| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulation resistance measuring device enabling an accuracy test to be performed through simple work without needing work fraught with danger, such as insertion and removal of a measurement resistance. SOLUTION: This insulation resistance measuring device has an accuracy testing circuit for impressing a low-frequency voltage on a measured cable way and impressing the impressed voltage on a current transformer 28 in a current-transforming/detecting device via a measurement resistance (Ro) 35, low-frequency voltage impressing parts 25 to 27, 34, 35, 37, 38 with a switch-over relay 38 attached thereto for switching between the accuracy testing circuit and a circuit for impressing the low-frequency voltage on the usual measured cable way, current-transforming/detecting parts 28 to 31 for detecting displacement of a current flowing through the cable way due to the low-frequency voltage, and a CPU 32 for comparing a detection result of the current- transforming/detecting device with a set value and displaying an alarm if the set value is exceeded. Because an accuracy test is made possible only by operating the switch-over relay 38, the accuracy test can be performed through simple work without needing work fraught with danger, such as insertion and removal of a measurement resistance.
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