General Characteristics; A. MVA rating – 10.71/14.29/17.86 with 55°C cont. temp. rise. B. MVA rating – 12.0/16.0/20.0 with 65°C cont. temp. rise. C. Type cooling - ONAN/ONAF/ONAF. D. Phase - Three. E. Frequency - 60 Hertz. F. Voltage: 1. High Voltage - 115kV, delta connection, 550kV BIL. 2. Low Voltage - 12.47/7.2kV wye connection, 110kV BIL. 3. High Voltage Taps - 120,750; 117,875; 115,000; 112,125; 109,250 volts. G. High side winding series/multiple switch – not included. H. Low side winding series/parallel switch – not included. I. Windings - Two. The low side winding shall lag the high side winding electrically by 30 degrees (lagging transformer). J. LTC - Not included. K. The transformer shall be power class, round core/coil design and construction. The high and low voltage coils shall include disk or helical windings; layer/barrel windings are not acceptable. All windings shall be wound using rectangular magnetic copper conductor. L. The transformer design shall be adequate to withstand short circuits with the fault current limited only by the impedance of the transformer itself.
