| 摘要 |
<p>PURPOSE:To prevent a flow of large circulating current with an equipment earthing mesh prevented from forming a closed circuit in a metal case of an equipment by dividing the equipment earthing mesh in every connection point of the metal case of the equipment. CONSTITUTION:In the case of a three-phase gas insulation switch 100, a main circuit switching mechanism, stored in the inside of a gas insulation switch sheath 101, is connected to an external circuit through bushings 102, 103. Switch earthing meshes 501, 502 are connected to a total unit earthing mesh 601 at its distant position through mesh earthing cables 701, 702. Thus connecting both end parts of the gas insulation switch sheath 101 through the total unit earth mesh 601, a circulating current is allowed to flow as shown by the arrow, but because impedance of the closed circuit is large, the flow of the circulating current in equipment grounding cables 401, 402 can be suppressed to a relatively small value.</p> |
