Carrier PrimeLINE 69NT40-561-200, Operation And Service Manual

Page: 75 / 198

4–35 T-362
AL23 Loss of Phase B
Cause:
Controller fails to detect current draw.
Component Incoming Power
Troubleshooting
Check incoming power source.
Corrective Action Correct power source as required.
AL24 Compressor IP
Cause:
Compressor internal protector (IP) is open.
Component Compressor
Troubleshooting
Shut down unit disconnect power and check resistance of compressor windings
at contactor T1-T2, T2-T3.
Corrective Action Monitor unit, if alarm remains active or is repetitive replace the compressor at the
next available opportunity. See Compressor Service Section 7.9 .
AL25 Condenser IP
Cause:
Condenser fan motor internal protector (IP) is open.
Component Insufficient Air Flow
Troubleshooting
Shut down unit and check condenser fan for obstructions.
Corrective Action Remove obstructions.
Component
Condenser Fan Motor
Troubleshooting Shut down unit, disconnect power and check Condenser Fan Motor IP at plug
connection pins 4 & 6.
Corrective Action
Replace defective condenser fan motor. See Condenser Fan Motor Assembly
Service
Section 7.12
.
AL26 All Sensors Failure: Supply / Return Probes
Cause: Sensors out of range.
Component
All sensors detected as out of range.
Troubleshooting Perform pre-trip P5.
Corrective Action
If P5 passes, no further action is required.
Corrective Action If P5 fails, replace the defective sensor as determined by P5. See Temperature
Sensor Service Section 7.29 .
AL27 Analog to Digital Accuracy Failure
Cause:
Controller AD converter faulty.
Component Controller
Troubleshooting
Power cycle the unit. If the alarm persists, it indicates a defective microprocessor.
Corrective Action Replace defective microprocessor. See Controller Service Section 7.27 .
AL28 Low Suction Pressure
Cause:
Suction pressure too low for normal operation.
Component N/A
Troubleshooting
Power cycle the unit.
Table 4–5 Alarm Indications and Descriptions