Introduction
A batch of SCB13 dry type transformers, customized for an important partner, has completed all manufacturing and testing procedures. The transformers have been packed for export and shipped to the designated port.
Core Component Manufacturing
1. Core Manufacturing
Slitting
Rolls of silicon steel sheets are cut into strips according to the designed width.
Cross-cutting
The strips are cut into individual laminations of specified length and angle.
Stacking
The cut laminations are interleaved and stacked piece by piece to form the transformer's the core limbs and yokes. After stacking, the assembled parts are clamped tightly with fixtures.
Coating & Curing
The core surface is coated with a special insulating varnish and cured to prevent short circuits and rust between the silicon steel laminations.
2. Winding Manufacturing
Winding
On specialized winding machines, electromagnetic wires are wound onto molds or insulating cylinders. For every layer wound, inter-layer insulating materials are placed.
Pre-baking & Pressing
Completed windings undergo low-temperature preheating to remove moisture, and then they are placed into a press to be compressed and shaped.
3. Epoxy Resin Casting
Vacuum Degassing: The mold containing the windings is placed into a vacuum casting tank. A high vacuum is applied to remove air and moisture from both the windings and the mold.
Mixing & Casting: In a separate vessel, epoxy resin, curing agent, and fillers are precisely mixed, heated, and degassed under vacuum. Then, the prepared resin mixture is injected into the mold to completely impregnate and encapsulate the windings.
Gelling & Curing: In an oven with a strictly controlled temperature curve, the resin first gels and then fully cures, forming a solid shell that is tightly bonded to the windings, and characterized by high strength, high insulation, and flame retardancy.
Demolding: After curing is complete, the mold is removed, yielding a complete cast winding.
Final Assembly Stage
Core & Winding Assembly
Installation of Upper & Lower Yokes
Installation of Clamping Structure & Fastening
Wiring and Lead Connection
Installation of Auxiliary Components
Testing and Delivery
| Test Category | Test Items |
| Routine Tests |
1. Winding Resistance Measurement |
| 2. Voltage Ratio Measurement & Vector Group Verification | |
| 3. Short-Circuit Impedance & Load Loss Measurement | |
| 4. No-Load Current & No-Load Loss Measurement | |
| 5. Applied Power Frequency Withstand Voltage Test | |
| 6. Induced Overvoltage Withstand Test | |
| Special Tests (as required) |
1. Partial Discharge Measurement |
| 2. Lightning Impulse Test | |
| 3. Sound Level Measurement |
Final Inspection & Packaging
After passing all tests, the transformer undergoes cleaning, visual inspection, and labeling before being properly packaged and prepared for shipment.