- Vacuuming is a critical process in transformer manufacturing because it removes moisture, air, and dissolved gases from the insulation system (pressboard, paper, and windings).
- Moisture and air pockets are the major causes of insulation failure, partial discharge, and reduced dielectric strength. Vacuuming ensures that the insulation is completely dry and free from trapped air before oil filling.
- Applying vacuum creates the ideal condition for oil impregnation, allowing purified insulating oil to fully penetrate the windings and insulation layers, improving long-term reliability.