Maintenance method of gas-filled test transformer:

1. The test transformer should be kept clean regularly, and the nylon bushing should be wiped clean before each test and covered with a plastic cloth.

2. Do not twist the bolts other than the wiring support at will to prevent air leakage caused by the damage of the seal.

3. Slight leakage is a normal phenomenon. It is estimated that the air pressure will decrease by 0.05Mpa every 4 years, and the air pressure at the factory will be between 0.2-0.4Mpa. As the environmental humidity changes, the air pressure slightly increases or decreases. When the air pressure drops to 0.3Mpa, make up the air in time.

4. Gas filling method of gas-filled test transformer

① Connect the pipes according to the schematic diagram.

② Open the valve on the sulphur hexafluoride gas cylinder to make the pressure on the oxygen meter around 20kg/cm.

③ Screw in the top of the screw on the oxygen meter and let the air pressure rise slowly. There is gas leakage at this time. Exhaust the air in the pipe.

④ Unscrew the inflation valve immediately (clockwise) and hear the air flow into the transformer body.

⑤ Adjust the screw top on the oxygen meter so that the outlet pressure of the oxygen meter is 5.5Kg/cm.

⑥ Monitor the transformer pressure gauge, when the pressure reaches 3.0-4Kg/cmj (ie 0.3-0.4Mpa), immediately close the inflation valve (counterclockwise). Prohibit overpressure to avoid danger.

⑦ Close the valve on the SF6 gas cylinder.

⑧ Close the valve on the oxygen meter, and the inflation work is over.

⑨ Remove the pipe and the inflation valve, let the gas fully mix and then work after it is fully inflated.