Circuit arrangement (G, S) with a rectifier and a circuit for protecting at least one DC network with one or more DC loads connectable to the circuit arrangement (G, S), wherein the DC network is supplied with electric power from an AC grid via the rectifier, the DC network is protected by means of the circuit from overvoltages from the AC grid, and - the circuit includes means for detecting overvoltage, by which overvoltage can be detected at the input of the DC network, - the rectifier has a choke (L G2) referred to as a second choke between a terminal for a negative potential of the rectifier and the terminal for a negative output potential, - the circuit has a second controllable switch element (TH G2) as means (TH G2) for discharging the choke (L G2) which switch element is arranged in a branch parallel to the choke (L G2), characterised in that the - the rectifier can be powered by a three-phase AC grid, - the rectifier has a first group of thyristors (TH U1, TH V1, TH W1) and a second group of thyristors (TH U2, TH V2, TH W2) which form a controlled six pulse bridge circuit, - the circuit comprises means (3, 4, TH 1, Ls, Cs, Du, Dv, Dw) for transferring the current from one or several current-carrying thyristors (TH U1, TH V1, TH W1) of the first group of thyristors (TH U1, TH V1, TH W1) of the rectifier, wherein the transfer is performed as soon as the means for detecting overvoltage has detected an overvoltage, and wherein the transfer of the current forces the thyristor or thyristors (TH U1, TH V1, TH W1) of the first group to turn off, - the rectifier has a first choke (L G1) between a terminal for a positive potential of the six pulse bridge circuit and the terminal for a positive output potential, - the circuit has an additional second controllable switch element (TH G1) as means (TH G1, TH G2) for discharging the first choke (L G1) of the three-phase rectifier, which switch element is arranged in a branch parallel to the first choke (L G1), - wherein the second controllable switch element (TH G1) and the further second controllable switch element (TH G2), as soon as an overvoltage has been detected by the means for detecting overvoltage, are controlled to close by a controller of the means (3, 4, TH 1, Ls, Cs, Du, Dv, Dw) for transferring the current. - the circuit includes means for detecting overvoltage, by which overvoltage can be detected at the input of the DC network, - the rectifier has a choke (L G2) referred to as a second choke between a terminal for a negative potential of the rectifier and the terminal for a negative output potential, - the circuit has a second controllable switch element (TH G2) as means (TH G2) for discharging the choke (L G2) which switch element is arranged in a branch parallel to the choke (L G2), characterised in that the - the rectifier can be powered by a three-phase AC grid, - the rectifier has a first group of thyristors (TH U1, TH V1, TH W1) and a second group of thyristors (TH U2, TH V2, TH W2) which form a controlled six pulse bridge circuit, - the circuit comprises means (3, 4, TH 1, Ls, Cs, Du, Dv, Dw) for transferring the current from one or several current-carrying thyristors (TH U1, TH V1, TH W1) of the first group of thyristors (TH U1, TH V1, TH W1) of the rectifier, wherein the transfer is performed as soon as the means for detecting overvoltage has detected an overvoltage, and wherein the transfer of the current forces the thyristor or thyristors (TH U1, TH V1, TH W1) of the first group to turn off, - the rectifier has a first choke (L G1) between a terminal for a positive potential of the six pulse bridge circuit and the terminal for a positive output potential, - the circuit has an additional second controllable switch element (TH G1) as means (TH G1, TH G2) for discharging the first choke (L G1) of the three-phase rectifier, which switch element is arranged in a branch parallel to the first choke (L G1), - wherein the second controllable switch element (TH G1) and the further second controllable switch element (TH G2), as soon as an overvoltage has been detected by the means for detecting overvoltage, are controlled to close by a controller of the means (3, 4, TH 1, Ls, Cs, Du, Dv, Dw) for transferring the current.