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CNT-SVX05A-EN
Troubleshooting
Table 60 — Valves stay closed
Table 61 — Outdoor air damper stays open
Probable cause
Explanation
Requested mode off
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 (valves are closed).
Power up control wait
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 when it receives
communicated information.
The controller exits power up control wait when the power up
control wait time expires.
Manual output test
The controller includes a manual output test sequence 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 not be open.
Refer to the
Manual output test
section.
Fan mode off
When a local fan mode switch (provided on the Trane zone sensor)
determines the fan operation, the Off position controls the unit off and
closes the valves.
Diagnostic present
Specific diagnostics affect valve operation. For more information,
see the
Diagnostics
section.
No power to the
controller
If the controller does not have power, a normally open valve remains closed.
For the controller or valve to operate normally, it must have an input voltage
of 24VAC. When the green LED is off continuously, the controller does not
have sufficient power or has failed.
No power to the valves If the valve does not have power, a normally open valve remains closed.
The valves are powered separately from the controller's output signal.
If the valves do not have 24VAC, the controller cannot operate the valves.
Unit configuration
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 valves may not work correctly.
Unit wiring
The wiring between the controller outputs and the valve(s) must be
present and correct for normal valve operation.
Probable Cause
Explanation
Normal operation
The controller opens and closes the outdoor air damper based on the control-
ler's occupancy mode and fan operation. Normally, the outdoor air damper is
open during occupied, occupied standby, and occupied bypass mode when
the fan is running and closed during unoccupied mode unless the controller is
economizing. Refer to the
Outdoor air damper
section for more information.
Manual output test
The controller includes a manual output test sequence you can use to verify
output operation and associated output wiring. However, based on the
current step in the test sequence, the outdoor air damper may be open.
Refer to the
Manual output test
section.
Unit configuration
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 outdoor air damper may not work correctly.
Unit wiring
The wiring between the controller outputs and the outdoor air damper
must be present and correct for normal outdoor air damper operation.
