Insulation Resistance Tester Related Precautions
With the continuous development of society, the capacity of power equipment is getting larger and larger, so the performance requirements for its insulation part are higher. Some traditional conventional megohmmeters can no longer complete high-requirement insulation tests. Nowadays, the insulation resistance tester is more commonly used. So what should we pay attention to when using this instrument? Let me explain it to you below.
1. Choose the appropriate test range and voltage
Before using the insulation resistance tester, you should first select the appropriate test range and voltage according to the characteristics of the device or circuit under test. This is a key step to ensure that the test voltage will not cause damage or danger to the equipment. At the same time, this also lays the foundation for the accuracy of subsequent tests.
2. Prepare test equipment and environment
Ensure that the insulation resistance tester and the device under test are in a good environment with dryness, dust-free and oil-free. Clean the equipment, remove external factors that may affect the test results, and provide a stable environment for the test.
3. Correct wiring and safe operation
Confirm that the wiring is correct (Note: the test line is prohibited from mopping the ground) and then turn on the machine for testing. When the "high voltage output" light is on, it means there is high voltage output. It is strictly forbidden to touch the high voltage line at this time.
During the test, it is strictly forbidden to unplug the test line or short-circuit the output to avoid endangering the person and damaging the instrument.
For high voltage testing, please ensure that the operator uses insulating gloves or other safety measures.
4. Measurement time and recording test data
According to the equipment specifications and requirements, select the appropriate measurement time. Long-term measurement can more accurately evaluate the insulation condition. During the test, record the test results in time, including insulation resistance value, test time, etc., in order to track the changes in the insulation state of the equipment.
5. Battery maintenance and storage environment
When measuring with the internal battery of the instrument, if the display is dim or does not display when turned on, it means that the battery is low and should be turned off and charged in time.
When the instrument is not used for a long time, the battery should be charged regularly (once a month). Turn off the instrument when not in use and when charging.
The instrument should be stored in a dry, dust-free, non-corrosive gas environment.
6. Discharge and large-capacitance capacitive load test
When testing large-capacitance capacitive loads, ensure that there is enough discharge time after the test, and the test line can be removed only after the discharge is completed. It is best to discharge the extra-large capacitive load for more than 1 minute.
The insulation resistance display value measured when the meter is not connected to the test product generally reaches the T level (1T=1000G). This value is generally a random infinite value and has no practical significance.
7. Avoid electromagnetic interference
When measuring insulation resistance on site, if it is carried out near a strong magnetic field or near equipment that is not powered off, it may cause a large measurement error. The measurement should be carried out away from strong electromagnetic fields or shielded using the shielding terminal G of the megohmmeter.
The correct use of the insulation resistance tester is crucial to ensure the safe operation of the power system. By following the above precautions, we can ensure the accuracy of the test results and the safety of the operators. As power testers, we should strictly understand and abide by the corresponding rules, do a good job in the test, and ensure the safety of the test process.
