Switching device (14a..14e), comprising - a housing, - two main terminals (16a, 16b) reaching through the housing, - a main current path, which connects the two main terminals (16a, 16b) within the housing and which comprises a first electrical conductor having a first resistance (R 1), and - a switch arranged within the housing in the main current path, characterized in - a second electrical conductor (5, 5a, 5b), completely within the housing or having a first part and a second part, wherein the second part is within the housing and the first part is detachably connected to the second part via secondary terminals such that the second electrical conductor (5, 5a, 5b), when formed by the first part and the second part, is led through the housing, wherein the second electrical conductor (5, 5a, 5b) is configured to be connected in parallel to the first electrical conductor, and wherein the second electrical conductor (5, 5a, 5b) has a second resistance higher than the first resistance, and - a hall sensor, which is prepared to measure a current (I 2) through the second electrical conductor (5, 5a, 5b), - wherein the first resistance (R 1) and the second resistance (R 2) each are below 0.1 Ω between connection points (P 1, P 2) between the first electrical conductor and the second electrical conductor (5, 5a, 5b) and - wherein the hall sensor is arranged a) on or near to the second electrical conductor (5, 5a, 5b) or b) in an air gap of an annular magnetic core around the second electrical conductor (5, 5a, 5b) or c) in an air gap of an annular magnetic core around which the second electrical conductor (5, 5a, 5b) is wound or d) on or near an open, non-annular magnetic core around which the second electrical conductor (5, 5a, 5b) is wound. - a housing, - two main terminals (16a, 16b) reaching through the housing, - a main current path, which connects the two main terminals (16a, 16b) within the housing and which comprises a first electrical conductor having a first resistance (R 1), and - a switch arranged within the housing in the main current path, characterized in - a second electrical conductor (5, 5a, 5b), completely within the housing or having a first part and a second part, wherein the second part is within the housing and the first part is detachably connected to the second part via secondary terminals such that the second electrical conductor (5, 5a, 5b), when formed by the first part and the second part, is led through the housing, wherein the second electrical conductor (5, 5a, 5b) is configured to be connected in parallel to the first electrical conductor, and wherein the second electrical conductor (5, 5a, 5b) has a second resistance higher than the first resistance, and - a hall sensor, which is prepared to measure a current (I 2) through the second electrical conductor (5, 5a, 5b), - wherein the first resistance (R 1) and the second resistance (R 2) each are below 0.1 Ω between connection points (P 1, P 2) between the first electrical conductor and the second electrical conductor (5, 5a, 5b) and - wherein the hall sensor is arranged a) on or near to the second electrical conductor (5, 5a, 5b) or b) in an air gap of an annular magnetic core around the second electrical conductor (5, 5a, 5b) or c) in an air gap of an annular magnetic core around which the second electrical conductor (5, 5a, 5b) is wound or d) on or near an open, non-annular magnetic core around which the second electrical conductor (5, 5a, 5b) is wound. a) on or near to the second electrical conductor (5, 5a, 5b) or b) in an air gap of an annular magnetic core around the second electrical conductor (5, 5a, 5b) or c) in an air gap of an annular magnetic core around which the second electrical conductor (5, 5a, 5b) is wound or d) on or near an open, non-annular magnetic core around which the second electrical conductor (5, 5a, 5b) is wound.