Pump X had efficiency greater than 100%

A Warning message in AFT Impulse.

Full message is:

Pump X had efficiency greater than 100%. This may be due to a density sufficiently greater than the basis of the power input data or an error in the power input data. For non-inertial models, only the output values for efficiency and power are affected. For inertial models, all pump results will be impacted.

This warning message could be caused by incorrect input data, or could be a result of using Four Quadrant pump curves:

  1. Check that the efficiency/power data is entered correctly in the Pump Configuration window, and that the correct selection is made for either efficiency or power in the dropdown header of the column. If power data is being used, a reference density may need to be entered to correct the data, see the Reference Density topic for more information.

  2. For a pump defined using a Trip with Inertia or Startup with Inertia transient, check that the Total Rotating Inertia is entered correctly. The power data and reference density should still be checked as discussed above.

  3. For a pump startup, verify that the provided torque data is the motor torque, and not the pump torque data, as is discussed in the Startup with Inertia topic.

  4. If a Four Quadrant pump curve model is being used, check if the Four Quadrant efficiency curve is at or above 100% for any of the flowrates experienced in the transient.