Maintenance diagnostics
Table M-D-6. 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 the “Manual Output Test” |
| section. |
Diagnostic present | A specific list of diagnostics affects electric heat operation. For more information, see the “Diagnostics” 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 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 |
| 24VAC input voltage must be applied. Whenthe 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 typicalunit wiring diagrams in the Appendix of this manual. |
Table M-D-7. 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 moccupied 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 thecurrent step in the test sequence, the fresh air damper may not 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 actualend 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 wiringdiagrams in the Appendix of this manual. |
Table M-D-8. Fresh Air Damper Stays Closed
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 moccupied mode when the fan is running and closed during unoccupied mode. |
Warmup and cooldown | The controller includes both a warmup and cooldown sequence to keep the fresh air damper closed during the transition from |
| unoccupied to occupied. This is an attempt to bring the space under control as quickly as possible. |
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 unit closes the fresh air damper. |
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 thecurrent step in the test sequence, the fresh air damper may not be open. Refer to |
| the “Manual Output Test” section. |
Diagnostic present | A specific list of diagnostics effects fresh air damper operation. For more information, see the “Diagnostics” 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 actualend device, the damper may not work correctly. |
No power to the controller | If the controller does not have power, the fresh air damper 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 fresh air damper must be present and correct for normal damper operation. Refer |
| to the typical unit wiringdiagrams in the Appendix of this manual. |
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