A system for transmitting electric power through a wall, including a housing intended for being rigidly connected to the wall, and two penetrator sub-units on either side of the housing, each including a conductive element and an insulating element rigidly connected to one another. The system is arranged so as to maintain electrical contact between the conductive elements of the penetrator sub-units while enabling the conducting elements to move axially relative to one another. The insulating elements of the two penetrator sub-units engage with the housing such that the compression forces to which each penetrator sub-unit is exposed are at least partially transmitted to the housing.