Residual current circuit breaker

The utility model relates to a residual current circuit breaker which comprises a housing, and a circuit breaker module and an electric leakage module which are arranged in the housing; a module separator plate and a connection separator plate are formed on the housing; a zero line connection hole corresponding to a zero line connection terminal is formed on the module separator plate; the zero line connection terminal extends towards the zero line connection hole and passes through the zero line connection hole; a zero line through-hole is formed in a position on the module separator plate, which corresponds to a connecting plate; one end of a braided wire of a zero line is connected with a zero line connection terminal, and the other end passing through a zero sequence transformer and the zero line through-hole is connected with the connecting plate; a bimetallic through-hole and a live wire through-hole are respectively formed in positions on the module separator plate, which correspond to a bimetallic strip and a coil; and one end of a braided wire of a live wire is connected to the bimetallic strip, and the other end sequentially passing through the bimetallic through-hole, the zero sequence transformer and the live wire through-hole is connected with the coil. Through the live wire in the circuit breaker and the through-holes between the circuit breaker module and the electric leakage module, the residual current circuit breaker achieves connection with the zero sequence transformer without using an external coiling, so that the residual current circuit breaker is compacter and smaller.