Circuit arrangement comprising - an inverter for feeding a power from a photovoltaic generator into an AC voltage grid, - a grounding device (GS1, GS2) for grounding the photovoltaic generator either at the positive terminal or at the negative terminal, - a first shunt (Rs), through which a grounding current flows on grounding at the positive terminal, and a second shunt, through which the grounding current flows on alternative grounding at the negative terminal, - wherein the two shunts (Rs, Rs2) are each inserted into a corresponding current mirror, - wherein the two current mirrors each consist of a pair of transistors of the same polarity, - wherein a resistor is connected in series with each transistor, - wherein the emitter connections of the two transistors of a current mirror are each connected via identical resistors to the two connections of the shunt, - wherein the two base connections of the two transistors of the current mirror are connected to one another and connected to a bias, and - wherein the two current mirrors are connected in opposition to one another at an evaluation point by connecting one collector connection of one current mirror to a collector connection of the other current mirror by means of an evaluation unit, - wherein the voltage drop caused by the grounding current through the respective shunt causes an asymmetry in the associated current mirror with a level proportional to the grounding current, and - wherein the asymmetry is evaluated at the evaluation point, at which the two current mirrors are connected in opposition to one another, by determining a differential current between the two nodes at the evaluation point and evaluating by the evaluation unit, and - wherein the potential of the evaluation point deviates considerably from the potential at which the respective grounding current flows. - an inverter for feeding a power from a photovoltaic generator into an AC voltage grid, - a grounding device (GS1, GS2) for grounding the photovoltaic generator either at the positive terminal or at the negative terminal, - a first shunt (Rs), through which a grounding current flows on grounding at the positive terminal, and a second shunt, through which the grounding current flows on alternative grounding at the negative terminal, - wherein the two shunts (Rs, Rs2) are each inserted into a corresponding current mirror, - wherein the two current mirrors each consist of a pair of transistors of the same polarity, - wherein a resistor is connected in series with each transistor, - wherein the emitter connections of the two transistors of a current mirror are each connected via identical resistors to the two connections of the shunt, - wherein the two base connections of the two transistors of the current mirror are connected to one another and connected to a bias, and - wherein the two current mirrors are connected in opposition to one another at an evaluation point by connecting one collector connection of one current mirror to a collector connection of the other current mirror by means of an evaluation unit, - wherein the two current mirrors each consist of a pair of transistors of the same polarity, - wherein a resistor is connected in series with each transistor, - wherein the emitter connections of the two transistors of a current mirror are each connected via identical resistors to the two connections of the shunt, - wherein the two base connections of the two transistors of the current mirror are connected to one another and connected to a bias, and - wherein the two current mirrors are connected in opposition to one another at an evaluation point by connecting one collector connection of one current mirror to a collector connection of the other current mirror by means of an evaluation unit, - wherein the voltage drop caused by the grounding current through the respective shunt causes an asymmetry in the associated current mirror with a level proportional to the grounding current, and - wherein the asymmetry is evaluated at the evaluation point, at which the two current mirrors are connected in opposition to one another, by determining a differential current between the two nodes at the evaluation point and evaluating by the evaluation unit, and - wherein the potential of the evaluation point deviates considerably from the potential at which the respective grounding current flows.