Applications Guide Tracer Graphical Programming - Trane
Applications Guide Tracer Graphical Programming - Trane
Applications Guide Tracer Graphical Programming - Trane
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®<br />
Reviewing the sequence of operation<br />
ture setpoint and the configured, default occupied and occupied standby<br />
setpoints.<br />
Note:<br />
Calculate the effective cooling and heating setpoints as in other<br />
Comm5 devices. See “Calculating the effective space setpoints”<br />
on page 135 for more information.<br />
Discharge air setpoints<br />
For discharge air control, use the configured, default discharge air temperature<br />
cooling and heating setpoints.<br />
Heat/Cool arbitration<br />
Determine the heat/cool decision of the air handler based on the effective<br />
occupied cooling and heating setpoints. Transition the air handler to cooling<br />
if the space temperature exceeds the cooling setpoint plus 1°F. Transition<br />
the air handler to heating if the space temperature falls below the<br />
heating setpoint minus 1°F.<br />
Control<br />
The following parameters for the sequence of operation are presented<br />
according to the equipment that must be controlled.<br />
Supply fan<br />
Operate the supply fan whenever the air handler is in occupied mode and<br />
modulate the fan speed to maintain the duct static pressure setpoint,<br />
1.5 in. wg (adjustable). Turn the supply fan off whenever one of the following<br />
occurs:<br />
• The air handler is unoccupied.<br />
• The run/stop interlock is open.<br />
• ThemixedairtemperatureistoocoldandtheLowTemperature<br />
Detection input is closed.<br />
• The supply fan status indicates a fan failure after a 1-minute delay.<br />
If the duct static pressure exceeds 4 in. wg, shut down the air handler<br />
immediately.<br />
Outdoor air damper<br />
When the economizer function is enabled and the outdoor air temperature<br />
is less than the economizer changeover setpoint, modulate the outdoor<br />
air damper between the adjustable minimum position and fully open<br />
to maintain the discharge air cooling setpoint. Modulate the outdoor air<br />
damper closed, overriding the minimum position, to maintain the mixed<br />
air temperature at or above the mixed air setpoint.<br />
If the economizer function is disabled, or the air handler is in the heat<br />
mode, control the outdoor air damper to its minimum position. If the outdoor<br />
air temperature falls below a low outdoor air temperature limit, control<br />
the outdoor air damper to its closed position. In unoccupied mode,<br />
CNT-APG001-EN 107
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