Date: December 2010
Company CA / Antofagasta – II Region.
A work of reparation and maintenance of Pad Mounted substation
Pad Mounted Transformer had deteriorated taps changer and fuse tube bayonet. The system had little silicon product in some filtrations, this is why the deterioration was caused.
– Verification that there is no voltage neither in high nor in low voltages.
– With nitrogen, the internal pressure is incremented so we can identify filtrations.
– Removal of transformer lid to work with the transformer from the inside.
– Removal of the silicon of the transformer. It is important to work in detail so that the displacement of copper over the nucleus towards the coils.
– Used material is retired on the nucleus, cause of the internal crack.
– Change of packages of caps and basement in low voltage insulators.
– Change of base packages of database inserts.
– Substitution of taps changer.
– Change of fuse tubes in the interior (bayonet).
– Cleaning of the active part with 40 l. of new dielectric silicon.
– Cleaning of 40 l. silicon used in the cleaning.
– Installation of a transformer lid and it is filled with 630 l. of silicon with a vacuum pump.
– Measurement of the reason of transformation in all taps.
– Measurement of resistance in all taps.
– Measurement of insulating resistance (high-low, high-mass, low-mass)
– Verification of hermeticism with pressure of nitrogen 0,5Kg/cm2.
– Cleaning of the transformer and room where it is installed.
– Energization of substation; the entity in charge of local electricity is in charge of the action.
– Verification of the service voltages and phase sequence.