These transformers shall meet all requirements of the latest applicable American National Standard Institute (ANSI), American Society of Testing and Materials (ASTM), Institute of Electrical and Electronic Engineers (IEEE), and the National Electrical Manufacturers Association (NEMA) standards. These transformers shall be threephase, 60 hertz, oil filled, self-cooled, compartmental, pad mount type distribution transformers, rated from 150kVA through 2,000kVA. The transformer oil must not contain PCBs. II. RATINGS These transformers shall be rated at 13,800GRDY/7,970 volts on the primary side. The BIL shall be 95kV on the primary side and 30kV on the secondary side. Transformer kVA ratings shall be 150, 300, 500, 750, and 1,000 for the 120/240, 208/120-volt class and 300, 500, 750, 1,000, 1,200, 1,500, and 2,000 for the 480/277-volt class as noted on the bid. KVA ratings are continuous and based on not exceeding either a 65-degree Centigrade average winding temperature rise, or an 80-degree Centigrade hot spot temperature rise above a 40-degree Centigrade ambient temperature. Transformer impedance shall be 5.75% (±10%) for sizes 750 to 2,000 kVA. (Not specified for 75 to 500 kVA)...
