The Nashville District Energy Plant, operated by Constellation Energy, has recently completed an upgrade to the six chilled water pumps that distribute water through the downtown Nashville system. The modifications were necessary to increase the plant’s capacity to deliver chilled water to facilitate the new requirements from the new 1,200,000 sq. ft. Music City Convention Center and surrounding development. The new convention center will use both chilled water and steam from the plant. The engineering staff at Tennessee Electric Motor Co. was contacted to specify the product to be used and design capability changes.

The original pumps were 500HP units rated at 7,600 gallons per minute with a differential head of 219 feet or 95 pounds per square inch. The City of Nashville wanted to increase supply to at least 10,000 gallons per minute to meet the demands of the new construction. This requirement was achieved by increasing the pump impeller size, and utilizing high efficiency WEG 550HP W22 AC motors along with WEG SSW06 soft starters besides medium voltage motors . Constellation Energy has recently commented on the fact that the new installation delivers more GPM than originally expected resulting in fewer motors needing to be on line at any given time. This alone reduces energy costs and provides additional peak capacity.

Another critical specification that was required in this application was that the motors needed to be within a 617 amp rating so that existing plant wiring could be utilized. WEG had the only motor that could deliver this important specification and still maintain the high HP rating.

The six WEG 550 HP AC motors operate at 1200 RPM and 460V. They are built on the revolutionary W22 motor platform, recently developed by WEG, to provide units that maximize performance and energy savings throughout the motors lifetime.

The WEG SSW06 Soft Starter utilized is the latest generation of WEG technology. This compact unit allows allow for efficient start-up, acceleration and deceleration of the pump motors. It incorporates a dual display LED keypad for maximum visibility and easier programming. Also integral bypass contacts eliminate heat dissipation once the motor is at full voltage.

Tennessee Motors Company, the largest WEG stocking distributor in the southeast, enabled us to provide this successful application to Constellation Energy. WEG looks forward to additional opportunities with both these important partners.