Danfoss FC 100 Series Operating Instructions Manual page 87

How to Programme the Frequ...
same. The minimum pressure required is the same for all VAV
boxes. This control method can be set up by setting
par. 20-20 Feedback Function to option [3], Minimum, and
entering the desired pressure in par. 20-21 Setpoint 1. The PID
Example 2 – Multi zone, multi setpoint
The previous example can be used to illustrate the use of multi
zone, multi setpoint control. If the zones require different
pressures for each VAV box, each setpoint may be specified in
par. 20-21 Setpoint 1, par. 20-22 Setpoint 2 and
par. 20-23 Setpoint 3. By selecting Multi setpoint minimum, [5],
in par. 20-20 Feedback Function, the PID Controller will
increase the speed of the fan if any one of the feedbacks is
below its setpoint and decrease the speed of the fan if all
feedbacks are above their individual setpoints.
20-21 Setpoint 1
Range:
0.000 [-999999.999 - Setpoint 1 is used in Closed Loop
ProcessCtr- 999999.999 Mode to enter a setpoint reference
lUnit ProcessCtrlU- that is used by the frequency
*
nit] converter's PID Controller. See the
description of par. 20-20 Feedback
Function.
NOTE
Setpoint reference entered
here is added to any other
references that are enabled
(see par. group 3-1*).
20-22 Setpoint 2
Range:
0.000 [-999999.999 -
ProcessCtrlU- 999999.999
nit ProcessCtrlUnit]
*
®
VLT HVAC Drive Operating Instructions
Function:
Function:
Setpoint 2 is used in Closed Loop
Mode to enter a setpoint
reference that may be used by the
®
MG.11.AD.02 - VLT is a registered Danfoss trademark
Controller will increase the speed of the fan if any one
feedback is below the setpoint and decrease the speed of the
fan if all feedbacks are above the setpoint.
20-22 Setpoint 2
Range:
NOTE
The set-point reference entered here is added to any
other references that are enabled (see par. group 3-1*).
20-70 Closed Loop Type
Option: Function:
This parameter defines the application
response. The default mode should be
sufficient for most applications. If the
application response speed is known, it can
be selected here. This will decrease the time
needed for carrying out PID autotuning. The
setting has no impact on the value of the
tuned parameters and is used only for the
autotuning sequence.
[0] Auto
*
[1] Fast Pressure
[2] Slow Pressure
[3] Fast Tempera-
ture
[4] Slow Tempera-
ture
Function:
frequency converter's PID Control-
ler. See the description of
Feedback Function,
par. 20-20 Feedback Function.
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