A protective cover (100), made of electrically insulating material, intended to be mounted on the rear bearing (14) of a polyphased rotating electrical machine of a type comprising, in addition to the cover (100) covering the rear bearing (14), an outer frame (13,14) comprised of a rear bearing (14) and having a polyphased wound stator (8), in which the phase outputs are connected to a phase connector (102) intended to be connected to an exterior electronic module and a support (100), made of electrically insulating material, and fixed-mounted on the rear bearing (14) and holding the phase connector (102), characterized in that the cover (100) is configured to both support the phase connector (102) and cover the rear bearing (14).