| 摘要 |
A surge arrester is disclosed comprising a first and a second electric terminal (1, 2) for connecting to the active leads of an electric plant, between which a protection element (3) is inserted provided with a pair of electrodes (4) electrically wired to said electric terminals, between said first electric terminal (1) and an electrode (4) of the protection element (3) a disconnector being provided comprising a conductive, resilient, flexible lamina (5) having a base end (5a) electrically wired to said first electric terminal (1) and a distal end (5d) maintained electrically connected to said electrode (4), in a state of elastic preload, by a welding with low-melt material. Lamina (5) is mounted elastically biased according to a direction so as to push said distal end (5d) away from said electrode (4) and it is made with a thickness below 0.5 mm and of a conductive material with a conductivity much lower than that of copper (IACS<60) such as to melt/sublimate following heating by Joule effect upon the passing of a short-circuit current. Between said base end (5a) of the lamina (5) and said electrode (4) of the protection element (3) a sliding guide (6) for an intercepting cursor (7) is provided, biased in a longitudinal direction of said sliding guide (6) by preloaded elastic means (8), and at least an inclined portion (5c) of said lamina (5) runs through said sliding guide (6) at a certain angle to the longitudinal sliding axis thereof, said inclined portion (5c) of the lamina acting as abutment and holding element for a head end (7b) of said cursor (7). |
