CNT-SVX07D-EN
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Status indicators for operation and communication
Smart reset diagnostics
After the controller detects the first smart reset diagnostic, the unit waits 30 minutes before
initiating the smart reset function. If another diagnostic of this type occurs again within 24 hours
after an automatic clearing, you must clear the diagnostic manually by using any of the ways shown
for “Manual (latching) diagnostics.”
Informational diagnostics
Informational diagnostics provide information about the status of the controller. They do not affect
machine operation. They can be cleared from the controller using any of the ways shown for
“Manual (latching) diagnostics.”
Table of diagnostics
presents each diagnostic that can be generated by the Tracer ZN521, its effect on outputs
(consequences), and its type.
Note:
The generic binary output is unaffected by diagnostics.
Table 16. Diagnostics
Diagnostic
Probable cause
Consequences
Diagnostic
type
Maintenance Required
Fan run hours exceed the time set
to indicate filter change
Fan unaffected
Valves unaffected
Electric heat unaffected
Face and bypass damper unaffected
Informational
Condensate Overflow
The drain pan is full of water
Fan off
Valves closed
Outdoor air damper closed
Face and bypass damper bypass
DX/electric heat off
Baseboard heat off
Manual
Low Coil Temp Detection
The leaving fluid temperature
may be close to freezing
Fan off
Valves open
Outdoor air damper closed
Face and bypass damper bypass
DX/electric heat off
Baseboard heat off
Smart reset/
Manual
Low Airflow—Fan Failure
The fan drive belt, contactor, or
motor has failed.
Fan off
Valves closed
Outdoor air damper closed
Face and bypass damper bypass
DX/electric heat off
Baseboard heat off
Manual
Space Temperature Failure
Invalid or missing value for zone
temperature
Fan off
Valves closed
Outdoor air damper closed
Face and bypass damper bypass
DX/electric heat off
Baseboard heat off
Automatic
Entering Water Temp Failure
Invalid or missing value for zone
temperature
Fan unaffected (enabled)
Valves unaffected
Outdoor air damper unaffected
Face and bypass damper unaffected
DX/electric heat unaffected
Baseboard heat off
Automatic
Discharge Air Temp Limit
Discharge air temperature has
fallen below the Discharge Air
Temperature Low Limit
Fan off
Valves open
Outdoor air damper closed
Face and bypass damper bypass
DX/electric heat off
Baseboard heat off
Automatic
Summary of Contents for Tracer ZN521
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