Abstract: A sensor arrangement for producing a signal representative of currents having frequencies and/or characteristics associated with arcing within an alternating current electrical system. The arrangement is coupled to an appropriate arc monitoring circuit which determines if the signal produced by the sensor is the result of arcing within the electrical system. One embodiment of the sensor arrangement includes an inductor, and a capacitor connected in series with the primary winding of a transformer. The inductor is typically connected in series with a phase conductor of the electrical system, and the capacitor and the primary winding are connected to the phase conductor in parallel to the inductor. Another embodiment of the sensor arrangement includes a capacitor and the primary winding of a transformer connected in series between the phase conductor of the electrical system and either a ground or neutral conductor of the system.