Comm Led (Yellow); Required Inputs For Unit Operation - Trane Tracer AH540 Setup And Operation

Chapter 6 Verifying operation and communication
Table 61. Required inputs
Control function
Variable-air-volume control
Discharge air temperature control
Space temperature control
Economizer operation
Space dehumidification
Two-pipe changeover
88

Comm LED (yellow)

The yellow Comm LED indicates the communication status of the control-
ler. Table 60 describes Comm LED activity.
Table 60. Comm LED (yellow)
LED activity
LED is Off continuously
LED blinks
LED is On continuously

Required inputs for unit operation

The following locally wired sensor or communicated inputs are required
for each control function listed in Table 61. If any one of the sensors does
not exist, the controller operates the control function.
Input required to be present
(locally wired sensor or
communicated value)
Duct static pressure
Discharge air temperature
Space temperature
Discharge air temperature
Outdoor air temperature
Mixed-air temperature
Space relative humidity
Entering water temperature
Explanation
The controller is not detecting any communica-
tion (normal for stand-alone applications).
The controller detects communication (normal
for communicating applications, including data
sharing).
An abnormal condition that may occur during
discovery. The LED may flash fast enough to
look as if it is on continuously. If this LED activity
occurs at any other time, the site may have
excessive radio frequency interference (RFI).
Controller operation if input is not
Diagnostic shutdown
Diagnostic shutdown
Diagnostic shutdown
Diagnostic shutdown
Economizer disabled
Dehumidification disabled
Hydronic capacity assumed to be
appropriate for cooling
present
CNT-SVX05B-EN