Energy production plant with power converter unit

An energy production plant with a power converter circuit configured to connect to a PV generator, wherein the PV generator comprises a plurality of PV main strings connected in parallel and each connected to the power converter circuit of the PV energy production plant via two DC input lines on an input side of the power converter circuit via a DC link circuit, wherein the DC link circuit of the power converter circuit is electrically isolated, the energy production plant further comprising a monitoring circuit comprising a differential current measuring sensor or circuit, an isolating circuit or switch and a controller circuit assigned to each pair of DC input lines assigned to a PV main string, wherein the controller circuit of the monitoring circuit is configured to switch the isolating circuit or switch and to isolate the PV main string after a fault has been identified by virtue of a differential current threshold value being exceeded, wherein at least one discharge capacitance to earth is arranged as a feedback path for an earth current measurement by the differential current measuring device, at at least one pole of the DC link circuit.