接地引线在零序电流互感器的穿法：
How to thread the grounding lead in the zero sequence current transformer:
1、错误接线时的接引方式：
1. Connection mode in case of wrong wiring:
电缆接地引线常见的错误接线方式有以下两种情况。
There are two common wrong wiring ways of cable grounding lead.
（1）、电缆头及电缆接地引线位于零序套管上方时的错误接线方式。
(1) wrong wiring mode when cable head and cable grounding lead are above zero sequence bushing.
当一次电缆的屏蔽层接地引线在零序套管上方直接接地时，若一次电缆屏蔽层只穿过零序套管互感器一次，则会造成该开路零序保护拒动或误动，从而造成保护越级故障扩大。
When the grounding lead of the primary cable shield layer is directly grounded above the zero sequence bushing, if the primary cable shield layer only passes through the zero sequence bushing transformer once, it will cause the open circuit zero sequence protection to refuse to operate or misoperate, thus resulting in the expansion of protection over level fault.
（2）、电缆头及电缆接地引线位于零序套管下方时的错误接线方式。当一次电缆的屏蔽层接地引线在零序套管下方又穿过套管进行接地时，相当于一次电缆屏蔽层只穿过零序套管互感器一次，则仍会造成该开路零序保护拒动或误动，从而造成保护越级故障扩大。
(2) wrong wiring mode when cable head and cable grounding lead are under zero sequence bushing. When the grounding lead of the primary cable shield layer passes through the bushing under the zero sequence bushing for grounding again, it is equivalent to that the primary cable shield layer passes through the zero sequence bushing transformer only once, which will still cause the open circuit zero sequence protection to fail to operate or misoperate, thus resulting in the expansion of protection over level fault.