A terminal casing includes an one upper cover and one lower cover making a housing that can be closed by a removable hatch having a curvilinear profile. The hatch includes grooves distributed longitudinally on two parallel faces following the curvilinear profile. The lower cover includes tabs distributed longitudinally on two parallel faces in following the curvilinear profile, each tab cooperating with an associated groove. The tabs and the grooves are shaped to enable: through a translational motion followed by a rotational motion of the hatch, an insertion and a guidance of the tabs in the grooves of the hatch, when the hatch is inserted into the lower cover; and through a rotational motion followed by a translational motion of the hatch, a guidance of the tabs in the grooves of the hatch and a withdrawal of the tabs from the grooves when the hatch is withdrawn from the cove.