An electrical connection device (1) including a (male) connection plug (2) provided with a plurality of pin- or blade-shaped electrical contacts (3) cantileverly extending from a front face (4) of the connection plug, substantially perpendicular to the face itself, so as to be insertable in use, for the whole length thereof, in a (female) power supply/electrical connection socket (5) for the electrical and mechanical coupling with respective conjugated electrical contacts (6) of the socket; and a removable protection element (10) including a plate (11) which may be frontally coupled in abutment with the front face of the connection plug and a plurality of through-holes (12) obtained through the plate, in the direction of the thickness thereof, so as to be arranged in use substantially perpendicular to the front face (4) of the connection plug, each hole (12) being adapted to throughly receive a respective said contact (3) so that, when the plate is coupled in abutment against the front face of the connection plug, the contacts (3) are housed for the most part of their length within the plate (11), though having respective free ends (13) cantileverly extending out from the plate, on the side opposite to the front face of the connection plug, so as to allow at least the electrical connection of the contacts to said power supply/electrical connection socket (5) or, at least, to a testing socket for the connection plug.