Metal wires are widely used for arc ignitions in power arc tests on electrical power installations, and their material and thickness are selected variously. However, the material and the thickness of the metal wire are thought to be influential factors in the severity of the power arc test, because they may change the arc duration and the physical characteristics of arc. Therefore it is important to understand the dependence of the severity of the power arc test on the material and the thickness of the metal wire. In this paper, we made the experiment, where arcs were generated in a closed chamber with changing the material and the diameter of the metal wire for arc ignition. By this experiment, we clarified the fusing characteristics for various metal wires, and then studied how the material and the thickness of the metal wire influence the arc energy for the 1st half-cycle of current. As a result of this study, we pointed out a possibility of changing the severity in the power arc test according to the metal wire for arc ignition.