| 摘要 |
PURPOSE:To facilitate the detection of the damage of an insulator at the exterior of a core slot by forming a semiconductor layer in the intermediate of ground insulating layer at the exterior of the core slot and applying a voltage between the layer and the core or the conductor. CONSTITUTION:A semiconductor layer 5 is formed in the intermediate of ground insulating layer 2 at the exterior 4 of a core slot of ground insulating layers wound on the periphery of a conductor 1, and the one end 6 of the layer 5 is led to the outer surface of the layer 2. A voltage applying unit 7 is connected between the layer 5 and the conductor 1 or the core, and the deterioration of the insulation of the layer 2 is measured. |
