Date: January 2010
Company: ET / RANCAGUA – VI Region.
Filtrations were repaired to the transformer or exterior mining substation:
– Nitrogen pressure was applied to reduce the quantity of silicon of the transformer and to situate it under the line of insulators.
– Change of base and cap packages of insulators in 4160V.
– Tightening of caps of insulators 13200V.
– Reincorporation of silicon apart to repair the transformer.
– Refill with 210 l. dielectric silicon to reach the normal level.
– By applying nitrogen pressure of 0.5kg/cm2 it is verified that the transformer filtrations are repaired.
– Measurement of the resistance of insulation:
- High voltage – Low voltage.
- High voltage – Mass.
- Low voltage – Mass.
– Measure of the resistance of primary and secondary coils in the position of tap it was placed.
– Measure of the reason of transformation in the position of tap it was placed.