1.Type designation: S11-M. It is Low loss series.

2.Structure design
2.1Core structure: The core is made by Hi-B grain-oriented and good quality cold rolled silicon steel sheet imported, the unique lamination structure with 45℃ mitered joint is adopted so that no-load losses are reduce. Compare to S10series, the no-load loss reduce 10%.

2.2 Special winding structure: the H.V. and L.V. winding shall be made of copper, with small in size, low on-load losses, high mechanical strength and great ability withstanding short-circuit. It can withstand enough the electromagnetic forces of three-phase short circuit, temperature rise and allowable current.

2.3 Tank structure: The 6mm thickness of steel plate is adopted in the tank that is with nice performance in welding and high mechanical strength, the tank cover is tightly welded with flange. The double sealed structure is adopted for drain valve, kinds of relay and pressure relief device, so that no oil would leak out.

2.4 Radiator structure: expansible radiator, which performance is including not only cooling but also breathing. The mechanical strengthen is much stronger than that of corrugation type especially to oil immersed transformer. The transformer adopts vacuum filling oil process at final assembly; it can’t absorb moisture and be oxidized so that the oil and insulation delay their ageing.

2.5 Fix method: The special clamp device and efficient loose-proof fastening are adopted in the core and the active part so that they are guaranteed not to be moved after the transformer is transported for a long distance, and without hanging the active part for inspection before the transformer is installed.

2.6 Ground pad: Two ground pads shall be fitted at diagonally opposite corners of the base. Each pad shall include clamp-type terminal and bolts suitable for earthling wire connection.

2.7 Temperature rise: The transformer is capable of continuous operation at the specified full rating, under the service conditions, without exceeding a maximum temperature rise of the oil, by thermometer, of 55K and of the windings, by resistance of 65K, which is the standard value of IEC and GB.

2.8 Protection Device: the transformer equipped with gas relay, pressure release, signal temperature indicator, they will alarm and trip while overpressure or overheat.