jia_suwei 发表于 2011-12-20 11:15

IEC60065 Annex N 保护接地问题求助！！！！

先上标准，IEC 60065 Annex N(routine test):
N.1.3 Protective earthing connection of screens and metal barriers
For CLASS I apparatus with a screen or metal barrier (see 8.5) between HAZARDOUS LIVE parts
and TERMINALS regarded as ACCESSIBLE (see 8.4) or ACCESSIBLE conductive parts respectively,
the continuity of the protective earthing connection should be checked as late as possible
during the production process between the screen or metal barrier and
– the protective earthing contact of the MAINS plug or appliance inlet, or
– the PROTECTIVE EARTHING TERMINAL in case of a PERMANENTLY CONNECTED APPARATUS.
The test current applied for 1 s to 4 s should be in the order of 10 A a.c., derived from a source
having a no-load voltage not exceeding 12 V.
The measured resistance should not exceed
– 0,1 Ω for apparatus with a detachable power supply cord,
– 0,2 Ω for apparatus with a non-detachable power supply cord.
NOTE Care should be taken that the contact resistance between the tip of the measuring probe and the metal
parts under test does not influence the test results.

红字部分是我的疑惑，为什么会有0.2的要求呢？这个出于什么考虑，是所有情况都是这样吗？还是需要有 screen or metal barrier 的情况下才有。正常情况下应该是按照15.2中关于接地导通的要求：
The resistance of the connection between the PROTECTIVE EARTHING TERMINAL or contact, and
parts required to be connected thereto, shall not exceed 0,1 Ω.
我想的是为什么会有0.2的要求，请各位大神相助~~~

jia_suwei 发表于 2011-12-20 11:16

自己先顶下防沉！

byeice 发表于 2011-12-20 11:21

防沉帮顶

jia_suwei 发表于 2011-12-20 11:22

byeice 发表于 2011-12-20 11:21 static/image/common/back.gif
防沉帮顶

谢谢~~

jia_suwei 发表于 2011-12-20 11:23

急需答案或者指导，懂的人情指导下谢谢~~

zhuzifei 发表于 2011-12-20 11:24

我觉得这个0.2是针对永久连接设备的
– the PROTECTIVE EARTHING TERMINAL in case of a PERMANENTLY CONNECTED APPAR
大家可以讨论下！

byeice 发表于 2011-12-20 11:27

0.1Ω的限值对应的是是可拆卸电源软线的设备
0.2Ω的限值对应的是是不可拆卸电源软线的设备

请各位大拿拍砖

jia_suwei 发表于 2011-12-20 11:37

byeice 发表于 2011-12-20 11:27 static/image/common/back.gif
0.1Ω的限值对应的是是可拆卸电源软线的设备
0.2Ω的限值对应的是是不可拆卸电源软线的设备



从标准上看确实是这样的，我想问的是这个规定是不是有一个前提，就是For CLASS I apparatus with a screen or metal barrier ，如果没有这个条件是不是也是这样的情况，还是没有这个前提的时候就按0.1来算。这个是问题的本质!

jia_suwei 发表于 2011-12-20 11:38

zhuzifei 发表于 2011-12-20 11:24 static/image/common/back.gif
我觉得这个0.2是针对永久连接设备的
– the PROTECTIVE EARTHING TERMINAL in case of a PERMANENTLY CON ...

这个在上面的标准中是明确说明的关键是在15.2章节中提出0.1欧姆的情况下，为什么还有一个0.2的要求？

jia_suwei 发表于 2011-12-20 11:38

引起讨论，请大大们现身说法:$
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