bonjovi521 发表于 2015-9-21 10:26 static/image/common/back.gif
恩,永久安装的ME设备的保护地线发生断开的概率极低这个我明白了,但是为什么不是永久安装的ME设备正常状 ...
8.7.4.6 * Measurement of the TOUCH CURRENT
a) ME EQUIPMENT is tested according to Figure 14, using an appropriate measuring supply circuit.
Measure with MD between earth and each part of the ENCLOSURE(S) that is not PROTECTIVELY EARTHED.
未保护接地的外壳和地之间
Measure with MD between parts of the ENCLOSURE(S) that are not PROTECTIVELY EARTHED.
未保护接地的外壳之间
In the SINGLE FAULT CONDITION of interruption of any one PROTECTIVE EARTH CONDUCTOR (when applicable, see 8.1 b)), measure with MD between earth and any part of the ENCLOSURE(S) that is normally PROTECTIVELY EARTHED.断开PE情况下(SFC),测量正常条件下保护接地的外壳和地之间。即此时对地漏电流转化成了接触漏电流。
NC下earth leakage current流经protective到达电网PE,PE open时会流经人体变为touch current,如接触到PE的金属外壳。
知道了这个过程,就可能发生两种情况:1)不让PE在SFC的open;2)operator碰不到接PE的金属外壳。 看晕了:Q
页:
[1]