Oil Treatment For Oil-Immersed Transformers

1. Pressure filtration method: The insulating oil used in power transformers must have insulating and thermal conductivity properties (national standard). At the installation site, the pressure filtration method is often used to complete the general drying (removal of moisture) and purification (removal of dirt) of the insulating oil.
2. Open valves 8 and 11, then start the oil pump, and then open valves 6 and 7. When stopping the oil, first close valves 6 and 7, then stop the oil pump, and then close valves 8 and 11. ⑵ During normal operation, the pressure gauge is working normally under a pressure of 3*10 ~4*10 Pa. If impurities and oil paper are blocked, the pressure increases. When the pressure reaches 6*10 Pa, it must be stopped and the filter paper replaced. ⑶ Before using the filter paper, dry it in an oven at 80-90℃ for 24 hours and place it in a clean container. ⑷ The filter screen should be cleaned every 10~15 hours. At the beginning, within 3-5 minutes of filtering the oil, the oil outlet is sent back to the dirty oil tank through valve 10 for re-filtration. The oil accumulated in the oil filter is sent back to the dirty oil system through valve 9 and filtered again. The above oil filtration should be refined and dried for many times until it is qualified.
3. Live oil filtration of transformer: ⑴ When the voltage is higher than 10V, live oil filtration should not be used. Because during filtration, more bubbles are generated, and bubbles will be free under the action of higher voltage, which will deteriorate the insulation performance of the oil and cause internal discharge. When performing live oil filtration, regularly release the gas released from the oil in the gas relay. ⑵ When filtering oil with electricity, the oil pipe and oil filter should be reliably grounded to protect the personal safety of the staff. The staff should be professional, supervised, and wear good insulating supplies. ⑶ Operation: Connect the pressure oil filter buckle at the interface of the diagonal valves 4 and 5, and the valve 4 will extract the oil and return it to the oil tank from the valve 5. After multiple cycles of filtration, it will meet the standards.