Bonneville Dam is located 145 miles from the mouth of the Columbia River, approximately 40 miles east of Portland, Oregon. A Public Works Administration project of President Franklin D. Roosevelt’s New Deal, Powerhouse 1 (BN1), spillway and original navigation lock were completed by the U.S. Army Corps of Engineers (USACE) in 1938 to improve navigation on the Columbia River and provide hydropower to the Pacific Northwest. Powerhouse 2 (BN2) was completed in 1982 and a modern navigation lock in 1993. BN1 has 10 main units with a total rated capacity of 518 MW and BN2 has eight main units with a total rated capacity of 612 MW.  During the recent station Service work completed at BN2, the SU and CQ panels were not included in this work. These 480V panels are original equipment and components are no longer being manufactured and the condition rating of the panels is marginal.