NOTE
If a feedback is not used, its source must be set to
[0] No
Function
.
determines how the
three possible feedbacks will be used by the PID
Controller.
20-01 Feedback 1 Conversion
This parameter allows a conversion function to be applied to
Feedback 1.
Option:
Function:
[0]
Linear
Linear
[0] has no effect on the feedback.
[1]
Square root
Square root
[1] is commonly used when a
pressure sensor is used to provide flow
feedback (
(
flow ∝ pressure)
).
[2]
*
Pressure to
temperature
Pressure to temperature
[2] is used in
compressor applications to provide
temperature feedback using a pressure
sensor. The temperature of the refrigerant is
calculated using the following formula:
Temperature =
A2
(ln(Pe + 1) − A1) − A3
, where
A1, A2 and A3 are refrigerant-specific
constants. The refrigerant must be selected
in
20-30 Refrigerant
.
through
allow the values of A1, A2
and A3 to be entered for a refrigerant that
is not listed in
20-30 Refrigerant
.
20-02 Feedback 1 Source Unit
This parameter determines the unit that is used for this Feedback
Source, prior to applying the feedback conversion of
20-01 Feedback 1 Conversion
. This unit is not used by the PID
Controller. It is used only for display and monitoring purposes.
Option:
Function:
[70]
mbar
[71]
*
bar
[72]
Pa
[73]
kPa
[74]
m WG
[170]
psi
[171]
lb/in
2
[172]
in WG
[173]
ft WG
NOTE
This parameter is only available when using Pressure to
Temperature Feedback Conversion.
20-03 Feedback 2 Source
Option:
Function:
See
for
details.
[0]
*
No function
[1]
Analog Input 53
20-03 Feedback 2 Source
Option:
Function:
[2]
Analog Input 54
[3]
Pulse input 29
[4]
Pulse input 33
[7]
Analog Input X30/11
[8]
Analog Input X30/12
[9]
Analog Input X42/1
[10]
Analog Input X42/3
[11]
Analog Input X42/5
[100] Bus Feedback 1
[101] Bus Feedback 2
[102] Bus feedback 3
20-04 Feedback 2 Conversion
Option:
Function:
See
20-01 Feedback 1 Conversion
for details.
[0]
*
Linear
[1]
Square root
[2]
Pressure to temperature
20-05 Feedback 2 Source Unit
Option:
Function:
See
20-02 Feedback 1 Source Unit
for details.
20-06 Feedback 3 Source
Option:
Function:
See
for
details.
[0]
*
No function
[1]
Analog Input 53
[2]
Analog Input 54
[3]
Pulse input 29
[4]
Pulse input 33
[7]
Analog Input X30/11
[8]
Analog Input X30/12
[9]
Analog Input X42/1
[10]
Analog Input X42/3
[11]
Analog Input X42/5
[100] Bus Feedback 1
[101] Bus Feedback 2
[102] Bus feedback 3
20-07 Feedback 3 Conversion
Option:
Function:
See
20-01 Feedback 1 Conversion
for details.
[0]
*
Linear
[1]
Square root
[2]
Pressure to temperature
Parameter Description
VLT
®
Refrigeration Drive Programming Guide
MG16H102 - VLT
®
is a registered Danfoss trademark
113
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