The unit shall be filled with Biotemp or any listed “less flammable liquid” similar to Biotemp as required by 2023 NEC 450-23. 9.4.2 The transformer shall carry its continuous rating with average winding temperature rise by resistance that shall not exceed 65 degrees C, based on an average ambient of 30 degrees C over 24 hours with a maximum of 40 degrees C. 9.4.3 Transformer shall include provisions for devices, wiring, fans, and auxiliary equipment necessary for automatic temperature controlled forced air cooling to obtain an additional 25% capacity. Control power for fans shall be 230 VAC, single phase furnished from a separate control power source. 9.4.4 The transformer shall be designed to carry short time emergency overloads in accordance with ANSI C57.12.92 as applicable. Duration and magnitude of designed withstand capability shall be as outlined in ANSI C57.12.90 and the latest draft of the IEEE short-circuit test code. 9.4.5 The transformer shall be designed to meet the sound level standards for liquid transformers as defined in NEMA TR1. The measurement procedure shall be as specified in ANSI C.57.12.90. 9.4.6 High-voltage and low-voltage windings shall be aluminum. Insulation between layers of the windings shall be by Insuldur paper or equal...
