The charged operation must be carried out on a sunny day; connecting inlet and outlet pipe should be performed in the field of power engineers under the command; the first is the preparation work: first prepare a transformer oil charge from 5 to 6% on the side qualified oil filter oil machine; the bottom of the transformer oil discharge valve opening and oil filter oil inlet pipe is matched, if it is not should remove the re welding a pipe; oil filter should be installed on the vacuum tank oil standard oil pipe qualified transformer oil filtering machine 1/2 (voltage = 50KV); open the transformer oil pillow cover, the oil filter oil into the oil level on the pillow, and then use a clean filter paper the film will cover or seal oil pillow; the oil inlet oil filter into the oil tank to prepare qualified; open the oil valve at the bottom of the transformer, the transformer off 3 ~ 5% oil (the 3 ~ 5% oil is the main impurities and water, should be placed in separate access); At the same time 6 steps, oil filter should be a high vacuum (less than -0.09MPa), and then add oil foot transformer oil tank; when the transformer is placed at the bottom of the oil valve from 3 to 5% "waste oil", the oil filter oil inlet pipe connected to the drain valve; you can filter oil machine to work properly.