Trane UniTrane Installation, Operation And Maintenance Instructions page 111

Table 34. Valves stay open
Probable Cause Explanation
Normal operation The controller opens and closes the valves to meet the unit capacity requirements.
Valve override The controller can communicate a valve override request to affect the valve operation.
Manual output test The controller includes a manual output test sequence that verifies analog and binary output operation and the
associated wiring. However, based on the current step in the test sequence, the valves may be open. Refer to
Output Test," p.
Diagnostic present A specific list of diagnostics affects valve operation. For more information, see
Sampling logic The controller includes entering water temperature sampling logic that automatically invokes during 2-pipe or 4-pipe
changeover to determine if the entering water temperature is correct for the unit operating mode. Refer to
Water Temperature Sampling Function," p.
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 device, 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.
Refer to the typical unit wiring diagrams (see
Table 35. Electric heat not operating
Probable Cause Explanation
Normal operation The controller cycles electric heat on and off to meet the unit capacity requirements.
Requested mode: off It is possible to communicate the operating mode (such as off, heat, cool) to the controller. When off is communicated
to the controller, the units shuts off the electric heat.
Communicated disable Numerous communicated requests may disable electric heat, including an auxiliary heat enable input and the heat/
cool mode input. Depending on the state of the communicated request, the unit may disable electric heat.
Manual output test The controller includes a manual output test sequence that verifies analog and binary output operation and associated
output wiring. However, based on the current step in the test sequence, the electric heat may not be on. Refer to
"Manual Output Test," p.
Diagnostic present A specific list of diagnostics affects electric heat operation. For more information, see
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 device, the electric heat may not work properly.
No power to the controller If the controller does not have power, electric heat does not operate. For the controller to operate normally, a 24 Vac
input voltage must be applied. When the green LED is off continuously, the controller does not have sufficient power
or has failed.
Unit wiring The wiring between the controller outputs and the electric heat contacts must be present and correct for normal
electric heat operation. Refer to the typical unit wiring diagrams (see
Table 36. Fresh air damper stays open
Probable Cause Explanation
Normal operation The controller opens and closes the fresh air damper based on the controller's occupancy mode and fan status.
Normally, the fresh air damper is open during occupied mode when the fan is running and closed during unoccupied
mode.
Manual output test The controller includes a manual output test sequence that verifies analog and binary output operation and associated
output wiring. However, based on the current step in the test sequence, the fresh air damper may not be open. Refer
to
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 device, the damper may not work correctly.
Unit wiring The wiring between the controller outputs and the fresh air damper must be present and correct for normal damper
operation. Refer to the typical unit wiring diagrams (see
UNT-SVX07B-EN
108.
108.
"Manual Output Test," p. 108.
86.
"Wiring Diagrams," p. 126).
"Wiring Diagrams," p.
"Wiring Diagrams," p.
Diagnostics
"Manual
"Diagnostics," p. 107.
"Entering
"Diagnostics," p. 107.
126).
126).
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