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Thread: Run Warning: pump operation out of range

  1. #1

    Join Date
    May 2018

    Run Warning: pump operation out of range

    The results of a steady state simulation give the following warning " ** Overall Run Warning ** Warning : pump operation out of range". How can I determine which pump the warning is referring to? Three pumps are operating during the simulation. One of the pumps has variable speed control. The other seven pumps in the model are closed and have controls to come on based on pressure settings.

  2. #2
    Forum Moderator

    Innovyze Employee

    Innovyze Employee

    Join Date
    May 2015
    Can you please verify what software you are using that you have a question about?

    If using InfoWater please confirm the following:
    1) What is the setting the VSP pump is trying to meet?
    2) What is the minimum and maximum speed set to in the VSP control?
    3) If you have output please also check what the Discharge pressure on the pump shows. Is this higher than the VSP setpoint or much lower?

    A VSP control in InfoWater that uses "downstream Junction" control actually uses one of the "hidden nodes" added to convert a pump from a line element to a point element. This means Downstream junction is using the hidden node which uses the pump elevation and the pump suction and discharge pressure output come from these "hidden" nodes. And these nodes are assigned elevations based on the pump elevation.

    If the downstream system creates and pressure higher than the VSP setting, there is no way the pump can operate and maintain the setting specified. Similarly if the pump cannot run at a speed low enough to meet the setting it cannot find an answer either and would give an error.

    Please verify the pump elevation is correct and examine the max and minimum speed pressures. If unsure what the system is doing without this pump running try running the model with the pump off or with the pump as a non VSP pump to see how the pump is responding to system conditions. Usually this is enough to identify any system issues interfering with the VSP pump.

    I would also review what your pump curve definition is for this pump. A multi-point curve is the best to use with a VSP pump as it accurately reflects the pump curve over the entire flow range. A design point or 3 point curve may not always accurately predict the pump operation over the entire flow range and should be used with caution for VSP pumps as the quality of the model results are highly dependent on the quality of the pump curve.

    If you are still having difficulties and need further assistance please reach out to us at and if you have an active InfoCare Annual Maintenance we would be able to either have a WebEx with you or have you send your model and we can help review might be occurring.

    Also please make sure you are using the following options in the Run report options to get the most information when troubleshooting a model issue:
    (click if you need a larger image)
    troubleshoot image1.jpg

    Patrick Moore
    Last edited by Patrick Moore; May 24, 2018 at 02:26 PM.

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