Section 6
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
No power to unit |
External power source OFF |
Turn On |
Start−Stop switch OFF or defective |
Check |
|
Circuit breaker tripped or OFF |
Check |
|
Loss of control power |
Circuit breaker OFF or defective |
Check |
Control transformer defective |
Check |
|
Fuse (F3A/F3B) blown |
Check |
|
Start−Stop switch OFF or defective |
Check |
|
Component(s) not operating |
Evaporator fan motor internal protector open |
|
Gas Cooler fan motor internal protector open |
||
Compressor internal protector open |
||
High pressure switch open |
||
Heat termination thermostat open |
Replace |
|
Malfunction of current sensor |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Container |
Hot load |
Normal |
Defective box insulation or air leak |
Repair |
|
Refrigeration system |
Shortage of refrigerant |
|
Evaporator coil covered with ice |
||
Evaporator coil plugged with debris |
||
Air bypass around evaporator coil |
Check |
|
Controller set too low |
Reset |
|
Dirty coil |
||
Current limit (function code Cd32) set to wrong value |
||
Economizer solenoid valve malfunction |
||
Electronic expansion valve |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Refrigeration system |
Abnormal pressures |
|
Abnormal temperatures |
||
Abnormal currents |
||
Controller malfunction |
||
Evaporator fan or motor defective |
||
Electronic expansion valve |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
No operation of any kind |
Start−Stop switch OFF or defective |
Check |
Circuit breaker OFF or defective |
Check |
|
External power source OFF |
ON |
|
No control power |
Circuit breaker or fuse defective |
Replace |
Control Transformer defective |
Replace |
|
Evaporator fan internal motor protector open |
||
Heat relay defective |
Check |
|
Heater termination thermostat open |
||
Unit will not heat or has insufficient heat |
Heater(s) defective |
|
Heater contactor or coil defective |
Replace |
|
Evaporator fan motor(s) defective |
||
Evaporator fan motor contactor defective |
Replace |
|
Controller malfunction |
||
Defective wiring |
Replace |
|
Loose terminal connections |
Tighten |
|
Low line voltage |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Unit fails to stop heating |
Controller improperly set |
Reset |
Controller malfunction |
||
Heater termination thermostat remains closed along with the heat relay |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Will not initiate defrost automatically |
Defrost timer malfunction (Cd27) |
|
Loose terminal connections |
Tighten |
|
Defective wiring |
Replace |
|
Defrost temperature sensor defective or heat termination thermostat open |
Replace |
|
Heater contactor or coil defective |
Replace |
|
Will not initiate defrost manually |
Manual defrost switch defective |
Replace |
Keypad is defective |
Replace |
|
Defrost temperature sensor open |
Replace |
|
Initiates but relay (DR) drops out Low line voltage |
||
Initiates but does not defrost |
Heater contactor or coil defective |
Replace |
Heater(s) burned out |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
High discharge pressure |
Gas Cooler coil dirty |
|
Gas Cooler fan rotating backwards |
||
Gas Cooler fan inoperative |
||
Refrigerant overcharge or non-condensibles |
||
High Pressure Expansion Valve (HPXV) control malfunction |
Replace |
|
Low suction pressure |
Incorrect software and/or controller configuration |
Check |
Failed suction pressure transducer (SPT) |
Replace |
|
No evaporator air flow or restricted air flow |
||
EEV control malfunction |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Compressor |
Loose mounting bolts |
Tighten/Replace |
Liquid slugging |
||
Gas Cooler or Evaporator Fan |
Bent, loose or striking venturi |
Check |
Worn motor bearings |
||
Bent motor shaft |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Will not control |
Incorrect software and/or controller configuration |
Check |
Defective sensor |
||
Defective wiring |
Check |
|
Low refrigerant charge |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Evaporator coil blocked |
Frost on coil |
|
Dirty coil |
||
No or partial evaporator air flow |
Evaporator fan motor internal protector open |
|
Evaporator fan motor(s) defective |
||
Evaporator fan(s) loose or defective |
||
Evaporator fan contactor defective |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Low suction pressure |
Incorrect software and/or controller configuration |
Check |
Failed suction pressure transducer (SPT) |
Replace |
|
No evaporator air flow or restricted air flow |
||
Excessive frost on evaporator coil |
||
EEV control malfunction |
||
Loose or insufficiently clamped sensor (ETS) |
Replace |
|
High suction pressure with low superheat |
Foreign material in valve |
|
Failed suction pressure transducer (SPT) |
Replace |
|
EEV control malfunction |
Replace |
|
Liquid slugging in compressor |
Failed suction pressure transducer (SPT) |
Replace |
Failed EEV |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
High discharge pressure |
HPXV coil loose, not fully engaged |
|
Incorrect software and/or controller configuration |
Check |
|
Failed discharge pressure transducer (DPT) |
Replace |
|
Filter drier restriction |
||
Loose or insufficiently clamped sensor (GCTS) |
Check |
|
Gas cooler coil dirty |
||
Gas cooler fan rotating backwards |
||
Gas cooler fan inoperative |
||
HPXV control malfunction |
Replace |
|
Failed HPXV |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
High discharge temperature |
Gas cooler coil dirty |
|
Gas cooler fan rotating backwards |
||
Gas cooler fan inoperative |
||
Refrigerant overcharge or non-condensibles |
||
Electronic expansion valve (EEV) control malfunction |
Replace |
|
Failed suction pressure transducer (SPT) |
Replace |
|
Discharge temperature sensor drifting high |
Replace |
|
Loose or insufficiently clamped sensor |
Replace |
|
ESV coil not fully engaged |
||
ESV or ESV coil malfunction |
Replace |
Condition |
Possible Cause |
Remedy/Reference Section |
---|---|---|
Unit reads abnormal currents |
Current sensor wiring |
Check |
Component is defective |
Check current draw/Replace as needed |