保护接零系统又叫作TN系统,N表示电气设备在正常情况下不带电的金属部分与配电网中性点之间直接连接。TN系统又分为TN-S、TN-C-S、TN-C三种情况,下列图
A <img width="321" height="177" src="https://www.beizhujiaoyu.com/uploads/202208/20201125202028_7270.png" /> B <img width="353" height="176" src="https://www.beizhujiaoyu.com/uploads/202208/20201125202029_4770.png" /> C <img width="329" height="170" src="https://www.beizhujiaoyu.com/uploads/202208/20201125202031_1489.png" /> D <img width="312" height="200" src="https://www.beizhujiaoyu.com/uploads/202208/20201125202031_6333.png" />