| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin-type low-cost SPD (Surge Protective Device) with a breaker plate for detaching zinc oxide-form varistors quickly and without fail in case of abnormal heat generation caused by deterioration or the like of zinc oxide-form varistors. SOLUTION: The SPD includes two pieces of zinc oxide-form varistors 20 juxtaposed in an insulating case 10 and connected in series between a single-phase AC-operated electric apparatus and the ground, a thermal fuse 30 made of low-temperature molten metal and connected between the two zinc oxide-form varistors 20 which melts by abnormal heat generated at least by one of the zinc oxide varistors 20, and an insulating breaker plate 40 arranged between the zinc oxide varistors 20 for displacing itself so that the thermal fuse 30 is cut off at a softening time of the thermal fuse 30 caused by abnormal heat generation of the zinc oxide varistors 20. COPYRIGHT: (C)2010,JPO&INPIT
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