Carrier 69NT40-561-399 Operation And Service Manual page 81

AL28 LOW SUCTION PRESSURE
Cause: Suction pressure too low for normal operation
Component
Corrective Action Resetting the unit may correct problem, monitor the unit.
Component
Corrective Action Replace SPT if defective
Component
Corrective Action Replace DPT if defective
AL29 AUTOFRESH FAILURE
Cause: Alarm 29 is triggered if CO
for longer than 90 minutes.
Component
Corrective Action The alarm is triggered off when atmospheric conditions are within lim-
AL50 AIR VENT POSITION SENSOR (VPS)
Cause: VPS Sensor out of range.
Component
Corrective Action Manually tighten panel.
Corrective Action Replace VPS.
N/A
Troubleshooting Power cycle the unit.
Suction Pressure Transducer (SPT)
Troubleshooting Confirm accurate SPT pressure readings, refer to MANIFOLD
GAUGE SET
Discharge Pressure Transducer (DPT)
Troubleshooting Confirm accurate DPT pressure readings, refer to MANIFOLD
GAUGE SET
or O level is outside of the limit range and the vent position is at 100%
2 2
Alarm LED will be activated and user intervention is required.
Troubleshooting Refer to eAutoFresh manual.
it settings.
Vent Position Sensor (VPS)
Troubleshooting Make sure VPS is secure.
Troubleshooting If the alarm persists, replace the sensor or the assembly.
Section 7.2
Section 7.2
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