A method for discharging a capacitor of an input or output circuit arrangement of an inverter for supplying current to a power supply grid includes determining voltage readings at connections of the input or output circuit arrangement and a DC link capacitor of the inverter; and calculating an upper limit voltage value of the DC link capacitor based on the measured values. The method also includes operating a DC/DC converter or a bridge arrangement of the inverter such that energy from the capacitor of the input or output circuit arrangement is transferred to the DC link capacitor, ending the method if the voltage across the DC link capacitor exceeds the upper voltage limit. Otherwise the method continues to transfer energy from the capacitor of the input or output circuit arrangement to the DC link capacitor until the capacitor is discharged to or below a lower limit voltage value.