chilled_water_pumpWashington Mutual Tower in Seattle, Washington Replaces Flexible Coupling with MagnaDrive ASD

1.0 Problem

The Washington Mutual Tower located in Seattle was experiencing high levels of vibration in a Chilled Water Pump that was part of the tower’s HVAC system due to the full head of the pump running against a pinched valve during normal operations. The increased vibration resulted in a need for increased maintenance on the pump and Chilled Water System. In addition, the building was wasting energy by controlling water pressure was through the valve.

2.0 Application

125 Hp / 1800 rpm 480 volt Motor running a centrifugal HVAC chilled water pump. The pump was designed to run at full speed against a pinch valve that was manually throttled depending upon the cooling equirements in the building. The pump was connected to the motor with an elastomeric coupling.

3.0 Solution

MagnaDrive replaced the control valve by installing an 18.5 MagnaDrive Adjustable Speed Drive. The motor was moved up onto a raised base and the ASD’s actuator was connected to the building’s HVAC process control system.

Customer Resolution: The MagnaDrive Coupling eliminated the bypass valve with a potential energy savings of 31%. The cavitation was eliminated and vibration was dramatically reduced, lowering long-term maintenance costs.

Customer Comments: “Control is much greater than any VFD. The large footprint is not needed, and harmonics are not an issue. We don’t have to replace couplings annually and deal with aligning the pumps and motors. The noise disappeared as soon as we started it. MagnaDrive… WOW!”