Residual current circuit breaker

The utility model relates to a residual current circuit breaker which comprises a tripping device, an acting mechanism, an arc extinguishing device and a zero sequence mutual inductor, wherein the tripping device comprises an oil cup, an iron core, a coil, a pole shoe, a magnetic yoke, an armature and a drive plate; the oil cup is internally filled with silicon oil, the iron core is arranged in the oil cup, the lower end of the iron core is provided with an iron core spring, the lower end of the oil cup is provided with the pole shoe, the magnetic yoke is arranged outside the oil cup, the coil cup is fixed on the magnetic yoke, the armature is arranged on the magnetic yoke, the armature and the oil cup are arranged side by side, one end of the armature props against the drive plate, the drive plate is connected with the acting mechanism, a return spring is arranged at the other end of the armature, and the coil is wound on the outer wall of the oil cup. The tripping device adopts electromagnetic hydraulic tri