Article title: Rated insulation level of primary end of transformer

Key words: transformer, Primary en, rated, insulation level

Overview: This article mainly introduces the rated insulation level of the primary end of the transformer.

Note 1: the highest insulation level is recommended for exposed installations.

Note 2: for the value under the inclined line, the rated main frequency withstand voltage is the withstand voltage value under the dry state of the external insulation of the equipment, and the rated lightning impulse withstand voltage is the withstand voltage value of the internal insulation of the equipment.

Note 3: the rated power frequency withstands voltage value on the inclined line is adopted for the induced withstand voltage test of ungrounded voltage transformer.

Note 4: for the transformer installed in GIS, its rated power frequency withstands voltage level shall be in accordance with GB 7674, but there may be differences.