Danfoss VLT Series Programming Manual page 132

Parameter Description
20-12 Reference/Feedback Unit
Option: Function:
See 20-02 Feedback 1 Source Unit for details.
20-13 Minimum Reference/Feedb.
Range:
0.000 [ -999999.999 -
ProcessCtrlUnit par. 20-14
*
ProcessCtrlUnit]
NOTE
If operating with 1-00 Configuration Mode set for Open
Loop [0], 3-02 Minimum Reference must be used.
20-14 Maximum Reference/Feedb.
Range:
100.000 [ par. 20-13 -
ProcessCtrlUnit 999999.999
*
ProcessCtrlUnit]
NOTE
If operating with 1-00 Configuration Mode set for Open
Loop [0], 3-03 Maximum Reference must be used.
NOTE
The dynamics of the PID controller will depend on the
value set in this meter. Please see also 20-93 PID Propor-
tional Gain.
20-13 Minimum Reference/Feedb. and20-14 Maximum
Reference/Feedb. also determine the feedback range when
using feedback for display readout with 1-00 Configuration
Mode set for Open Loop [0]. Same condition as above.
®
VLT HVAC Drive Programming Guide
Function:
Enter the desired minimum
value for the remote
reference when operating
with 1-00 Configuration
Mode set for Closed Loop
[3] operation. Units are set
in 20-12 Reference/Feedback
Unit.
Minimum feedback will be
-200% of either the value
set in 20-13 Minimum
Reference/Feedb. or in
20-14 Maximum Reference/
Feedb., which ever numeric
value is the highest.
Function:
Enter the maximum
reference/feedback for
closed loop operation.
The setting determines
the highest value
obtainable by summing
all reference sources for
closed loop operation.
The setting determines
100% feedback in open
and closed loop (total
feedback range: -200% to
+200%).
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3.18.2 20-2* Feedback & Setpoint
This meter group is used to determine how the frequency
converter's PID Controller will use the three possible
feedback signals to control the output frequency of the
frequency converter. This group is also used to store the
three internal setpoint references.
20-20 Feedback Function
Option: Function:
This meter determines how the three possible
feedbacks will be used to control the output
frequency of the frequency converter.
[0] Sum Sum [0] sets up the PID Controller to use the
sum of Feedback 1, Feedback 2 and Feedback 3
as the feedback.
NOTE
Any unused feedbacks must be set to No
Function in 20-00 Feedback 1 Source,
20-03 Feedback 2 Source, or 20-06 Feedback
3 Source.
The sum of Setpoint 1 and any other references
that are enabled (see meter group 3-1*) will be
used as the PID Controller's set-point reference.
[1] Difference Difference [1] sets up the PID controller to use
the difference between Feedback 1 and
Feedback 2 as the feedback. Feedback 3 will not
be used with this selection. Only Setpoint 1 will
be used. The sum of Setpoint 1 and any other
references that are enabled (see meter group
3-1*) will be used as the PID controller's set-
point reference.
[2] Average Average [2] sets up the PID Controller to use the
average of Feedback 1, Feedback 2 and
Feedback 3 as the feedback.
NOTE
Any unused feedbacks must be set to No
Function in 20-00 Feedback 1 Source,
20-03 Feedback 2 Source, or 20-06 Feedback
3 Source. The sum of Setpoint 1 and any
other references that are enabled (see
meter group 3-1*) will be used as the PID
Controller's set-point reference.
[3] Minimum Minimum [3] sets up the PID Controller to com
Feedback 1, Feedback 2 and Feedback 3 and
*
use the lowest value as the feedback.
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