| 摘要 |
PCT No. PCT/US91/04413 Sec. 371 Date Dec. 18, 1992 Sec. 102(e) Date Dec. 18, 1992 PCT Filed Jun. 21, 1991 PCT Pub. No. WO92/00580 PCT Pub. Date Jan. 9, 1992.A faulted circuit detector having an electrically isolated and remotely positioned indicator detects fault currents in a monitored conductor. When a fault of a predetermined magnitude is detected, a light pulse is transmitted from the detector to the indicator via a fiber optic cable where, upon receipt, the pulse is converted to an electrical pulse causing the indicator to indicate a "fault" state. A reset circuit within the indicator resets the indicator at regular intervals to the "normal" state as long as a predetermined minimum voltage is present on the monitored conductor. The detector includes a temperature compensation circuit and low pass filter circuit so as to prevent misoperation due to varying ambient temperatures or high frequency transients. A test circuit is also provided to allow service personnel to field-test the device with the monitored conductor in an energized state.
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