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Diagnosis: Troubleshooting, Status Messages, Alarm Codes
172
19
Temperature Too Far From Setpoint
(Check Alarm)
• After 75 minutes of operation, supply or return air
temperature is not in-range and does not approach
setpoint within preset pull-down rate.
• Indicates:
• Ice or frost on evaporator coil
• Low refrigerant charge
• Air exchange vent open too much
• Container air leakage (doors open)
• Press S
UP
/R
ET
key to check supply and return
air sensor temperatures. Compare
temperatures to evaluate unit cooling capacity
and performance.
• Temperature difference should be 4 C to 6 C
(39 F - 43 F).
• Open evaporator door. Inspect coil for ice or
frost and initiate manual defrost if necessary.
• Check refrigerant charge
NOTE: This alarm can be activated if the
supply or return air temperature varies,
even if the mean temperature does
approach setpoint.
20
Defrost Time Too Long
(Check Alarm)
• Heat signal has been on for more than 90 minutes
on 60 Hz power during Defrost (120 minutes on 50
Hz power).
• Indicates:
• Low power supply voltage
• Defective heater elements
• Defective evaporator high temperature protection
switch
• Defective heat relay
• Evaporator fans running during defrost
• Evaporator sensor placed wrong
• Initiate a manual defrost and check amperage
draw and evaporator coil temperature.
Evaluate defrost performance.
• Open evaporator door and check location of
evaporator coil sensor.
NOTE: This alarm can be activated at low
voltage and very low box temperature
conditions, even under normal operating
conditions.
Alarm Codes, Descriptions and Corrective Actions (Continued)
Code
Description
Corrective 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...