THIS IS A HAMMOND POWER SOLUTIONS DM051KK DRIVE ISOLATION TRANSFORMER, GENERAL PURPOSE TYPE, RATED FOR 51KVA AND 3-PHASE OPERATION. IT FEATURES A 480 DELTA PRIMARY VOLTAGE AND A 480Y/277V SECONDARY VOLTAGE. THE TRANSFORMER UTILIZES ALUMINUM WINDING MATERIAL AND IS HOUSED IN A NEMA 3R ENCLOSURE. ITS PHYSICAL DIMENSIONS ARE 23.9 INCHES WIDE, 25 INCHES DEEP, AND 28.75 INCHES HIGH, WITH A CASE STYLE OF NH6 AND WIRING DIAGRAM SCD 7.