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Diagnosis: Troubleshooting, Status Messages, Alarm Codes
165
24
Supply Air Temperature Too Low
(Check Alarm)
• During Chill or Frozen Mode: Supply air
temperature is too low compared to return air
temperature under operating conditions.
• Indicates:
• Ice or frost on evaporator coil
• Low heating capacity
• Incorrect evaporator fan operation
• Incorrect connection or location of supply or
return air sensors
• Check for sensor or evaporator fan alarm codes.
• Open evaporator door. Inspect coil for ice or frost
and initiate manual defrost if necessary. Check
for correct evaporator fan motor rotation and
operation.
• Check supply and return sensor connections
and locations.
25
Return Air Temperature Too High
(Check Alarm)
• During Defrost: Return air temperature
increases above 40 C (104 F).
• Indicates:
• Defective return or evaporator coil sensor
• Return and evaporator coil sensor
connections are reversed
• Check for sensor alarm codes.
• Check supply and return sensor connections
and locations.
26
Evaporator Coil Temperature Too High
(Check Alarm)
• During Chill or Frozen Mode: Evaporator coil
temperature is too high compared to return air
temperature under operating conditions.
• Indicates:
• Low refrigerant charge.
• Defective evaporator coil or return air
sensor
• Incorrect connection or location of
evaporator coil or return air sensor
• Check for sensor alarm codes.
• Check discharge and suction pressure gauge
readings and check refrigerant charge.
• Check evaporator coil and return air sensor
connections and locations.
27
Evaporator Coil Temperature Too Low
(Check Alarm)
• During Chill or Frozen Mode: Evaporator coil
temperature is too low compared to return air
temperature under actual operating
conditions.
• Controller initiates defrost if no recent defrost.
• Indicates:
• Airflow is blocked in the container
• Evaporator fans do not operate
• Fresh air exchange vent open too much on
frozen load
• Defective evaporator coil or return air
sensor
• Check for sensor or evaporator fan alarm codes.
• Open evaporator door. Inspect coil for ice or frost
and initiate manual defrost if necessary. Check
for correct evaporator fan rotation and operation.
• Inspect return air grille and cargo load. Remove
any debris or cargo from blocking return air
grille.
• At setpoints below 5 C (41 F), maximum air vent
setting is not allowed.
• Check evaporator coil and return air sensor
connections and locations.
Status Messages and Controller Actions (Continued)
Message
No.
Status Message
Controller Action
Summary of Contents for 098916
Page 5: ......
Page 11: ...Table of Contents 10...
Page 19: ...Service Guide 18...
Page 28: ...Specifications 27 Figure 2 Physical Specifications AMA313...
Page 41: ...Unit Description Features Options 40...
Page 105: ...Operating Instructions 104...
Page 155: ...Servicing The Unit 154...
Page 187: ...Index 186...
Page 189: ...Wiring and Schematic Diagrams Index 188...
Page 190: ...189 Wiring Schematic...
Page 191: ...190 Wiring Diagram Page 1 of 2...
Page 192: ...191 Wiring Diagram Page 2 of 2...