| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for measuring a leakage current capable of acquiring currents Igc in each phase and as total flowing through a ground electrostatic capacitance of a distribution circuit of three-phase four wires or three-phase three wires of distribution system, and capable of determining the leakage current Igr including no error caused by an unbalanced state, and a phase where the leakage current Igr increases. SOLUTION: In the device, three-phase electric power source voltage is input from an output terminal 3 of a switching electric power source 2 into a measuring instrument 17 via a measuring cable 11, and a zero-phase current Io is input from an electric power supply cable 4 into the measuring instrument 17 via a zero-phase current transformer 8. The device includes a measuring capacitor 10 for measuring a current from the switching electric power source 2, as a measured current Ic, a shunt current resistor 12, and a shunt current resistor 13 for detecting a ground voltage E, finds an insulation resistance Gr by calculating respectively the currents Igc, Igr flowing in the ground electrostatic capacitance and a leak resistance by a signal processing part 14 and a computing part 15, based on a measure voltage and current, and is provided with a display part 16 for displaying the results. COPYRIGHT: (C)2008,JPO&INPIT
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