Low voltage power distribution level DC circuit breaking

Three methods (series arcs, solid-state hybrid, and magnetic field enhanced arcing) for switching/interrupting DC distribution level circuits are described including advantages and limitations of each switching method. An experimental analysis of the effects of applying an external magnetic field, produced from permanent magnets, on the switching performance of a DC disconnect switch is the main focus. The test switch consisted of a double-break contact assembly with a mechanical over-center mechanism, metal arc chute plates, and nylon 6/6 arc chamber walls. Current, clearing time, and arc voltage were measured for various levels of externally applied magnetic field to show the effect the B-field had on arc interruption at voltage levels of 380V
_dc
and 600V
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with currents of 10A and 150A with time constants of 0.7ms and 8ms respectively. These results could be applied for developing DC switching devices for use in future DC power systems.