Pumps & Systems, July 2008
Much has been reported recently about surface water reservoirs in the Southeast and West maintaining dangerously low levels.
In many cases, water levels have dropped to below the raw water intake cribs, rendering the cribs unusable. In these circumstances, the municipalities and water purveyors have had to severely limit or stop using raw water intake pumps. We recently became involved in a project for floating a set of vertical turbine pumps onto Lake Cumberland in Kentucky to regain reliable access to the remaining water in the reservoir.
The pumps were set onto a barge and the pump controls were in a pre-fabricated, factory-built electrical apparatus building. This building was built at our plant in Centralia, Ill., and shipped complete to the jobsite, to be placed on a concrete foundation on the bank of the reservoir.
Background
The project was driven by a critical water shortage due to low water levels at the raw water supply. This work was performed under an emergency procurement negotiated directly between the owner, engineer and our company.
To save time, the controls building and pumps were pre-purchased by the owner directly. While the equipment procurement negotiations were ongoing, the site construction was in design and was bid separately.
Because of the water emergency, there was $5,000 per day liquidated damages on the contract if we delivered later than September 26, 2007. The order was placed June 4, and the unit shipped September 24. The project's start-up date was November 30, 2007.
Application
The application was to provide new raw water supply from a floating barge on Lake Cumberland in Kentucky. The design requirement for the pumps was 5,200-gpm at 416-ft TDH. The water level on the lake can vary up to 40-ft during the year. The pumps were shipped loose and installed on a barge by the installing contractor.
Scope
We designed, manufactured and delivered a controls building, complete with a 1,200-amp main disconnect, automatic transfer switch, distribution panel, four 250-hp VFDs with Mirus Harmonic Mitigation, an Allen-Bradley 5/05 Series PLC for pump control and sequencing and a complete building HVAC System with 4 tons of cooling. The building was complete, requiring only setting, anchoring and the electrical and instrumentation connections at the site.