IEC 60950-1: 2005是这样规定的(IEC 60065也有类似的规定):
1.5 components
1.5.1 General
Where safety is involved, components sahll comply either with the requirements of this standard or with the safety aspects of the relevant IEC component standards.
1.5.9 Surge suppressors
If a surge suppressor is used in a primary ciurcit, it shall be a VDR and it shall comply with Annex Q.
Annex Q
A VDR used in a primary ciurcit shall comply with IEC 61051-2, with the following details.
a) Preferred climatic categories (2.1.1 of IEC 61051-2)
Lower category temperature : -10 oC
upper category temperature: +85 oC
可见在测试中对VDR还是对其环境温度有温度限制的.平时如果没有刻意考核此限值,是放松了限制.过高的温度会加速其燃烧或爆裂.