A device for connecting a single-phase device into a multiphase electric network

The invention relates to a device for connecting a single-phase electric device into a multiphase electric network, especially a three-phase network which supplies in particular single-phase electric devices connected to the supply network in many points of this network through single-phase electric sockets. The device (1) is connected with the phases (L1, L2, L3) of the supply network at the input and it is equipped with an electric socket (5) for connecting single-phase electric devices (2a) or (2b) in it, and it comprises a single-phase phase switch (4) for phase selection connected with a control unit (7). An executive unit (8) of the single-phase switch (4) for phase selection is electrically connected with a conductor (L) supplying the single-phase socket (5) and with one of the phases of the supply line (L1, L2, L3) through terminals (A', B', C') and it is coupled with the control unit (7) which is adapted to set signals that control the position of the executive element of the switch (4). The device (1) is characterized in that it comprises phase voltage meters (3) which are connected into the supply lines (L1, L2, L3) before the terminals (A', B', C') and they are connected with the control unit (7) to which there is also connected a current measuring device (6) connected with the wire (L) which supplies the single-phase socket (5).