Diagnosis
154
Condition
Possible Cause
Remedy
Load temperature too high
(unit not cooling)
Compressor does not operate
See “Mechanical Diagnosis”
Shortage of refrigerant
Repair leak and recharge
Overcharge of refrigerant
Purge system
Air in refrigeration system
Evacuate and recharge
Defective controller or main relay
board
Diagnose main relay board and
controller. Replace defective component
Controller setpoint too high
Adjust controller setpoint
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 dehydrator
Change dehydrator
Compressor inefficient
Perform compressor efficiency test.
Check valves and pistons
Evaporator pressure regulator (KVQ)
valve stuck closed or defective
Repair or replace valve
Condenser coil dirty or airflow
restricted
Clean condenser coil, clear restriction,
or repair or replace fan motor or
condenser fan blade
Water-cooled Condenser: COndenser
Fan switch OFF and no water flow to
water-cooled condenser
Restore water flow to water-cooled
condenser-receiver tank or turn
Condenser fan blade
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
Condition
Possible Cause
Remedy
Summary of Contents for CRR-40 119
Page 4: ......
Page 16: ...Safety Precautions 16...
Page 18: ...Service Guide 18...
Page 20: ...Model Features 20...
Page 32: ...Specifications 32...
Page 120: ...MP 3000a Controller 120...
Page 160: ...Wiring and Schematic Diagrams Index 160...
Page 161: ...161 MPC2000 Wiring Schematic...
Page 162: ...162 MPC2000 High Voltage Wiring Diagram...
Page 163: ...163 MPC2000 Low Voltage Wiring Diagram...
Page 164: ...164 MPC2000 WCC Wiring Schematic...