Trane TR200 Series Programming Manual page 191

Parameter Description
[5] Multi Setpoint Min
[6] Multi Setpoint Max
NOTE: Any unused feedback must be set to "No function" in its Feedback Source parameter: par.20-00
1 Source, par.20-03 Feedback 2 Source
The feedback resulting from the function selected in par.20-20
troller to control the output frequency of the frequency converter. This feedback can also be shown on the
frequency converter's display, be used to control a frequency converter's analog output, and be transmitted
over various serial communication protocols.
The frequency converter can be configured to handle multi zone applications. Two different multi zone appli-
cations are supported:
• Multi zone, single setpoint
• Multi zone, multi setpoint
The difference between the two is illustrated by the following examples:
Example 1 – Multi zone, single setpoint
In an office building, a VAV (variable air volume) TR200 system must ensure a minimum pressure at selected
VAV boxes. Due to the varying pressure losses in each duct, the pressure at each VAV box cannot be assumed
to be the 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
20-21 Setpoint 1. The PID 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.
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Only Setpoint 1 will be used. The sum of Setpoint 1 and any other refer-
ences that are enabled (see par. group 3-1*) will be used as the PID
Controller's setpoint reference.
Multi-setpoint minimum
[5] sets up the PID Controller to calculate the dif-
ference between Feedback 1 and Setpoint 1, Feedback 2 and Setpoint 2,
and Feedback 3 and Setpoint 3. It will use the feedback/setpoint pair in
which the feedback is the farthest below its corresponding setpoint ref-
erence. If all feedback signals are above their corresponding setpoints,
the PID Controller will use the feedback/setpoint pair in which the differ-
ence between the feedback and setpoint is the least.
NOTE: If only two feedback signals are used, the feedback that is not to
No Function
be used must be set to
20-03 Feedback 2 Source or par.20-06
setpoint reference will be the sum of its respective parameter value (par.
20-21 Setpoint 1, par.20-22
other references that are enabled (see par. group 3-1*).
Multi-setpoint maximum
[6] sets up the PID Controller to calculate the dif-
ference between Feedback 1 and Setpoint 1, Feedback 2 and Setpoint 2,
and Feedback 3 and Setpoint 3. It will use the feedback/setpoint pair in
which the feedback is farthest above its corresponding setpoint refer-
ence. If all feedback signals are below their corresponding setpoints, the
PID Controller will use the feedback/setpoint pair in which the difference
between the feedback and the setpoint reference is the least.
NOTE: If only two feedback signals are used, the feedback that is not to
No Function
be used must be set to
20-03 Feedback 2 Source or par.20-06
setpoint reference will be the sum of its respective parameter value (par.
20-21 Setpoint 1, par.20-22
other references that are enabled (see par. group 3-1*).
or par.20-06 Feedback 3 Source.
Feedback Function
to option [3], Minimum, and entering the desired pressure in par.
in par.20-00 Feedback 1
Feedback 3 Source. Note that each
Setpoint 2 and par.20-23 Setpoint
in par.20-00 Feedback 1
Feedback 3 Source. Note that each
Setpoint 2 and par.20-23 Setpoint
will be used by the PID Con-
TR200 Programming Guide
Source, par.
3) and any
Source, par.
3) and any
Feedback