Drying treatment and requirements for box type transformers

Box-type padmounted transformer drying treatment and requirements Box-type transformer repair winding or insulation replacement, the body in the air leakage time exceeded, measured by the insulation resistance of the absorption ratio proved transformer winding moisture, etc. to dry the transformer. Transformer drying treatment common methods are: induction heating method, hot air drying method, oven drying method. 1 pad mount transformer insulation drying standards (1) transformer oil does not contain moisture. Oil breakdown voltage of not less than 75% of factory data. (2) insulation resistance of not less than 70% of factory data. (3) Dielectric loss tangent is not greater than 130% of factory data. 2 Transformer should meet the following conditions should be dry (1) overhaul replacement winding or insulation. (2) In the repair or installation of the body inspection, the body exposed to air for more than the corresponding time. (3) Insulation resistance and absorption ratio measurement proved that the transformer winding damp.