Danfoss VLT AQUA Drive FC 202 Programming Manual page 181

Parameter Description
In a dry-pump detection set-up, 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
Start of auto set-up of power data for no-flow power tuning.
Option: Function:
[0] Off
*
NOTICE
[1] Enabled
Do the auto set-up when the system has
reached normal operating temperature.
NOTICE
It is important that parameter 4-13 Motor
Speed High Limit [RPM] or
parameter 4-14 Motor Speed High Limit [Hz]
is set to the maximum operational speed
of the motor.
It is important to do the auto set-up before
configuring the integrated PI controller as
settings are reset when changing from
closed loop to open loop in
parameter 1-00 Configuration Mode.
NOTICE
Carry out the tuning with the same
settings in parameter 1-03 Torque Charac-
teristics as for operation after the tuning.
An auto set-up sequence is activated, automat-
ically setting the speed to approximately 50% and
85% of nominal motor speed
(parameter 4-13 Motor Speed High Limit [RPM],
parameter 4-14 Motor Speed High Limit [Hz]). At
those 2 speeds, the power consumption is
automatically measured and stored.
Before enabling auto set-up:
1. Close valves to create a no-flow
condition.
2. Set the frequency converter to open
loop (parameter 1-00 Configuration Mode).
It is important also to set
parameter 1-03 Torque Characteristics.
22-21 Low Power Detection
Option: Function:
[0] Disabled
*
[1] Enabled To set the parameters in parameter group 22-3*
No-Flow Power Tuning for proper operation, carry
out the low-power detection commissioning.
MG20OB02
Programming Guide
22-22 Low Speed Detection
Option:
[0] Disabled
*
[1] Enabled
[2] Enabled
with boost
[3] Enabled for
multiple
drives
[4] Enabled
multidrive
boost
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Function:
Detects when the motor operates with a speed
as set in parameter 4-11 Motor Speed Low Limit
[RPM] or parameter 4-12 Motor Speed Low Limit
[Hz].
This option is available when [3] Closed Loop is
selected in parameter 1-00 Configuration Mode.
Enable this option to improve the low-speed
detection for applications with at least 1 of the
following characteristics:
•
Varying inlet pressure.
•
A pressure drop at the outlet caused
by closing a non-return valve.
In such applications, the frequency converter
potentially does not reduce the speed to the
minimum as required for the normal low speed
detection.
When this option is selected, the frequency
converter creates a pressure pulse (boost of the
pressure) when the feedback is within the
range defined in parameter 7-39 On Reference
Bandwidth for a time period defined in
parameter 22-40 Minimum Run Time or longer.
Parameter 22-45 Setpoint Boost adjusts the
height of the pulses.
Parameter 22-46 Maximum Boost Time defines
the maximum length of the pulse.
NOTICE
Ensure that the system can withstand
the boost pressure.
For applications with multiple frequency
converters. Enable low speed detection with
the following features:
•
Minimum run time.
•
Minimum sleep time.
•
Boost.
For applications with multiple frequency
converters. This option is available when [3]
Closed Loop is selected in
parameter 1-00 Configuration Mode.
Enable this option to improve the low-speed
detection for applications with at least 1 of the
following characteristics:
•
Varying inlet pressure.
•
A pressure drop at the outlet caused
by closing a non-return valve.
In such applications, the frequency converter
potentially does not reduce the speed to the
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