A- Transformer 1) Define the inrush current on transformers, explain the inrush current cause, effects, and how to reduce it. 2) read the nameplate of the following transformer and describe the following: a) Duty (meaning and what types of duties can be found for transformers) b) Vector group ((meaning and what types of vector groups can be found for transformers) c) Cooling (meaning and what types of cooling can be found for transformers) 3) The rated frequency of the transformer below is 50 Hz, if it is exported to the USA /the frequency there is 60 Hz, how the change of frequency will affect the rated value of the transformer? ADD ABB Ltd. 3-PHASE DISTRIBUTION TRANSFORMER Rating (KVA) 3500 Frequency (Hz) 50 Duty CONT Vector group Dyn11 Cooling ONAN Standard IEC 60076 125-50 HV insulation level Top oil/winding temp.rise(C) Temp. Class Impedance (%) 60165 A Serial Number 1LVN2070028 ABC Poution Voll cmp Manufacturing date 2007 22550 Max ambient 22000 919 690 40 Temp.(C) 21450 Type of 20900 Nytro 10GBNP insulation oil 5 20350 Oil weight (kg) 2200 Total weight (kg) 10000 omp