Danfoss VLT FC 100 Series Programming Manual page 154

3. Parameter Description
NB!
If a feedback is not used, its source must be set to
will be used by the PID Controller.
20-01 Feedback 1 Conversion
3
Option:
*
Linear
[0]
[1] Square root
[2] Pressure to tempera-
ture
20-02 Feedback 1 Source Unit
Option:
[0] None
* %
[1]
[5] PPM
[10] 1/min
[11] RPM
[12] Pulse/s
[20] l/s
[21] l/min
[22] l/h
[23]
m 3 /s
[24] 3
m /min
[25]
m 3 /h
[30] kg/s
[31] kg/min
[32] kg/h
[33] t/min
[34] t/h
[40] m/s
[41] m/min
[45] m
[60] °C
[70] mbar
[71] bar
[72] Pa
154
No Function
Function:
This parameter allows a conversion function to be applied to Feedback 1.
Linear
[0] has no effect on the feedback.
Square root [1] is commonly used when a pressure sensor is used to provide flow feedback
( )
flow ∝ pressure
( ).
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:
A
2
Temperature
=
( ln ( Pe + 1 ) −
refrigerant must be selected in parameter 20-30. Parameters 20-21 through 20-23 allow the values of A1, A2
and A3 to be entered for a refrigerant that is not listed in parameter 20-30.
Function:
This parameter determines the unit that is used for this Feedback Source, prior to applying the feedback con-
par. 20-01, Feedback 1 Conversion
version of
display and monitoring purposes.
MG.11.C5.02 - VLT ® is a registered Danfoss trademark
®
VLT HVAC Drive Programming Guide
[0]. Parameter 20-10 determines how the three possible feedbacks
A
− 3
, where A1, A2 and A3 are refrigerant-specific constants. The
A 1 )
. This unit is not used by the PID Controller. It is used only for