Danfoss VLT Aqua Drive FC 202 Programming Manual page 488

Programming Guide | VLT® Aqua Drive FC 202
is programmed in parameter group 22-3* No-flow Power Tuning. It is also possible to run a parameter 22-20 Low Power Auto Set-up,
automatically stepping through the commissioning process, and also automatically storing the data measured. Set the drive for open
loop in parameter 1-00 Configuration Mode when carrying out the auto setup (see parameter group 22-3* No-flow Power Tuning).
When using the integrated PI controller, carry out no-flow tuning before setting the PI controller parameters.
Low-speed detection
Low-speed detection gives a signal if the motor operates with minimum speed as set in parameter 4-11 Motor Speed Low Limit [RPM]
or parameter 4-12 Motor Speed Low Limit [Hz]. Actions are common with no-flow detection (individual selection not possible). The use
of low-speed detection is not limited to systems with a no-flow situation. It can be used in any system where operation at minimum
speed allows for a stop of the motor until the load calls for a speed higher than minimum speed. An example is systems with fans and
compressors.
In pump systems, ensure that the minimum speed in parameter 4-11 Motor Speed Low Limit [RPM] or parameter 4-12 Motor
Speed Low Limit [Hz] has been set high enough for detection as the pump can run with a rather high speed, even with valves
closed.
Dry-pump detection
No-flow detection can also be used to detect if the pump has run dry (low power consumption and high speed). It can be used with both
the integrated PI controller and an external PI controller. The conditions for dry-pump signal are:
Power consumption below no-flow level.
l
Pump running at maximum speed or maximum reference open loop, whichever is lowest.
l
The signal must be active for a set time (parameter 22-27 Dry Pump Delay) before the selected action takes place. Possible actions to
select (in parameter 22-26 Dry Pump Function) are:
Warning
l
Alarm
l
Enable the low-power detection in parameter 22-21 Low Power Detection. Perform the tuning using parameter group 22-3* No-Flow
Power Tuning.
In a dry-pump detection setup, select [0] Off in parameter 22-23 No-Flow Function. Otherwise, make sure that the options in that
parameter do not prevent the dry-pump detection.
22-20 Low Power Auto Set-up
Default value:
[0] Off
Setup: All setups
Data type: Uint8
Start of auto setup of power data for no-flow power tuning.
488 | © 2024.06
NOTICE
NOTICE
Parameter type:
Conversion index:
Change during operation:
Parameter Descriptions
Option
–
False
AU361182657213en-002101 / 130R0338