On site testing method for dielectric strength tester of insulating oil

The use of insulation oil dielectric strength tester:

1) On site oil sampling

When taking oil samples, dry, clean, and well sealed containers should be used to prevent impurities and moisture from affecting the test results. It is best to use brown glass bottles as sample containers, or plastic containers that do not interact with insulating oil, but cannot be reused. The sample volume is approximately three times the capacity of the sample cup.

2) Clean the oil cup

Long term unused or contaminated electrodes and oil cups must be washed with gasoline, benzene, or carbon tetrachloride before drying. When washing, clean silk should be used instead of cloth, toilet paper, and cotton yarn. Frequently used electrodes and oil cups can be placed in a dry and dust-proof dryer when not in use, and rinsed twice with test oil before use. Electrode surfaces with burn marks or gaps cannot be reused.

3) Inject oil sample into the oil cup

Before the experiment, use a 2.5mm ruler to check the distance between the electrodes of the oil cup, making it exactly 2.5mm. Immediately clean the cup wall, electrodes, and other parts with the oil sample to be tested, and then slowly pour the oil sample to reduce the generation of bubbles. The oil level should be higher than the upper edge of the electrode; Put the oil cup inInsulation oil dielectric strength testerIn the test chamber, the oil cup should be placed steadily, and the metal parts at both ends should be in reliable contact with the electrode columns inside the chamber. Cover the lid of the test chamber (if this lid is not closed or not closed properly, the instrument cannot be powered on for testing, which provides protection for the testing personnel), and let the oil sample stand for 10-15 minutes.

4) Set instrument test parameters according to relevant requirements

Connect the instrument to a reliable ground, connect the AC220V working power supply, turn on the instrument power switch, set the test frequency to 6 times (GBT507-2002), set the stirring time to between 10s and 40s, and set the settling time to 5 minutes.

5) Experimental process

After setting the parameters, press the run button, and the insulation oil dielectric strength tester will automatically perform the steps of stirring, standing, boosting, and breakdown voltage reduction according to the set time to complete each breakdown test. After each breakdown test is completed, the instrument will automatically calculate the six mean values and display the breakdown voltage value and the six mean values.

6) Treatment of test oil

Pour the tested sample oil into the designated container, clean the oil cup, and place it in a dryer for future use.

Test precautions

1. When taking oil samples on site, it is necessary to ensure that the oil sample bottle is clean and dry, avoid introducing impurities and moisture, seal and store the oil sample, and conduct the test as soon as possible.

2. Ensure that the electrode gap is 2.5mm during each experiment

3. The maximum voltage output of the instrument is 80KV, please ground it reliably.

4. The oil level in the oil cup should be higher than the upper edge of the electrode to prevent air breakdown from affecting the test results.

5. Each oil sample test should take the average of multiple breakdown values, usually 6 times, to reduce testing errors caused by chance.

6. After each stirring, let it stand for no less than 5 minutes.