Gp: Proportional Gain Coefficient; Gi: Integral Gain Coefficient; Fs: Maximum Rotation Frequency; Fl: Minimum Rotation Frequency - DAB PUMPS MCE-22/P Instruction For Installation And Maintenance

6.6.4

GP: Proportional gain coefficient

The proportional gain should generally be increased for elastic systems (wide and PVC pipelines) and reduced in the case of rigid
systems (narrow and steel pipelines).
To maintain constant system pressure, the inverter performs a PI check on the measured pressure error. On the basis of this error,
the inverter calculates the power to supply to the electric pump. The behaviour of this check depends on the set parameters GP and
GI. To meet the different requirements of the various types of hydraulic systems where the system may operate, the inverter enables
the selection of parameters that are different from the default settings. On virtually all systems, the factory setting of parameters
GP and GI are optimal. However, in the event of problems with regulation, these settings may be modified as required.
6.6.5

GI: Integral gain coefficient

In the event of significant pressure drops on sudden increases in flow, or a slow system response, increase the value of GI. Otherwise,
in the event of pressure oscillations around the setpoint, reduce the value of GI.
A typical example in which the value of GI should be reduced is that in which the inverter is located far from the electric
pump. This distance causes hydraulic elasticity which influences control of PI and therefore pressure regulation.
IMPORTANT: To obtain satisfactory pressure settings, both values GP and GI should be adjusted.
6.6.6

FS: Maximum rotation frequency

This sets the maximum pump rotation frequency.
This sets a maximum rpm limit and can be set between FN and FN - 20%.
FS, in any conditions of regulation, ensures that the electric pump is never controlled at a frequency higher than the set value.
FS can be automatically reconfigured following modifications to FN, when the above ratio is not verified (e.g. if the value of FS is less
than FN - 20%, FS will be reset to FN - 20%).
6.6.7

FL: Minimum rotation frequency

FL is used to set the minimum pump rotation frequency. The minimum admissible value is 0 [Hz], and the maximum is 80% of FN; for
example, if FN = 50 [Hz], FL can be set between 0 and 40[Hz].
FL can be automatically reconfigured following modifications to FN, when the above ratio is not verified (e.g. if the value of FL is
greater than 80% of the set FN value, FL will be reset to 80% of FN).
Set a minimum frequency according to the pump manufacturer's specifications.
The inverter will not control the pump at a frequency below FL; this means that if the pump, at the frequency FL, generates
a pressure above the set point, there will be a pressure overload in the system.
6.6.8

Setting the number of inverters and reserves

6.6.8.1

NA: Active inverters

This sets the maximum number of inverters involved in pumping.
It can be set with a value between 1 and the number of inverters present (max. 8). The default value for NA is N, i.e. the number of
inverters in the series; this means that if inverters are removed or inserted in the series, NA always has the same number as that of
the inverters, as read automatically. If a value other than N is entered, the system sets to the maximum number of inverters that can
be involved in pumping.
This parameter is used when there is a limited number of pumps to be kept in operation, and if one or more inverters are to be kept as
reserves (see IC: Configurazione della riserva section 6.6.8.3 and the following examples).
In the same menu page, the user can view (without the option of modification) a further two system parameters related to this value,
i.e. N, the number of inverters detected automatically by the system, and NC, the maximum number of simultaneous inverters.
ENGLISH
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