XFR SUB 00140

Burlington Electric Department (BED) is requesting quotations for single phase, 60 Hz, mineral oil immersed, self-cooled distribution transformers with a 55 degree Celsius rise. The transformers must be submersible vault type units with loop feed configuration and must comply with ANSI/IEEE standards C57.12.00, C57.12.23, C57.12.32, C57.12.70, C57.12.80, C57.12.90, C57.91, and IEEE 386.

Key technical specifications include: nominal high voltage rating of 13800 Grd Y/7970 volts with 95 kV BIL; low voltage options of 120/240 volts or 277 volts with 30 kV BIL; impedance voltage of 1.60-2.25 percent for 15-250 kVA units and 3.25 percent (plus/minus 7.5 percent tolerance) for 333 kVA and larger units. All transformers must have tank and cooling fins constructed from 304 grade stainless steel with corrosion-resistant coating. Maximum overall diameter shall not exceed 30 inches (33 inches for 167 kVA and above units), with maximum height of 66 inches from base to cover. The transformer must fit through a 36-inch diameter clear round opening. All components must be PCB-free as certified on the nameplate.

Testing requirements include full wave voltage impulse testing, no load losses at 20 degrees Celsius/100 percent voltage, total losses at 85 degrees Celsius/100 percent voltage, percent impedance at 85 degrees Celsius, and exciting current at 100 percent rated voltage. Certified test reports by serial number must be provided prior to shipment for BED approval. High voltage terminations must be 200 amp loadbreak, separable, insulated connectors with two universal bushing wells for loop feed configuration. Low voltage bushings shall be cover mounted with copper alloy NEMA 4-hole pads. Over-current protection must include a loadbreak BAY-O-NET type oil immersed fuse (RTE type 353C or equal) with an RTE type ELSP or equal back-up current limiting fuse.

Delivery is required no later than February 6, 2026 at 5:00 PM EST. All proposals must be submitted via BED's secure website using the vendor's unique login. Quotations must include outline drawings showing transformer dimensions, one-line diagram, average and guaranteed maximum losses, impedance values, X/R ratios, exciting current percentages, and warranty information with location of nearest manufacturer service shop. Certified test reports must be emailed to engineering@burlingtonelectric.com at time of shipment. Payment will be held until reports are received and accepted by BED.