35kv Wall Bushing Resistance Test

After a series of high-voltage insulation resistance tests, the results show:
1. Normal resistance value: Under normal circumstances, the insulation resistance value of 35kV through-the-wall epoxy bushing should not be less than 10MΩ. The insulation resistance value of this test is stable above 20MΩ, indicating that the insulation performance of epoxy resin bushing is good and meets the safety operation standards.
2. Local problems: In the test of individual epoxy resin cast bushing, weak current leakage was found, resulting in a slight decrease in insulation resistance, but it still remained within the qualified range. After further inspection, the leakage point may be related to the surface dirt of epoxy bushing manufacturer; it is recommended to strengthen regular maintenance and cleaning.
Experimental analysis and discussion
Through this experiment, we can draw some important conclusions.
The insulation resistance value of 35kV through-the-wall epoxy bushing for transformer should usually be maintained at a high level and should not be less than 10MΩ. The results of this experiment show that the resistance values ​​of most bushings meet the standards, indicating that their insulation performance in the power system is reliable. Even if the test results are normal, it does not mean that the equipment can rest assured. Although the resistance value of some bushings is within the allowable range, there is still a certain amount of current leakage. This problem is often closely related to the use environment of the bushing. Long-term exposure to wind and rain will easily accumulate dirt on the surface of the bushing, resulting in a decrease in insulation performance, which in turn affects the test results. The equipment must be cleaned and maintained regularly to ensure that there are no pollutants on the surface of the bushing to avoid the occurrence of reduced insulation performance due to pollution. This experiment also highlights the safety issues of high-voltage testing. Any negligence may cause serious safety accidents due to high-voltage current. During the experiment, strict safety regulations and operating procedures are essential. From the experimental results, the insulation performance of most 35kV wall bushings is in a safe state and can meet the requirements of grid operation. However, to ensure the long-term stable operation of the equipment, it is recommended to conduct high-voltage insulation resistance tests regularly. Especially for old equipment and bushings exposed to harsh environments for a long time. More stringent inspection and maintenance should be carried out. The cleaning and protection of the equipment should be strengthened to reduce the impact of environmental factors on the insulation performance of the bushing. Before each test, the test instrument should be strictly checked to ensure its accuracy and safety to avoid inaccurate test data caused by human errors. Through continuous experiments and optimization, the insulation performance of 35kV wall bushings in the power system will be effectively improved, thereby ensuring the safety and stability of the entire power grid system.