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上海人民电器厂讲解漏电断路器如何选型

2020/8/5 10:32:41      点击:

漏电断路器如何选型?为了大家的使用安全,必须注意漏电断路器的选型原则,这里给大家分享一下,希望大家能够受益:

一:根据电路和设备的正常泄漏电流来选择

①主干线或全网总;さ穆┑缍下菲,其动作电流应大于电网正常运行时泄漏电流的2.5倍。

②单机配用的漏电断路器.动作电流应大于设备正常运行时泄漏电流的4倍。

③用于分支线路的漏电断路器,动作电流应大于线路正常运行时泄漏电流的2.5倍,同时也要大于线路中泄漏电流最大的电气设备的泄漏电流的4倍。

二:如果不容易测量线路或电气设备的泄漏电流,可按照下面的经验公式进行估算:

照明回路或居民生活用电回路:漏电断路器的动作电流IDZ>ISJ/2000;动力与照明混合回路:漏电断路器的动作电流IDZ>ISJ/1000

公式中IDZ为漏电断路器动作电流,ISJ为电路中的最大电流。

①三相三线制380V电源供电的电气设备,应选用三极四线式或四极四线式漏电断路器。

单相220V电源供电的电气设备应选用二极二线式或单极二线式漏电断路器。

②三相三线制380V电源供电的电气设备,应选用三极四线式或四极四线式漏电断路器。

三:根据使用目的和电气设备所在的场所来选择

①直接接触触电的防护

因直接接触触电的危害比较大,引起的后果严重,所以要选用灵敏度较高的漏电断路器,对电动工具、移动式电气设备和临时线路,应在回路中安装动作电流为30mA,动作时间在0.1s之内的漏电断路器。对家用电器较多的居民住宅,最好安装在进户电能表后。

如果一旦触电容易引起二次伤害(比如高空作业),应在回路中安装动作电流为15mA,动作时间在US之内的漏电断路器。对于医院中的电气医疗设备,应安装动作电流为6mA,动作时间在US之内的漏电断路器。

②间接接触触电防护

不同场所的间接接触触电,能对人身造成不同程度的伤害,所以,不同场所应安装不同的漏电断路器。对容易触电的危害性较大的场所,要求用灵敏度比较高的漏电断路器。在潮湿场所比在干燥场所触电的危险性要大得多,一般应安装动作电流为15-30mA,动作时间在0.1s之内的漏电断路器。对于水中的电器设备,应安装动作。电流为6-l0mA,动作时间在US之内的漏电断路器。对于操作人员必须站在金属物体上或金属容器内的电气设备,只要电压高于24V,就应安装动作电流为15mA以下,动作时间在US之内的漏电断路器。对电压为220V或380V的固定电气设备,当外壳接地电阻在500fZ以下时,单机可安装动作电流为30mA,动作时间在0.19之内的漏电断路器。对额定电流在100A以上的大型电气设备或带有多台用电设备的供电回路,可安装动作电流为50--100mA的漏电断路器,对用电设备的接地电阻在1000以下时,可安装动作电流为200-500mA的漏电断路器。

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