8.2.13 Flush settings
Flush settings
"Flush settings" are used to prevent blocking of the pump and to
minimise the risk of sedimentation in the upstream pipeline.
Enable flush functions:
• Reverse start
• Start flushing
• Run flushing
• Stop flushing.
See the figure below.
y
rf rf
z
x
f[Hz]
TM046708TM046708
TM046711
Flushing
Reverse start
This function can only be used if the pump is designed for
reverse start.
Max reverse speed must be set according to pump
specification. Using a too high speed can cause the
impeller to loosen and fall off.
"Reverse start" (x) is used to prevent pump blocking caused by
sedimentation in the pit. The user has to enable the function and set
the time in seconds that the pump has to rotate in the reverse
direction.
"Min. delay between reversing" must also be set.
This function can only be used when using linear or minimum
control mode.
Start flushing
"Start flushing" (y) starts the pump at full speed and lets it run for a
few seconds (set by the user). Then the pump ramps down to the
frequency (z) according to the parameters set in the specific control
mode.
Run flushing
"Run flushing" (rf) minimises the risk of sedimentation in the
upstream pipeline when the pump is running at low speed. The
pump ramps up to rated frequency for a set time and ramps down
again. The user has to set the time in seconds and the interval
between "Run flushing" cycles.
Stop flushing
"Stop flushing" ensures that the pump ramps up and flushes the
upstream pipeline before stop. The user has to set the time in
seconds.
Path:
Settings > Advanced functions > Variable-frequency drives >
VFD settings, pump 1 > Flush settings, pump 1
4-2-10-1-2_VFD_FLUSH_145
Flush settings, pump 1
8.2.14 Start level variation
"Start level variation" is used to reduce sedimentation on the inner
pit walls.
In this display, "Start level variation" is set. "Start level variation" is
only possible if an analog level sensor is used.
This function has to be enabled or disabled, and "Max. variation
above start level 1" has to be set.
Start level variation
"Start level variation" is a function connected to pump group 1.
When "Start level 1" varies, these rules must be followed:
• (Start level 1 + Max. variation) < Start level 2.
Each time "Pit level" < "Stop level 1", a new start level for pump
group 1 is calculated.
TM046712
Start level variation
Pos. Description
1
Start level 2
(= Max start level 1)
2 Start level 2
3 Start level variation
4 Upper measurement limit
5 Lower measurement limit
If a mixer is installed in the system, "Start level, mixer" is
also variable. "Start level, mixer" depends on an offset of
"Start level 1".
Example
The "Start level variation" function is enabled and is set to 20 cm.
Path:
Settings > Advanced functions > Start level variation
44
English (GB)
To Next Page
Loading...
