PURPOSE: To reduce a temperature rise by the high-frequency wave, and the generation of a radio noise in a shield pipe, and to facilitate the handling without increasing the size of the shield pipe even when the output current is large.

CONSTITUTION: A power source cable connected to output terminals is divided into wires 1U to 3U, 1V to 3V, and 1W to 3W in the phases U, V, and W, and wires of each phase 1U, 1V, and 1W; 2U, 2V, and 2W; and 3U, 3V, and 3W; are picked up and stranded. They are made into three sets of stranded cables X, Y, and Z, and shield pipes 4X, 4Y, and 4Z are covered to the three sets of stranded cables X, Y, and Z. On the other hand, at the three phase terminals of a motor 1, the three sets of stranded cables X, Y, and Z are restored again to the original groups 1U, 2U, 3U, 1V, 2V, 3V, 1W, 2W, and 3W, and connected. The balance of the phase impedances is improved by making the phase wires into stranded wires, and the elimination of induction wave can be carried out effectively. The diameters and the lengths of the wires of respective phases are made equal.