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2000线以上长话局联合接地装置的接地电阻值要求()欧姆。

发布日期:2021-03-12

2000线以上长话局联合接地装置的接地电阻值要求()欧姆。
A

(小于5)

B

(小于3)

C

(小于1)

试题解析

接地装置

接地装置是指埋设在地下的接地电极与由该接地电极到设备之间的连接导线的总称。

中文名
接地装置
别名
接地一体化装置
技术
建筑电气施工技术
外文名
Grounding device
组成
接地体、

长话

长话,汉语词语,拼音是cháng huà,意思是冗长拉杂的话。

中文名
长话
释义
冗长拉杂的话
注音
cháng huà
出处
《西游记》

接地

接地(earthing)接地指电力系统和电气装置的中性点、电气设备的外露导电部分和装置外导电部分经由导体与大地相连。可以分为工作接地、防雷接地和保护接地。工作接地就是由电力系统运行需要而设置的(如中性点接地),因此在正常情况下就会有电流长期流过接地电极,但是只是几安培到几十安培的不平衡电流。在系统发生接地故障时,会有上千安培的工作电流流过接地电极,然而该电流会被继电保护装置在0.05~0.1s内切除,即使是后备保护,动作一般也在1s以内。防雷接地是为了消除过电压危险影响而设的接地,如避雷针、避雷线和避雷器的接地。防雷接地只是在雷电冲击的作用下才会有电流流过,流过防雷接地电极的雷电流幅值可达数十至上百千安培,但是持续时间很短。保护接地是为了防止设备因绝缘损坏带电而危及人身安全所设的接地,如电力设备的金属外壳、钢筋混凝土杆和金属杆塔。保护接地只是在设备绝缘损坏的情况下才会有电流流过,其值可以在

中文名
接地
拼音
jiē dì
释义
一种用电安全措施
外文名
earthing
相关领域
电学
常见种类
保护接地、工作接地、防雷接地等

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