Troubleshooting
Questionable Unit
Operation
Table 14: Compressor(s) not running
Probable Cause | Explanation | |
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Normal operation. | The controller compressor(s) turn on and off to meet the unit capacity | |
requirements. | ||
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| The desired operating mode (such as off, heat and cool) can be communicated to | |
Requested mode off. | the controller. When off is communicated to the controller, the unit shuts off all | |
| unit compressor(s). | |
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| Numerous communicated requests may disable the compressor, including a | |
Communicated disable. | compressor enable input. Depending on the state of the communicated request, | |
| the unit may disable the compressor. | |
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| The controller includes a manual output test sequence that may be used to verify | |
Manual output test. | output operation and associated output wiring. However, based on the current | |
step in the test sequence, the compressor(s) may not be on. Refer to the manual | ||
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| output overrides on page 9. | |
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| A specific list o f diagnostics affects compressor operation, depending whether | |
Diagnostic present. | the unit is configured as heat pump. For more information, see the Diagnostics | |
| section on page 27. | |
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| The controller must be properly configured based on the actual installed end | |
Unit configuration. | devices and application. When the unit configuration does not match the actual | |
| end device, the compressor may not work correctly. | |
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| If the controller does not have power, the compressor does not operate. For the | |
No power to the controller. | ZN510 controller to operate normally, a voltage input of 24 VAC must be applied. | |
When the green LED is off continuously, the controller does not have sufficient | ||
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| power or has failed. | |
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Unit wiring. | The wiring between the controller outputs and the compressor contacts must be | |
present and correct for normal compressor operation. | ||
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Table 15: Outdoor air damper stays open
Probable Cause | Explanation | |
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| The controller opens and closes the outdoor air damper based on the controller’s | |
Normal operation. | occupancy mode and fan status. Normally, the outdoor air damper is open | |
during occupied mode when the fan is running and closed during unoccupied | ||
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| mode. Refer to the outdoor air damper section on page 8. | |
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| The controller includes a manual output test sequence that may be used to verify | |
Manual output test. | output operation and associated output wiring. However, based on the current | |
step in the test sequence, the outdoor air damper may not open. Refer to the | ||
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| manual output overrides on page 9. | |
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| The controller must be properly configured based on the actual installed end | |
Unit configuration. | devices and application. When the unit configuration does not match the actual | |
| end device, the outdoor air damper may not work correctly. | |
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Unit wiring. | The wiring between the controller outputs and the compressor contacts must be | |
present and correct for normal damper operation. | ||
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