Feedback Function; Sum; Difference; Average - Danfoss vlt FC 102 Operating Instructions Manual

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VLT HVAC Drive Operating Instructions

20-20 Feedback Function

This parameter determines how the three possible feedbacks will be used to control the output frequency of the
frequency converter.
[0]

Sum

[1]

Difference

[2]

Average

*
Minimum
[3]
[4] Maximum
[5] Multi setpoint min
[6] Multi setpoint max
Sum
[0] sets up the PID Controller to use the sum of Feedback 1, Feedback 2 and Feedback 3 as
the feedback.
NB!
Any unused feedbacks must be set to
The sum of Setpoint 1 and any other references that are enabled (see par. group 3-1*) will be used
as the PID Controller's setpoint reference.
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 par. group 3-1*) will be used as
the PID Controller's setpoint reference.
Average [2] sets up the PID Controller to use the average of Feedback 1, Feedback 2 and Feedback
3 as the feedback.
NB!
Any unused feedbacks must be set to
The sum of Setpoint 1 and any other references that are enabled (see par. group
3-1*) will be used as the PID Controller's setpoint reference.
Minimum
[3] sets up the PID Controller to compare Feedback 1, Feedback 2 and Feedback 3 and
use the lowest value as the feedback.
NB!
Any unused feedbacks must be set to
Only setpoint 1 will be used. The sum of Setpoint 1 and any other references that
are enabled (see par. group 3-1*) will be used as the PID Controller's setpoint
reference.
Maximum
[4] sets up the PID Controller to compare Feedback 1, Feedback 2 and Feedback 3 and
use the highest value as the feedback.
NB!
Any unused feedbacks must be set to
Only Setpoint 1 will be used. The sum of Setpoint 1 and any other references that are enabled (see
par. group 3-1*) will be used as the PID Controller's setpoint reference.
Multi-setpoint minimum
[5] sets up the PID Controller to calculate the difference between Feedback
1 and Setpoint 1, Feedback 2 and Setpoint 2, and Feedback 3 and Setpoint 3. It will use the feedback/
setpoint pair in which the feedback is the farthest below its corresponding setpoint reference. If all
feedback signals are above their corresponding setpoints, the PID Controller will use the feedback/
setpoint pair in which the difference between the feedback and setpoint is the least.
NB!
If only two feedback signals are used, the feedback that is not to be used must
be set to No Function
erence will be the sum of its respective parameter value (20-11, 20-12 and 20-13)
and any other references that are enabled (see par. group 3-1*).
Multi-setpoint maximum
[6] sets up the PID Controller to calculate the difference between Feedback
1 and Setpoint 1, Feedback 2 and Setpoint 2, and Feedback 3 and Setpoint 3. It will use the feedback/
setpoint pair in which the feedback is farthest above its corresponding setpoint reference. If all
feedback signals are below their corresponding setpoints, the PID Controller will use the feedback/
setpoint pair in which the difference between the feedback and the setpoint reference is the least.
MG.11.A6.02 - VLT ® is a registered Danfoss trademark
6. How to programme the frequency converter
No Function
in par. 20-00, 20-03, or 20-06.
No Function
in par. 20-00, 20-03, or 20-06.
No Function
in par. 20-00, 20-03, or 20-06.
No Function in par. 20-00, 20-03, or 20-06.
in par. 20-00, 20-03 or 20-06. Note that each setpoint ref-
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