目前,我国供电系统大都采用TN-C配电方式。在TN-C系统中,配电变压器低压侧中性点(N)直接接地,系统内所有用电设备外壳的保护线(PE)和中性线(N)连接。保护线连接必须可靠,否则会造成人身触电伤亡事故。保护线断开或接触不良造成人身触电伤害原因如 At present, most of our power supply systems use TN-C power distribution mode. In TN-C systems, the low voltage side neutral point (N) of the distribution transformer is directly grounded, and the protective conductor (PE) and the neutral (N) of all powered equipment housings in the system are connected. Protection line connection must be reliable, otherwise it will cause personal electric shock casualties. Protection of the line disconnect or poor contact cause personal injury causes such as electric shock