In May of 2014, Olsson Industrial Electric was awarded a prime contract to modernize the station service electrical distribution system at the McNary Lock and Dam. Over the next four years, nearly all of the existing 4160V distribution will be replaced. Construction will begin with two iso-phase bus taps feeding new 15kV switchgear assemblies for redundant distribution to new 480V substations. Twenty-eight 4160V governor oil pumps will be rewound to 480V for compatibility with the new station service distribution.
Ultimately, the modernization will convert the entire powerhouse to a redundant 480V system. With the majority of new equipment installed in green field locations, the new system can be commissioned and energized in advance to minimize outages and disruptions to the plant. OS Engineering and Olsson Controls will provide significant support throughout the project making this a complete team effort.
- Remove nearly all existing 4160V components
- Install seven 15kV and five 480V switchgear lineups
- Install 12 high resistance grounds and two 15kV CLRs
- Install two 4.16/13.8kV 5MVA transformers, ten 13.8kV/480V transformers, one 13.8V/12.47kV 750kA PSJ transformer, a 13.8kV/480V 1000kVA transformer, two 13.8kV/480V 500kVA transformers and two 480v/208Y-120V 225kVA transformers
- Install 13 480V AC MCCs
- Install 7 main unit switchboards
- Designed and implemented temporary power solutions for continuity of powerhouse operations