TOPJOB®S main distribution set FI, for the main distribution with two residual current circuit breakers, contains all the components required for wiring a feed-in and connecting 14 alternating current and 2 three-phase circuits, distribution of the FI potentials via 2 N busbars 10 x 3 mm, separation of the N potentials for the insulation resistance measurement via a separating slide in the installation level terminal.