Grundfos Control MPC Montage- Und Betriebsanleitung Seite 59

8.6.46 Fixed inlet pressure (4.3.22)
Fixed inlet pressure
Description
The function is only used when no inlet-pressure sensor is fitted in
the system and the inlet pressure is fixed and known.
If the system has a fixed inlet pressure, you can enter it in the
display so that 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
and disabled.
Setting via the operating panel
• Settings > Secondary functions > Fixed inlet pressure.
• Select: Enabled or Disabled.
• Set: Fixed inlet pressure.
Factory settings
The function is disabled.
8.6.47 Flow estimation (4.3.23)
Flow estimation
Description
As described in section Pump curve data (4.3.19), CU 352 can
optimise operation according to performance curves and motor
data. In this display, you can select the curve types which CU 352
uses for the optimisation if they are available.
At large flow rates, there may be a considerable head loss between
the pump outlet 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
nd
• 2 order QH polynomial
th
• 5 order QH polynomial
• Power polynomial, QP
• Head loss.
It is possible to select several curve types, as CU 352
makes a priority based on the data available.
Setting via the operating panel
• Settings > Secondary functions > Flow estimation.
Factory settings
All polynomials are selected.
Related information
8.6.43 Pump curve data (4.3.19)
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