What problems should be paid attention to when using insulation resistance?

Which of the following problems should be paid attention to when using insulation resistance?

HV Hipot GD3000B Insulation Resistance Tester

First of all, when testing the insulation resistance of the test object, we need to know the capacity and voltage level of the test object, and combine the test data over the years or the factory test report to facilitate the comparison of the data results. Before the test, try to remove the relevant leads as far as possible to fully discharge the tested object to prevent the influence of residual voltage on the insulation resistance, and also use alcohol to wipe the contamination on the surface of the tested object wiring to prevent the increase of leakage current and lead to insulation resistance. Compared with the actual insulation resistance, the temperature during the test is 18~26℃, and the humidity is about 70%. If the temperature and humidity are too high or too low, the test results will be affected. Choose the appropriate output voltage for measurement. If the voltage is too low or too high, it will also affect the data.

When the surface leakage current is too large, it is necessary to increase the shielding point to prevent the insulation resistance. low situation. During the test, wait for more than 30S or when the number of digits of the resistance value beating is relatively stable to read the resistance value. However, due to the different capacity of the measured object, the length of the process of DC current absorption and polarization is also different. Generally, the time to read the insulation resistance is different. Guodian Xigao suggested to refer to the actual situation on site. After the test is completed, the tested phase needs to be fully discharged again, and the discharge time is longer for the object that needs to be retested. The frequency of insulation resistance is very high in daily use. It is not difficult to use. If the insulation resistance is not on time, you can check it one by one through the above methods. If the resistance value still does not rise after the check, then it should be considered that the insulation level of the tested Low or insulation breakdown.