An electrical apparatus including, for the connection and disconnection of a conductive cable (37, 38): - an orifice (21, 22, 23, 24; 89, 90) for introducing said cable (37, 38); - a resilient strip (33, 34; 91) including a holding ridge (41, 42), which resilient strip (33, 34; 91) is facing said introduction orifice (21, 22, 23, 24; 89, 90) and facing a contact portion (39, 40) of a conductive element connected to the rest of said apparatus, said resilient strip (33, 34; 91) as well as the introduction orifice it is facing as well as the conductive element, including the contact portion (39, 40), it is facing being configured so that a contact end (43, 44) of one said conductive cable (37, 38) is insertable into the introduction orifice to come into a connection position where the contact end (43, 44) is pinched between the holding ridge (41, 42) and the contact portion (39, 40); and - a pusher (50; 72) associated with said resilient strip (33, 34; 91), configured to bear against said resilient strip (33, 34; 91) and drive the holding ridge (41, 42) of said resilient strip (33, 34; 91) away from said contact portion (39, 40) whereby the conductive cable (37, 38) whose contact end (43, 44) was pinched can be removed, said pusher (50; 72) including a control button (31, 32; 70, 71) which is movable between an extended position and a retracted position in which the pusher (50; 72) is bearing on the resilient strip (33, 34; 91) to put the holding ridge (41, 42) away from the contact portion (39, 40); characterized in that said pusher (50; 72) and walls included in a casing of said apparatus to delimit a housing in which said key (31, 32; 70, 71) is located are configured so that said key (31, 32; 70, 71) is movable with respect to the rest of the pusher (50; 72) between a relative nominal position and a relative locking position that the key (31, 32; 70, 71) can take exclusively when the pusher (50; 72) is in the retracted position, with the pusher (50; 72) which is freely movable between said extended position and said retracted position when the key (31, 32; 70, 71) is in the relative nominal position and with the pusher (50; 72) which is held in the retracted position when the key (31, 32; 70, 71) is in the relative locking position. - an orifice (21, 22, 23, 24; 89, 90) for introducing said cable (37, 38); - a resilient strip (33, 34; 91) including a holding ridge (41, 42), which resilient strip (33, 34; 91) is facing said introduction orifice (21, 22, 23, 24; 89, 90) and facing a contact portion (39, 40) of a conductive element connected to the rest of said apparatus, said resilient strip (33, 34; 91) as well as the introduction orifice it is facing as well as the conductive element, including the contact portion (39, 40), it is facing being configured so that a contact end (43, 44) of one said conductive cable (37, 38) is insertable into the introduction orifice to come into a connection position where the contact end (43, 44) is pinched between the holding ridge (41, 42) and the contact portion (39, 40); and - a pusher (50; 72) associated with said resilient strip (33, 34; 91), configured to bear against said resilient strip (33, 34; 91) and drive the holding ridge (41, 42) of said resilient strip (33, 34; 91) away from said contact portion (39, 40) whereby the conductive cable (37, 38) whose contact end (43, 44) was pinched can be removed, said pusher (50; 72) including a control button (31, 32; 70, 71) which is movable between an extended position and a retracted position in which the pusher (50; 72) is bearing on the resilient strip (33, 34; 91) to put the holding ridge (41, 42) away from the contact portion (39, 40);