Trane Tracer VV550 Installation, Operation And Maintenance Manual page 85

Table 56. Reheat outputs do not energize (continued)
Probable cause
Manual output test
Unit wiring
Low primary airflow
Primary air temperature
above reheat enable setpoint
Invalid reheat enable setpoint
Invalid primary air
temperature
Fan override active
Auxiliary heat enable
Water valve override
Table 57. Fan output does not energize
Probable cause
Power-up control wait
Unoccupied operation
Requested mode Off
Diagnostic present
No power to the controller
Unit configuration
Manual output test
Unit wiring
Fan override
Table 58. Air valve and/or water valve stay open
Probable cause
Normal operation
Manual output test
CNT-SVX17G-EN
Explanation
The controller includes a manual output test function you can use to verify output operation and associated
output wiring. However, based on the current step in the test sequence, the unit reheat may not be on. For
more information on manual output test, refer to sections
Test," p. 28.
The wiring between the controller outputs and the fan relays and contacts must be present and correct for
normal reheat operation.
The unit must have sufficient primary airflow to energize the local electric reheat outputs. If the airflow never
reaches this level or falls below this level, the reheat is not energized. For more information on reheat
control, refer to "Reheat Control," p.
The primary air temperature must be below the reheat enable setpoint before the reheat can be energized.
This prevents damage to the reheat coils due to excessive heat.
Invalid reheat enable setpoint disables local electric heat.
Disables local electric heat when the system mode is heat or if system mode is auto with warm default
primary air temperature.
Fan override Off with a fan present disables local electric reheat.
Communicated auxiliary heat enable is limiting reheat unit capacity or disabling reheat completely.
Water valve override, when in effect, controls outputs.
Explanation
When power-up control wait is enabled (non-zero time), the controller remains Off until one of two
conditions occurs:
• The controller exits power-up control wait once it receives communicated information.
• The controller exits power-up control wait once the power-up control wait time expires.
When the controller is in the unoccupied mode, the fan is cycled between On and Off with capacity to
maintain zone temperature control.
You can communicate a desired operating mode (such as Off, heat, and cool) to the controller. When Off
is communicated to the controller, the unit controls the fan Off. There is no heating or cooling.
A specific list of diagnostics affects fan operation. For more information on controller diagnostics, refer to
Table 50, p. 81.
If the controller does not have power, the unit fan does not operate. For the controller to operate normally,
it must have an input voltage of 24 Vac. When the green LED is Off continuously, the controller does not
have sufficient power or has failed. For more information on green LED, refer to
The controller must be properly configured based on the actual installed end devices and application. When
the unit configuration does not match the actual end devices, the fan may not work correctly.
The controller includes a manual output test function you can use to verify output operation and associated
output wiring. However, based on the current step in the test sequence, the unit fan may not be On. For
more information on manual output test, refer to sections
Test," p. 28.
The wiring between the controller outputs and the fan relays and contacts must be present and correct for
normal fan operation.
Fan is overridden via communicated fan speed command.
Explanation
The controller opens and closes the valves to meet the unit capacity requirements.
The controller includes a manual output test function you can use to verify output operation and associated
output wiring. However, based on the current step in the test sequence, the valve(s) may be open. For more
information on manual output test, refer to sections
p. 28.
"Manual Output Test," p. 80
45.
"Manual Output Test," p. 80
"Manual Output Test," p. 80
Troubleshooting
and "Manual Output
"Green Status LED," p. 80.
and "Manual Output
and "Manual Output Test,"
85