Provided is a plug for use as a disconnector for current transformers. Two types of short circuits are provided in the plug. A first short circuit is used for diverting overvoltages by short-circuiting the electrical contacts in the plug. A second short circuit is provided for short-circuiting electrical contacts in the plug when the plug is not contacted. The short circuits are designed in such a way that the first short circuit is used as a fuse when the second short circuit fails.