earth continuity test
我想问一下有关灯具测接地电阻时仪器的一端接金属部件,另一端接到灯具里面的内部的接地线
还是接在外部接地线上测试呢? 可能出现的最不利接地处. 如果有结构图片来看下就好了。
一般的:从金属部件到供电电源的接地点之间的电阻,如果电源线包括在这段距离里,并且电源线是detachable,那么电源线这部分电阻就不包括在内。 认证是不包括外部的电源线的! 这样啊,如果电源线是XYZ型连接也不包括吗? 引用第4楼yishenger于2007-09-10 11:47发表的:
这样啊,如果电源线是XYZ型连接也不包括吗?
Cl.27.5NOTE 2 The resistance of the Supply cord is not inculded in the measurement.
所以,无论什么类型连接的电源线的阻值是不包含在内的! 引用第5楼nellhu于2007-09-10 11:57发表的:
Cl.27.5NOTE 2 The resistance of the Supply cord is not inculded in the measurement.
所以,无论什么类型连接的电源线的阻值是不包含在内的!
灯具的标准里面好像从来没有这么说过。你应用的这条应该不是598里面的条文吧。
Cl 7.2.3 Note: In the case of a luminaire with a non-detachable flexible cable for the supply
connection, the earthing contact is at the plug or supply end of the flexible cable or cord.
就是说只要灯具使用的是不可拆卸的软线作为供电连接的话,那接地电阻就要把线的电阻也算进去。 LZ问的是灯具,楼上的怎么拿335的标准来说呢? A current of at least 10 A, derived from a source with a no-load voltage not exceeding 12 V,
shall be passed between the earthing terminal or earthing contact and each of the accessible
metal parts in turn.
The voltage drop between the earthing terminal or earthing contact and the accessible metal
part shall be measured and the resistance calculated from the current and the voltage drop. In
no case shall the resistance exceed 0,5 Ω. When type testing, the current shall be applied for a
period of at least 1 min.
NOTE In the case of a luminaire with a non-detachable flexible cable for the supply connection, the earthing
contact is at the plug or supply end of the flexible cable or cord. 标准是BS EN 60598或GB7000.1
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