| 摘要 |
PURPOSE:To obtain a safe device able to cut off a broken arrester in a short time from a rail conductor by housing a soluble metal line connected with the rail side and the earthing side in a coiled shape inside the resin having high mechanical strength while arranging an insulator generating a large amount of gas when the outer periphery of said soluble metal line is exposed to high heat. CONSTITUTION:When an arrester 12 is broken and a commercial frequency current flows to the cutting-off device 20, said current change rate is far small in compared with the thunder current so that the parallel gap 3 does not discharge, while the current flows to a soluble metal line 5. The soluble metal line is fused in an instant while generating an arc in the gap between the conductors 1a and 1b and burning a bobbin 4 and an insulator of polyethylene or the like in its periphery and generating a large amount of gas. Said gas raises inside pressure inside the outer cover 7 for breaking off the outer cover 7 thus obtaining the axial driving force of the conductors 1a and 1b. Said driving force drives the arrester 12 in the direction of being separated from the high voltage conductor 13 around its upper end to execute cutting-off of the arrester. |
