CNT-SVX11A-EN 41
Troubleshooting
Probable cause Possible 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).
Unoccupied mode When the controller is in the unoccupied mode, the outdoor air damper remains closed.
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 is an attempt to bring the space
under control as quickly as possible.
The controller opens and closes the outdoor air damper based on the controller's occupancy mode and
Normal operation 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.
Table 23:
Outdoor air damper stays closed - continued
Probable cause Possible Explanation
Unit wiring The wiring between the controller outputs and the outdoor air damper must be present and correct for
normal damper operation.
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 damper may not work correctly.
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 unit damper
may be open. For more information see, Manual Output Test, on page 32 for more information.)
The controller opens and closes the outdoor air damper based on the controller's occupancy mode and
fan operation. Normally, the outdoor air damper is open during occupied, occupied standby, and
Normal operation occupied bypass mode when the fan is running and closed during unoccupied mode unless the
controller is economizing.
Table 24:
Outdoor air damper stays open
Probable cause Possible Explanation
Sensor reading too low
Unit economizing without much cooling capacity or unit stops DX heating early and switches to boiler-
less electric heat.
Sensor reading too high
Unit not utilizing economizer capacity when possible or DX heating stays on longer than possible for
boilerless electric heat unit.
Reading out of range Boilerless electric heat or waterside economizer disabled.
Table 25:
Entering Water Temperature sensor read-out error
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