A 35 kV oil-immersed power transformer is selected for power conversion at the specified system voltage level. The reference catalogue provides configurations with rated capacity, winding voltages, tapping ranges, vector groups and impedance values. On-load and off-circuit tap-changing arrangements are listed separately and must be selected to suit the operating requirement. The design review should establish the required number of windings, network voltages, load profile and installation environment. Rated voltage alone is not enough to define a complete transformer specification. Buyers should also provide the frequency, required losses, insulation requirements, cooling arrangement and applicable project specification. Accessories, terminal arrangements and protection interfaces are agreed with the installation designer. For replacement projects, include the existing nameplate and foundation drawing. The catalogue tables supplied with this material package are reference data from the existing product documents. Final guaranteed values, test scope and overall dimensions must be confirmed in the project technical agreement and approved drawing before manufacture.