Overhaul and recovery of critical assets · Morón Petrochemical Complex

• Scope of Service: Preventive fleet maintenance (9 units) and full rehabilitation (Overhaul) of 3 power transformers (4.2 MVA and 6 MVA) with active-part intervention at the Costel workshops.

1. Executive Summary

Key Impact: Extended service life and recovered reliability of 3 critical power transformers through workshop engineering processes (untanking and oven drying), guaranteeing factory insulation parameters and avoiding the costly replacement of assets.

2. Technical Challenge (The Problem)

• Critical Diagnosis: During the initial on-site testing at the Morón Complex, 3 units (4.2 MVA and 6 MVA) were found to have severe deviations in insulation resistance and internal contamination, which prevented safe operation.
• Field Limitation: The complexity of the repairs required (moisture in the active part and seal degradation) made correction on site impossible, calling for the controlled environment of a specialized workshop.

3. Comprehensive Solution (Costel Workshop Engineering)

The 3 units were transported to the Costel plant in Valencia, where a major recovery protocol was carried out:

• Active-Part Intervention: Complete untanking to inspect cores and windings.
• Thermal Treatment: Washing and oven drying of the active part to completely remove moisture from the solid (cellulose) insulation.
• Rebuilding and Sealing: Full replacement of gaskets and replacement of high- and low-voltage bushings.
• Fluid Treatment: Filling with new dielectric oil under high-vacuum processes.
• Laboratory Test Protocol:
• Applied voltage and induced voltage.
• Measurement of load and no-load losses (efficiency validation).
• Insulation power factor.
• Winding resistance.
• Transformation turns ratio.
• Insulation resistance.
• Physical and chemical analysis of the dielectric oil.
• Polarization index.
• Dissolved gas analysis (DGA).
• Application of paint with a special coating for corrosive environments (in accordance with national and international standards).

4. Results and Value Metrics

• Asset Recovery: Transformers that were out of standard were returned to an "as new" condition, with formal acceptance by the client after successful functional testing.
• Technical Precision: The ability to perform induced and applied voltage tests in-plant guaranteed that the equipment would withstand the demands of the client's electrical system, with no risk of internal arcing.
• Capital Savings (CAPEX): The major rehabilitation cost a fraction of the price of new equipment, with significantly shorter lead times.

5. Technical Data