医用电气设备安全接地简介

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                    <section><section powered-by="gulangu"><section><section><p><img src="image/20201019/d6e89edf6139ad8643ba162be5e9a663_1.gif" /></p></section></section></section><section powered-by="gulangu"><section><section><p>设备接地的目的</p></section> <p><img src="image/20201019/237ff723e23881a3d146532f7bfe985e_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 为实现电气安全防护的接地，例如防电击，叫保护接地；为实现某种功能而进行的接地，例如减少电磁干扰，这种目的的接地叫功能接地。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/a176d9b80615f7dd22facac20c6eac62_3.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>保护接地的原理</p></section> <p><img src="image/20201019/237ff723e23881a3d146532f7bfe985e_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 为了实现防电击目的而把可触及的导体部件与建筑物接地系统或大地相导通的一种系统结构。 当电气设备绝缘损坏或产生漏电流时，保护接地能引起所配置的过流保护装置切断发生故障部分的供电，使人接触到外露的可导电部件时能免受到电击危险。另外保护接地还能将静电荷导入大地，防止由于静电荷的积聚造成对设备或人员的伤害。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/c2321035c1a0af04358472476384348a_5.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>保护接零的原理</p></section> <p><img src="image/20201019/237ff723e23881a3d146532f7bfe985e_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;保护接零就是将电气设备在正常情况下不带电的金属部分（外壳），用导线与低压配电网的零线（中性线）紧密地直接连接。应当注意的是，在三相四线制的电力系统中，通常是把电气设备的金属外壳同时接地、接零，这就是所谓的重复接地保护措施，但还应该注意，零线回路中不允许装设熔断器和开关。&nbsp; &nbsp;</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/a0490cec34ee93e8a3bd7eaec200c23e_7.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;电气设备保护接零后，当设备发生碰壳短路时，短路电流就由相线流经外壳到零线，再回到变压器的中性点。因故障回路的电阻、电抗都很小，所以故障电流很大，它足以使线路上保护装置（熔断器或自动开关）迅速动作，从而将漏电的设备断开电源，消除危险。</p></section></section></section><section powered-by="gulangu"><section><section><p>重复接地的原理</p></section> <p><img src="image/20201019/237ff723e23881a3d146532f7bfe985e_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 在低压三相四线制采用保护接零的系统中，为了加强接零的安全性，在零线的一处或多处通过接地装置与大地再次连接，称为重复接地。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/d8bdbfe8890a559f458609ace2323953_9.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 重复接地的主要作用：</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 1）减轻零线断线的危险。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 2）降低漏电设备对地电压。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 3）缩短故障持续时间。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 4）改善防雷性能。</p></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section> <section powered-by="gulangu"><section><section><p>欢</p></section></section></section> </section><section> <section powered-by="gulangu"><section><section><p>迎</p></section></section></section> </section><section> <section powered-by="gulangu"><section><section><p>关</p></section></section></section> </section><section> <section powered-by="gulangu"><section><section><p>注</p></section></section></section> </section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section> <section powered-by="gulangu"><section><section><p><img src="image/20201019/7856584fda94ba1983014b524dead643_10.jpg" /></p></section></section></section> </section><section> <section powered-by="gulangu"><section><section> </section></section></section> </section><section> <section powered-by="gulangu"><section><section><p>关注我们</p><p>一起涨姿势！</p></section></section></section> </section></section></section></section>