发明名称 Earth leakage-current protection system
摘要 <p>An earth leakage-current protection system comprises a first and a second earth leakage-current detecting means ELB3, ELB2. The first is electrically connected to a load and has a characteristic of sensitivity current vs. frequency which varies with values each below the threshold value having a predetermined characteristic of sensitivity current vs. frequency which is defined for the purpose of protection of the human body. The second has a frequency-characteristic of sensitivity current vs. frequency represented by values each larger than each value indicative of the characteristic of the first earth leakage-current detecting means. When the earth leakage current of a frequency higher than the commercial frequency flows, the first earth leakage-current detecting means is first activated so as to break the earth leakage current which is danger to the human body. The second earth leakage-current detecting means can make a protection coordination with respect to the earth leakage current. &lt;IMAGE&gt;</p>
申请公布号 EP0810707(A2) 申请公布日期 1997.12.03
申请号 EP19970111929 申请日期 1991.06.21
申请人 HITACHI, LTD.;HITACHI TECHNO ENGINEERING CO., LTD. 发明人 SUZUKI, YUKIO;IKEDA, YUTAKA;KIRYU, TOMIYOSHI;ISHII, HIDEO;TERAOKA, WATARU;HAYAKAWA, HIDEKI
分类号 H02H3/33;H02H3/52;H02H7/30;(IPC1-7):H02H3/33 主分类号 H02H3/33
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