Operating instructions
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: Function:
0.000
ProcessCtr-
lUnit
*
[-999999.999 -
999999.999
ProcessCtrlU-
nit]
Setpoint 1 is used in Closed Loop
Mode to enter a setpoint reference
that is used by the frequency
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: Function:
0.000
ProcessCtrlU-
nit
*
[-999999.999 -
999999.999
ProcessCtrlUnit]
Setpoint 2 is used in Closed Loop
Mode to enter a setpoint
reference that may be used by the
frequency converter’s PID Control-
ler. See the description of
Feedback Function,
par. 20-20 Feedback Function.
NOTE
The set-point reference entered here is added to any
other references that are enabled (see par. group 3-1*).
20-23 Setpoint 3
Range: Function:
0.000
ProcessCtr-
lUnit
*
[-999999.999 -
999999.999
ProcessCtrlU-
nit]
Setpoint 3 is used in Closed Loop
Mode to enter a setpoint reference
that may be used by the frequency
converter’s PID Controller. See the
description of par. 20-20 Feedback
Function.
NOTE
The setpoint reference
entered here is added to any
other references that are
enabled (see parameter
group 3-1*).
Parameter Description
VLT
®
HVAC Drive Programming Guide
126 MG.11.CA.02 - VLT
®
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