24
Feb
The assembly of an oil-immersed transformer begins with preparing the **core and windings**. The laminated silicon steel core is stacked and clamped, followed by mounting insulated copper/aluminum windings (primary and secondary) onto the core limbs. Insulation barriers and spacers ensure electrical separation between windings. Next, the core-winding unit is lowered into a **steel tank** using cranes. The tank is pre-cleaned and coated internally to resist corrosion. **Radiators** or cooling tubes are welded or bolted to the tank walls to facilitate heat dissipation. A **conservator tank** (connected via piping) and **bushings** (mounted on the tank cover) are installed to manage oil expansion and external electrical connections.
After mechanical assembly, the tank is filled with **insulated oil** under vacuum to eliminate air bubbles. The oil undergoes filtration and degassing to ensure purity. Auxiliary components like **pressure relief valves**, **temperature sensors**, and a **breather** (with silica gel) are installed to monitor and protect the system.
Finally, electrical tests (e.g., turns ratio, insulation resistance) and leakage checks are performed. The transformer is dried in a vacuum oven to remove moisture, sealed, and prepared for commissioning
