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Diagnosis: Troubleshooting, Status Messages, Alarm Codes
159
Troubleshooting Refrigeration Problems
Condition
Possible Cause
Remedy
Load temperature too high—
unit not cooling
Compressor does not operate
See “Mechanical Diagnosis”
Controller setpoint too high
Adjust controller setpoint
Defective container insulation or poor
fitting doors
Repair container
Shortage of refrigerant
Repair leak and recharge
Overcharge of refrigerant
Purge system
Air in refrigeration system
Evacuate and recharge
Vapor injection valve open
Check vapor injection valve circuit
and compressor discharge
temperature sensor
Too much compressor oil in system
Remove compressor oil from
compressor
Iced or dirty evaporator coil
Defrost or clean evaporator coil
Restricted lines on high side
Clear restriction
Plugged filter drier/in-line filter
Change filter drier
Compressor Digital Control Valve
defective
Replace defective valve
Condenser coil dirty or airflow
restricted
Clean condenser coil, clear
restriction, or repair or replace fan
motor or condenser fan blade
No water flow to water-cooled
condenser
Restore water flow to water-cooled
condenser-receiver tank
Defective water pressure switch
(Option)
Replace switch
Expansion valve open too much
Adjust or replace valve
Expansion valve power element lost
its charge
Replace power element
Expansion valve feeler bulb
improperly mounted, poorly insulated
or making poor contact
Correct feeler bulb installation
Head pressure too low
NOTE: This unit has a digital
capacity control system. Suction and
discharge pressures may drop below
expected normal readings when the
unit is in Modulation Cool (control
temperature within 10 C [18 F] of
setpoint or in Power Limit mode).
Shortage of refrigerant
Repair leak and recharge
Low ambient air temperature
No remedy
Service gauge out of calibration
Replace gauge
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...