NB!
If a feedback is not used, its source must be set to
No Function
[0]. par.20-20
Feedback 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 for-
mula:
Temperature
=
A
2
(
ln
(
Pe
+1
)
−
A
1
)
−
A
3
, where A1, A2 and A3 are refrigerant-specific con-
stants. The refrigerant must be selected in parameter 20-30. Parameters 20-31 through 20-33 allow
the values of A1, A2 and A3 to be entered for a refrigerant that is not listed in parameter 20-30.
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
par. 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
NB!
This parameter is only available when using Pressure to Temperature Feedback Conversion.
3 Parameter Description ADAP-KOOL
®
Drive Programming Guide
146
MG.11.N1.02 - VLT
®
is a registered Danfoss trademark
3