CNT-SVX05A-EN
73
Troubleshooting
Table 62 — Outdoor air damper stays closed
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.
Warm-up and cool
down
The controller includes both a morning warm-up and cool down sequence to
keep the outdoor air damper closed during the transition from unoccupied to
occupied. This sequence is an attempt to bring the space under control as
quickly as possible.
Unoccupied mode
When the controller is in the unoccupied mode, the outdoor air damper
remains closed unless economizing is enabled.
Low ambient damper
lock out
When the outdoor air temperature is less than the low ambient damper
lockout setpoint (which can be changed with the Rover™ service tool),
the outdoor air damper is closed.
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).
The outdoor air damper is 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 outdoor air damper may not be open.
Refer to the
Manual output test
section.
Fan mode off
When a zone sensor fan mode switch determines the fan operation,
the Off position controls the unit off and closes the outdoor air damper.
No power to the
controller
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 24VAC.
When the green status LED is off continuously, the controller does not
have sufficient power or has failed.
Diagnostic present
Specific diagnostics affect outdoor air operation. For more information,
see the
Diagnostics
section in the manual.
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 damper operation.
