An electrical device for protection against residual currents, which comprises an insulating casing having a rear wall, a front wall, a bottom wall, a top wall, and two side walls. Inside said casing there are: a residual-current sensor, which comprises a toroidal core, a primary winding and a secondary winding; and a tripping relay, having a containment box, from a wall of which there protrude a first pin and a second pin designed to enable operative connection of the relay with the current sensor via circuit-connection means positioned between them. Said connection means comprise a first substantially rigid body, on which there are defined two distinct electrically conductive paths; the first conductive path has a first end connected to the secondary winding and a second free end designed to be connected operatively to said first pin, and the second path has a third end connected to the secondary winding and a fourth free end designed to be connected to said second pin, said first and second pins and said second and fourth free ends being located in a spatial position that is pre-defined with respect to one of said walls of the casing.