As part of the electrical and control systems preliminary design task for this 4160V pump station, Triunity performed a life-cycle cost analysis to compare alternatives to the existing method for flow control. The existing system relies on throttling valves to limit the discharge pressure from the two 400 hp fixed-speed pumps. Triunity evaluated both variable frequency drives (VFDs) and a method that relies on a magnetic clutch between the fixed-speed motor and pump to vary pump speed.

Triunity is performing the electrical power, lighting, and control system design for the station that will require a complete 4160V electrical system replacement and extensive building remodel. The control system, instrumentation, and several valves will be replaced. A new Seattle City Light service and provisions for a mobile standby generator are planned.

Triunity’s engineers will support the construction phase with submittal review, RFIs, and change management. Triunity will also support station start-up and commissioning.