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漏电断路器的选择上海人民电器厂概述

2020/11/30 14:56:43      点击:

 漏电断路器的选择

  漏电断路器一般分为二极、三极、四极,分别应用于不同的线路中。只有正确的选择与使用才能起到应有的作用,所以选择漏电断路器时要注意以下五点:

  1)过载脱扣器的额定电流≥线路的* 大负载电流;2)断路器的极限通断能力≥电路* 大短路电流;3)线路应保护的漏电电流应≤断路器的规定漏电保护电流;4)线路设备的正常工作电压和电流≤断路器的额定电压、电流;5)有较短的分断反应时间,能够起到保护线路和设备的作用。

  有时在应用中对于是否选用四极断路器很难做出判断,在此提出对于是否选择四极断路器需遵循的原则,在下列情况下应选择四极断路器:

  1)根据IEC465.1.5条规定,正常供电电源与备用发电机之间的转换断路器;2)带漏电保护的双电源转换断路器应采用四极断路器。两个上级断路器带漏电保护,其下级的电源转换断路器;3)在两种不同接地系统间电源切换断路器;4)TT系统的电源进线断路器;5)IT系统中当有中性线引出时采用的断路器。

  在下列情况下一般不需要使用四极断路器或禁止使用四极断路器:

  1)TN-S、TN-C-S系统一般不需要设置四极断路器;2)TN-C系统严禁使用四极断路器。