Troubleshooting

Section 6

Troubleshooting

6.1Unit Will Not Start Or Starts Then Stops
Condition	Possible Cause	Remedy / Reference
No power to unit	External power source OFF	Turn On
	Start-Stop switch OFF or defective	Check
	Circuit breaker OFF or tripped	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	Section 7.13
	Gas Cooler fan motor internal protector open	Section 7.9
	Compressor internal protector open	Section 7.3
	High Pressure Switch (HPS) open	Section 5.8
	Heat Termination Thermostat (HTT) open	Replace
	Current sensor malfunction	Replace

6.2Unit Operates Long Or Continuously In Cooling
Condition	Possible Cause	Remedy / Reference
Container	Hot load	Normal
Container	Box insulation defective or air leak	Repair
Refrigeration system	Refrigerant shortage	Section 7.2.6
	Evaporator coil covered with ice	Section 6.6
	Evaporator coil plugged with debris	Section 7.11
	Evaporator coil has air bypass around it	Check
	Controller set too low	Reset
	Coil dirty	Section 7.8
	Current limit (Cd32) set to wrong value	Section 4.4.3
	Economizer Solenoid Valve (ESV) malfunction	Section 7.17
	Electronic Expansion Valve (EEV)	Replace

6.3Unit Runs But Has Insufficient Cooling
Condition	Possible Cause	Remedy / Reference
Refrigeration system	Pressures abnormal	Section 6.7
	Temperatures abnormal	Section 6.13
	Currents abnormal	Section 6.14
	Controller malfunction	Section 6.9
	Evaporator fan or motor defective	Section 7.13
	Electronic Expansion Valve (EEV)	Replace

6.4Unit Will Not Heat Or Has Insufficient Heating
Condition	Possible Cause	Remedy / Reference
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	Section 7.13
	Heat relay defective	Check
	Heat Termination Thermostat (HTT) open	Section 7.11
Unit will not heat or has insufficient heat	Heater(s) defective	Section 7.11
	Heater contactor or coil defective	Replace
	Evaporator fan motor(s) defective	Section 7.11 / Section 7.13
	Evaporator fan motor contactor defective	Replace
	Controller malfunction	Section 6.9
	Wiring defective	Replace
	Terminal connections loose	Tighten
	Line voltage low	Section 3.4

6.5Unit Will Not Terminate Heating
Condition	Possible Cause	Remedy / Reference
Unit fails to stop heating	Controller improperly set	Reset
	Controller malfunction	Section 6.9
	Heat Termination Thermostat (HTT) remains closed along with the heat relay	Section 7.11

6.6Unit Will Not Defrost Properly
Condition	Possible Cause	Remedy / Reference
Will not initiate defrost automatically	Defrost timer malfunction (Cd27)	Table 4–7
	Terminal connections loose	Tighten
	Wiring defective	Replace
	Defrost Temperature Sensor (DTS) defective or Heat Termination Thermostat (HTT) open	Replace
	Heater contactor or coil defective	Replace
Will not initiate defrost manually	Manual defrost switch defective	Replace
	Keypad defective	Replace
	Defrost Temperature Sensor (DTS) open	Replace
Initiates but relay DR drops out	Low line voltage	Section 3.4
Initiates but does not defrost	Heater contactor or coil defective	Replace
Initiates but does not defrost	Heater(s) burned out	Section 7.11

6.7Abnormal Pressures
Condition	Possible Cause	Remedy / Reference
High discharge pressure	Gas Cooler coil dirty	Section 7.8
	Gas Cooler fan rotating backwards	Section 7.9
	Gas Cooler fan inoperative	Section 7.9
	Refrigerant overcharge or non-condensibles	Section 7.2.6
	High Pressure Expansion Valve (HPXV) control malfunction	Replace
Low suction pressure	Software incorrect and/or controller configuration incorrect	Check
	Suction Pressure Transducer (SPT) failed	Replace
	Evaporator air flow not present or restricted	Section 7.11
	Electronic Expansion Valve (EEV) control malfunction	Replace

6.8Abnormal Noise Or Vibrations
Condition	Possible Cause	Remedy / Reference
Compressor	Mounting bolts loose	Tighten / Replace
Compressor	Liquid slugging	Section 7.15
Gas Cooler or Evaporator Fan	Bent, loose or striking venturi	Check
	Motor bearings worn	Section 7.9 / Section 7.13
	Motor shaft bent	Section 7.9 / Section 7.13

6.9Microprocessor Malfunction
Condition	Possible Cause	Remedy / Reference
Will not control	Software incorrect and/or controller configuration incorrect	Check
	Sensor defective	Section 7.22
	Wiring defective	Check
	Refrigerant charge low	Section 7.2.6

6.10No Evaporator Air Flow Or Restricted Air Flow
Condition	Possible Cause	Remedy / Reference
Evaporator coil blocked	Coil has frost	Section 6.6
Evaporator coil blocked	Coil dirty	Section 7.11
No or partial evaporator air flow	Evaporator fan motor internal protector open	Section 7.13
	Evaporator fan motor(s) defective	Section 7.13
	Evaporator fan(s) loose or defective	Section 7.13
	Evaporator fan contactor defective	Replace

6.11Electronic Expansion Valve (EEV) Malfunction
Condition	Possible Cause	Remedy / Reference
Low suction pressure	Software incorrect and/or controller configuration incorrect.	Check
	Suction Pressure Transducer (SPT) failed	Replace
	Evaporator air flow not present or restricted	Section 7.11
	Evaporator coil has excessive frost	Section 6.6
	Electronic Expansion Valve (EEV) control malfunction	Section 7.15
	Evaporator Temperature Sensor (ETS) loose or insufficiently clamped	Replace
High suction pressure with low superheat	Valve contains foreign material	Section 6.11
	Suction Pressure Transducer (SPT) failed	Replace
	Electronic Expansion Valve (EEV) control malfunction	Replace
Liquid slugging in compressor	Suction Pressure Transducer (SPT) failed	Replace
Liquid slugging in compressor	Electronic Expansion Valve (EEV) failed	Replace

6.12High Pressure Expansion Valve (HPXV) Malfunction
Condition	Possible Cause	Remedy / Reference
High discharge pressure	High Pressure Expansion Valve (HPXV) coil not seated properly, loose, or not fully engaged.	Section 7.15.2
	Software incorrect or controller configuration incorrect	Check
	Discharge Pressure Transducer (DPT) failed	Replace
	Filter drier restriction	Section 7.10
	Gas Cooler Temperature Sensor (GCTS) loose or insufficiently clamped	Check
	Gas cooler coil dirty	Section 7.8
	Gas cooler fan rotating backwards	Section 7.9
	Gas cooler fan inoperative	Section 7.9
	HPXV control malfunction	Replace
	HPXV failed	Replace

6.13Abnormal Temperatures
Condition	Possible Cause	Remedy / Reference
High discharge temperature	Gas cooler coil dirty	Section 7.8
	Gas cooler fan rotating backwards	Section 7.9
	Gas cooler fan inoperative	Section 7.9
	Refrigerant overcharge or non-condensibles	Section 7.2.6
	Electronic Expansion Valve (EEV) control malfunction	Replace
	Suction Pressure Transducer (SPT) failed	Replace
	Discharge Temperature Sensor drifting high	Replace
	Sensor loose or insufficiently clamped	Replace
	Electronic Solenoid Valve (ESV) coil not fully engaged	Section 7.17.2
	ESV or ESV coil malfunction	Replace

6.14Abnormal Currents
Condition	Possible Cause	Remedy / Reference
Unit reads abnormal currents	Current sensor wiring	Check
Unit reads abnormal currents	Component is defective	Check current draw / Replace as needed.

6.15Fuse F1 or F2 Blown
Condition	Possible Cause	Remedy / Reference
Fuse F1 or F2 Blown	Electronic Expansion Valve (EEV) drive module wires were grounded.	Check EEV drive module by unplugging it, replacing the fuse(s) and turning the unit back on.