Overview Grand Coulee Dam, located on the main stem of the Columbia River about 90 miles west of Spokane, Washington, is one of the largest concrete structures ever built, and the power production facilities at Grand Coulee are the largest in North America.

The BUREAU OF RECLAMATION has awarded GARDNER ZEMKE the contract for replacing 24 circuit breakers for the 65,000 horse-power irrigation pumps and 125MVA hydroelectric generators at Grand Coulee Dam. The breakers will replace equipment installed in the 1940s, 1950s and 1960s with work beginning in the fall of 2003 and completion mid 2005.

Details The project consists of removing the existing equipment, furnishing and installing six manual disconnect switch assemblies for pumping units P1 through P6, three power circuit breakers for pumping unit feeder buses including disconnects and ground switches, 18 power circuit breakers including disconnects between generators and breakers and ground switches on the transformer side of breakers for generating units G1 through G18, making additions and revisions to wiring within the generating and pumping unit control boards, installing three relay cabinets, and modifying the existing 15kV Isophase bus, for the Left Powerhouse and the Pump/Generating Plant.