335-1标准上22.33条款的理解
本帖最后由 305634483 于 2015-9-19 08:21 编辑家用的标准22.33上这个条款看的不是很明白,请大神帮忙解答一下。
Conductive liquids that are or may become accessible in normal use and conductive
liquids that are in contact with unearthed accessible metal parts shall not be in direct
contact with live parts. Electrodes shall not be used for heating liquids.
For class II construction, conductive liquids that are or may become accessible in normal
use and conductive liquids that are in contact with unearthed accessible metal parts shall
not be in direct contact with basic insulation or reinforced insulation unless the reinforced
insulation consists of at least 3 layers.
For class II construction, conductive liquids which are in contact with live parts shall not be
in direct contact with reinforced insulation unless the reinforced insulation consists of at
least 3 layers
其中第二段中讲到可导电液体不能与加强绝缘直接接触,除非加强绝缘是三层绝缘。那是不是说还有一种是双重绝缘的结构也是可以的?
第二段与第三段讲的区别是什么?
说出你不理解的地方,我来解答,列出个12345
这个最好提供具体案例,仅仅拿着标准来理解标准比较难解释 我觉得标准在这里其实考量点不在绝缘,而是在绝缘结构或机械性能上的可靠性,基本绝缘一般只有一层,就算有多层就基本绝缘的要求而言可能也非常之薄,三层组成的加强绝缘标准说可以接受,单层或双层加强绝缘不接受,据此分析,标准就是在表明只有单层的或双层的基本绝缘加强绝缘其结构完整性或机械强度在受外力作用时容易被破坏,关键是在有水的环境下,可能一条小缝隙通过液体渗漏就会导致绝缘失效,因此强调必须要有三层,如果是在干燥环境下裂条小缝估计问题不大,只不过由固体绝缘变成了爬电距离或电气间隙,不算完全失效
至于双重绝缘,区别于两层的加强绝缘,我认为是可以的,因为加强绝缘的两层是结合在一体的,很可能要裂一起裂要破一起破,而双重绝缘一般是分开的,不太容易同时出问题,因此可以接受
另外空气间隙构成的绝缘应该不在其考虑范围内
个人见解,仅供参考:P
本帖最后由 ID长就牛b 于 2015-9-20 21:52 编辑
22.33 Conductive liquids that are or may become accessible in normal use and conductive
liquids that are in contact with unearthed accessible metal parts shall not be in direct
contact with live parts or unearthed metal parts that are separated from live parts by basic
insulation only. Electrodes shall not be used for heating liquids.
For class II construction, conductive liquids that are or may become accessible in normal
use and conductive liquids that are in contact with unearthed accessible metal parts shall
not be in direct contact with basic insulation or reinforced insulation unless the reinforced
insulation consists of at least 3 layers.
For class II construction, conductive liquids which are in contact with live parts shall not be
in direct contact with reinforced insulation unless the reinforced insulation consists of at
least 3 layers.
An air layer shall not be used as basic insulation or supplementary insulation in a double
insulation system if it is likely to be bridged by leaking liquid.
Compliance is checked by inspection.我理解的应该就是热哥所说的那样,至于两段的区别,一个是正常使用中可能碰触的导电性液体和带电部件接触的导电性液体,大概就是一个内一个外吧,
言简意赅:
在II类结构中,当加强绝缘用于隔离液体时(不管是液体为易触及,通过加强绝缘与带电部件隔离,还是液体带电,通过加强绝缘与可触及部位隔离),加强绝缘应该具有3层或3层以上的结构才被认为是足够安全的。
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