... VFD, direct input of3,3.3,4.16,6,606 and 10 kV,direct output of 3,4.16, 6,6.6 and10 kV,no output transformer necessary ... pumps, etc2. Metal: dusting fans, furnace fans, oxygen-generators of steel productions, etc3. Petrochemical and chemical; oil transfer pumps ... 3859.2-1993 Semiconductor converters-Application guideGB/T 3859.3-1993 Semiconductor converters-Transformers and reactorsGB 4208-1993 Degrees ...