Project Description


Olsson Industrial Electric was contracted in May of 2014 to complete a comprehensive modernization of McNary Lock and Dam’s station service electrical distribution system with support from OS Engineering and Olsson Controls. This four-year project included initial construction involving two new iso-phase bus taps feeding 15kV switchgear assemblies for the purpose of redundant distribution to 480V substations, the rewinding of 28 4160V governor oil pumps to 480V for the purpose of compatibility with the updated station service distribution, and the replacement of virtually all of the 4160V components. 

The result of this upgrade was a conversion of the powerhouse to a redundant 480V system with new equipment installed in green-field locations optimized to minimize plant outages and disruptions.

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  • Removed virtually all existing 4160V distribution
  • Installed five 480V and seven 15kV switchgear lineups
  • Installed two 15kV CLRs and 12 high-resistance grounds
  • Installed 13 480V AC MCCs
  • Installed seven main unit switchboards
  • Installed two 4.16/13.8kV 5MVA transformers
  • Installed 10 13.8kV/480V transformers
  • Installed one 13.8V/12.47kV 750kA PSJ transformer
  • Installed one 13.8kV/480V 1000kVA transformer
  • Installed two 13.8kV/480V 500kVA transformers 
  • Installed two 480V/208Y-120V 225kVA transformers


  • Maximized continuity of powerhouse operations through design and implementation of temporary power solutions

Project Details

  • Location: Umatilla, OR

  • Client: U.S. Army Corps of Engineers

  • Timeline: May 2014 – Current