NOTE
If a feedback is not used, its source must be set to
No
Function
[0].
determines how the
three possible feedbacks will be used by the PID Controller.
20-01 Feedback 1 Conversion
Option:
Function:
This parameter allows a conversion function to
be applied to Feedback 1.
[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
.
through
allow the values of A1, A2 and
A3 to be entered for a refrigerant that is not
listed in
[3] Pressure to
flow
Pressure to flow is used in applications where the
air flow in a duct is to be controlled. The
feedback signal is represented by a dynamic
pressure measurement (pitot tube).
Flow = Duct Area × Dynamic Pressure
×
Air Density Factor
See also
20-34 Duct 1 Area [m2]
through
for setting of duct area and air
density.
[4] Velocity to
flow
Velocity to flow is used in applications where the
air flow in a duct is to be controlled. The
feedback signal is represented by an air velocity
measurement.
Flow = Duct Area × Air Velocity
See also
20-34 Duct 1 Area [m2]
through
20-37 Duct 2 Area [in2]
for setting of duct area.
20-02 Feedback 1 Source Unit
Option:
Function:
This parameter
determines
the unit that is
used for this
Feedback
Source, prior
to applying
the feedback
20-02 Feedback 1 Source Unit
Option:
Function:
conversion of
.
This unit is not
used by the
PID Controller.
[0]
*
reference_feedback_unit_choices_None_textid
[1]
%
[5]
PPM
[10]
1/min
[11]
RPM
[12]
Pulse/s
[20]
l/s
[21]
l/min
[22]
l/h
[23]
m³/s
[24]
m³/min
[25]
m³/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
[73]
kPa
[74]
m WG
[75]
mm Hg
[80]
kW
[120] GPM
[121] gal/s
[122] gal/min
[123] gal/h
[124] CFM
[125] ft³/s
[126] ft³/min
[127] ft³/h
[130] lb/s
[131] lb/min
[132] lb/h
[140] ft/s
[141] ft/min
[145] ft
[160] °F
[170] psi
[171] lb/in²
[172] in WG
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG.11.CB.02 - VLT
®
is a registered Danfoss trademark
123
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