An arc fault detection arrangement for a DC electric bus, the DC electric bus having one or more electric lines adapted to electrically connect a source section and a load section of an electric apparatus, the arc fault detection arrangement including an arc fault detector adapted to receive and process detection signals indicative of AC currents flowing along the electric lines. The arc fault detection arrangement comprises a current sensing device including: primary winding means including a first primary winding conductors and a second primary winding conductors adapted to be electrically connected in series with source portions and load portions of corresponding first and second line conductors of the electric lines, so that common-mode electric currents flowing along the first and second primary winding conductors generate magnetic fluxes with opposite directions; secondary winding means magnetically coupleable with the first primary winding means, the secondary winding means comprising a first secondary winding conductor electrically connected with the arc fault detector to provide the detection signals to the arc fault detector.