Fixed Inlet Pressure; Flow Estimation - Grundfos Control MPC Installation And Operating Instructions Manual

8.7.41 Fixed inlet pressure (4.3.22)

Fig. 91 Fixed inlet pressure
Description
This function is only used when no inlet-pressure sensor is fitted
in the system and the inlet pressure is fixed and known.
If the booster system has a fixed inlet pressure, it can be entered
in this display so that the CU 352 can optimise the performance
and control of the system.
Setting range
A fixed inlet pressure can be set, and the function can be
enabled/disabled.
Setting via control panel
• Settings > Secondary functions > Stop function > Fixed inlet
pressure.
• Select: Enabled / Disabled.
• Set: Fixed inlet pressure.
Factory setting
The function is disabled.
48

8.7.42 Flow estimation (4.3.23)

Fig. 92 Flow estimation
Description
As described in section
8.7.39 Pump curve data
CU 352 can optimise operation according to performance curves
and motor data. In this display, you can select the curve types
which the CU 352 will use for the optimisation if they are
available.
At large flow rates, there may be a considerable head loss
between the pump discharge flange and the pressure sensor.
The loss is caused by non-return valves and pipe bends.
To improve the flow estimation of the system, it is necessary to
compensate for the difference between the measured and the
actual differential pressure across the pump. This is done by
entering the head loss in non-return valves and pipe bends at the
rated flow rate of one pump.
Setting range
• 2nd order QH polynomial
• 5th order QH polynomial
• Power polynomial, QP
• Head loss
It is possible to select several curve types, as the CU
Note
352 makes a priority based on the data available.
Setting via control panel
• Settings > Secondary functions > Stop function > Flow
estimation.
Factory setting
All polynomials are selected.
(4.3.19), the