For insulation test, the insulation resistance at a certain moment can not entirely reflect the insulation performance of tested object, as the insulation resistance absorbs and polarizes electric charges after high voltage is applied on the insulation material. For insulation tests on sites with main transformers, cables, motors and others, absorption ratio (the ratio between R60s and R15s) and polarization index (the ratio between R10min and R1min) should be measured, so as to determine the insulation performance.
This phenomenon is normal. 5.5GΩ will be displayed when the insulation resistance of measured object exceeds the specified range of the tester, it is recommended to test an object with resitance below 5GΩ.
This phenomenon is normal. OL will be displayed when the insulation resistance of measured object exceeds the specified range of the tester.
For example, the maximum measured resistance for different ranges of voltage is:
20GΩ for 500V
40GΩ for 1000V
100GΩ for 2500V
1000GΩ for 5000V