对于水壶上的PTC元件,由于内部的发热元件通常会用3层绝缘胶纸密封良好,该绝缘胶纸单层可以通过1750V要求,采用3层即可满足加强绝缘的要求。
引用EN 60335-1 29.3对于附加绝缘和加强绝缘的要求:
29.3 Supplementary insulation and reinforced insulation shall have adequate thickness, or have a sufficient number of layers, to withstand the electrical stresses that can be expected during the use of the appliance.
Compliance is checked by
– measurement, in accordance with 29.3.1, or by
– an electric strength test in accordance with 29.3.2, if the insulation consists of more than one separate layer, other than natural mica or similar flakey material, or by
29.3.2 Each layer of material shall withstand the electric strength test of 16.3 for supplementary insulation. Supplementary insulation shall consist of at least 2 layers of material and reinforced insulation of at least 3 layers.
此时对PTC元件外面的金属外壳的要求是加强绝缘的要求,根据EN 60335-1的要求,是打3000V,一分钟,不出现击穿即可。 |