Observation of break arc movements of AgSnO2 contacts under external magnetic field in light-level inductive DC load conditions

Break arc behaviors of AgSnO
2
contact pairs in a DC inductive load circuit with 14V or 20V and up to 16A were studied with/without application of an external magnetic field and at a contact opening speed in the range of 5 to 200 mm/s. Even with smaller load current levels and at slower opening speeds, slight shortening of arc durations was observed with the applied external magnetic field, although magnetic arc blowing did not occur. Arc movement observations were tried to study influences of external magnetic field application on such arc shortening effects of non-blown-out cases.