2500 KVA THREE PHASE PADMOUNT DISTRIBUTION TRANSFORMER, 277/480 SECONDARY VOLTAGE This specification is for the purchase and delivery of oil-filled, three-phase, pad-mounted distribution transformers. Standards: All applicable ANSI, IEEE, NEMA, ASTM, DOE, IUB (Iowa Utilities Board), IDOT (Iowa Department of Transportation) and OSHA standards of the latest issue must be followed in the design, manufacture, delivery and labeling of transformers furnished under this specification. In case of conflict between the industry standards and this Specification, the manufacturer must notify AMES and secure a written clarification before proceeding. Exceptions: The manufacturer must clarify all exceptions to this specification with their bid/quotation. Transformers found not in compliance with this specification will be returned, credited, or brought into full compliance at the manufacturer's expense, including handling, shop time, and shipping costs. Quality Assurance/Experience: The Manufacturer must manufacture, inspect and test all materials provided under this specification under a declared Quality Management System (QMS) that is currently certified to ISO 9001:2015. Supplier must have manufactured oil-filled distribution transformers a minimum of 10 years and must have operated the facility that will supply transformers under this specification for a minimum of 3 years. kVA/Thermal Rating: The size in KVA must be as specified in the bid and proposal form. The unit must be designed for the following thermal rise conditions: 65°C continuous average winding temperature rise, 80°C hot spot; 65°C maximum top oil temperature rise (this applies to transformers rated 1500 kVA and below; see the 55°C exception for 2500kVA transformers, below). All current-path components external to the winding must have a minimum continuous current rating of 200% of rated nameplate current including winding leads, HV taps, connections and contacts. Permitted exceptions to this requirement include 200Amp primary bushings and fuse elements –all other exceptions must be clarified & requested with the quotation. The objective of this requirement is to reduce long-term oil heating and gassing.
