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This coherence is based on the adjustment of 2 sets of speed and associated power at no-flow. Monitoring power enables detection
of no-flow conditions in systems with fluctuating suction pressure, or of the pump having a flat characteristic towards low speed.
The 2 sets of data must be based on measurement of power at approximately 50% and 85% of maximum speed with the valves
closed. The data is programmed in
parameter group 22-3* No-Flow Power Tuning
.
Enable and commission no-flow detection in
parameter 22-23 No-Flow Function
and
parameter group 22-3* No-Flow Power Tuning
.
22-23 No-Flow Function
Default value: [0] Off
Parameter type: Option
2-setup: All setups
Conversion index: -
Data type: u_int8
Change during operation: True
Select desired action if no flow or minimum speed detected.
Table 385: Option:
[0]
Off
[1]
Sleep mode
[2]
Warning
[3]
Alarm
22-24 No-Flow Delay
Default value: 10 s
Parameter type: Range
2-setup: All setups
Conversion index: 0
Data type: u_int16
Change during operation: True
Set delay before action set in
parameter 22-23 No-Flow Function
takes place if a no-flow condition is detected.
Table 386: Range:
Min: 1 s
Max: 600 s
Default value: 10 s
Dry-pump detection
If the pump has run dry (low power consumption-high speed), no-flow detection can also be used for detecting with both the inte-
grated PI controller and an external PI controller.
The 2 conditions for dry-pump signal are as follows:
Power consumption below no-flow level.
Pump running at maximum speed or maximum reference open loop, whichever is lowest.
The signal must be active for a set time (
parameter 22-27 Dry Pump Delay
) before the selected action takes place. Possible actions
can be selected from
parameter 22-26 Dry Pump Function
.
22-26 Dry Pump Function
Default value: [0] Off
Parameter type: Option
2-setup: All setups
Conversion index: -
Data type: u_int8
Change during operation: True
Select desired action for dry pump operation.
N O T I C E
For drives with constant speed bypass, if an automatic bypass function starts the bypass at persistent alarm conditions, disa-
ble the automatic bypass function when
[2] Alarm
or
[3] Man. Reset Alarm
is selected for the dry pump function.
AU363928304090en-000101 / 130R0982 | 167
Danfoss A/S © 2021.07
Parameters
VLT® Flow Drive FC 111
Programming Guide
