Technical information

20-36 Fan 2 Area [m2]
Range: Function:
0.500
m2*
[0.000 -
10.000
m2]
20-37 Fan 2 Area [in2]
Range: Function:
Used for setting the area of the air ducts in
connection with feedback conversion
pressure/velocity to flow. The unit (in
2
) is
determined by the setting of 0-03 Regional
Settings. Fan 2 is used with feedback 2. In
case of flow difference control, set
20-20 Feedback Function to [1] Difference, if
flow fan 1 – flow fan 2 is to be controlled.
750
in2*
[0 -
15000 in2]
20-38 Air Density Factor [%]
Range: Function:
100 %* [50 - 150
%]
Set the air density factor for conversion
from pressure to flow in % relative to the
air density at sea level at 20 °C (100% ~
1,2 kg/m
3
).
3.18.4 20-6* Sensorless
Parameters for Sensorless. See also 20-00 Feedback 1
Source, 18-50 Sensorless Readout [unit], 16-26 Power Filtered
[kW] and 16-27 Power Filtered [hp].
NOTE
Sensorless unit and Sensorless Information requires set up
by MCT 10 Set-up Software with sensorless specific plug in.
20-60 Sensorless Unit
Option: Function:
Select the unit to be used with 18-50 Sensorless
Readout [unit].
[20] l/s
[21] l/min
[22] l/h
[23] m³/s
[24] m³/min
[25] m³/h
[70] mbar
[71] bar
[72] Pa
[73] kPa
[74] m WG
[75] mm Hg
[120] GPM
20-60 Sensorless Unit
Option: Function:
[121] gal/s
[122] gal/min
[123] gal/h
[124] CFM
[125] ft³/s
[126] ft³/min
[127] ft³/h
[170] psi
[171] lb/in²
[172] in WG
[173] ft WG
[174] in Hg
20-69 Sensorless Information
Range: Function:
0 * [0 - 0 ] View information about the sensor-less data.
3.18.5 20-7* PID autotuning
The frequency converter PID Closed Loop controller
(parameter group 20-**, FC Drive Closed Loop) can be
auto-tuned, simplifying and saving time during commis-
sioning, whilst ensuring accurate PID control adjustment.
To use auto-tuning it is necessary for the frequency
converter to be configured for closed loop in 1-00 Configu-
ration Mode.
A Graphical Local Control Panel (LCP) must be used in
order to react on messages during the auto-tuning
sequence.
Enabling 20-79 PID Autotuning, puts the frequency
converter into auto-tuning mode. The LCP then directs the
user with on-screen instructions.
The fan/pump is started by pressing [Auto On] button on
the LCP and applying a start signal. The speed is adjusted
manually by pressing the [
▲
] or [
▼
] navigation keys on the
LCP to a level where the feedback is around the system
set-point.
NOTE
It is not possible to run the motor at maximum or
minimum speed, when manually adjusting the motor
speed due to the need of giving the motor a step in the
speed during auto-tuning.
PID auto-tuning functions by introducing step changes
whilst operating at a steady state and then monitoring the
feedback. From the feedback response, the required values
for 20-93 PID Proportional Gain and 20-94 PID Integral Time
are calculated. 20-95 PID Differentiation Time is set to value
Parameter Description
VLT
®
HVAC Drive Programming Guide
136 MG11CD02 - VLT
®
is a registered Danfoss trademark
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