The transformer shall provide rated low-voltage output at rated high-voltage input. The transformer high-voltage winding shall be 12,000V connected delta. The wye-connected transformer low-voltage winding shall be 208/120 or 480/277 volts as specified on the bid submittal forms with the neutral brought out and made accessible on an insulated bushing. The delta-delta-connected transformer low-voltage winding shall be 240V delta with 120V midtap. 3.00 TEMPERATURE The winding temperature rise above ambient temperature, when tested at the rated kVA, shall not exceed 65° C. The hottest spot winding temperature rise above ambient temperature, when tested at the rated kVA, shall not exceed 80° C. 4.00 IMPEDANCE The nominal impedance of transformers rated 750 kVA or more shall be 5.75% as per ANSI C57.12.34. In all cases, the maximum impedance shall not exceed 125 percent of the minimum nominal impedance allowed. (No exception will be granted outside the above-defined ranges.)...
