| 摘要 |
PURPOSE:To prevent a fuse cylinder from flying away and a main insulator from being broken into pieces to scatter and drop, namely from those troubles possibly caused by excessively severe thunder surge by disposing a pressure-resisting electrode on the side close to the fuse cylinder inside a cavity and housing a cap unit and a non-linear resistor unit between the electrode and a gap metal fitting in such a manner as arranging those units in a mutual connection in series. CONSTITUTION:A pressure-proof electrode 35 made of conductive ceramics is disposed on the side close to a fuse cylinder 13 inside a cavity 21a and a gap unit 23 and a non-linear resistor unit 24 are housed between the electrode and a cap member 51 capable of releasing pressure in such a manner as arranging those unit in form of a mutual connection in series. When any thunder surge enters a lightning arresting unit disposed in a range from a fixed electrode 6 on load side to a terminal metal fitting 53 for grounding line, the thunder surge is discharged to the ground through the non-linear resistance element 29 of the non-linear resistor unit 24 and the gap unit 23. And even if the lightning arresting unit is disabled for cutting out dynamic current on account of excessive thunder surge, etc., and high pressure gas is generated, the gas is shielded by the pressure-proof electrode 35 and not ejected downward. Thus, the main insulator 1 is prevented from breakage due to uneven heating so that the cutout may be prevented from scattering and dropping.
|
