Abstract: A system (1, 100) with socket (20, 120)/plug (10, 110) is described, designed to prevent access to the electrical phase contacts (32, 132) and neutral contacts (33, 133) of the socket (10, 120) when the plug (10, 110) is not inserted in the socket (20, 120), and designed to ensure a phase to phase and neutral to neutral connection, in which, inside the socket (20, 120) there is a contact holder element (30) which, following the insertion of the plug (10, 110), retracts and interacts with a system of inclined guides (25) obtained in a structural rear part (24, 124) of the socket (20, 120), causing a transversal movement of the electrical phase contacts (32, 132) and neutral contacts (33, 133), able to make a connection with the corresponding electrical phase contacts (13, 113) and neutral contacts (14, 114) present on the plug (10, 110).