1. 1) The Meaning of the First Alphabet
1. Error Display
   1) The Meaning of the First Alphabet E P U A
Error concluded by self-diagnosis
E101~E700
Detailed item refers error code
Pre Error Code
P701~P800
Items that need more than 2 times detection to conclude through error
The address of Outdoor Unit occurred error
U200 : Main Unit
U201 : Sub1 Unit
U202 : Sub2 Unit
U203 : Sub3 Unit
The address of Indoor Unit occurred error
A047 : Error Occurred At Indoor Unit Whose address 47
  2) Error Display method
Error Type
Error Display Method
Examples
Error Occurred at Indoor Unit
Error Number →Address of Indoor unit → Error Number (repeat indication)
E471→A002→E471→A002
Error Occurred at Outdoor Unit
or Other Error
Error Number →Address of Outdoor unit → Error Number (repeat indication)
E471→U200→E471→U200
 ○ In case of several Error should be registered at the same time, Indicator will display one error whose priority is highest. ( Refer Error Code Table to know priority order )
 ○ When the same Error Occurred in several Indoor Units, Indicator will display one address of
indoor unit whose address number is lowest.

2. Error Code (Priority Order)
Error Details
E221
Short or Open of the Outdoor air temperature sensor
E251
Short or Open of the discharge temperature sensor of Digital compressor
E256
Short or Open of the discharge temperature sensor of Fixed compressor 1
E257
Short or Open of the discharge temperature sensor of Fixed compressor 2
E258
Short or Open of the discharge temperature sensor of Fixed compressor 3
E291
Short or Open of the high pressure sensor
E296
Short or Open of the low pressure sensor
E271
Short or Open of the Sump. Temperature sensor of the compressor 1
E231
Short or Open of the Cond. out temperature Sensor
E307
Short or Open of the Oil balance temperature Sensor1
E308
Short or Open of the Suction temperature sensor
E311
Short or Open of the sub cooler temperature sensor
E425
Reverse Phase or Phase Open
E452
Voltage Dip Error
E440
Stop Operating Heating mode when Outdoor temperature is over 30℃
E442
Stop Operating Heating charging mode when Outdoor temperature is over 15℃
E443
Stop Operation by Low Pressure
E431
Self diagnosis failure of Oil balance valve 1
E202
No response error after tracking is completed
E201
Communication error among outdoor units and indoor units
(Pre-tracking failure or setup indoor unit number is different from the real)

3. Error Code (Priority Order)
Error Details
E203
Communication error between Outdoor unit’s main and sub MICOM or among outdoor Units
E407
Comp down By high pressure
E410
Comp down By low pressure
E403
Comp down By Anti-freezing control
E413
Comp down By Sump Protection Control
E554
Loading failure
E416
Comp down by compressor discharge temperature
E241
Cond. out temperature Sensor breakaway
E269
Suction temperature Sensor breakaway
E453
Error of Fan Motor’s high temperature
E454
Fan motor RPM Error
E455
Error of fan motor IPM high temperature
E458
CT over current
E457
Error of fan motor’s reverse revolution
E162
Outdoor Unit’s EEPROM Error
E560
Switch Option Set up Error
E428
Comp down by compression ratio control
E121
Short or Open of indoor unit’s air temperature sensor
E122
Indoor Unit EVA in Sensor’s Short or open
E123
Indoor Unit EVA out Sensor’s Short or open

4. Error Code (Priority Order)
Error Details
E154
Indoor Unit’s Fan Error
E124
Communication error message sent from the indoor unit
E153
Indoor Unit Floating S/W error (2nd check)
P701
Indoor Unit Floating S/W error (1st check)
E152
Indoor Unit EEV Closing error (2nd check)
P702
Indoor Unit EEV Closing error (1st check)
E151
Indoor Unit EEV opening error (2nd check)
P703
Indoor Unit EEV opening error (1st check)
E128
Indoor Unit EVA in Sensor Breakaway
E129
Indoor Unit EVA Out Sensor Breakaway
E131
Indoor Unit Heater Sensor Breakaway
E265
Sump temperature Sensor of Digital Comp. or Fixed Comp.1 Breakaway
E267
Fixed Comp.2 Sump’s Temperature Sensor Breakaway
E268
Fixed Comp.3 Sump’s Temperature Sensor Breakaway
E262
Fixed Comp.1 Discharge’s Temperature Sensor Breakaway
E263
Fixed Comp.2 Discharge’s Temperature Sensor Breakaway
E264
Fixed Comp.3 Discharge’s Temperature Sensor Breakaway
E456
Fan Motor Over Current Error
E461
CT Low Current CH
Stop Operating the unit when the crank case heater is on

5. Stop Operating Heating mode when Outdoor temperature is over 30℃
E440, E442 :
E440
Stop Operating Heating mode when Outdoor temperature is over 30℃
E442
Stop Operating Heating charging mode when Outdoor temperature is over 15℃
Decision Method
E440 : Just before outdoor unit operates in heating mode, Outdoor air temperature sensor reading over 30℃
E442 : Just before outdoor unit operates in heating charging mode by key mode(K1 S/W in the outdoor unit’s PCB ), Outdoor air temperature sensor reading over 15℃
Possible Cause
It is not error of product. (spec. to protect products)
It is desired that refer and use working conditions range of temperature.
If the value of outdoor air temperature sensor is different from the real, please replace the outdoor air temperature sensor with new one.

6. Stop Operation by Low Pressure
Decision Method
If the low pressure of the main unit is below 3.1kgf/㎠G for 3 seconds continuously In cooling mode before Pump down start, Stop operation
If the low pressure of the main unit is below 2.6kgf/㎠G for 3 seconds continuously In Heating mode before Pump down start, Stop operation
Possible Cause
Refrigerant Leakage
Low pressure sensor breakdown
Action
Measure the low pressure using manifold gage
Read the low pressure of the system using S-NET or View mode
Compare the value of case1 with case2.
If these value are similar, most of refrigerant is leaked. Please emit remainder refrigerant and do re-vacuum & re-charging
If these value are different greatly, please check the connector of the low pressure sensor or replace the low pressure sensor with new one
Attention :
After recovery of refrigerant (Pump down), because refrigerant fills only in outdoor heat exchanger, preceding descriptions error can arise .
In this case, If you open service valve after connecting pipe normally with indoor unit, error will be eliminated because refrigerant circulates to low-pressure side.

7. Self diagnosis failure of Oil balance valve 1
Decision Method
1. No check in case that one outdoor unit is installed
2. In module application, check the condition of Oil balance valve 1 or senor breakaway
3. When hot gas engaged after close the Oil balance valve 1, if the temperature of oil balance tube arise over 5℃, display error (Valve Is not closed)
4. During Oil balance operation with the Oil balance valve 1 open, if the temperature of oil balance tube doesn’t change over 7℃, display error (Valve Is not open)
Possible Cause
Temperature Sensor of Oil balance valve 1 breakaway
Malfunction of Oil balance valve 1
Solenoid coil of electric connection badness
Action
Check the temperature sensor is inserted correctly in sensor holder
Check the value of the temperature sensor is proper
Check the oil service valve is open
Check the solenoid Coil of the valve is properly installed
Check the resistance of the Coil (Was it not short-circuited?)
Replace the Oil Valve with new one
Attention :
Never use welding machine when cut off the oil valve, Do use Tube cutter.
( there is danger of production of fire because oil fills in pipe )

8. Comp down By high pressure
Decision Method
The Value of the high pressure sensor is over 41kgf/㎠
Possible Cause
<Cooling Mode>
Outdoor Unit’s fan motor breakdown or restriction, Fan motor Driver wire is bad or open
Outdoor Heat exchanger contamination, Service Valve is closed, Excessive refrigerant
<Heating Mode>
Indoor Unit’s fan motor breakdown or restriction
Indoor unit’s fan motor capacitor badness or connecting wire open
Service Valve is closed, Excessive refrigerant
Action
Check the service valve is open
Check the value of the high pressure sensor is proper using manifold gage
Check the EEV of both indoor unit and outdoor unit
Check the fan operation
Confirm refrigerant quantity

9. Comp down By low pressure
Decision Method
If the low pressure of the main unit is below 2.6kgf/㎠G In cooling mode, Stop operation
If the low pressure of the main unit is below 1.4kgf/㎠G In Heating mode, Stop operation
Possible Cause
Refrigerant shortage, EEV choked, Service valve Closed,
Compressor Unloading badness, Leakage of discharge check valve of stopped unit
Working conditions deviation ; Outdoor temperature is below -5℃ <Cooling Mode>
Outdoor temperature is below -20℃ <heating Mode>
Action
Check the service valve is open
Check the value of the low pressure sensor is proper using manifold gage
Check the EEV of both indoor unit and outdoor unit
Check the fan operation
Confirm refrigerant quantity

10. Comp down By Anti-freezing control
Decision Method
The temperature of the operating indoor unit’s heat exchanger keeps below -4℃
(more than 5 minutes)
Possible Cause
EEV does not work properly
Indoor unit fan motor restriction or badness
Air filter of the indoor unit is choked severely
Action
Removes obstacle and cleans dust filter. Error reset (K3)
Operate the only relevant indoor unit and check the fan operation
Check the PCB & motor
Check the Pressure
Confirm refrigerant quantity

11. Comp down By Sump Protection Control
Decision Method
The temperature of Sump keeps below 95℃
(more than 5 minutes)
Possible Cause
Compressor Loading badness
Sump temperature sensor badness
Action
Connect the S-Net
Check the operation of PWM Valve (normal loading/unloading)
Check the attachment status of sump temperature sensor
Take the sump sensor apart from the compressor and leave it alone in ambient air for about 10 minutes, and check the value of the sump sensor is similar with the ambient air temperature.
Replace sump sensor

12. Comp down by compressor discharge temperature
Decision Method
The value of discharge temperature sensor is over 135℃
Possible Cause
Refrigerant Shortage, EEV Choking, Service valve is closed, Sensor badness,
Liquid EEV badness, Liquid Tube Valve badness,
Leakage of discharge check valve of stopped unit
Action
Check the resistance of the discharge temperature sensor (refer E251)
Check the Service Valve is open
Check the EEV Operation
In case of partial outdoor units are operated, Check leakage from liquid tube valve or discharge check valve of no-operating outdoor units
Confirm refrigerant quantity

13. Cond. out temperature Sensor breakaway
Decision Method
No Check in cooling mode
In Heating mode, it must satisfy below conditions simultaneously (more than 20min.)
1. average high pressure : 25kgf/㎠G
2. average low pressure : 8.5kgf/㎠G
3. Teva,out – Tair,in ≥ 3℃
4. Teva,in – Tair,in ≥ 2℃
5. Tcond,out – Tair,out ≤ -2℃
6. All Compressor Operation & All indoor Unit operation (thermo on)
Possible Cause
Cond. Out sensor breakaway or badness
Outdoor heat exchanger path pipe is choked
Action
Check the temperature sensor is inserted correctly in sensor holder
Check the resistance of the discharge temperature sensor (refer E231)
Is change  in sensor value at heating operation after stop?
Replace Heat exchanger assembly with new one.

14. Suction temperature Sensor breakaway
Decision Method
Tsuc,ini ; Suction temperature of the compressor on the verge of operation
Tsuc,real ; Suction temperature of the compressor operating now
| Tsuc,real - Tsuc,ini | ＜ 2℃ (more than 30 min.)
Possible Cause
Suction temperature sensor breakaway or badness
Action
Check the temperature sensor is inserted correctly in sensor holder
Check the resistance of the discharge temperature sensor (refer E231)

15. E458:
E458
CT over current
Decision Method
The CT value of the relevant compressor is over 20A ( more than 5 sec.)
Possible Cause
CT sensor badness
Compressor Breakdown
Action
Check the resistance of the CT sensor connector
Check the value of CT sensor is zero at stop
Compare the value of CT sensor with another measurement device
Replace the relevant compressor

16. Comp down by compression ratio control
Decision Method
(High pressure + 1) / (Low Pressure + 1) ≥ 8.5 (more than 10 min.)
Possible Cause
Pressure sensor badness
EEV malfunction
Pipe is clogged
Action
Check the service valve is open
Check the value of the pressure sensor (S-Net or View mode) is proper using manifold gage
Check the operation of EEV (Outdoor units / indoor units)
Check pipe status
In case of partial outdoor units are operated, Check leakage from liquid tube valve or discharge check valve of no-operating outdoor units
Confirm refrigerant quantity

17. ※ After Service, Indoor unit should be reset by power supply
E153 ↔ A***
Indoor Unit Floating S/W error (2nd check)
P701
Indoor Unit Floating S/W error (1st check)
Decision Method
Possible Cause
Drain pump Breakdown
Floating S/W malfunction
Action
After separating Floating S/W connector, check the resistance of both ends of the Floating S/W is infinity. (OPEN when there is no water)
Check the supplied voltage to the Drain pump is proper Replace PCB of Indoor Unit.
Check the operation of Drain pump Replace Drain pump of Indoor Unit.
※ After Service, Indoor unit should be reset by power supply

18. E152: Indoor Unit EEV Closing error (2nd check)
E152 ↔ A***
Indoor Unit EEV Closing error (2nd check)
P702
Indoor Unit EEV Closing error (1st check)
Decision Method
In Cooling mode, it must satisfy below conditions simultaneously (more than 20min.)
1. Tcond,out – Tair,out ＞ 3℃
2. Tair,in – Teva,in ＞ 4℃
3. Tair,in – Teva,out ＞ 4℃
4. Compressor is operating normally & relevant indoor Unit is ON (thermo on)
In Heating mode, it must satisfy below conditions simultaneously (more than 3min.)
1. average high pressure : over 18kgf/㎠G
2. after 5 minutes from safety start ends
3. more than 2 indoor unit are operating in heating mode (thermo on)
4. Tair,in – Teva,in ＞ -3℃ & Tair,in – Teva,out ＞ -3℃
Possible Cause
Indoor unit’s EEV does not open
Action
Check the EEV connector is inserted correctly in the indoor PCB
Check the EEV Coil is inserted correctly in the EEV body
Check the resistance of the coil
Replace EEV assembly with new one.

19. E151: E151 ↔ A*** Indoor Unit EEV opening error (2nd check) P703
Indoor Unit EEV opening error (1st check)
Decision Method
No check In Heating mode
In Cooling mode, it must satisfy below condition (more than 20min.)
- Either Teva,in or Teva,out of stopped indoor unit is below to zero
Possible Cause
Indoor unit’s EEV does not close
Action
Check the EEV connector is inserted correctly in the indoor PCB
Check the EEV Coil is inserted correctly in the EEV body
Check the resistance of the coil
Replace EEV assembly with new one.

20. Indoor Unit EVA in Sensor Breakaway
Decision Method
In Cooling mode, it must satisfy below conditions simultaneously
1. Tcond,out – Tair,out ＞ 3℃
2. Tair,in – Teva,in ≤ 4℃ *
3. Tair,in – Teva,out ＞ 4℃
4. Compressor is operating normally & relevant indoor Unit is ON (thermo on)
In Heating mode, it must satisfy below conditions simultaneously
1. average high pressure : over 25kgf/㎠G
2. average low pressure : below 8.2kgf/㎠G
3. Tcond,out – Tair,out ＜ -2℃
4. Teva,in - Tair,in ＜ 2℃ *
5. Teva,out - Tair,in ≥ 3℃
6. Compressor is operating normally & relevant indoor Unit is ON (thermo on)
Possible Cause
Indoor unit’s Eva in sensor breakaway
Action
Check the Eva in sensor is inserted correctly in the sensor holder

21. Indoor Unit EVA out Sensor Breakaway
Decision Method
In Cooling mode, it must satisfy below conditions simultaneously
1. Tcond,out – Tair,out ＞ 3℃
2. Tair,in – Teva,out ≤ 4℃ *
3. Tair,in – Teva,in ＞ 4℃
4. Compressor is operating normally & relevant indoor Unit is ON (thermo on)
In Heating mode, it must satisfy below conditions simultaneously
1. average high pressure : over 25kgf/㎠G
2. average low pressure : below 8.2kgf/㎠G
3. Tcond,out – Tair,out ＜ -2℃
4. Teva,out - Tair,in ＜ 3℃ *
5. Teva,in - Tair,in ≥ 2℃
6. Compressor is operating normally & relevant indoor Unit is ON (thermo on)
Possible Cause
Indoor unit’s Eva out sensor breakaway
Action
Check the Eva out sensor is inserted correctly in the sensor holder

22. Sump temperature Sensor of Digital Comp. or Fixed Comp.1 Breakaway
Decision Method
Tsump,ini ; Sump temperature of the compressor on the verge of operation
Tsump,real ; Sump temperature of the compressor operating now
| Tsump,real - Tsump,ini | ＜ 2℃ (more than 60 min.)
No Check after 60 min. from starting operation
Possible Cause
Sump temperature sensor breakaway
Action
Check the attachment status of sump temperature sensor
Note : Only Digital compressor or Fixed 1 compressor has the sump sensor

23. E262,E263,E264: Fixed Comp.1 Discharge’s Temperature Sensor Breakaway
E262 ↔ U***
Fixed Comp.1 Discharge’s Temperature Sensor Breakaway
E263↔ U***
Fixed Comp.2 Discharge’s Temperature Sensor Breakaway
E264↔ U***
Fixed Comp.3 Discharge’s Temperature Sensor Breakaway
Decision Method
It must satisfy below condition (more than 30min.)
1. The CT sensor value of the relevant compressor is over 5A
2. Discharge temperature ＜ Saturation temperature calculated with high pressure
Possible Cause
Compressor Discharge Temperature sensor breakaway
Compressor Discharge Temperature sensor badness
Action
1. Check the temperature sensor is inserted correctly in sensor holder Insert the sensor in the sensor holder
2. Check the resistance of the discharge temperature sensor (refer E251) Replace the sensor
3. Check the sensor position corresponds to compressor correctly Change the sensor position correctly

24. E461:
E461
CT low current
Decision Method
The CT value of the relevant compressor is below 4A ( more than 10min.)
Possible Cause
CT sensor badness
Compressor Breakdown
OLP Trip
Action
Check the resistance of the CT sensor connector
Check the value of CT sensor is zero at stop
Compare the value of CT sensor with another measurement device
Check whether OLP trip is occurred
Replace the relevant compressor

25. 1. System operation is prohibited.
Vacuum Mode : Tact S/W K1
7-Segment display
K1 8 times
Vacuum mode (Main)
“K” “5” “M“ “BLANK“
K times
Vacuum mode (Sub1)
K” “5” “S“ “1“
K times
Vacuum mode (Sub2)
K” “5” “S“ “2“
K times
Vacuum mode (Sub3)
K” “5” “S“ “3“
K times
Vacuum mode (All)
“K” “5” “A” “BLANK”
Action
Outdoor Units with vacuum mode set
Outdoor EEV
Liq. EEV
Valves
4way Valve
Fully open
Open
Cooling mode
Outdoor Units with normal mode set
Outdoor EEV
Liq. EEV
Valves
4way Valve
Fully Closed
Closed
Cooling mode
In vacuum mode,
1. System operation is prohibited.
2. System does not execute both self diagnosis and protection control.

26. Pump down Mode : Tact S/W K2
7-Segment display
K2 3 times
Pump down (All Unit)
“K” “7” “BLANK“ “BLANK“
Pump down (Main)
“K” “7” “M“ “BLANK“
Pump down (Sub1)
“K” “7” “S“ “1“
Pump down (Sub2)
“K” “7” “S“ “2“
Pump down (Sub3)
“K” “7” “S“ “3“
How to pump down all units
Close the liquid service valve of all units
Press Tact S/W K2 3 times
System start the pump down operation
Outdoor unit that pump down is ended stops operation
Close the gas service valve in order that operation stops
※ Pump down operation under long pipe installation is NOT desirable.
Please Use adequate refrigerant recovery device.

27. Pump out Mode : Tact S/W K1
7-Segment display
K times
Pump out Main
“K” “3” “M“ “BLANK“
K times
Pump out Sub1
K” “3” “S“ “1“
K times
Pump out Sub2
K” “3” “S“ “2“
K times
Pump out Sub3
K” “3” “S“ “3“
How to pump out Sub1 unit (example)
Close the liquid service valve of Sub1 unit
Press Tact S/W K1 4 times
Sub1 Unit start the pump out operation
Check low pressure in view mode(K4 S/W) ; Do not operate system under 1.6kgf/㎠G (L.P.)
Close the gas service valve
Press K3 to reset the system

28. Disbranch breakdown compressor : DIP S/W K6, K7, K8
※ Should be set in individual unit
S/W K6 K7 K8 On
Digital comp1_main
Fixed comp1_sub1
Fixed comp1_sub2
Normal
Fixed comp2_main
Fixed comp2_sub1
Fixed comp2_sub2
Fixed comp3_main
Fixed comp3_sub1
Fixed comp3_sub2
Off
Disbranch
How to Disbranch Compressor Sub1 unit (example)
Set DIP S/W K6 ON, K7 OFF of Sub1 Unit
Press K3 to reset the system
Sub1
Fixed comp.2 is broken
※ It is temporary expedient and service is needed for long term operation

29. Monitoring Program : S-NET I+