Pump data: current thresholds

With positive displacement pumps, and in absence of an integrated power converter, the motor will require an over-current before starting to rotate.

This panel asks you to define these over-currents for Head Min, Head Max, and an intermediate HeadMed at the midpoint between them. The final function at any Head in the model will result from linear interpolation.

Additionally, the threshold voltage should be defined. This is the voltage at which the pump (that is, flow production) will stop. It usually corresponds to the elbow of the measured current/voltage curve.

This elbow is not always well defined (not provided in the datasheets). The model chooses a point below the lowest specified operating point. The I = f(U) behavior between the last significant point and the origin (U=0, I=0) is approximated by a quadratic curve for completeness of the model, but its exact values are not critical during the simulation process.