| 摘要 |
PURPOSE:To protect machinery against damage due to application of AC high voltage by providing an AC blocking means for grounding a pantograph upon detection of an AC voltage under configuration of DC circuitry. CONSTITUTION:A universal electric rolling stock comprises a pantograph 1, a main circuit breaker 2, a fuse 4, a DC arrester 10 at an AC blocking means, a current detector 11, an operating coil 12A, a protective switch 13, and the like. A discharge short circuit takes place upon application of AC high voltage onto the DC arrester 10 under a state where universal switches 3, 7 are turned to DC side. The short circuit current is detected through the current detector 11 output of which causes excitation of the operating coil 12A in the protective switch 13 thus causing throw-in of the protective switch 13 and grounding of a stringing. Consequently, a ground side circuit breaker is tripped to cause power interruption thus removing the AC voltage and protecting the machinery against a damage. |
