| 摘要 |
PURPOSE:To prevent corrosion of the exposed part of texture and to contrive to enhance stability and reliability for long period of an electrical machinery and apparatus installed in an underground conduit by a method wherein a metal having electric potential lower than the apparatus main body, zinc for example, is used for the quality of the material of an earth bar to be connected to the earth terminal part of the main body. CONSTITUTION:The quality of the material of the earth bar 22 connected with a lead wire 11 from the earth terminal part 10 of the apparatus main body 3 to be provided in the underground hole is formed with the metal, zinc, etc., for example, having electric potential lower than the apparatus main body (iron). Accordingly, even when the main body having the exposed part of texture is inundated or submerged, a corroding current flows through the earth bar 22- water-the exposed part 3a of texture-the earth terminal part 10-the lead wire 11-the earth bar 22, and the current flows in the direction to prevent corrosion of the exposed part 3a of texture by zinc. Accordingly the damage trouble of the apparatus can be prevented, and the apparatus can withstand the use for a long period. |
