Minimum Timers; Required Inputs For Unit Operation; Diagnostics - Trane Tracer AH.540 Installation Owner Diagnostics

CNT-SVX05A-EN
Troubleshooting

Minimum timers

The controller automatically exits the manual test mode after ten hours and
reverts back to normal operation. The outputs are not subject to minimum times
during the test sequence. However, the test sequence only permits one step per
second, which enforces a minimum output time.

Required inputs for unit operation

The following locally wired sensor or communicated inputs are required for each
listed control function. If any one of the sensors does not exist, the controller
operates the control function.
Table 55 — Required sensors
Control function Sensor(s) required to be
present - wired sensor or
communicated value
Variable air volume Duct static pressure
control Discharge air temperature
Discharge air Discharge air temperature
temperature control
Space temperature Space temperature
control Discharge air temperature
Economizer operation Outdoor air temperature
Mixed air temperature

Diagnostics

Three different types of diagnostics are generated by the Tracer
controller to help you troubleshoot abnormal unit operation.
Table 56 — Diagnostic types
Critical alarm The controller shuts down the unit to protect the air handling unit and avert
possible damage, or the controller cannot operate until the diagnostic
condition is corrected.
Service required The controller disables certain sequences of operation only and attempts to
maintain unit operation. For example, if the mixed air temperature sensor fails
or is not wired, the Tracer AH.540 controller disables (does not allow)
economizer operation.
Informational This type of diagnostic does not affect controller operation.
Table 57 — Controller diagnostics
Diagnostic or Condition Control type
configuration
Low Temp Detect CV Space temp control
(Notes 1, 6) CV Discharge air control
Variable air volume control
Duct Static Press Variable air volume control
High Limit (Note 6)
Unit Shutdown CV Space temp control
(Note 6) CV Discharge air control
Variable air volume control
Low Supply Fan Air Flow CV Space temp control
(Note 6) CV Discharge air control
Variable air volume control
Dirty Filter CV Space temp control
(informational) CV Discharge air control
Variable air volume control
Controller operation if
input is not present
Diagnostic shutdown
Diagnostic shutdown
Diagnostic shutdown
Diagnostic shutdown
Diagnostic shutdown
Economizer disabled
Economizer disabled
™
AH.540
Supply Other outputs
fan (Enabled = Normal Operation)
Off Valves Open (hydronic)
Valves Cycled (steam)
Outdoor air damper Closed
Face and bypass damper Face
Exhaust fan Off
Off Valves Closed
Outdoor air damper Closed
Face and bypass damper Bypass
Exhaust fan Off
Off Valves Closed
Outdoor air damper Closed
Face and bypass damper Bypass
Exhaust fan Off
Off Valves Closed
Outdoor air damper Closed
Face and bypass damper Bypass
Exhaust fan Off
Enabled Valves Enabled
Outdoor air damper Enabled
Face and bypass damper Enabled
Exhaust fan Enabled
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