+86 18751738721
sales@unitatransformer.com
Transformer insulation performance is the core guarantee of its safe operation. In Southeast Asia’s high temperature and humid environment, insulation performance is easily affected by moisture, salt spray, and aging, leading to insulation degradation and even short circuit accidents. Many non-professional users (such as factory managers, rural power operators) do not know how to test transformer insulation performance, resulting in failure to find hidden dangers in time.
In fact, testing transformer insulation performance does not require professional technical skills or complex equipment. Using simple testing tools and following standardized operation steps, non-professionals can also complete the basic insulation test, effectively detect hidden dangers of insulation degradation, and ensure the stable operation of the transformer.
This article introduces the simple method of testing transformer insulation performance, suitable for non-professional users in Southeast Asia, and sorts out the common test results and processing suggestions.
| Test Item | Testing Tool | Operation Steps | Qualified Standard | Processing Suggestions for Unqualified Results |
|---|---|---|---|---|
| Insulation Resistance Test | Megohmmeter (commonly used 500V) | 1. Cut off the power of the transformer and disconnect all external wiring. 2. Connect the megohmmeter to the transformer winding and ground respectively. 3. Rotate the megohmmeter handle at a uniform speed (120r/min) and read the data after 1 minute. 4. Repeat the test 2-3 times to take the average value. | Oil-immersed transformer: ≥10MΩ; Dry-type transformer: ≥20MΩ | 1. Check for moisture ingress and dry the transformer. 2. Clean the winding and terminals to remove dirt and oxidation. 3. If the insulation resistance is still low, replace the insulation parts or carry out overall maintenance. |
| Surface Insulation Test | Multimeter | 1. Cut off the power and disconnect the wiring. 2. Use a multimeter to test the resistance between the transformer shell and the winding. 3. Test the resistance between different windings. | Resistance ≥1MΩ; no short circuit (infinite resistance between windings) | 1. Clean the shell and winding surface to remove dust and moisture. 2. Check for insulation damage and repair or replace it in time. 3. Strengthen sealing and moisture-proof measures. |
| Oil Insulation Test (Oil-Immersed Transformer) | Oil Insulation Tester (simple type) | 1. Take a proper amount of transformer oil sample. 2. Put the oil sample into the tester and follow the instrument instructions to operate. 3. Read the breakdown voltage value of the oil sample. | Breakdown voltage ≥35kV/2.5mm | 1. Filter the transformer oil to remove moisture and impurities. 2. If the breakdown voltage is still low, replace the transformer oil. 3. Check for internal leakage and repair it. |
It should be noted that the insulation test should be carried out in a dry environment, avoiding the monsoon season or high humidity weather. Before the test, ensure that the transformer is completely shut down and cooled to room temperature to avoid test errors caused by high temperature. For non-professional users, it is recommended to carry out the test once a quarter, and increase the test frequency during the monsoon season.
By mastering this simple insulation test method, non-professional users in Southeast Asia can timely detect hidden dangers of transformer insulation degradation, take targeted processing measures, and avoid serious accidents caused by insulation failure, ensuring the long-term stable operation of the transformer.
