Arc ignition through pre-arc from extra fine copper wire

Metal ignition wires are widely used in power arc tests on insulator sets and similar. Finer metal ignition wires are preferred from the point of view of influence on the apparatus tested. However, if the metal ignition wires are too fine, the arc cannot be sustained. To perform power arc tests successfully, therefore, they need to have some degree of thickness. With these requirements in mind, we proposed a new arc ignition method that allows the use of extra fine wires by leading to the pre-arc in a current of several dozens amperes, and examined it for practical use. In this paper, the sustainment characteristics of arcs ignited from extra fine copper wires using this new method were investigated with a gap between the rod electrodes. The results showed that kA-class arcs with a gap length of 1.5 m could be ignited through pre-arc from 0.03 mm diameter copper wire at a voltage of 12 kV. The influence of the ignition wire thickness on arc characteristics was also studied by comparing the arcs ignited by this new method with those ignited by the general method in which copper wires exceeding 0.3 mm in diameter was used.