Applications Guide Tracer Graphical Programming - Trane

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Writing the fan control program
Figure 133: Fan control program properties
Writing the fan control program
Begin constructing the fan control program for the constant-volume airhandling
unit by creating a new program and setting its properties as
showninFigure133.
Controlling the supply fan
Control the supply fan on and off according to the sequence of operation.
Note that this sequence is the same as that for the VAV air-handling unit
with the omission of duct static pressure considerations. Turn the supply
fan on whenever the unit is occupied. Turn the supply fan off when any of
the following is true:
• The unit is unoccupied, with the exception of night heat/cool.
• The run/stop interlock is open.
• The low temperature detection is closed.
• The supply fan status indicates a fan failure after a 1-minute delay.
The module shown in Figure 134 on page 156 is identical to that used in
the fan control program for the VAV air handler.
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