Using controls to change the target pressure / HGL setting of a variable speed pump

Product(s): WaterCAD, WaterGEMS
Version(s): 08.11.XX.XX, 10.XX.XX.XX
Area: Modeling


Is it possible to add a control to a variable speed pump (VSP) that will change the target pressure setting based on a condition such as tank level and time of day?

Problem ID#: 43944


In V8i SELECTseries 6 (08.11.06.XX) and in the CONNECT Edition and above (10.XX.XX.XX), HGL target is an available control action. Read more here.

In earlier versions, there is a workaround:

First, calculate the model with the VSP setting as Fixed Head with the pressure settings needed. Note the calculated Relative Speed Factor. This calculated value can be used in the control for the pump. In the Control dialog, change the Pump Attribute in the control to "Pump Setting" and use the calculated Relative Speed Factor as the setting. Do the same the other pressure setting of the VSP.

Note that you can also use a Pattern Based variable speed pump setting instead of controls, using the same relative speed factor settings noted above. Pattern based VSPs adjust the relative speed factor based on time.

See Also

Is it possible to model a fixed flow Variable Speed Pump where the flow changes over time?