The SZ11-M and SZ13-M series of fully sealed, on-load distribution transformers are suitable for residential areas, commercial centers, high-rise buildings, remote areas, and locations with high dust levels and pollution. These transformers feature high technical content, excellent energy-saving performance, and significant application value. The performance indicators of this series meet IEC standards and relevant national standards. The products are designed with a reasonable structure, high operational reliability, notable energy-saving effects, strong overload capacity, and low noise.

The 10kV side of the product is equipped with an on-load tap changer. When the grid voltage fluctuates, the transformer can automatically or electrically switch the taps of the high-voltage winding under normal load operation, stabilizing the secondary output voltage within a certain range. This improves the quality of the power supply voltage, enhances the efficiency of electrical equipment, and ensures the safety and normal operation of the equipment.

Compared to the S9 type transformers, the no-load loss of this series is reduced by an average of 30-50%, and the no-load current is reduced by 80-90%. The series uses corrugated oil tanks made of 08 aluminum cold-rolled plates, which are compact, structurally robust, and aesthetically pleasing. The insulating oil inside the tank is completely isolated from the outside air, effectively preventing moisture and aging. Under normal usage conditions, these transformers require no maintenance or inspection for twenty years, significantly reducing operational costs. They are the preferred products for upgrading and replacing transformers in the power grid.