| 摘要 |
PROBLEM TO BE SOLVED: To obtain a three-phase alternate current electrical switchgear capable of making the number of parts smaller than a conventional one. SOLUTION: This three-phase alternate current electrical switchgear comprises high frequency current generating circuits of which the currents have a higher frequency than a three-phase alternate current circuit and are superimposed on respective breakers 7 of any two phases in three-phase breakers 7, and a second driving unit which is controlled by a control unit 80 and starts the high frequency current generating circuits by electromagnetic force of second electromagnetic coils 100 respectively. Wherein, if a trouble occurs, the control unit 80 drives the second driving units 100 to feed high frequency currents from the high frequency current generating circuit to the two-phase breakers 7 respectively, allowing the currents sent to the two-phase breakers 7 to form the zero point, which makes the two-phase breakers 7 opened. COPYRIGHT: (C)2004,JPO
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