Residual current protection device

The invention discloses a residual current protection device in the technical field of low-voltage apparatuses. A wire inlet end wiring terminal assembly connected with a main circuit is beside a wire inlet side of a zero sequence current transformer, a wire outlet end wiring terminal assembly connected with the main circuit is beside a wire outlet side, a first insulator is arranged between the wire inlet end wiring terminal assembly and the zero sequence current transformer, a second insulator is arranged between the wire outlet end wiring terminal assembly and the zero sequence current transformer, the outer edges of the peripheries of the first insulator and the second insulator are square and the two are oppositely combined together to form a rectangular cavity, the zero sequence current transformer is accommodated in the cavity at one side, a second loop circuit board is accommodated at the other side in the cavity, a nested structure of inner and outer layer insulators is adopted, achieving a very good