Related information
8.2.9.3 Minimum control
"Minimum control" is basically the same as "Linear control", but in
this control mode the parameter "Min. economy frequency" also has
to be set. When the water level is lower than "Economy level", the
pump runs at "Min. economy frequency".
This control mode is selected when the user wants to keep the
pump running at low speed. Having the pump running at low speed
minimises the risk of sedimentation in the upstream pipeline.
In some applications, this control mode could be the best
solution since the total energy consumption is lower when
the pumps are running.
1
2
3
4
5
6
7
1
2
TM043327
Pit levels
Pos.
Description
1
High level
2
Start level 2
3
Max. economy level
4
Start level 1
5
Economy level
6
Stop level
7
Dry-running level
Pump operation:
1-2: The pump is operating in the control mode selected.
2-3: The pump is running at maximum speed.
3-4: The pump is running with minimum control.
4-5: The pump is running with minimum control.
5-6: The pump is running at "Economy frequency" (buffer range
before stop).
6-7: The pump has been stopped.
When the inflow allows the pump to run at "Economy frequency",
the pump runs at this frequency and adjusts the frequency if the
inflow changes.
Select economy parameters:
•
Economy level
•
Max. economy level
•
Economy frequency
•
Min. economy frequency.
"Minimum control" is basically the same as "Linear control", but in
this control mode the parameter "Min. economy frequency" also has
to be set. When the water level is lower than "Economy level", the
pump runs at "Min. economy frequency".
This control mode is selected when the user wants to keep the
pump running at low speed. Having the pump running at low speed
minimises the risk of sedimentation in the upstream pipeline.
In some applications, this control mode could be the best
solution since the total energy consumption is lower when
the pumps are running.
1
2
3
4
5
6
7
1
2
TM043327
Pit levels
Pos.
Description
1
High level
2
Start level 2
3
Max. economy level
4
Start level 1
5
Economy level
6
Stop level
7
Dry-running level
Pump operation:
1-2: The pump is operating in the control mode selected.
2-3: The pump is running at maximum speed.
3-4: The pump is running with minimum control.
4-5: The pump is running with minimum control.
5-6: The pump is running at "Economy frequency" (buffer range
before stop).
6-7: The pump has been stopped.
When the inflow allows the pump to run at "Economy frequency",
the pump runs at this frequency and adjusts the frequency if the
inflow changes.
Select economy parameters:
•
Economy level
•
Max. economy level
•
Economy frequency
•
Min. economy frequency.
Max. economy level
At "Max. economy level", the pump runs at maximum frequency.
When the level is below the "Max. economy level", the
pump ramps down until the "Economy level" is reached.
Min. economy frequency
At "Min. economy frequency", the pump ramps down to the set
frequency and keeps the pump running at low speed.
The parameters can be changed via the following:
•
PC Tool WW Controls
•
SCADA system
•
CU 362 operating panel.
If flush settings have to be made, see section about flush settings.
VFD interface:
Select how the VFD is to be controlled:
•
CUE (GENIbus). See the installation and operating instructions
for Dedicated Controls.
•
Analog output (0-10 V). See section about analog outputs.
"Min. frequency" is set to 30 Hz as default.
"Max. frequency" is set to 50 hz as default.
These parameters are the limits for the fixed frequency. This means
that the frequency cannot be set higher than 50 Hz or lower than 30
Hz.
Path:
Settings > Advanced functions > Variable-frequency drives >
VFD settings, pump 1
41
English (GB)
