出版的第二版，并构成编辑修订，以使本标准与第21部分和第22部分兼容。

IEC 61857-1:2008 specifies a general test procedure for the thermal evaluation and qualification of electrical insulation systems (EIS) and establishes a procedure that compares the performance of a candidate EIS to that of a reference EIS. This standard is applicable to existing or proposed EIS used in electrotechnical products with an input voltage of up to 1 000 V where the thermal factor is the dominating ageing factor. This third edition cancels and replaces the second edition published in 2004, and constitutes editorial revisions to make this standard compatible with Parts 21 and 22.