To realize the transmission of energy with an opened network, by so providing each switch in each conductor segment as to start its operation when at least one voltage of each conductor segment is lowered below a first starting threshold or exceeds a second starting threshold, and by making each current limiting element bridge each switch.

A generator 10 generates a voltage fed to two conductors 11, 12, and so operates as to feed energies/data to stations 13, 14, 15... connected with the two conductors 11, 12. Separating units 16 for separating all the stations of a system therefrom are provided in the conductors 11, 12, and a separating unit 18 for separating only one predetermined user is provided in the feeding leads to this user. Giving each reference number to each conductor segment 11a, each conductor segment 11a is disposed behind each separating unit 16, observing it from the generator 10. When short-circuits and overcurrents are generated in the stations of each conductor segment 11a, they are separated from the remaining portions of the system, together with all users connected with this conductor segment 11a.