| 摘要 |
PROBLEM TO BE SOLVED: To take risk countermeasures of a hermetic switchboard so as to safely protect a load-side device from an electric-arc which is generated in a correlation of a bus conductor by a short-circuiting accident of a master circuit bus laid within the board.SOLUTION: In a hermetic switchboard 1, a master circuit bus of a naked bar conductor is laid for supplying power from a power source side to a load side. In the hermetic switchboard, in an intermediate portion of a laying rout of a power source side conductor 2, an arc block layer 4 formed from an insulation material such as a POM resin is attached to a conductor circumferential surface while aligning a position and surrounding the power source side conductor 2 for each bus for each of R, S, and T phases. Short-circuiting arc generated in a route of the power source side conductor 2 is blocked by the arc block layer 4 and prevented from being propagated to the load side, and the arc 3 is sedated by ablation gas ablated from the arc block layer 4 upon receiving arc heat. |
