| 1 |
Alarm Code |
Cause |
Components |
Troubleshooting |
Corrective Actions |
| 2 |
AL05 Manual Defrost Switch Failure |
Controller has detected continuous Manual Defrost Switch activity for five minutes or more. |
Keypad |
Power cycle the unit. |
Resetting the unit may correct problem, monitor the unit. If the alarm reappears after 5 minutes replace the keypad. |
| 3 |
AL06 Keypad or Keypad Harness Fail |
Controller has detected one of the keypad keys is continuously activity. |
Keypad or Harness |
Power cycle the unit. |
Resetting the unit may correct problem, monitor the unit. If the alarm reappears replace the keypad and harness. |
| 4 |
AL07 Fresh Air Vent Open with Frozen Set Point |
The VPS is reading greater than 0 CMH while unit is in frozen mode. |
Vent Position Sensor (VPS) |
Manually reposition vent and confirm using Cd45. Refer to VENT POSITION SENSOR SERVICE Section 6.25. |
If unable to obtain zero reading, replace defective VPS. |
| 5 |
AL10 CO2 Sensor Failure |
Alarm 10 is triggered when the CO2 sensor voltage is operating outside of the 0.9 v to 4.7 v range, or if the sensor is out of range. |
This is a display alarm and has no associated failure action. |
Refer to eAutoFresh manual. |
The alarm is triggered off when voltage is within operating range. |
| 6 |
AL11 Evaporator fan 1 IP |
Alarm 11 is triggered when configured for single evap operation and MC6 sensed high. |
Evaporator Fan 1 |
The unit will suspend probe check diagnostic lo- gic and disable the probe check portion of defrost cycle. |
AL11 is triggered off when MC6 sensed low. |
| 7 |
AL12 Evaporator fan 2 IP |
Alarm 12 is triggered when configured for single evap operation and KB10 sensed high. |
Evaporator Fan 2 |
The unit will suspend probe check diagnostic lo- gic and disable the probe check portion of defrost cycle. |
AL11 is triggered off when KB10 sensed low. |
| 8 |
AL15 Loss of cooling |
Unit fails to achieve 0.25C temperature delta for eight minutes before a probe−check defrost and then fails again for thirty minutes after the probe−check. |
N/A |
Power cycle the unit. |
Resetting the unit may correct problem, monitor the unit. |
| 9 |
AL20 Control Contactor Fuse (F3) |
Control power fuse (F3A or F3B) is open. |
Check F3A, if the fuse is open: |
Check PA, PB, CH coils for short to ground, if short is found: |
Replace the defective coil. Replace the fuse. |
| 10 |
Check F3B, if the fuse is open: |
Check ESV coil resistance at TP7 to TP9, if short to ground, or if resistance is less than 4 ohms, coil is defective. Check CF, ES, EF, HR coils for short to ground, if short is found, coil is defective. |
Replace the defective coil. Replace the fuse. |
|
|
| 11 |
Check Voltage at QC1: |
If voltage is present, it indicates a defective microprocessor. |
Refer to Controller Service Section 6.23. |
|
|
| 12 |
AL21 Control Circuit Fuse (F1/F2) |
One of the 18 VAC controller fuses (F1/F2) is open. Refer to Cd08. |
System Sensors |
Check system sensors for short to ground. |
Replace defective sensor(s) |
| 13 |
Wiring |
Check wiring for short to ground. |
Repair as needed. |
|
|
| 14 |
Controller |
Controller may have an internal short. |
Replace controller, refer to Controller Service Section 6.23. |
|
|
| 15 |
AL22 Evaporator IP |
Evaporator motor internal protector (IP) is open. |
Evaporator Motor |
Shut down unit, disconnect power, & check Evaporator Motor IP at plug connection pins 4 & 6. |
Replace defective evaporator fan motor, refer to EVAPORATOR FAN MOTOR Service Section 6.16. |
| 16 |
AL23 Loss of Phase B |
Controller fails to detect current draw. |
Incoming Power |
Check incoming power source. |
Correct power source as required. |
| 17 |
AL24 Compressor IP |
Compressor internal protector (IP) is open. |
Compressor |
Shut down unit disconnect power, & check resistance of compressor windings at contactor T1−T2, T2−T3. |
Monitor unit, if alarm remains active or is repetitive replace the compressor at the next available opportunity, refer to COMPRESSOR Service Section 6.8. |
| 18 |
AL25 Condenser IP |
Condenser fan motor internal protector (IP) is open. |
Insufficient Air Flow |
Shut down unit and check condenser fan for obstruc- tions. |
Remove obstructions. |
| 19 |
Condenser Fan Motor |
Shut down unit, disconnect power, & check Condenser Fan Motor IP at plug con- nection pins 1 & 2. |
Replace defective condenser fan motor, refer to Condenser Fan Motor Assembly Service Section 6.11. |
|
|
| 20 |
AL26 All Sensors Failure: Supply/Return Probes |
Sensors out of range. |
All sensors. detected as out of range |
Perform Pre−trip P5: |
If P5 passes, no further action is required. |
| 21 |
If P5 fails, replace the defective sensor as determined by P5, refer to TEMPERATURE SENSOR Service Section 6.24. |
|
|
|
|
| 22 |
AL27 Analog to Digital Accuracy Failure |
Controller AD converter faulty. |
Controller |
Power cycle the unit. If the alarm persists, it indicates a defective microprocessor. |
Replace defective microprocessor, refer to Controller Service Section 6.23. |
| 23 |
AL29 AutoFresh Failure |
Alarm 29 is triggered if CO2 or O2 level is outside of the limit range and the vent position is at 100% for longer than 90 minutes. |
Alarm LED will be activated and user intervention is re- quired. |
Refer to eAutoFresh manual. |
The alarm is triggered off when atmospheric con- ditions are within limit settings. |
| 24 |
AL50 Air Vent Position Sensor (VPS) |
VPS Sensor out of range. |
Vent Position Sensor (VPS) |
Make sure VPS is secure. |
Manually tighten panel. |
| 25 |
If the alarm persists, replace the sensor or the assembly. |
Replace VPS. |
|
|
|
| 26 |
AL51 EEPROM Failure |
Controller Memory Failure |
Controller |
Pressing the ENTER key when “CLEAr” is displayed will result in an attempt to clear the alarm. |
If action is successful (all alarms are inactive), AL51 will be reset. |
| 27 |
Power cycle the unit. If the alarm persists, it indicates defective controller memory. |
Replace defective controller, refer to Controller Service Section 6.23 |
|
|
|
| 28 |
AL52 EEPROM Alarm List Full |
Alarm list queue is full. |
Active Alarms |
Repair any alarms in the queue that are active. Indicated by “AA”. |
Clear alarms, refer to CONTROLLER ALARMS Table 3-6. |
| 29 |
AL53 Battery Pack Failure |
Battery voltage low |
Battery |
If this alarm occurs on start up, allow a unit fitted with rechargeable batteries to operate for up to 24 hours to charge rechargeable batteries sufficiently. Once fully charged, the alarm will deactivate. |
To clear the alarm press ENTER and ALT simul- taneously at the startup of Cd19 (Battery Check). If alarm persists, replace the battery pack, refer to Section 6.23.5 Battery Replacement. |
| 30 |
AL54 Primary Supply Sensor (STS) |
Invalid Supply Temperature Sensor (STS) reading. |
Supply Temperature Sensor (STS) |
Perform Pre−trip P5: |
If P5 passes, no further action is required. |
| 31 |
If P5 fails, replace the defective sensor as determined by P5, refer to TEMPERATURE SENSOR Service Section 6.24. |
|
|
|
|
| 32 |
AL56 Primary Return Sensor (RTS) |
Invalid Return Temperature Sensor (RTS) reading. |
Return Temperature Sensor (RTS) |
Perform Pre−trip P5: |
If P5 passes, no further action is required. |
| 33 |
If P5 fails, replace the defective sensor as determined by P5, refer to TEMPERATURE SENSOR Service Section 6.24. |
|
|
|
|
| 34 |
AL57 Ambient Sensor (AMBS) |
Invalid Ambient Temperature Sensor (AMBS) reading. |
Ambient Temperature Sensor (AMBS) |
Test the AMBS, refer to TEMPERATURE SENSOR Service Section 6.24. |
Replace AMBS if defective, refer to TEMPERATURE SENSOR Service Section 6.24. |
| 35 |
AL58 Compressor High Pressure Safety (HPS) |
High pressure safety switch remains open for at least one minute. |
High Pressure Switch (HPS) |
Test the HPS; refer to High Pressure Switch, Section 6.9. |
Replace HPS if defective, refer to High Pressure Switch, Section 6.9. |
| 36 |
Refrigeration System |
Check unit for air flow restrictions. |
Clean or remove any debris from coils. |
|
|
| 37 |
AL59 Heater Termination Thermostat (HTT) |
Heat Termination Thermostat (HTT) is open. |
Alarm 59 is trig- gered by the open- ing of the Heat Ter- mination Thermo- stat (HTT) and will result in the disab- ling of the heater. |
Check for 24 volts at test point TP10, if no voltage at TP10 after unit has reached set point HTT is open. |
Replace HTT if defective. |
| 38 |
AL60 Defrost Temperature Sensor (DTS) |
Failure of the Defrost Temperature Sensor (DTS) to open. |
Defrost Temperature Sensor (DTS) |
Test the DTS; refer to Sensor Checkout Proced- ure Section 6.24.1. |
Replace the DTS if defective, refer to Sensor Replacement Section 6.24.2. |
| 39 |
AL61 Heater Current Draw Fault |
Improper current draw during heat or defrost mode. |
Heater(s) |
While in heat or defrost mode, check for proper current draw at heater contactors, refer to ELECTRICAL DATA Section 2.3. |
Replace heater(s) if defective, refer to Section 6.15.2 Evaporator Heater Removal and Replacement. |
| 40 |
Contactor |
Check voltage at heater contactor on the heater side. If no voltage present: |
Replace heater contact- or if defective. |
|
|
| 41 |
AL63 Current Limit |
Unit operating above current limit. |
Refrigeration System |
Check unit for air flow restrictions. |
Clean or remove any debris from coils. |
| 42 |
Check unit for proper operation. |
Repair as needed. |
|
|
|
| 43 |
Power supply |
Confirm supply voltage/fre- quency is within specifica- tion and balanced accord- ing to ELECTRICAL DATA Section 2.3. |
Correct power supply. |
|
|
| 44 |
Current limit set too low. |
Check current limit setting Code Cd32. |
The current limit can be raised (maximum of 23 amps) using Cd32. |
|
|
| 45 |
AL64 Discharge Temperature Sensor (CPDS) |
Discharge Temperature sensor out of range. |
Discharge temperature sensor (CPDS). |
Test the CPDS; refer to TEMPERATURE SENSOR Service Section 6.24.. |
Replace the CPDS if defective, refer to TEMPERATURE SENSOR Service Sec- tion 6.24. |
| 46 |
AL65 Discharge Pressure Transducer (DPT) |
Compressor Discharge Transducer is out of range. |
Compressor Discharge Transducer (DPT) |
Confirm accurate DPT pressure readings, refer to MANIFOLD GAUGE SET Section 6.2. |
Replace DPT if defective. |
| 47 |
AL66 (SPT) Suction Pressure Transducer, (EPT) Evaporator Pressure Transducer |
Suction Pressure Transducer (SPT) out of range. |
Suction Pressure Transducer (SPT) |
Confirm accurate EPT and SPT pressure readings, refer to MANIFOLD GAUGE SET Section 6.2. Performing a Pre−trip 5−9 test will also check the transducers. |
Replace EPT/SPT if defective. |
| 48 |
Monitor |
If the alarm persists, it may indicate a failing compressor, refer to COMPRESSOR Service Section 6.8. |
|
|
|
| 49 |
AL67 Humidity Sensor |
Humidity Sensor (HS) reading out of range. |
Humidity Sensor (HS) |
Make sure the humidity sensor is properly connec- ted in the socket and the wires have not been dam- aged. |
Monitor, replace HS if alarm persists. |
| 50 |
AL68 CPC Pressure Sensor (PS3) |
Condenser Pressure Transducer (CPC) out of range. |
Condenser Pres- sure Transducer (CPC) |
NA |
Unit will disable Con- denser Pressure Control if Configured. |
| 51 |
AL69 Suction Temp Sensor (CPSS) |
Suction Temperature Sensor (CPSS) out of range. |
Suction Temperature Sensor (CPSS) |
Test the CPSS, refer to TEMPERATURE SENSOR Service Section 6.24. |
Replace CPSS if defective, refer to TEMPERATURE SENSOR Service Section 6.24. |
| 52 |
AL70 Secondary Supply Sensor (SRS) |
Secondary Supply Sensor (SRS) is out of range. |
Secondary Supply Sensor (SRS) |
Perform Pre−trip P5: |
If P5 passes, no further action is required. |
| 53 |
If P5 fails, replace the defective sensor as determined by P5, refer to TEMPERATURE SENSOR Service Section 6.24. |
|
|
|
|
| 54 |
AL71 Secondary Return Sensor (RRS) |
Secondary Return Sensor (RRS) is out of range. |
Secondary Return Sensor (RRS) |
Perform Pre−trip P5: |
If P5 passes, no further action is required. |
| 55 |
If P5 fails, replace the defective sensor as determined by P5, refer to TEMPERATURE SENSOR Service Section 6.24. |
|
|
|
|
| 56 |
AL72 Control Temp Out of Range |
After the unit goes in− range for 30 minutes then out of range for a continuous 120 minutes. |
Refrigeration System |
Ensure unit is operating correctly. |
Power cycle unit. Control Temperature is in In−range. Any Pre−trip mode, re- sets the timers. |
