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CNT-SVX05A-EN
Analog inputs
The analog inputs are connected to the Tracer AH.540 termination board on
inputs IN 1 through IN 6. A special connector (J43) on the termination board is
used for the duct static pressure input, analog input J43.
Analog inputs
• IN 1: Space temperature
• IN 2: Local setpoint
• IN 3: Fan mode input
• IN 4: Discharge air temperature
• IN 5: Outdoor air temperature
• IN 6: Mixed air temperature
• Terminal J43 Duct static pressure
A communicated variable input like setpoint, space temperature, or outdoor air
temperature has priority over a locally wired input to the controller. For example,
if the Tracer™ AH.540 controller has a wired outdoor air temperature sensor, and
Tracer Summit
™
or another Comm5 controller sends it a communicated outdoor
air temperature, the communicated value is used by the Tracer AH.540 controller.
Space temperature
The space temperature analog input IN 1 measures space temperature only. The
space temperature is measured with a 10k
Ω
thermistor included with Trane zone
sensors. The Tracer AH.540 controller receives the space temperature from either
a wired zone sensor or as a communicated value. A communicated value has
precedence over a locally wired sensor input. Therefore, the communicated
value, when present, is automatically used by the controller.
If the Tracer AH.540 controller is operating in constant volume space
temperature control mode and the space temperature fails or does not receive a
communicated value, the controller generates a
Space Temperature Failure
diagnostic.
The space temperature input may also be used to generate timed override On/
Cancel requests to the controller. If a momentary short of the space
temperature signal occurs, the Tracer AH.540 interprets the signal as a timed
override On request.
The Tracer AH.540 uses the timed override On request (while the zone is
unoccupied) as a request to go to the occupied bypass mode (occupied
bypass). The occupied bypass mode lasts for the duration of the occupied
bypass time, typically 120 minutes. The occupied bypass time can be changed
using the Trane Rover
™
service tool.
Press the Cancel button on the zone sensor to cancel the override request and
return the controller to unoccupied mode. This creates a momentary fixed
resistance (1.5k
Ω
), which sends a cancel request to the space temperature
input.
