Trane Technologies IntelliPak Signature SCWF Installation, Operation And Maintenance Manual page 97

Category Diagnostic
If have an external sensor connected to the NSB panel zone sensor input, then the internal NSB panel zone sensor should be disabled. Verify
Check
sensor resistance. If in valid range, check wiring between the sensor and NSB panel.
NSB Panel Comm Failure
The RTM has lost communications with the night setback panel (programmable zone sensor).
Problem
Field/unit wiring between RTM and NSB Panel.
Check
Reason for
The RTM has lost communication with the NSB panel.
Diagnostic
The unit reverts to the next lower priority mode switching source (typically the HI default mode). If the NSB panel zone sensor is the designated
Controls
sensor source for any functions, those functions are disabled.
Reaction
Reset
(PAR) An automatic reset occurs after communication has been restored.
Required
O
O/A Humidity Sensor Failure
The outside air humidity sensor data is out of range.
Problem
Check field/unit wiring between the sensor and RTM.
Check
Reason for
The unit is reading a signal that is out of range for the outside air humidity sensor (humidity < 5% or humidity > 100%).
Diagnostic
Controls
The economizer enable enthalpy function reverts to dry-bulb temperature changeover ("Level 1") control.
Reaction
Reset
(PAR) An automatic reset occurs after the OA humidity input returns to its allowable range for 10 seconds.
Required
O/A Temp. Sensor Failure
The outside air temperature sensor input is out of range.
Problem
Sensor resistance should be between 830 ohms (200°F) and 345.7 ohms (-40°F). If so, check field/unit wiring between sensor and RTM.
Check
Reason for
The unit is reading a signal that is out of range for the outside air temperature input on the RTM (temp. < -55°F or temp > 209°F).
Diagnostic
These unit functions occur:
• Low Ambient Compressor Lockout Disables
Controls
Reaction
• O/A damper drives to minimum position
• On VAV units with S/A temp. reset type selected as O/A temp. reset, the reset type reverts to "none" for the duration of the failure
Reset (PAR) an automatic reset occurs after the O/A temperature input returns to its allowable range. To prevent rapid cycling of the diagnostic, there
Required is a 10 second delay before the automatic reset.
Occupied Zone Heat Setpoint Failure
The occupied zone heat setpoint input is out of range.
Problem
Reason for The input designated as occupied zone heating setpoint source is out of range for the outside air temperature input on the RTM (temp. < 45°F
Diagnostic or temp > 94°F).
The active occupied zone heating setpoint reverts to the default value.
Reaction
Reset (PAR) an automatic reset occurs after the occupied zone heating setpoint input returns to its allowable range for 10 continuous seconds, or
Required after a different occupied zone heating setpoint selection source is user-defined.
R
Return Air Humidity Sensor Failure
On units with both airside economizer and comparative enthalpy installed, the return air humidity sensor input is out of range.
Problem
Check field/unit wiring between the sensor and ECEM.
Check
SCXF-SVX01T-EN
Diagnostics
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