When installing the transformer, when the gas content of the new transformer oil or the transformer oil in operation or the oil chromatography or the water fails, the gas in the oil must be removed to the qualified range, which is Transformer Oil Degassing. Degassing processing mainly uses a Vacuum Transformer Oil Purification Plant. When the oil passes through, the gas is gradually precipitated and removed due to the action of vacuum. Degassing can use the "moving method" or "circulating method" to the oil. The former is to pump the oil in the transformer oil tank into another oil tank (commonly known as the oil tank) through the Vacuum Oil Purifier, and pump the oil in the transformer oil tank all the time, and then pump it in the opposite direction, so that the oil is moved away, because there is no leftover every time. The has high degassing efficiency and can shorten the degassing time, it connects the transformer oil from the lower part of the oil tank to the Transformer Oil Purification Plant, connects the oil return pipe to the upper part of the oil tank, and circulates the purified oil to degas, without the need for an empty oil tank, but Transformer Oil Degassing time is longer.

The specific measures and steps to deal with are as follows:

1) When the main transformer is powered off, the Vacuum Oil Purifier is connected, the oil is discharged from the oil drain valve of the main transformer body, and the oil is fed from the main transformer oil conservator.

2) Circulate the transformer oil. Before the Transformer Oil Purification Plant is turned on, the original oil filter paper should be replaced with a new dry oil filter paper. Turn on the heating tube of the Vacuum Oil Purifier during the cycle treatment, keep the oil temperature at 60-700℃, and replace the oil filter paper every 24 hours.

3) Before degassing the main transformer, make the oil level of the on-load tap-changer lower than the oil level of the main transformer. During the degassing process, when the acetylene content of the main transformer oil is less than 2 × 10-6, replace the on-load tap-changer with new oil.

4) Sampling every day to analyze the acetylene content during the cycle treatment. When the acetylene content is below 0.5×10-6, do a full set of tests on the body oil, and all data are required to be within the qualified range. The treatment can be stopped (actually after 5 days of dehydration) Gas, acetylene dropped to 0.36 × 10-6 to stop.

5) Let it stand for 24 hours, deflate all parts, and do the insulation test of the main transformer. At the same time, take samples to do the oil color, simplification, emblem, water, and oil dielectric loss analysis tests. If the data is normal, the work is over.

6) Remove the Vacuum Oil Purifier and connect the oil pipe, and the main transformer is ready for operation (the oil level of the on-load tap-changer is lower than the oil level of the main transformer).