Washington Mutual Tower in Seattle,
Washington Replaces Flexible Coupling with MagnaDrive ASD
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.
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.
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!"
