When the vacuum is injected, the air in the pipeline must be discharged.

For transformers of voltage grade 60 KV or above, vacuum oil injection, static discharge and hot oil cycling should be carried out when the transformer is newly installed, repaired or damped.

1 vacuum oil injection

The control values of vacuum degree of a and vacuum oil filling equipment are:

Transformer voltage grade

Vacuum pressure (residual pressure) information origin: negative pressure value

16000 kVA and below 20000 kVA and above information sources: tede. CN 16000 kVA and below 20000 kVA and above 66-110 kV class 0.05 MPa please log in to read more information 0.02 Mpa-0.05 MPa-0.08 MPa 220 kV class 133Pa-0.1 MPa

B. In the initial stage of vacuum pumping, the vacuum degree should be increased averagely to meet the requirement of vacuum mechanical strength of oil tank. The 66-110 kV transformer can reach the above requirement within at least one hour.

C. When the transformer body is exposed for a long time or for other reasons, it is considered that there are signs of dampness, and the vacuum degree should be connected for a long time after leisure. The connecting time can be determined by the dampness level, generally up to 8-24 hours to facilitate the evaporation of water. Information origin:

D. When filling oil, the air in the pipeline must be completely discharged. When discharging to full oil at the oil injection valve, start to open the oil injection valve. The oil injection should be bottom-up, and the oil injection speed is 2-3t/h, and it can not cross 6t/h to prevent oil flow electrification. When the oil surface is 100-200 mm away from the top of the box, the oil injection should be stopped and the vacuum should be connected continuously. The vacuum of 110 kV class transformer should be connected for more than 2 hours, and that of 220 kV class transformer for more than 4 hours.

E. Requirements of main accessories of transformer in vacuum: Butterfly valves should be closed to insulate the oil tank, oil purifier, cooler (radiator, cooler) and other accessories which can not withstand the mechanical strength of vacuum; on-load switches should be connected with the transformer oil tank and vacuum at the same time.

F. Vacuum oil filter should be used for products above 66kV grade. Plate oil filter should not be used to avoid deterioration of oil and bring air and humidity.

G. The oil temperature should be higher than the body temperature, the minimum temperature of the body should be above 10-20 degrees centigrade, or when the temperature is low, the oil temperature should be increased to 30-50 degrees centigrade.

H. Oil injection in on-load switch oil chamber should also be guaranteed to be injected in vacuum and at the same time when the tank is filled with oil.