TOPJOB®S main distribution set FI, for the main distribution with several residual current switches and correspondingly small circuit groups, contains all the components required for wiring a feed and connecting 14 alternating current and 2 three-phase circuits. The residual current potentials are fed individually into each terminal. Using optional jumpers, the residual current potentials can be cross-bridged to adjacent terminals and small circuit groups can be formed. Separation of the N potentials for insulation resistance measurement via isolating knife in the installation level terminal.