Rise Effect of DC Arc Voltage in Silica Sand: Various Interelectrode Distances and Arrangement of PA66-Cylinder

The following three experiments were conducted as an attempt to raise the DC arc voltage during current interrupting process in silica sand. The purpose of the first experiment is to examine the influence of the interelectrode distance of the graphite electrode on the arc length. The three types of interelectrode distance were set in the arc quenching chamber and supplied a damping DC current. As experimental results, voltage between electrodes was not effectively rose with elongation in interelectrode distance in the silica sand. The purpose of the second experiment is to achieve further rise in the arc voltage. In this experiment, PA66-cylinder was arranged between electrodes. As the experiment result, arrangement of PA66-cylinder effectively increases the arc voltage. This may be because the expansion of the arc diameter was restricted to the interaction between the arc and the inner wall of the cylinder. The purpose of the third experiment is to investigate the influence of arc voltage rise effect on the inner diameter of the cylinder. The main factors causing the arc voltage rise are the effect of limiting the arc diameter by the inner diameter and the effect of ablating of silica sand.