A method for protecting an inverter assembly against a direct current arc, the inverter assembly comprising: an input (DC IN) adapted to be connected to a direct current supply; an output (AC OUT) adapted to be connected to an alternating current load; an inverter operationally connected between the input (DC IN) and the output (AC OUT), the inverter is adapted to convert direct current supplied through the input (DC IN) into alternating current, and to supply the alternating current to the output (AC OUT); a direct current conductor system electrically conductively connecting the input (DC IN) to the inverter, the direct current conductor system comprising a positive conductor (CD+) and a negative conductor (CD-), the method comprising detecting a direct current arc present in the direct current conductor system by means of an arc detection process, and extinguishing the direct current arc detected by the arc detection process, characterized in that the arc detection process comprises: determining an input power of the inverter assembly; determining an output power of the inverter assembly; comparing the input power and the output power in order to determine whether there is an indicative power difference between the input power and the output power; and detecting the direct current arc if predetermined arc conditions are fulfilled, the predetermined arc conditions include presence of the indicative power difference. an input (DC IN) adapted to be connected to a direct current supply; an output (AC OUT) adapted to be connected to an alternating current load; an inverter operationally connected between the input (DC IN) and the output (AC OUT), the inverter is adapted to convert direct current supplied through the input (DC IN) into alternating current, and to supply the alternating current to the output (AC OUT); a direct current conductor system electrically conductively connecting the input (DC IN) to the inverter, the direct current conductor system comprising a positive conductor (CD+) and a negative conductor (CD-), the method comprising detecting a direct current arc present in the direct current conductor system by means of an arc detection process, and extinguishing the direct current arc detected by the arc detection process, characterized in that the arc detection process comprises: determining an input power of the inverter assembly; determining an output power of the inverter assembly; comparing the input power and the output power in order to determine whether there is an indicative power difference between the input power and the output power; and detecting the direct current arc if predetermined arc conditions are fulfilled, the predetermined arc conditions include presence of the indicative power difference. determining an input power of the inverter assembly; determining an output power of the inverter assembly; comparing the input power and the output power in order to determine whether there is an indicative power difference between the input power and the output power; and detecting the direct current arc if predetermined arc conditions are fulfilled, the predetermined arc conditions include presence of the indicative power difference.