Fujitsu ASU18RMLQ, ASU9RMLQ, ASU12RMLQ, ARU18RML, AUU9RML Service Instruction

SPLIT TYPE
ROOM AIR CONDITIONER

WALL MOUNTED / DUCT /
CASSETTE

INVERTER MULTI

SERVICE

INSTRUCTION

Models Indoor unit Outdoor unit

ASU9RMLQ
ASU12RMLQ
ASU18RMLQ

ARU9RML
ARU12RML
ARU18RML

type

AOU24RML
AOU36RML

AOU24RML1
AOU36RML1

R410A

AUU9RML
AUU12RML
AUU18RML

CONTENTS

1. DESCRIPTION OF EACH CONTROL OPERATION

1. CAPACITY CONTROL................................................................................................

2. AUTO CHANGEOVER OPERATION..........................................................................

2-1-1 INDOOR UNIT DISPLAY...................................................................................

2-1-2 INDOOR UNIT DISPLAY...................................................................................

3. INDOOR FAN CONTROL...........................................................................................

4. OUTDOOR FAN CONTROL.......................................................................................

5. LOUVER CONTROL...................................................................................................

5-1 Wall Mounted (AS) type........................................................................................

5-2 Caseette (AU) type...............................................................................................

6. COMPRESSOR CONTROL........................................................................................

7. TIMER OPERATION CONTROL................................................................................

7-1 Wireless Remote Controller..................................................................................

7-1 Wired Remote Controller......................................................................................

8. ELECTRONIC EXPANSION VALVE CONTROL........................................................

9. TEST OPERATION CONTROL..................................................................................

10. PREVENT TO RESTART FOR 3 MINUTES ( 3 MINUTES ST ).................................

11. FOUR-WAY VALVE EXTENSION SELECT...............................................................

12. AUTO RESTART.........................................................................................................

13. MANUAL AUTO OPERATION ( Indoor unit body operation ).....................................

14. FORCED COOLING OPERATION..............................................................................

15. COMPRESSOR PREHEATING..................................................................................

16. FRESH AIR CONTROL (For AR type)........................................................................

EXTERNAL ELECTRICAL CONTROL (For AR type).................................................

17.

18. DRAIN PUMP OPERATION (For AU, *AR type).........................................................

19. COIL DRY AND CLEAN OPEARTION CONTROL (For AS type)...............................

20. AIR CLEAN OPERATION........................................................................................... 01-18

21. ENERGY SAVE FUNCTION (For AR type)................................................................ 01-19

22. DEFROST OPERATION CONTROL.......................................................................... 01-19

22. VARIOUS PROTECTIONS......................................................................................... 01-21

01-01
01-01

01-01
01-02
01-03
01-07
01-08
01-08

01-09
01-10
01-11

01-11

01-13

01-15
01-15
01-15
01-15
01-15
01-16
01-16
01-16
01-17

01-17
01-17

01-18

2. TROUBLE SHOOTING

2-1 ERROR DISPLAY......................................................................................................

2-1-1 INDOOR UNIT DISPLAY....................................................................................

2-1-2 OUTDOOR UNIT DISPLAY................................................................................

2-1-3 WIRED REMOTE CONTROLLER DISPLAY......................................................

2-2 TROUBLE SHOOTING WITH ERROR CODE..........................................................

2-3 TROUBLE SHOOTING WITH NO ERROR CODE....................................................

2-4 SERVICE PARTS INFORMATION............................................................................

3. REPLACEMENT PARTS

1. EXPLODED VIEW......................................................................................................

2. INVERTER ASSEMBLY SPECIFICATION.................................................................

02-01
02-01
02-03
02-04
02-08
02-40

02-45

03-01
03-16

R410A

WALL MOUNTED / DUCT /
CASSETTE type

INVERTER (MULTI )

1 . DESCRIPTION OF EACH
CONTROL OPERATION

1. CAPACITY CONTROL

1-1 COOLING, HEATING, DRY CAPACITY CONTROL

Compressor frequency decides by capacity of an indoor unit, operation number of an indoor unit,
set temperature, room temperature and outside temperature.

2. AUTO CHANGEOVER OPERATION

2-1 For AS, AU type

When the air conditioner is set to the AUTO mode by remote control, operation starts in the optimum
mode from among the HEATING, COOLING, DRY and MONITORING modes. During operation, the
optimum mode is automatically switched in accordance with temperature changes. The temperature
can be set between 64°F(18°C) and 88°F(30°C) in 2°F(1°C) steps.

.When operation starts, only the indoor and outdoor fans are operated for 1 minute. After 1 minute,

1

the room temperature and outside air temperature are sensed and the operation mode is
selected in accordance with the table below.

( Fig.1 : Outside air temperature zone selection )

C zone

90°F(32°C)

B zone

32°F(0°C)

A zone

( Table.1 Operation mode selection table)

Outside air temperature (TO)

Room temperature (TB)

TB > TS+4°F(2°C)

TS+4°F(2°C) TB TS - 4°F(2°C)

<

TB TS- 4°F(2°C) Heating Heating Monitoring

2

.When COOING was selected at , the air conditioner operates as follow:

The same operation as COOLING OPERATION of item 1 above is performed.

When the room temperature has remained at (set temperature -2°F(1°C)) for 8 minutes, operation is

automatically switched to DRY and the same operation as DRY OPERATION of item 3 above
is performed.

If the room temperature reaches (set temperature +4°F(2°C) during DRY operation, operation returns to
COOLING operation.

1

A zone B zone C zone

Monitoring

Monitoring Monitoring Monitoring

Cooling

(automatic dry)

Cooling

(automatic dry)

3

.When HEATING was selected at , the same operation as HEATING OPERATION of item 2
above is performed.

4

When the compressor was stopped for 6 consecutive minutes by the temperature control function
after the COOLING or HEATING operation mode was selected at above, operation is switched
to MONITORING and the operation mode is selected again.

1

1

01-01

2-2 For AR type

When the air conditioner is set to the AUTO mode by remote control, operation starts in the optimum
mode from among the HEATING, COOLING and MONITORING modes. During operation, the
optimum mode is automatically swiched in accordance with temperature changes. The temperature
can be set between 18°C and 30°C in 1 degC steps.

When operation starts, only the indoor fan is operated for 1 minute. (Air flow mode: S- Lo)

1

After 1 minute, depends on the room temperature and outdoor unit's operarion mode,
the operation mode is selected in accordance with the table below.

( Table 1 : Operation mode selection table )

Room temperature :TR

TR > Ts +2 degC

=

Ts +2 degC > TR > Ts-2 degC

Ts +2 degC > TR

Ts : Setting temperature
TR: Room temperature

2

When COOLING was selected at , the same operation as COOLING OPERATION is performed.

3

When HEATING was selected at , the same operation as HEATING OPERATION is performed.

4

When the compressor was stopped for 6 consecutive minutes by the temperature control function
after the COOLING or HEATING operation mode was selected at above, operation is switched
to MONITORING and the operation mode is selected again.

=

Operation mode

Cooling

Monitoring

Heating

1

1

1

01-02

3. INDOOR FAN CONTROL

(1).Fan speed

( Table 2 : Indoor Fan Speed )

ASU9RMLQ

Operation mode Air flow mode Speed (rpm)

Heating

Cooling

Dry 8 00

ASU18RMLQ

Operation mode Air flow mode Speed (rpm)

Heating

Cooling

Dry 1,060

Hi 1,200

Me+ 1,200

Me 1,070

Lo 970

Quiet 850

Cool air

prevention

S-Lo 480

Hi 1,200

Me 1,070

Lo 900

Quiet 800

Hi 1,480

Me+ 1,480

Me 1,380

Lo 1,200

Quiet 1,060

Cool air

prevention

S-Lo 480

Hi 1,480

Me 1,380

Lo 1,200

Quiet 1,060

800

850

Operation mode Air flow mode Speed (rpm)

Heating

Cooling

Dry 9 00

ASU12RMLQ

prevention

Hi 1,380

Me+ 1,380

Me 1,230

Lo 1,110

Quiet 960

Cool air

S-Lo 480

Hi 1,380

Me 1,230

Lo 1,050

Quiet 900

850

ARU9RML

Operation mode Air flow mode Speed (rpm)

Heating

Cooling

Quiet

Cool air

prevention

Dry

ARU18RML

Operation mode Air flow mode Speed (rpm)

Heating

Cooling

Quiet

Cool air

prevention

Dry

Hi

Me

Lo

S-Lo

Hi

Me

Lo

S-Lo

1,070
880
800
800

450

450
800

1,010
850
800
800

350

350
800

ARU12RML

Operation mode Air flow mode Speed (rpm)

Heating
Cooling

Quiet

Cool air

prevention

Dry

Hi

Me

Lo

S-Lo

01-03

850
790
700
700

310

310
700

AUU9RML

AUU12RML

Operation mode Air flow mode

Cooling
Fan

Heating

Dry
Monitoring

Hi 590

Me

Lo

Quiet

Hi
Me+
Me

Lo

Quiet
Auto
S- Lo

AUU18RML

Operation mode Air flow mode

Cooling
Fan

Heating

Dry
Monitoring

Hi 790
Me

Lo

Quiet

Hi
Me+
Me

Lo

Quiet
Auto
S- Lo

Speed (rpm)

540
490
440
590
570
540
490
440
460
300

Speed (rpm)

660
570
460
840
800
750
650
500
460
300

Operation mode Air flow mode

Cooling
Fan

Heating

Dry
Monitoring

Hi 660

Me

Lo

Quiet

Hi
Me+
Me

Lo

Quiet
Auto
S- Lo

Speed (rpm)

580
520
460
650
620
580
520
460
460
300

(2).FAN OPERATION

The airflow can be switched in 5 steps such as AUTO, QUIET, LOW, MED, HIGH, while the indoor
fan only runs.
When Fan mode is set at (Auto), it operates on (MED) Fan Speed. < for AS, AU type >
it operates intermittent on (LO) Fan speed and (OFF)
by one minute. <for AR type>

(3). COOLING OPERATION

Switch the airflow [AUTO], and the indoor fan motor will run according to a room temperature,
as shown in Figure 2.
On the other hand, if switched in [HIGH] [QUIET], the indoor motor will run at a constant airflow of [COOL]
operation modes QUIET, LOW, MED, HIGH,as shown in Table 2.

(Fig.2)

airflow change - over ( Cooling: AUTO )

Hi mode

+4°F(+2°C)

Me mode

+2°F(+1°C)

Lo mode

*1

When the room
temperature rises

+6°F(+3.0°C)
+5°F(+2.5°C))

*(

+3°F(+1.5°C)

(+3°F ) (+1.5°C)

*

*For AS / AU / Type

When the room
temperature lowers

(Room temperature) D (Setting temperature)

*1 : Contains a condition to the following

When the operation mode is set to AUTO mode
at the start of operation.
When the setting temperature was changed.
When the operation mode was changed to COOLING mode.
When the airflow mode was changed to AUTO mode.

01-04

(4). DRY OPERATION

During the dry mode operation, the fan speed setting can not be changed.
The indication of the remote controller is fixed in [AUTO].
The fan operates on [S-Lo] mode or OFF.

(5). HEATING OPERATION

5-1. For AU / AS Type

Switch the airflow [AUTO], and the
indoor fan motor will run according
to a room temperature, as shown in
Figure 3.
On the other hand, if switched

[HIGH]

[QUIET], the indoor motor
will run at a constant airflow of [HEAT]
operation modes QUIET, LOW, MED,
HIGH, as shown in Table 2.

5-2. For AR Type

When the airflow is set to [AUTO], the indoor fan
motor operates [MED] mode.
Then the indoor fan motor will run according
to a room temperature, as shown in Figure 4.

On the other hand, if switched in [HIGH] [QUIET],
the indoor motor will run at a constant airflow
of [HEAT] operation modes QUIET, LOW, MED, HIGH,
as shown in Table 2.

-2°F(-1°C)

-4°F(-2°C)

(Fig.3)

airflow change - over ( Heating: AUTO)

When the room

temperature rises

LOW mode

-3°F(-1.5°C)

MED mode

-5°F(-2.5°C)

MED + mode

(Room temperature) - (Setting temperature)

When the room

temperature lowers

( Fig.4 : Airflow change - over ( Heating : AUTO ) )

Indoor heat exchanger
temperature

Go up one-step

117°F(47°C)

Hold

105.8°F(41°C)

Go down one-step

(6). COOL AIR PREVENTION CONTROL (Heating mode)

6-1. For AS Type

The maximum value of the indoor fan speed is set as shown in Figure 5, based on the detected
temperature by the indoor heat exchanger sensor on heating mode.

(Fig.5 : Cool Air Prevention Control)

Indoor heat exchanger Indoor heat exchanger
temperature temperature

117°F(47°C)

104°F(40°C)

99°F(37°C)

(30°C)

86°F

Hi

Me+

Lo

Cool air prevention

S-Lo

01-05

104°F(40°C)

93°F(34°C)

90°F(32°C)

82°F(28°C)

6-2. For AR Type

The maximum value of the indoor fan speed is set as shown in Figure 6, based on the detected
temperature by the indoor heat exchanger sensor on heating mode.

( Fig.6 : Cool Air Prevention Control )

Indoor heat exchanger
temperature

Indoor heat exchanger
temperature

Setting

91.4°F(33°C)

Fan mode

Lo mode

86°F(30°C)

86°F(30°C)

S-Lo mode

6-3. For AU Type

When the compressor operates, the maximum value of the indoor fan speed is set as shown in Figure 7,
based on the detected temperature by the indoor heat exchanger sensor on heating mode.
When the compressor does not operate, the indoor fan motor operates [S-Lo] mode.

( Fig.7 : Cool Air Prevention Control )

< [Hi] setting >

Indoor heat exchanger
temperature

107.6°F(42°C)

102.2°F(39°C)

99°F(37°C)

86°F(30°C)

Hi

Me+

Lo

Cool air
prevention

S-Lo

Indoor heat exchanger
temperature

99°F(37°C)

93°F(34°C)

90°F(32°C)

75.2°F(24°C)

Indoor heat exchanger
temperature

102.2°F(39°C)

99°F(37°C)

86°F(30°C)

< The other of [Hi] setting >

Setting
FAN mode

Lo (Qu)

Cool air
prevention

S-Lo

Indoor heat exchanger
temperature

01-06

93°F(34°C)

90°F(32°C)

75.2°F(24°C)

4. OUTDOOR FAN CONTROL

(1). Fan Speed

The speed of outdoor unit fan motor is determined at outside temperature and compressor rotation.

( Table 2 : Target fan speed )

AOU24/36RML

Frequency rise

Frequency down

Outdoor temperature

Cooling

Heating

AOU24/36RML

Frequency rise

Frequency down

Outdoor temperature

Cooling

Heating

Compressor rotation [Hz]

<

10 F<20 20 F<30 30 F<40 40 F<50 50 F<60

=

<

7 F<17 17 F<27 27 F<37 37 F<47 47 F<57

=

<
=

<
=

<
=

<
=

<
=

<
=

<
=

<
=

Fan rotation

>

Tout 45 HI HI HI HI HI

=

>

45>Tout 38 HI HI HI HI HI

=
>

38>Tout 31 HI HI S-HI S-HI S-HI

=
>

31>Tout 26 MED HI HI HI HI

=
>

26>Tout 22 LOW MED MED HI HI

=
>

22>Tout 18 LOW MED MED MED MED

=
>

18>Tout 12 S-LOW S-LOW LOW MED MED

=

>

12>Tout 7 S-LOW S-LOW S-LOW LOW LOW

=

>

7>Tout 3 S-LOW S-LOW S-LOW LOW LOW

=

>

3>Tout -3 S-LOW S-LOW S-LOW S-LOW LOW

=

-3>Tout S-LOW S-LOW S-LOW S-LOW S-LOW

>

Tout 24 S-LOW S-LOW LOW LOW MED

=

>

24>Tout 20 S-LOW S-LOW LOW LOW MED

=
>

20>Tout 16 LOW MED MED HI HI

=
>

16>Tout 12 MED HI HI HI HI

=

>

12>Tout 5 HI HI HI H-HI H-HI

=

>

5>Tout -1 H-HI H-HI H-HI H-HI H-HI

=

>

-1>Tout -6 H-HI H-HI H-HI H-HI H-HI

=

>

-6>Tout -11 H-HI H-HI H-HI H-HI H-HI

=

-11>Tout H-HI H-HI H-HI H-HI H-HI
Compressor rotation [Hz]

<

60 F<70 70 F<80 80 F<90 90 F

=
<

57 F<67 67 F<77 77 F<87 87 F

=

<
=

<
=

<
=

<
=

<
=

<
=

Fan rotation

>

Tout 45 HI HI HI HI

=

>

45>Tout 38 HI HI HI HI

=
>

38>Tout 31 S-HI S-HI S-HI S-HI

=
>

31>Tout 26 HI HI S-HI S-HI

=
>

26>Tout 22 HI HI HI HI

=
>

22>Tout 18 HI HI HI HI

=
>

18>Tout 12 MED HI HI HI

=

>

12>Tout 7 MED MED MED HI

=

>

7>Tout 3 LOW MED MED MED

=

>

3>Tout -3 LOW LOW LOW MED

=

-3>Tout LOW LOW LOW LOW

>

Tout 24 MED MED MED HI

=

>

24>Tout 20 MED MED MED HI

=
>

20>Tout 16 HI HI HI HI

=
>

16>Tout 12 HI HI HI HI

=

>

12>Tout 5 H-HI H-HI H-HI H-HI

=

>

5>Tout -1 H-HI H-HI H-HI H-HI

=

>

-1>Tout -6 H-HI H-HI H-HI H-HI

=

>

-6>Tout -11 H-HI H-HI H-HI H-HI

=

-11>Tout H-HI H-HI H-HI H-HI

( Table 4 : Outdoor fan speed )

Speed

Mode Cooling Heating Cooling Heating Cooling Heating Cooling Heating Cooling Heating Cooling Heating

AOU24RML

AOU36RML

Upper Fan 780 780 780 780 780 780 400 400 300 300 200 200
Lower Fan 780 780 780 780 780 780 400 400 300 300 200 200
Upper Fan 850 900 850 900 780 780 400 400 300 300 200 200
Lower Fan 850 900 850 900 780 780 400 400 300 300 200 200

H-HI S-HI HI MED

LOW S-LOW

(rpm)

01-07

5. LOUVER CONTROL

5-1 Wall Mounted ( AS ) type

(1). VERTICAL LOUVER CONTROL

(Function Range)

Each time the button is pressed, the air direction range will change as follow:

(Fig 5: Air Direction Range)

(Operation Range)

Cooling / Dry mode
Heating mode
Fan mode

Use the air direction adjustments within the ranges shown above.

The vertical airflow direction is set automatically as shown, in accordance with the type of operation
selected.

When the temperature of the air being blown out is low at the start of heating operation or during
defrosting, the airflow direction temporarily becomes

During use of the Cooling and Dry modes, do not set the Air Flow Direction Louver in the Heating

range (
drop of water may drip from the air conditioner. During the Cooling and Dry modes, if the Air Flow
Direction Louvers are left in the hating range for more than 30 minutes, they will automatically
return to position

During Monitor operation in AUTO CHANGEOVER mode, the airflow direction automatically
becomes

Cooling / Dry mode
Heating mode

) for long period of time, since water vapor many condense near the outlet louvers and

.

, and it cannot be adjusted.

Horizontal flow
Downward flow

to prevent cold air being blown onto the body.

(2). SWING OPERATION

When the swing signal is received from the remote controller, the vertical louver starts to
swing.

(Swinging Range)

Cooling mode / Dry mode / Fan mode(
Heating mode / Fan mode(

When the indoor fan is either at S-lo or Stop mode, the swinging operation is interrupted
and the louver stops at the memorized position.

)

)

01-08

5-2 Cassette (AU) type

1. VERTICAL LOUVER CONTROL

(Function Range)

Each time the button is pressed, the air direction range will change as follows:

(Air Direction Range)

(Operation Range)

During Cooling/Dry mode/Fan mode :
During Heating mode :

Use the air direction adjustments within the ranges shown above.

3

4

The vertical airflow direction is set automatically as shown, in accordance with the type of operation
selected.

Cooling / Dry / Fan mode

Horizontal flow

Heating mode Downward flow

During AUTO mode operation, for the first minute after beginning operation, air-flow will be horizontal
; the air direction cannot be adjusted during this period.

1-2. SWING OPERATION

When the swing signal is received from the remote controller, the vertical louver starts to swing.
The range of swing depends on the set airflow direction.

(Swinging Range)

The type of operation

Cooling/Dry/Fan

Heating

Range of swing

to

to

1

2

When the indoor fan is either at S-Lo or Stop mode, the swinging operation is interrupted
and the louver stops at the memorized position.
( Stop mode means Operation stop.)

01- 09

6. COMPRESSOR CONTROL

(1). OPERATION FREQUENCY RANGE

The operation frequency of the compressor is different based on the operation mode as
shown in the table 4.

(Table 4 : Compressor Operation Frequency Range)

Cooling Heating

Min Max Min Max

AOU24RML 15Hz 90Hz 20Hz 95Hz
AOU36RML 15Hz 90Hz 20Hz 95Hz

(2). OPERATION FREQUENCY CONTROL AT START UP

The compressor frequency soon after the start-up is controlled as shown in the figure 6.

(Fig.6 : Compressor Control at Start-up)

56rps

40rps

46

134 120 (Sec)60~720

1) Compressor operates for 180 seconds by 40 rotations.

2) In the case of lower than 40 rotations, it operates at these rotations.

3) Compressor operates for 60 to 720 seconds.
When discharge temperature exceeds 30 degrees in the meantime, it shifts to 56 rotations.

4) Compressor operates at target rotations after 120 second operation.

01-10

7. TIMER OPERATION CONTROL

7-1 Wireless Remote Controller

For AS type

ON / OFF TIMER
PROGRAM TIMER

SLEEP TIMER

(1). OPERATION FREQUENCY RANGE

OFF timer : When the clock reaches the set time, the air conditioner will be turned off.

Operation mode

Stop mode

Set time of timer

ON timer : When the clock reaches the set time, the air conditioner will be turned on.

Operation mode

Stop mode

Set time of timer

(2). PROGRAM TIMER

The program timer allows the OFF timer and ON timer to be used in combination one time.

Operation mode

Stop mode

Set time

Operation mode

Stop mode

Set time Set time Set time

Operation mode

Stop mode

Operation will start from the timer setting (either OFF timer or ON timer) whichever is closest

to the clock's current timer setting. The order of operations is indicated by the arrow in the remote
control unit's display.
SLEEP timer operation cannot be combined with ON timer operation.

01-11

(3). SLEEP TIMER

If the sleep is set, the room temperature is monitored and the operation is stopped automatically.
If the operation mode or the set temperature is change after the sleep timer is set, the operation is
continued according to the changed setting of the sleep timer from that time ON.

In the cooling operation mode

When the sleep timer is set, the setting temperature is increased 2°F(1°C).
It increases the setting temperature another 2°F(1°C) after 1 hour.
After that, the setting temperature is not changed and the operation is stopped at the time
of timer setting.

Set temperature rises

( Ts : Set temperature )

+4°F(+2°C)
+2°F(+1°C)

Ts

Stop of operation

Set

60min

In the heating operation mode

When the sleep timer is set, the setting temperature is decreased 2°F(1°C).
It decreases the setting temperature another 2°F(1°C) every 30 minutes.
Upon lowering 8°F(4°C), the setting temperature is not changed and the operation stops at
the time of timer setting.

Set temperature lowers
( Ts : Set temperature )

Ts

-2°F(-1°C)

-4°F(-2°C)

-6°F(-3°C)

-8°F(-4°C)

Stop of operation

Set

30min

01-12

30min

30min

7-2 Wired Remote Controller

For AR / AU type

ON / OFF TIMER
WEEKLY TIMER
TEMPERATURE SET BACK TIMER

1. ON / OFF TIMER

OFF timer : When the clock reaches the set time, the air conditioner will be turned off.

Operation mode

Set time of timer

ON timer : When the clock reaches the set time, the air conditioner will be turned on.

Stop mode

Stop mode

Operation mode

Set time of timer

2. WEEKLY TIMER

2-1. WEEKLY TIMER

Use this timer function to set operating time for each day of the week.
The weekly timer allows up to two ON and OFF time to set up per day.

Operation mode

Stop mode

Set time

The operating time can be set in 30 min increments only.
The OFF time can be carried over to next day.
The ON timer and the OFF timer functions cannot be set with using the weekly timer.

Both ON and OFF time must be set.

Operation mode

Stop mode

Set time Set time Set time

Operation mode

Stop mode

01-13

2-2. DAY OFF setting

The DAY OFF setting is only available for days for which weekly settings already exist.
If the operating time carries over to the next day (during a next day setting), the effective

DAY OFF range will be set as shown below.

Normal

DAY OFF

Operation mode

Operation mode

Stop mode

Stop mode

Preceding day Next day

Setting day

Stop mode

Next day setting

DAY OFF

Stop mode

Operation mode

Stop mode

Preceding day Next daySetting day

Operation mode

Stop mode

The DAY OFF setting can only be set one time. The DAY OFF setting is cancelled automatically
after the set day has passed.

3. TEMPERATURE SET BACK TIMER

The SET BACK timer only changes the set temperature for 7 days, it cannot be used to start or stop
air conditioner operation.

The SET BACK timer can be set to operate up to two times per day but only one temperature setting
can be used.

During the COOL/DRY mode, the air conditioner will operate at a minimum of 18°C even if
the SET BACK temperature is set to 17

°C or lower.

Case of SET BACK timer on the Cooling operation.
( Setting temperature :22°C, SET BACK temperature :26°C)

SET BACK setting

Operation
temperature

*1

Operation
temperature

*1: During the SET BACK function,
the setting temperature is changed.

ON OFF OFFON

26°C

22°C

26°C

24°C

22°C

Chenge the setting temperature:
22°C 24°C

01-14

8. ELECTRONIC EXPANSION VALVE CONTROL

The most proper opening of the electronic expansion valve is calculated and controlled under the
present operating condition based on the following values.
The compressor frequency, the temperatures detected by the discharge temperature sensor
and the outdoor temperature sensor.

The pulse range of the electronic expansion valve control is between 30 to 480 pulses.

At the time of supplying the power to the outdoor unit, the initialization of the electronic
expansion valve is operated (1000 pulses are input to the closing direction).

9. TEST OPERATION CONTROL

Under the condition where the air conditioner runs, press the test operation button of the remote
control, and the test operation control mode will appear. During test running, the operation lamp
and timer lamp of the air conditioner body twinkle simultaneously. Set the test operation mode,
and the compressor will continue to run regardless of whether the room temperature sensor detects.

The test operation mode is released if 60 minutes have passed after setting up the test operation.

10. PREVENT TO RESTART FOR 3 MINUTES ( 3 MINUTES ST )

The compressor won't enter operation status for 3 minutes after the compressor is
stopped, even if any operation is given.

11. FOUR-WAY VALVE EXTENSION SELECT

At the time when the air conditioner is switched from the cooling mode to heating mode,
the compressor is stopped, and the 4-way valve is switched in 3 minutes later
after the compressor stopped.

12. AUTO RESTART

When the power was interrupted by a power failure, etc. during operation, the operation contents
at that time are memorized and when power is recovered, operation is automatically started with
the memorized operation contents.
When the power is interrupted and recovered during timer operation, since the timer operation time
is shifted by the time the power was interrupted, an alarm is given by blinking (7 sec ON/2 sec OFF)
the indoor unit body timer lamp.

[Operation contents memorized when the power is interrupted]

Operation mode
Set temperature
Set air flow
Timer mode and timer time
Set air flow Direction
Swing

The detection position of the thermistor (When it used the wired remote controller for AS and AU)

01-15

13. MANUAL AUTO OPERATION (Indoor unit body operation)

If MANUAL AUTO Button is set, the operation is controlled as shown in Table 6.
If the remote control is lost or battery power dissipated, this function will work without the remote
control.

(Table 6)

Manual auto operation
OPERATION MODE Auto changeover
FAN CONT. MODE Auto
TIMER MODE Continuous
SETTING TEMP. 75°F(24°C)
SETTING LOUVER Standard
SWING OFF

(No timer setting available)

14. FORCED COOLING OPERATION

Forced cooling operation is started when pressing MANUAL AUTO button for 10 seconds or more.
During the forced cooling operation, it operates regardless of room temperature sensor.
Operation LED and timer LED blink during the forced cooling operation. They blink for 1 second ON
and 1 second OFF on both operation LED and timer LED (same as test operation).
Forced cooling operation is released after 60 minutes of starting operation.
The FORCED COOLING OPERATION will start as shown in Table 7.

(Table 7)

Forced cooling operation
OPERATION MODE
FAN CONT. MODE
TIMER MODE
SETTING TEMP.
SETTING LOUVER
SWING

Cooling
Hi

­Room Temp is not controlled
Horizontal
OFF

15. COMPRESSOR PREHEATING

When the outdoor heat exchanger temperature is lower than Operation temperature (Refer to Table 8)
and the heating operation has
the compressor is heated.
(By heating the compressor, warm air is quickly discharged when operation is started.)
When operation was started, and when the outdoor temperature rises to Release temperature or greater,
preheating

is over.

(Table 8 : Preheating Operation / Release Temperature)

Operation
temperature

AOU24RML
AOU36RML

been stopped for 3 hours, power is applied to the compressor and

Before 24 hour After 24 hour

Operation
temperature

32°F
(0°C)

Release
temperature

39.2°F
(4°C)

37.4°F
(3°C)

Release
temperature

44.6°F
(7°C)

01-16

16. FRESH AIR CONTROL (For AR type)

The fan motor for Fresh Air is operated in synchronization with the indoor fan operation
as shown in Figure 11.

(Fig.11 : Fresh air control)

Fan motor
(Indoor unit)

Fan motor
(for Fresh Air)

Operation

Stop

Operation

Stop

17. EXTERNAL ELECTRICAL HEATER CONTROL (For AR type)

The external electrical heater is operated as shown in Figure 12.

(Fig.12 : External electrical heater control)

When the room
temperature rises

Heater : OFF

Ts -1°C

Ts -3°C

Ts -12°C

Heater : ON

Heater : OFF

Ts -10°C

Ts : Setting temperature

When the compressor stop,
External electrical heater is OFF.

When the room
temperature drops

18. DRAIN PUMP OPERATION ( For AU, *AR type )

During Cooling / Dry operation

1. When the compressor starts, the drain pump starts simultaneously.

2. The drain pump operates continuously for 3 minutes after the compressor is turned off.

3. When the compressor stops by the "Indoor heat exchanger de-icing function", the drain pump is turned off in 1 hour
after the compressor stops.

4.When the water level in the drain pan rises up and then the float switch functions:
The compressor, indoor and outdoor fan motor operation are stopped.

1
2

Drain pump operates continuously for 3 minutes after the float switch is turned off.
(Almost condensing water may be drained)

5. When the float switch turns ON continuously for 3 min., "FAILURE INDICATION" operates.

6. When the float switch turns OFF within 3 min., the unit starts cooling operation.

During Heating / Fan / Stop operation

1.When the water level in the drain pan rises up and then the float switch functions:
Drain pump operates continuously for 3 minutes after the float switch is turned off.

1

(Almost condensing water may be drained)

2. When the float switch turns ON continuously for 3 min., "FAILURE INDICATION" operates.

*When installed the drain pump which procured locally, it operates

01-17

19. COIL DRY AND CLEAN OPERATION CONTROL (For AS type)

The coil-dry and clean operation functions by pressing COIL DRY button on the remote controller.
The coil-dry operation is consisted of 3 cycles of [Fan operation 3 minutes / Heating operation
2 minutes], and Fan operates for 3 minutes at last before ending the air conditioner operation.
(It takes 18 minutes to complete the coil-dry operation.)
It continues from coil-dry operation, it turns on electricity to Air clean unit, sterilization is
performed for 15 minutes.
Indoor unit fan motor operation under coil-clean operation : The cycle of 480rpm Fixation
5 sec ON / 1 min OFF is repeated.
(It takes 33 minutes to complete the air cleaning operation.)

(Table 9: COIL-DRY AND CLEAN Operating Functions)

ASU9RMLQ
ASU12RMLQ
ASU18RMLQ

Indoor Fan Speed

coil-dry coil-clean

900rpm
900rpm
900rpm

480rpm
480rpm
480rpm

Louver
Position

Operating COIL DRY : ON
Other indication : OFF

Main Unit
Indication

MW09/ 12/ 18Y3FM model (For Friedrich) is only COIL-DRY OPERATION.

20. AIR CLEAN OPERATION (Only for ASU9/ 12/18RMLQ)

The air clean operation switches ON and OFF as follows
every time it receives AIR CLEAN signal from remote controller.

Status before receiving Air Clean signal Status upon receiving Air Clean signal

Operation stops

In operation
(Air Clean operation is OFF.)

Operation keeps stopping

It continues to operate
(Air Clean operation becomes ON.)

In operation
(Air Clean operation is ON.)

When Air Clean operation is ON, Indoor fan speed becomes at [S-Lo](480rpm),
and not at 0rpm even if the indoor fan is in stop condition.

Air Clean operation becomes OFF during the defrost operation.

It continues to operate
(Air Clean operation becomes OFF.)

01-18

21. ENERGY SAVE FUNCTION (For AR type)

1. During Cooling / Dry operation:

The thermostat temperature setting increases by 1 degC as soon as the ENERGY SAVE button is pressed,
and then increases by 1 degC after 1 hour later.
Afterwards, energy consumption is saved by continuing to cool or dry at a thermostat temperature of 2 degC
higher than setting temperature.

ENERGY
SAVE ON

1hour.

1 degC

2 degC

Setting
temperature

2. During Heating operation:

The thermostat temperature setting decreases by 1 degC as soon as the ENERGY SAVE button is pressed,
and then decreases by another 1 degC every 30 minutes.
Afterwards, energy consumption is saved by continuing to heat at a thermostat temperature of 4 degC
lower than setting temperature.

ENERGY
SAVE ON

1degC 2degC 3degC 4degC

30min.

1 hour.

1 hour
30 min.

Setting
temperature

22. DEFROST OPERATION CONTROL

1. CONDITION OF STARTING THE DEFROST OPERATION

The defrost operation starts when the outdoor heat exchanger temperature sensor detects
the temperature lower than the values shown in Table 9.

(Table 9 : Condition of starting Defrost Operation)

Compressor integrating

Compressor integrating
operation :Less than 45min.

AOU24RML
AOU36RML

*1. It means contiguous operation time.

*2. Compressor stop time: Below 20min. Select 6min.
Above 20min. Select 10min.

Does not operate

2. CONDITION OF THE DEFROST OPERATION COMPLETION

Defrost operation is released when the conditions become as shown in Table 10.

(Table 10 : Defrost Release Condition)

AOU24RML

AOU36RML

Outdoor heat exchanger temperature sensor value is higher than 53.6°F(12°C) or
Compressor operation time has passed 15 minutes.

operation :45min and over

Less than 6 min. *1
or 10min. *2

Release Condition

After 6 min. *1
or 10min. *2

°F(-8°C) *3

17.6
14

°F (-10°C) *4

*3. Outdoor temp. > 30.2°F (-1°C)
*4. Outdoor temp. < 30.2°F (-1°C)

=

01-19

Defrost Flow Chart

The defrosting shall proceed by the integrating operation time and outdoor heat exchanger temperature as follows.

Heating operation start : Compressor ON

(Not defrosted for 6 or 10 minutes)

Compressor integrating
operation:
45 minutes and over

Outdoor temp. > 30.2°F
(-1°C)

Outdoor heat exchanger
temperature:
Below 17.6°F (-8°C)

=

Outdoor temp. < 30.2°F
(-1°C)

Outdoor heat exchanger
temperature:
Below 14°F (-10°C)

Defrost start

Defrost Indicator:
[Operation lamp]
7 sec ON / 1 sec OFF

Outdoor fan motor OFF
4-way valve OFF
Compressor ON
(Frequency : 92 Hz)

Outdoor heat exchanger temperature: Over 53.6°F (12°C)
or
Compressor ON time: Over 15 minutes

Defrost end

01-20

23. VARIOUS PROTECTIONS

(1). DISCHARGE GAS TEMPERATURE OVERRISE PREVENSION CONTROL

The discharge gas thermosensor (discharge thermistor : Outdoor side) will detect discharge gas
temperature.

When the discharge temperature becomes higher than Temperature ,the compressor frequency
is decreased 20 Hz, and it continues to decrease the frequency for 20 Hz every 120 seconds until
the temperature becomes lower than Temperature .

When the discharge temperature becomes lower than Temperature ,the control of the control of the
compressor frequency is released.

When the discharge temperature becomes higher than Temperature ,the compressor is stopped
and the indoor unit LED starts blinking.

(Table 11 : Discharge Temperature Over Rise Prevension Control / Release Temperature)

Temperature

AOU24/36RML 230°F(110°C) 212°F(100°C) 239°F(115°C)

Temperature

(2). CURRENT RELEASE CONTROL

The compressor frequency is controlled so that the outdoor unit input current does not exceeds
the current limit value that was set up with the outdoor temperature.
The compressor frequency returns to the designated frequency of the indoor unit at the time
when the frequency becomes lower than the release value.

Temperature

(3). ANTI-FREEZING CONTROL (Cooling mode)

The compressor frequency decreases on cooling mode when the indoor heat exchanger
temperature sensor detects the temperature lower than 37.4°F (3°C).
Then, the anti-freezing control is released when it becomes higher than 42.8°F (6°C).

(Fig 7 : Anti-freezing Protection Operation / Release Temperature)

Indoor heat exchange
temperature

The compressor frequency is

37.4°F
(3°C)

42.8°F
(6°C)

46.4°F
(8°C)

decreased 10Hz every 120 seconds.

Hold

Compressor OFF : Hold
Compressor ON : Release of protection

Release of protection

(4). COOLING PRESSURE OVER RISE PROTECTION

When the outdoor unit heat exchange sensor temperature rises to

158.9°F (70.5°C) or greater,

the compressor is stopped and error display is indicated.

01-21

(5). HIGH TEMPERATURE RELEASE CONTROL ( HEATING MODE )

On heating mode, the compressor frequency is controlled as following based on the
detection value of the indoor heat exchanger temperature sensor.

(Fig 8 : Heating Overload Protection Control)

Indoor heat exchange
temperature

Compressor is OFF

145.4°F
(63°C)

132.8°F
(56°C)

125.6°F
(52°C)

The compressor frequency is
decreased 10Hz every 60 seconds.

Hold

Compressor OFF :
Release of protection
Compressor ON :
The compressor frequency is
increased 10Hz every 60seconds.

01-22

R410A

WALL MOUNTED / DUCT
CASSETTE type

INVERTER (MULTI)

2 . TROUBLE SHOOTING

2. TROUBLESHOOTING

2-1 ERROR DISPLAY

2-1-1 INDOOR UNIT DISPLAY

For ASU9 - 18RMLQ

The OPERATION, TIMER, AIR CLEAN and COIL DRY lamps operate
as follows according to the error contents.

Error display

Error contents

Communication error
(Serial reverse transfer error)

Outdoor communication signal error
(Forward transfer signal error)

Communication error

(indoor unit remote control)

Room temperature thermistor error

Indoor heat exchanger temperature
thermistor (middle) error

Outdoor discharge pipe temperature
thermistor error

Outdoor heat exchanger temperature
thermistor error

Outdoor temperature thermistor error

OPERATION

(RED) (GREEN) (GREEN)

2 times

2 times

3 times

3 times

3 times

TIMER

2 times
3 times

4 times
5 times

8 times

2 times

3 times

2 times

3 times

4 times

AIR CLEAN
or QUIET

COIL DRY

(ORANGE)

Trouble
shooting

2

11

1

3

4

8

5

7

Heat sink temperature thermistor error

Compressor temperature thermistor error

2-way valve temperature thermistor error

3-way valve temperature thermistor error

Manual auto switch error

Power supply frequency detection error

VDD permanence stop protection
(Electric air clean)

Reverse-VDD permanence stop protection
(Electric air clean power supply circuit abnormal)

IPM error

CT error

Compressor rotor location cannot detect

(permanent stop)

Outdoor unit fan motor error

Connected indoor unit error

Main CPU-Sub CPU communication error

Indoor fan motor abnormal

Discharge temperature error

3 times

3 times

3 times 2 times

3 times 3 times

4 times

4 times

4 times

4 times

5 times

5 times

5 times

5 times

5 times

5 times

6 times

7 times

7 times

8 times

2 times

4 times

7 times

8 times

2 times

3 times

5 times

6 times

7 times

8 times

2 times
3 times

2 times

19

12

21

22

25

26

29

30

14

15

17

18

23

24

10

31

Exessive high pressure protection on cooling

Pressure switch error

Active filter module (AFM) error

Indoor EEPROM abnormal (Model No.)

0.5s ON / 0.5s OFF (Flash)

:

:

OFF

7 times

7 times

8 times

Continuous
blink

02-01

3 times

5 times

2 times
3 times

Continuous
blink

Continuous
blink

Continuous
blink

32

13

16

9

For AUU9 - 18RML

The OPERATION, TIMER and FILTER lamps operate as follows according to the error contents.

Error contents

Communication error
(Serial reverse transfer error)

Outdoor communication signal error
(Forward transfer signal error)

Communication error

(Main PCB Display PCB)

Communication error

(Main PCB Display PCB)

Communication error

(indoor unit remote control)

Room temperature thermistor error

Indoor heat exchanger temperature
thermistor (middle) error

Water drain abnormal

Outdoor discharge pipe temperature
thermistor error

Outdoor heat exchanger temperature
thermistor error

Outdoor temperature thermistor error

Heat sink temperature thermistor error

Error display

OPERATION TIMER FILTER

(GREEN) (ORANGE) (RED)

2 times
3 times

4 times
5 times

6 times

7 times

8 times

2 times

2 times

2 times

3 times

3 times

2 times

3 times

6 times

2 times

3 times3 times

4 times3 times

7 times

Trouble
shooting

2

11

27

28

1

3

4

6

8

5

7

19

Compressor temperature thermistor error

2-way valve temperature thermistor error

3-way valve temperature thermistor error

Manual auto switch error

IPM error

CT error

Compressor rotor location cannot detect

(permanent stop)

Outdoor unit fan motor error

Connected indoor unit error

Main CPU-Sub CPU communication error

Indoor fan motor abnormal

Discharge temperature error

Exessive high pressure protection on cooling

4 way valve error operation

3 times

3 times

3 times

4 times

5 times

6 times

7 times

8 times

2 times

2 times

3 times5 times

5 times5 times

6 times5 times

7 times5 times

8 times5 times

2 times
3 times

2 times7 times

3 times7 times

4 times

2 times

3 times

12

21

22

25

14

15

17

18

23

24

10

31

32

35

Pressure switch error

Compressor temperature error

Indoor EEPROM abnormal error

0.5s ON / 0.5s OFF (Flash)

:

:

OFF

continuance
blink

02-02

5 times7 times

6 times7 times

continuance
blink

continuance
blink

13

33

9

2-1-2 OUTDOOR UNIT DISPLAY

1. ERROR DISPLAY

Error Contents

Outdoor communication signal error
(Forward transfer signal error)

Outdoor discharge pipe temperature
thermistor error

Outdoor heat exchanger temperature
thermistor error

Outdoor temperature thermistor error

2-way valve temperature thermistor A error

2-way valve temperature thermistor B error

2-way valve temperature thermistor C error

2-way valve temperature thermistor D error

3-way valve temperature thermistor A error

3-way valve temperature thermistor B error

3-way valve temperature thermistor C error

3-way valve temperature thermistor D error

LED

AB C D

1 times blink

OFF

OFF OFF

OFF OFF

2 times blink

3 times blink

4 times blink

5 times blink

6 times blink

6 times blink

OFF

1 times blink

5 times blink

OFF

OFF

OFFOFF

OFF

1 times blink

OFF

OFFOFF

OFFOFF

OFFOFF

OFFOFF

OFFOFF

5 times blink

OFFOFFOFF

6 times blink

OFFOFFOFF

OFF

OFF

OFF

1 times blink

OFF

OFF

OFF

OFF

OFF

OFFOFFOFF

5 times blink

OFFOFF

OFFOFFOFF

OFF

6 times blink

Trouble
shooting

11

8

5

7

21

22

Compressor temperature thermistor error

Heat sink temperature thermistor error

Pressure switch 1 error

Pressure switch 2 error

Connected indoor unit error

IPM error

Compressor rotor location cannot detect

(permanent stop)

Compressor Start-up error

(permanent stop)

Outdoor unit fan motor error

Main CPU - sub CPU communication error

7 times blink

8 times blink

9 times blink

10 times blink

11 times blink

12 times blink

13 times blink

14 times blink

15 times blink

17 times blink

OFF

OFF

OFF

OFF

OFF

OFF

OFF

OFF

2. ERROR DISPLAY METHOD

Outdoor LED Blink (1 to 18 times) 0.5sec ON / 0.5sec OFF blinking

0.5sec 0.5sec 2sec

ON

OFF

OFF

OFF

OFF

OFF

OFF

OFF

OFF

OFFOFF

OFFOFF

OFF

OFF

OFF

OFF

OFF

OFF

OFF

OFF

OFF

OFF

12

19

13

23

14

17

20

18

24

OFF

3. NORMAL OPERATION DISPLAY

Operation

Normal operation

㪣㪜㪛㩷㪘 㪣㪜㪛㩷㪙 㪣㪜㪛㩷㪚 㪣㪜㪛㩷㪛

Continuously lighting

02-03

䌏䌆䌆䌏䌆䌆 䌏䌆䌆

2-1-3 WIRED REMOTE CONTROLLER DISPLAY

For ARU9-18RML (AR-3TA)

1. SELF - DIAGNOSIS

When the error indication "E:EE" is displayed, inspection of the air conditioning system is necessary.
Please consult authoilzed servise personnel.

Run [Self-Diagnosis] if [E:EE] flashes on the clock display of the remote controller.

Display

SUMOTUWETH FR

CLOCK ADJUST

SET BACK

DELETE SET

DAY

DAY OFF

SA

ENERGY

SAVE

1. Stop the air conditioner operation.

2. Press the SET TEMPERATURE buttons and simultaneously for 5 seconds or more
to start the self-diagnosis.

3. Press the SET TEMPERATURE buttons and simultaneously for 5 seconds or more
or there is no key input for 20 seconds to stop the self-diagnosis.

Error code

Communication error (indoor unit remote control)

Communication error (Serial reverse transfer error)

Room temperature thermistor open

Room temperature thermistor short-circuited

Indoor heat exchanger temperature thermistor open

Indoor heat exchanger temperature thermistor short-circuited

Outdoor heat exchanger temperature thermistor open

Outdoor heat exchanger temperature thermistor short-circuited

Power supply frequency detection error

Water drain abnormal

Outdoor temperature thermistor open

Outdoor temperature thermistor short-circuited

Outdoor discharge pipe temperature thermistor open

Outdoor discharge pipe temperature thermistor short-circuited

Heat sink temperature thermistor error

Discharge pipe temperature thermistor error

Indoor EEPROM abnormal (Model No.)

Indoor fan motor abnormal

Outdoor communication signal error (Forward transfer signal error)

Exessive high pressure protection on cooling

Compressor temperature thermistor error

Pressure switch error

IPM error

CT error

Active Filter Module (AFM) error

Compressor rotor location cannot detect

Outdoor unit fan motor error

Main CPU - sub CPU communication error

2-way valve temperature thermistor error

3-way valve temperature thermistor error

Connected indoor unit error

Error contents

02-04

CLOCK ADJUST

SET BACK

DELETE SET

DAY

DAY OFF

SET

ENERGY

SAVE

THERMO
SENSOR

Trouble
shooting

1
2

3

4

5

26
6

7

8

19

8

9

10

11
32
12
13
14
15
16

17
18
24
21

22

23

Error code

SUMOTUWETH FR

SA

Ex. Self-diagnosis

2. ERROR CODE HISTORY DISPLAY

Up to 16 memorized error codes may be displayed for the indoor unit connected to the remote controller.

1. Stop the air conditioner operation.

2. Press the SET TEMPERATURE buttons , simultaneously for 5 seconds or more to
start the self-diagnosis.

Error code

Error history number

DAY

SUMOTUWETH FR

3. Press the SET TEMPERATURE button to select the error history number.

SA

Lower

DAY

Raise

01234 567

FEdcb A9 8

ı

ı

4. Press the SET TEMPERATURE buttons , simultaneously for 3 seconds or more
or there is no key input for 60 seconds to stop the display.

02-05

For AUU09-18RML (AR-6TC)

1. SELF - DIAGNOSIS

When "EE" in Temperature Display is displayed, inspection of the air conditioning system is necessary.
Please consult authoilzed servise personnel.

Unit number (usually 0)

Error code

SU MOTUWETH FR SA

ex. Self-diagnosis check

Error code

Error contents

Communication error (indoor unit remote control)

Communication error (Serial reverse transfer error)

Room temperature sensor error

Indoor heat exchanger temperature sensor error

Outdoor heat exchanger temperature sensor(outlet) error

Water drain abnormal

Outdoor temperature sensor error

Outdoor discharge pipe temperature sensor error

Heatsink temperature thermistor error

Discharge temperature error

Indoor EEPROM abnormal

Indoor fan motor abnormal

Outdoor communication signal error (Forward transfer signal error)

Compressor temperature sensor error

Pressure switch error

IPM error

CT error

Active filter module error

Compressor rotor location cannot detect (permanent stop)

Outdoor unit fan motor error

2-way valve temperature thermistor error

3-way valve temperature thermistor error

Main CPU - sub CPU communication error

Connected indoor unit error

Indoor manual auto switch error
Exessive high pressure protection on cooling

Communication error (Main PCB Display PCB)

Communication error (Main PCB Display PCB)

4-way valve error

Trouble
shooting

1
2
3
4
5

6

7

8

19

31

9
10

11
12
13

14
15
16

17
18
21

22
24
23
25
32
27

28
35

If “CO” appears in the unit number display, there is a remote controller error.
Refer to the installation instruction sheet included with the remote controller.

02-06

2. ERROR CODE HISTORY DISPLAY

Up to 16 memorized error codes may be displayed for the indoor unit connected to the remote controller.

1. Stop the air conditioner operation.

2. Press the SET TEMPERATURE buttons , and the START/STOP button simultaneously
for 5 seconds or more to start the self-diagnosis.

DAY

SUMOTUWETH FR

SA

3. Press the START/STOP button.

Error code

Error history number

DAY

SUMOTUWETH FR

SA

4. Press the SET TEMPERATURE button to select the error history number.

Lower

DAY

Raise

01234 567

FEdcbA98

ı

ı

5. Press the SET TEMPERATURE buttons , and START/STOP button simultaneously
for 5 seconds or more or there is no key input for 20 seconds to stop the display.

02-07

2-2 TROUBLE SHOOTING WITH ERROR CODE

Trouble shooting 1

INDOOR UNIT Error Method:

Indicate or Display:

Refer to error code table.

Communication Error
(Indoor unit Remote control)

Detective Actuators:

Indoor unit controller PCB circuit
Wired Remote Control

Detective details:

When the indoor unit cannot receive the signal from Wired Remote
more than 10seconds after power ON, or the indoor unit cannot receive
the signal more than 1minute during normal operation.

Forecast of Cause:

1. Terminal connection abnormal 2. Wired Remote Control failure 3. Control PCB failure (AS, AR)

Check Point 1 : Check the connection of terminal

After turning off the power, check & correct the followings.

Check the connection of terminal between remote control and Indoor unit,
and check if there is a disconnection of the cable.

OKOK

Check Point 2 : Check Remote Control and Control PCB

Main PCB (AU)

Check Voltage at CN10 (AS type) of Control PCB. (Power supply to Remote Control)

CN17 (AR type)
CN14 (AU type)

>> If it is DC12V, Remote Control is failure. (
>> If it is DC 0V,
Main PCB is failure. (Check Remote Control once again) >> Replace

Upon correcting the removed connector or mis-wiring, reset the power.

Control PCB is failure. (Check Remote Control once again) >> Replace Control PCB (AS, AR)

Control PCB is normal) >> Replace Remote Control

Main PCB (AU)

02-08

Trouble shooting 2

OUTDOOR UNIT Error Method:

Communication Error
(Serial Reverse Transfer Error)

Indicate or Display:

Refer to error code table.

Detective Actuators:

Detective details:

Outdoor Unit Main PCB Circuit
Active Filter Module

Forecast of Cause:

1. Connection failure 2. External cause 3. Main PCB failure 4. Active Filter Module failure

Check Point 1-1 : Reset the power and operate

Does Error indication show again?

YESYES

Check Point 2 : Check Connection

Check any loose or removed connection line of
Indoor unit and Outdoor unit.

>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data &
Technical Manual.

Check connection between Outdoor Unit Main PCB
and Filter PCB.
(If there is loose connector or open cable)

When the indoor unit cannot receive the serial signal from Outdoor unit
more than 10seconds.

NO

Check Point 1-2:

Check external cause such as noise

Check the complete insulation of the grounding.

Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).

OK

Check Point 3 : Check the voltage of power supply

Check the voltage of power supply

>> Check if AC208 - 230V appears at Outdoor Unit Terminal L - N.

OK

Check Point 4 : Check Serial Signal (Reverse Transfer Signal)

Check Serial Signal (Reverse Transfer Signal)

>> Check if Indicated value swings between AC70V and AC130V at Outdoor Unit Terminal N - 3.

>> If it is abnormal, Check Active Filter Module. (PARTS INFORMATION 3)

>>If Active Filter Module is abnormal, replace it.

>>If Active Filter Module is normal, replace Main PCB.

WHITE

BLACK

RED

N

L

3

+

-

02-09

Trouble shooting 3
INDOOR UNIT Error Method:

INDOOR UNIT

Room Temperature Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB(AS, AR) ,
Main PCB(AU) or Room Temperature

Detective details:

When Room Temperature Thermistor open or short-circuit is
detected at power ON.

Thermistor

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Control PCB (AS,AR),MainPCB (AU) failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OK

Check Point 2 : Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

32°F
(0°C)

41°F
(5°C)

50°F
(10°C)

59°F
(15°C)

68°F
(20°C)

77°F
(25°C)

10.012.515.820.225.933.6Resistance Value (k )

86°F

(30°C)

8.04

95°F
(35°C)

6.51

Temperature

104°F
(40°C)

113°F
(45°C)

122°F
(50°C)

3.594.355.30Resistance Value (k )

If Thermistor is either open or shorted, replace it and reset the power.

OK

Check Point 3 : Check Point 3 : Check voltage of Controller PCB (DC5.0V)

Make sure circuit diagram of indoor unit and check terminal voltage at Thermistor (DC5.0V)

GRAY

1

GRAY

2

BLACK

1

BLACK

2

CN8 CN7 (AR)

CN8 CN5 (AU)

CN5 CN6 (AS)

If the voltage does not appear, replace Controller PCB(AS, AR), Main PCB(AU).

THERMISTOR
(PIPE TEMP.)

THERMISTOR
(ROOM TEMP.)

02-10

Trouble shooting 4
INDOOR UNIT Error Method:

INDOOR UNIT

Indoor Heat Exchanger Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB (AS, AR) ,
Main PCB (AU) or Room Temperature

Detective details:

When Heat Exchanger Temperature Thermistor open or short-circuit is
detected at power ON.

Thermistor

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Control PCB (AS,AR),MainPCB (AU) failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

32°F
(0°C)

41°F
(5°C)

50°F
(10°C)

59°F
(15°C)

68°F
(20°C)

77°F
(25°C)

49.762.980.3103134176Resistance Value (k )

86°F

(30°C)

39.6

95°F
(35°C)

31.7

Temperature

104°F
(40°C)

113°F
(45°C)

122°F
(50°C)

17.120.825.6Resistance Value (k )

If Thermistor is either open or shorted, replace it and reset the power.

OK

Check Point 3 : Check voltage of Controller PCB (DC5.0V)

Make sure circuit diagram of indoor unit and check terminal voltage at Thermistor (DC5.0V)

GRAY

1

GRAY

2

BLACK

1

BLACK

2

CN8 CN7 (AR)

CN8 CN5 (AU)

CN5 CN6 (AS)

If the voltage does not appear, replace Controller PCB(AS, AR), Main PCB(AU).

THERMISTOR
(PIPE TEMP.)

THERMISTOR
(ROOM TEMP.)

02-11

Trouble shooting 5
OUTDOOR UNIT Error Method:
Outdoor Heat Exchanger Temperature

Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Heat Exchanger Temperature Thermistor

Detective details:

When Heat Exchanger Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

14°F
(-10°C)

23°F
(-5°C)

32°F
(0°C)

41°F
(5°C)

50°F
(10°C)

59°F
(15°C)

7.679.7312.416.120.927.5Resistance Value (k )

68°F
(20°C)

6.10

77°F
(25°C)

4.89

86°F
(30°C)

3.95

If Thermistor is either open or shorted, replace it and reset the power.

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

THERMISTOR

BLUE

(PIPE)

BLACK

THERMISTOR

(DISCHARGE)

BROWN

1 21 21 21 21 2

THERMISTOR

THERMISTOR

(HEAT SINK)

(COMPRESSOR)

BLACK

THERMISTOR

(OUTDOOR)

BROWN

CN25 CN26 CN23 CN22 CN21

If the voltage does not appear, replace Main PCB.

DC

02-12

Trouble shooting 6
INDOOR UNIT Error Method:

Water Drain Abnormal

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Main PCB Circuit

Detective details:

When Float Switch is ON for more than 3 minutes.

Float Switch

Forecast of Cause :

1. Float Switch failure 2. Shorted connector/ wire 3. Main PCB failure

Check Point 1 : Check Float Switch

Check operation of float switch. (any blocking by dust, etc.)

Remove Float switch and check ON/OFF switching operation
by using a meter.

>>If Float switch is detective, replace it.

OKOK

Check Point 2 : Check Point 2 : Check Connector (CN9) / Wire

Check loose contact of CN9 /shorted wire (pinched wire).

>>Replace Float switch if the wire is abnormal

ONON OFFOFF

OKOK

Check Point 3 : Replace Main PCB

If Check Point 1 & 2 do not improve the symptom, change Controller PCB.

02-13

Trouble shooting 7
OUTDOOR UNIT Error Method:

INDOOR UNIT

Outdoor Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Outdoor Temperature Thermistor

Detective details:

When Outdoor Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

Temperature

- 4°F
(-20°C)

86°F
(30°C)

14°F
(-10°C)

104°F
(40°C)

23°F
(-5°C)

122°F
(50°C)

32°F
(0°C)

140°F
(60°C)

41°F
(5°C)

158°F
(70°C)

50°F
(10°C)

59°F

(15°C)

16.1

68°F
(20°C)

12.620.726.935.246.662.3115Resistance Value (k )

5.187.97

If Thermistor is either open or shorted, replace it and reset the power.

3.45 2.36 1.65Resistance Value (k )

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

THERMISTOR

BLUE

(PIPE)

BLACK

THERMISTOR

(DISCHARGE)

BROWN

1 21 21 21 21 2

THERMISTOR

THERMISTOR

(HEAT SINK)

(COMPRESSOR)

BLACK

THERMISTOR

(OUTDOOR)

BROWN

CN25 CN26 CN23 CN22 CN21

If the voltage does not appear, replace Main PCB.

02-14

Trouble shooting 8
OUTDOOR UNIT Error Method:

INDOOR UNIT

Outdoor Discharge Pipe Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Discharge Pipe Temperature Thermistor

Detective details:

When Discharge Pipe Temperature Thermistor open or short-circuit
is detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

32°F
(0°C)

41°F
(5°C)

50°F
(10°C)

59°F
(15°C)

68°F
(20°C)

86°F
(30°C)

41.164.581.8105135176Resistance Value (k )

Temperature

158°F
(70°C)

176°F
(80°C)

194°F
(90°C)

212°F
(100°C)

248°F
(120°C)

284°F
(140°C)

104°F
(40°C)

320°F
(160°C)

122°F
(50°C)

18.126.9

356°F
(180°C)

140°F
(60°C)

12.5

1.211.983.434.616.318.78Resistance Value (k )

If Thermistor is either open or shorted, replace it and reset the power.

0.77

0.51

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

THERMISTOR

BLUE

(PIPE)

BLACK

THERMISTOR

(DISCHARGE)

BROWN

1 21 21 21 21 2

THERMISTOR

THERMISTOR

(HEAT SINK)

(COMPRESSOR)

BLACK

THERMISTOR

(OUTDOOR)

BROWN

CN25 CN26 CN23 CN22 CN21

If the voltage does not appear, replace Main PCB.

02-15

Trouble shooting 9

INDOOR UNIT Error Method:

Indoor EEPROM abnormal
(Model No.)

Indicate or Display:

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB (AS,AR),
Main PCB (AU) circuit

Detective details:

When the model information being read from EEPROM has
an apparent error.

Forecast of Cause:

1. External cause 2. Defective connection of electric components 3. Control PCB failure (AS,AR),
Main PCB (AU)

Check Point 1-1 : Reset Power Supply and operate

Does Error indication show again?

YESYES

Check Point 2 :
Check Indoor Unit electric components

Check all connectors.
(loose connector or incorrect wiring)

Check any shortage or corrosion on PCB.

Check Point 3 : Replace Controller PCB

Change Control PCB (AS,AR), Main PCB (AU).

NO

Check Point 1-2 :
Check external cause at Indoor and Outdoor
(Voltage drop or Noise)

Instant drop : Check if there is a large load electric apparatus
in the same circuit.

Momentary power failure : Check if there is a defective contact
or leak current in the power supply
circuit.

Noise : Check if there is any equipment causing harmonic
wave near electric line.(Neon bulb or electric
equipment that may cause harmonic wave)
Check the complete insulation of grounding.

Note : EEPROM

EEPROM(Electronically Erasable and
Programmable Read Only Memory) is a non­volatile memory which keeps memorized
information even if power is turned off. It can
change the contents electronically.
To change the contents, it uses higher
voltage than normal, and it can not change a
partial contents. (Rewriting shall be done
upon erasing the all contents.)
There is a limit in a number of rewriting.

02-16

Trouble shooting 10

INDOOR UNIT Error Method:

Indoor Fan Motor abnormal

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB (AS,AR),
Main PCB, Power PCB (AU) Circuit.
Indoor Fan Motor

Detective details:

When the condition that actual frequency of Indoor Fan is below 1/3
of target frequency is continued more than 56 seconds.
Or the condition of fan speed is 0rpm is continued more than 56 seconds.

Forecast of Cause:

1. Fan rotation failure 2. Motor protection by surrounding temperature rise 3. Control PCB (AS,AR),
Main PCB ,Power PCB (AU)

Check Point 1 : Check rotation of Fan

Rotate the fan by hand when operation is off.
(Check if fan is caught, dropped off or locked motor)

>>If Fan or Bearing is abnormal, replace it.

OK

Check Point 2 : Check ambient temp. around motor

Check excessively high temperature around the motor.
(If there is any surrounding equipment that causes heat)

>>Upon the temperature coming down, restart operation.

OK

Check Point 3 : Replace Control PCB

If Check Point 1,2 do not improve the symptom, change Control PCB (AS,AR),

Main PCB ,Power PCB (AU)

02-17

Trouble shooting 11

INDOOR UNIT Error Method:

Outdoor Communication Signal Error
(Forward Transfer Signal Error)

Indicate or Display:Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB (AS,AR),
Main PCB, Power PCB (AU) Circuit

Forecast of Cause:

1. Connection failure 2. External cause 3. Controll PCB (AS,AR), Main PCB, Power PCB (AU) failure

Check Point 1-1 : Reset the power

Does Error indication reappear?

YESYES

Check Point 2 : Check Connection

Check any loose or removed connection line of
Indoor unit and Outdoor unit.

>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data &
Technical Manual.

Check connection between Indoor Unit Control PCB
and Filter PCB.(AR)
(If there is loose connector or open cable)

Check connection between Indoor Unit Main PCB
and Power PCB.(AU)
(If there is loose connector or open cable)

Detective details:

When the outdoor unit cannot receive the serial signal from Indoor unit
more than 10seconds.

NO

Check Point 1-2:

Check external cause such as noise

Check the complete insulation of the grounding.

Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).

OK

Check Point 3 : Check the voltage of power supply

Check the voltage of power supply

>> Check if AC208 - 230V appears at Outdoor Unit Terminal L - N.

OK

Check Point 4 : Check Serial Signal (Forward Transfer Signal)

Check Serial Signal (Forward Transfer Signal)

>> Check if Indicated value swings between AC70V and AC130V at Outdoor Unit Terminal N - 3.

>> If it is abnormal, Controller PCB is failure. >> Replace Control PCB (AS,AR),
Main PCB , Power PCB (AU)

WHITE

BLACK

RED

N

L

3

+

-

02-18

Trouble shooting 12
OUTDOOR UNIT Error Method:

Compressor Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Compressor Temperature Thermistor

Detective details:

When Compressor Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2. Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Rough value)

Temperature

32°F
(0°C)

41°F
(5°C)

50°F
(10°C)

59°F
(15°C)

68°F
(20°C)

86°F
(30°C)

41.164.581.8105135176Resistance Value (k )

Temperature

158°F
(70°C)

176°F
(80°C)

194°F
(90°C)

212°F
(100°C)

248°F
(120°C)

284°F
(140°C)

104°F
(40°C)

320°F
(160°C)

122°F
(50°C)

18.126.9

356°F
(180°C)

140°F
(60°C)

12.5

1.211.983.434.616.318.78Resistance Value (k )

If Thermistor is either open or shorted, replace it and reset the power.

0.77

0.51

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

THERMISTOR

BLUE

(PIPE)

BLACK

THERMISTOR

(DISCHARGE)

BROWN

1 21 21 21 21 2

THERMISTOR

THERMISTOR

(HEAT SINK)

(COMPRESSOR)

BLACK

THERMISTOR

(OUTDOOR)

BROWN

CN25 CN26 CN23 CN22 CN21

If the voltage does not appear, replace Main PCB.

02-19

Trouble shooting 13
OUTDOOR UNIT Error Method:

INDOOR UNIT

Pressure Switch Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Pressure Switch

Detective details:

When pressure switch open is detected in 10 seconds
after the power is turned on.

Forecast of Cause :

1. Connector connection failure 2. Pressure Switch failure 3. Main PCB failure

Check Point 1 : Reset Power Supply and operate

Does abnormal LED indication show again?

NONO

YESYES

Check Point 3 : Check Point 2 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage
at Pressure Switch. (DC5.0V)

PRESSURE SWITCH 1

RED

1

CN37

RED

2

PRESSURE SWITCH 2

RED

1

CN36

If the voltage does not appear, replace Main PCB.

RED

2

OK

Check Point 3 : Check Pressure Switch

Check if connector is loose or cable is open.

>> If no abnormal connection is found,
replace Pressure Switch.

After replacing Pressure Switch, check operating
condition and pressure in operation.

OK

Check Point 4 : Check High Pressure Protection on cooling

Check Excessive high pressure protection on cooling.
(Refer to Trouble shooting 31)

02-20

Trouble shooting 14

OUTDOOR UNIT Error Method:

IPM error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Compressor

Detective details:

When more than normal operating current to IPM in Main PCB flows,
the compressor stops.
After the compressor restarts, if the same operation is repeated within 40sec,
the compressor stops again.
If and repeats 5 times, the compressor stops permanently.

Forecast of Cause :

1. Defective connection of electric components 2. Outdoor Fan Operation failure

3. Outdoor Heat Exchanger clogged 4. Compressor failure 5. Main PCB failure

Check Point 1 : Check connections of Outdoor Unit Electrical Components

Check if the terminal connection is loose.
Check if connector is removed.

Check erroneous connection.
Check if cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OK

Check Point 2 : Check Outdoor Fan, Heat Exchanger

Is there anything obstructing the air distribution circuit?
Is there any clogging of Outdoor Heat Exchanger?
Is the Fan rotating by hand when operation is off ?

>> If the Fan Motor is locked, replace it.

Check Outdoor Fan Motor. (Refer to Trouble shooting 18)

>> If the Fan Motor is failure, replace it.

OK

Check Point 3 : Check Compressor

Check Compressor.

(PARTS INFORMATION 2)

OKOK

Check Point 4 : Replace Main PCB

If Check Point 1, 2, 3 do not improve the symptom, change Main PCB.

02-21

Trouble shooting 15

OUTDOOR UNIT Error Method:

CT error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Outdoor Unit Filter PCB Circuit
(Input current sensor unit)

Detective details:

When Input Current Sensor has detected lower than 0A
while Inverter Compressor is operating at higher than 50Hz,
after 1minute upon starting the Compressor.
(Except during the defrost operation)

Forecast of Cause :

1. Defective connection of electric components 2. External cause 3. Filter PCB failure 4. Main PCB failure

Check Point 1-1 : Reset Power Supply and operate

Does Error indication show again?

NO

YES

Check Point 2 :
Check connections of Outdoor Unit Electrical Components

Check if the terminal connection is loose.
Check if connector is removed.
Check erroneous connection.
Check if cable is open.

>>Upon correcting the removed connector or mis-wiring,
reset the power.

OK

Check Point 1-2 :
Check external cause at Indoor and Outdoor
(Voltage drop or Noise)

Instant drop : Check if there is a large load electric
apparatus in the same circuit.

Momentary power failure : Check if there is a defective
contact or leak current in the
power supply circuit.

Noise : Check if there is any equipment causing harmonic
wave near electric line.(Neon bulb or electric
equipment that may cause harmonic wave)
Check the complete insulation of grounding.

Check Point 3 : Check Filter PCB and Main PCB

Check DC voltage of CN1 (between 2 (Brown) and 3 (Red)) on Filter PCB.

>> After 40seconds upon starting the Compressor,
If it is higher than 0.2V, Main PCB is failure. (Filter PCB is normal) >> Replace Main PCB
>> If it is lower than 0.2V, Filter PCB is failure. >> Replace Filter PCB

If it does not improve the symptom, change Main PCB.

02-22

Trouble shooting 16
OUTDOOR UNIT Error Method:

INDOOR UNIT

Active Filter Module (AFM) error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Active Filter Module

Detective details:

When inverter input DC voltage is higher than 467V or
lower than 237V.
When a momentary power cut off occurred on low voltage.

Forecast of Cause :

1. External cause 2. Connector connection failure 3. Active Filter Module failure˴㧠. Main PCB failure

Check Point 1 : Check external cause at Indoor and Outdoor (Voltage drop or Noise)

Instant drop : Check if there is a large load electric apparatus in the same circuit.

Momentary power failure : Check if there is a defective contact or leak current
in the power supply circuit.

Noise : Check if there is any equipment causing harmonic wave near electric line.
(Neon bulb or electric equipment that may cause harmonic wave)
Check the complete insulation of grounding.

OKOK

Check Point 2 : Check connection of Connector

Check if connector is removed.
Check erroneous connection.
Check if cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 3 : Check Active Filter Module

Check Active Filter Module. (PARTS INFORMATION 3)

>>If Active Filter Module is abnormal, replace it.

OKOK

Check Point 4 : Replace Main PCB

If Check Point 1, 2 do not improve the symptom, change Main PCB.

02-23

Trouble shooting 17

OUTDOOR UNIT Error Method:

Compressor rotor location cannot detect
(Permanent Stop)

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit

Detective details:

While running the compressor, if the detected rotor location is out of
phase with actual rotor location more than 90 degrees,
the compressor stops.
After the compressor restarts, if the same operation is repeated
within 40sec, the compressor stops again.
If and repeats 5 times, the compressor stops permanently.

Forecast of Cause :

1. Defective connection of electric components 2. Main PCB failure

Check Point 1 : Check connection of around the Compressor components

For Compressor Terminal, Main PCB

Check if connector is removed.

Check erroneous connection.
Check if cable is open.

(Refer to PARTS INFORMATION 2)

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 : Replace Main PCB

If Check Point 1 do not improve the symptom, change Main PCB.

02-24

Trouble shooting 18
OUTDOOR UNIT Error Method:

Outdoor Unit Fan Motor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Outdoor Fan Motor

Detective details:

When outdoor fan rotation speed is less than 100rpm in 20 seconds
after fan motor starts, fan motor stops.
After fan motor restarts, if the same operation within 60sec is repeated
3 times in a row, compressor and fan motor stops.
If and repeats 5 times in a row, compressor and fan motor stops
permanently.

Forecast of Cause:

1. Fan rotation failure 2. Motor protection by surrounding temperature rise 3. Main PCB failure

Check Point 1 : Check rotation of Fan

Rotate the fan by hand when operation is off.
(Check if fan is caught, dropped off or locked motor)

>>If Fan or Bearing is abnormal, replace it.

OK

Check Point 2 : Check ambient temp. around motor

Check excessively high temperature around the motor.
(If there is any surrounding equipment that causes heat)

>>Upon the temperature coming down, restart operation.

OK

Check Point 3 : Check Output Voltage of Main PCB

Check outdoor unit circuit diagram and the voltage.
(Measure at Main PCB side connector)

FAN MOTOR

FM

CN802

RED

1
2

BLACK

3

WHITE

4

YELLOW

5

BLUE

6

Read wire DC voltage

Red - Black

White - Black

If the voltage is not correct, replace Main PCB.

㨪

150 380V

15 1.5V

02-25

Trouble shooting 19

OUTDOOR UNIT Error Method:

Heat Sink Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Heat Sink Temperature Thermistor

Detective details:

When Heat Sink Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

Temperature

32°F
(0°C)

140°F
(60°C)

41°F
(5°C)

158°F
(70°C)

50°F
(10°C)

176°F
(80°C)

59°F
(15°C)

7.67

194°F
(90°C)

68°F
(20°C)

6.109.7312.416.1Resistance Value (k )

212°F
(100°C)

86°F
(30°C)

230°F
(110°C)

104°F

(40°C)

2.623.95

248°F
(120°C)

122°F
(50°C)

1.79

1.25 0.89Resistance Value (k )

If Thermistor is either open or shorted, replace it and reset the power.

0.65

0.48

0.36

0.27

0.21

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

THERMISTOR

BLUE

(PIPE)

BLACK

THERMISTOR

(DISCHARGE)

BROWN

1 21 21 21 21 2

THERMISTOR

THERMISTOR

(HEAT SINK)

(COMPRESSOR)

BLACK

THERMISTOR

(OUTDOOR)

BROWN

CN25 CN26 CN23 CN22 CN21

If the voltage does not appear, replace Main PCB.

02-26

Trouble shooting 20

OUTDOOR UNIT Error Method:

Compressor Start-up error
(Permanent Stop)

Indicate or Display:Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit

Detective details:

The detect rotor position operation is repeat up to 50 times.
3min ST operates if the compressor fails on start-up,
it start try again of the detect rotor position operation.

If start try repeats 3 times, the compressor stops permanently.

Forecast of Cause :

1. Defective connection of electric components 2. Main PCB failure

Check Point 1 : Check connection of around the Compressor components

For Compressor Terminal, Main PCB

Check if connector is removed.
Check erroneous connection.
Check if cable is open.

(Refer to PARTS INFORMATION 2)

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 : Replace Main PCB

If Check Point 1 do not improve the symptom, replace Main PCB.

02-27

Trouble shooting 21

OUTDOOR UNIT Error Method:

2-way valve Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
2-way valve Temperature Thermistor

Detective details:

When 2-way valve Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

Temperature

14°F
(-10°C)

104°F
(40°C)

23°F
(-5°C)

122°F
(50°C)

32°F
(0°C)

140°F
(60°C)

41°F
(5°C)

134

158°F
(70°C)

50°F
(10°C)

103176233312Resistance Value (k )

176°F
(80°C)

59°F
(15°C)

194°F
(90°C)

68°F
(20°C)

62.980.3

212°F
(100°C)

86°F
(30°C)

39.6

25.6 17.1Resistance Value (k )

11.6

8.12

5.78

4.19 3.09

If Thermistor is either open or shorted, replace it and reset the power.

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

AOU24RML

BLACK
WHITE
WHITE
WHITE
WHITE
WHITE
WHITE
WHITE

1

2
3
4
5
6
7
8

WHITE

1

RED

2
3

YELLOW

4
5

BLUE

6
7

BLACK

8

2-WAY VALVE A

3-WAY VALVE A

2-WAY VALVE B

3-WAY VALVE B

1
3
4
5

CN39

6
7
8
9

If the voltage does not appear, replace Main PCB.

AOU36RML

BLACK

1

WHITE

3

WHITE

4

WHITE

5

CN39

WHITE

6

WHITE

7

WHITE

8

WHITE

9

BLACK

1

RED

2

RED

4

RED

5

CN40

RED

6

RED

7

RED

8

RED

9

VALVE THERMISTOR A, B

1

1

RED

2

2

3

3

YELLOW

4

4

5

5

BLUE

6

6

7

7

BLACK

8

8

WHITE

VALVE THERMISTOR C, D

1

1

GRAY

2

2

3

3

BROWN

4

4

5

5

ORANGE

6

6

7

7

GREEN

8

8

RED

2-WAY VALVE A

3-WAY VALVE A

2-WAY VALVE B

3-WAY VALVE B

2-WAY VALVE C

3-WAY VALVE C

2-WAY VALVE D

3-WAY VALVE D

02-28

Trouble shooting 22

OUTDOOR UNIT Error Method:

3-way valve Temperature
Thermistor Error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
3-way valve Temperature Thermistor

Detective details:

When 3-way valve Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.

Forecast of Cause :

1. Connector connection failure 2.Thermistor failure 3. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 :

Check Point 2 : Remove connector and check Thermistor resistance value

Thermistor Characteristics (Approx. value)

Temperature

Temperature

14°F
(-10°C)

104°F
(40°C)

23°F
(-5°C)

122°F
(50°C)

32°F
(0°C)

140°F
(60°C)

41°F
(5°C)

134

158°F
(70°C)

50°F
(10°C)

103176233312Resistance Value (k )

176°F
(80°C)

59°F
(15°C)

194°F
(90°C)

68°F
(20°C)

62.980.3

212°F
(100°C)

86°F
(30°C)

39.6

25.6 17.1Resistance Value (k )

11.6

8.12

5.78

4.19 3.09

If Thermistor is either open or shorted, replace it and reset the power.

OKOK

Check Point 3 :

Check Point 3 : Check voltage of Main PCB (DC5.0V)

Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)

AOU24RML

BLACK
WHITE
WHITE
WHITE
WHITE
WHITE
WHITE
WHITE

1

2
3
4
5
6
7
8

WHITE

1

RED

2
3

YELLOW

4
5

BLUE

6
7

BLACK

8

2-WAY VALVE A

3-WAY VALVE A

2-WAY VALVE B

3-WAY VALVE B

1
3
4
5

CN39

6
7
8
9

If the voltage does not appear, replace Main PCB.

AOU36RML

BLACK

1

WHITE

3

WHITE

4

WHITE

5

CN39

WHITE

6

WHITE

7

WHITE

8

WHITE

9

BLACK

1

RED

2

RED

4

RED

5

CN40

RED

6

RED

7

RED

8

RED

9

VALVE THERMISTOR A, B

1

1

RED

2

2

3

3

YELLOW

4

4

5

5

BLUE

6

6

7

7

BLACK

8

8

WHITE

VALVE THERMISTOR C, D

1

1

GRAY

2

2

3

3

BROWN

4

4

5

5

ORANGE

6

6

7

7

GREEN

8

8

RED

2-WAY VALVE A

3-WAY VALVE A

2-WAY VALVE B

3-WAY VALVE B

2-WAY VALVE C

3-WAY VALVE C

2-WAY VALVE D

3-WAY VALVE D

02-29

Trouble shooting 23
OUTDOOR UNIT Error Method:

INDOOR UNIT

Connected Indoor unit error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit

Detective details:

When the total capacity of the connected indoor units exceed
the connectable range of the total capacity.

Forecast of Cause :

1. The selection of connected indoor unit is incorrect 2.Main PCB failure

Check Point 1 : Check the total capacity of indoor unit

Check the total capacity of the connected indoor units.

>>If abnormal condition is found, correct it by referring
to Installation Manual or Data & Technical Manual.

OKOK

Check Point 2 : Replace Main PCB

If Check Point 1 do not improve the symptom, change Main PCB.

Trouble shooting 24
OUTDOOR UNIT Error Method:

INDOOR UNIT

Main CPU - Sub CPU
communication error

Detective Actuators:

Outdoor Unit Main PCB Circuit

Forecast of Cause :

1. Main PCB failure

Check Point 1 : Replace Main PCB

Change Main PCB.

Indicate or Display:

Refer to error code table.

Detective details:

When it cannot receive an effective signal for 10sec between
the Main CPU and Sub CPU in outdoor unit.

02-30

Trouble shooting 25
INDOOR UNIT Error Method:

INDOOR UNIT

Manual auto switch error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB Circuit (AS)

Detective details:

When the manual auto switch becomes ON for 60 consecutive seconds.(AS)

Main PCB Circuit (AU)
Display PCB (AU)
Manual auto switch

Forecast of Cause :

1. Forced auto switch failure 2.Controller PCB failure

Check Point 1 : Check the Forced auto switch

Check if Forced auto switch is kept pressed.
Check ON/OFF switching operation by using a meter.

>>If Forced auto switch is detective, replace it.

OKOK

Check Point 2 : Replace Controller PCB

If Check Point 1 do not improve the symptom, change Control PCB. (AS)

change Control PCB. (AU)
change Display PCB. (AU)

30 consecutive seconds.(AU)

02-31

Trouble shooting 26
INDOOR UNIT Error Method:

INDOOR UNIT

Power supply frequency
detection error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Control PCB Circuit (AS,AR)

Detective details:

The power supply frequency cannot be recognized after 4sec of power ON.

Forecast of Cause :

1. Connection failure 2. External cause 3. Control PCB Circuit (AS,AR)

Check Point 1-1 : Reset the power and operate

Does Error indication show again?

YESYES

Check Point 2 : Check Connection

Check any loose or removed connection line of
Indoor unit and Outdoor unit.

>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data &
Technical Manual.

Check connection between Outdoor Unit Main PCB
and Filter PCB.
(If there is loose connector or open cable)

NO

Check Point 1-2:

Check external cause such as noise

Check the complete insulation of the grounding.

Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).

OK

Check Point 3 : Check the voltage of power supply

Check the voltage of power supply

>> Check if AC208 - 230V appears at Outdoor Unit Terminal L - N.

OK

Check Point 3 : Replace Controller PCB

If Check Point 1 3 do not improve the symptom, change Control PCB Circuit (AS,AR)

02-32

Trouble shooting 27

INDOOR UNIT Error Method:

Communication Error
(Main PCB ---> Display PCB)

Indicate or Display:Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Main PCB Circuit

Detective details:

When the Display PCB cannot receive the signal from the Main PCB.

Display PCB

Forecast of Cause:

1. Connection failure 2. External cause 3. Display PCB failure 4. Main PCB failure

Check Point 1-1 : Reset the power and operate

Does Error indication show again?

YESYES

Check Point 2 : Check Connection

Check connection between Main PCB and
Display PCB.
(If there is loose connector or open cable)

OK

NO

Check Point 1-2:

Check external cause such as noise

Check the complete insulation of the grounding.

Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).

Check Point 3 : Replace Display PCB

>> If Check Point 1, 2 do not improve the symptom, change Display PCB.
(If the symptom does not change, replace Main PCB.)

02-33

Trouble shooting 28

INDOOR UNIT Error Method:

Communication Error
(Main PCB <--- Display PCB)

Indicate or Display:Indicate or Display:

Refer to error code table.

Detective Actuators:

Indoor Unit Main PCB Circuit

Detective details:

When the Main PCB cannot receive the signal from the Display PCB.

Display PCB

Forecast of Cause:

1. Connection failure 2. External cause 3. Display PCB failure 4. Main PCB failure

Check Point 1-1 : Reset the power and operate

Does Error indication show again?

YESYES

Check Point 2 : Check Connection

Check connection between Main PCB and
Display PCB.
(If there is loose connector or open cable)

OK

NO

Check Point 1-2:

Check external cause such as noise

Check the complete insulation of the grounding.

Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).

Check Point 3 : Replace Display PCB

>> If Check Point 1, 2 do not improve the symptom, change Display PCB.
(If the symptom does not change, replace Main PCB.)

02-34

Trouble shooting 29
INDOOR UNIT Error Method:

INDOOR UNIT

VDD permanence stop protection
(Electric air clean)

Indicate or Display:

Refer to error code table.

Detective Actuators:

Electric air clean unit

Detective details:

When the air cleanness monitor trial protection operates 4 times.

Indoor Unit Control PCB Circuit

Forecast of Cause :

1. Electric air clean unit failure 2. Control PCB failure

Check Point 1 : Check the Electric air clean unit

Check the front panel is closed.

Check the Micro switch in Electric air clean unit.
(Check ON/OFF switching operation by using a meter.)

>>If Micro switch is detective, replace Electric air clean unit.

OKOK

Check Point 2 : Replace Controller PCB

If Check Point 1 do not improve the symptom, change Control PCB.

Trouble shooting 30
INDOOR UNIT Error Method:

INDOOR UNIT

Reverse-VDD permanence stop protection

Indicate or Display:

Refer to error code table.

(Electric air clean power supply circuit
abnormal)

Detective Actuators:

Electric air clean unit
Indoor Unit Control PCB Circuit

Forecast of Cause :

1. Electric air clean unit failure 2. Control PCB failure

Check Point 1 : Replace Electric air clean unit

Change Electric air clean unit.

OKOK

Check Point 2 : Replace Controller PCB

If Check Point 1 do not improve the symptom, change Control PCB.

Detective details:

The air clean operation signal was detected for 1 minute at the time
of air clean mode OFF.

02-35

Trouble shooting 31
OUTDOOR UNIT Error Method:

INDOOR UNIT

Discharge temperature error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Discharge Pipe Temperature Thermistor

Detective details:

When the discharge temperature becomes higher than 115°C,
the compressor stops.

Forecast of Cause :

1. Valve is close 2. EEV failure 3. Gas Leak, less 4. Discharge Thermistor failure

5. Outdoor Fan Operation failure 6. Outdoor Heat Exchanger clogged

< Cooling mode >

Check Point 1 : Check if Gas Valve is open

If it is not open, open it and check the operation.

< Heating mode >

Check Point 1 : Check if LIquid Valve is open

If it is not open, open it and check the operation.

OK OK

Check Point 2 : Check EEV and Strainer

Are EEV and Strainer open?
(Refer to PARTS INFORMATION 4)

>>If EEV or Strainer is defective, replace it.

OK

MPa MPa

Check Point 2 : Check EEV and Strainer

Are EEV and Strainer open?
(Refer to PARTS INFORMATION 4)

>>If EEV or Strainer is defective, replace it.

OK

Check Point 3 : Check if gas leak or less gas

Measure Gas pressure, if there is a leak, correct it.

>>If recharging refrigerant, make sure to perform
vacuuming and

recharge the specified amount.

OK

Check Point 4 : Check Discharge Thermistor

Isn’t it fallen off the holder?
Is there a cable pinched?

>> Check characteristics of thermistor (Refer to Trouble shooting 8),
If defective, replace the thermistor

OK

Check Point 5 : Check Outdoor FAN, Heat Exchanger

Is there anything obstructing the air distribution circuit?
Is there any clogging of Outdoor Heat Exchanger?
Is the Fan rotating? (Check by hand and if it is locked, replace the motor)
Check Outdoor Fan Motor.

>>If the Fan Motor is defective, replace it.

02-36

Trouble shooting 32

OUTDOOR UNIT Error Method:

Excessive high pressure protection
on cooling

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Outdoor Fan Motor

Detective details:

Excessive high pressure protection on cooling mode has been
activated.

Heat Exchanger Temp. Thermistor
Outdoor unit Electronic Expansion Valve

Forecast of Cause :

1. Defective connection of electric components 2. Outdoor Fan Operation failure

3. Outdoor Heat Exchanger clogged 4. Thermistor failure 5. EEV failure 6. Main PCB failure

Check Point 1 : Check connections of Outdoor Unit Electrical Components

Check if the terminal connection is loose.
Check if connector is removed.

Check erroneous connection.
Check if cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OK

Check Point 2 : Check Outdoor Fan, Heat Exchanger

Is there anything obstructing the air distribution circuit?
Is there any clogging of Outdoor Heat Exchanger?
Is the Fan rotating by hand when operation is off ?

>> If the Fan Motor is locked, replace it.

OK

Check Point 3 : Check Outdoor Fan

Check Outdoor Fan Motor. (Refer to Trouble shooting 18)

>> If the Fan Motor is failure, replace it.

OKOK

Check Point 4 : Check Thermistor

Check Thermistor. (Refer to Trouble shooting 5)

>> If the Thermistor is failure, replace it.

OKOK

Check Point 5 : Check Electronic Expansion Valve

Check EEV.

(PARTS INFORMATION 4)

OKOK

Check Point 6 : Replace Main PCB

If Check Point 1 5 do not improve the symptom, change Main PCB.

02-37

Trouble shooting 33
OUTDOOR UNIT Error Method:

INDOOR UNIT

Compressor temperature error

Indicate or Display:

Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Compressor Temperature Thermistor

Detective details:

When the compressor temperature becomes higher than 125°C,
the compressor stops.

Forecast of Cause :

1. Valve is close 2. EEV failure 3. Gas Leak, less 4. Compressor Thermistor failure

5. Outdoor Fan Operation failure 6. Outdoor Heat Exchanger clogged

< Cooling mode >

Check Point 1 : Check if Gas Valve is open

If it is not open, open it and check the operation.

< Heating mode >

Check Point 1 : Check if LIquid Valve is open

If it is not open, open it and check the operation.

OK OK

Check Point 2 : Check EEV and Strainer

Are EEV and Strainer open?
(Refer to PARTS INFORMATION 4)

>>If EEV or Strainer is defective, replace it.

OK

MPa MPa

Check Point 2 : Check EEV and Strainer

Are EEV and Strainer open?
(Refer to PARTS INFORMATION 4)

>>If EEV or Strainer is defective, replace it.

OK

Check Point 3 : Check if gas leak or less gas

Measure Gas pressure, if there is a leak, correct it.

>>If recharging refrigerant, make sure to perform
vacuuming and

recharge the specified amount.

OK

Check Point 4 : Check Compressor Thermistor

Isn’t it fallen off the holder?
Is there a cable pinched?

>> Check characteristics of thermistor (Refer to Trouble shooting 12),
If defective, replace the thermistor

OK

Check Point 5 : Check Outdoor FAN, Heat Exchanger

Is there anything obstructing the air distribution circuit?
Is there any clogging of Outdoor Heat Exchanger?
Is the Fan rotating? (Check by hand and if it is locked, replace the motor)
Check Outdoor Fan Motor.

>>If the Fan Motor is defective, replace it.

02-38

Trouble shooting 35
OUTDOOR UNIT Error Method:

4-way valve error

Indicate or Display:Refer to error code table.

Detective Actuators:

Outdoor Unit Main PCB Circuit
Heat Exchanger Temperature
Thermistor (middle)
Indoor Temperature Thermistor
4-way valve

Detective details:

The following condition is monitored every one minute after the
compressor operates consecutively for 19 minutes, and 7 min ST
operates when the condition is detected two times in succession.

< Cooling or Dry operation >
[Indoor heat exchanger temp (middle)] - [Room temp] > +10degC
< Heating operation >
[Indoor heat exchanger temp (middle)] - [Room temp] < -10degC

The compressor restarts after 7 min ST is released.
When the continuance operation time of the compressor becomes
19 minutes, it detect difference between the heat exchanger
temperature (middle) and room temperature again.
when protective function repeats five times, the outdoor unit stops
permanently and displays an error.

Forecast of Cause :

1. Connector connection failure 2. Thermistor failure 3. Coil failure 4. 4-way valve failure

5. Main PCB failure

Check Point 1 : Check connection of Connector

Check if connector is removed.

Check erroneous connection.
Check if thermistor cable is open.

>>Upon correcting the removed connector or mis-wiring, reset the power.

OKOK

Check Point 2 : Check thermistor

Isn’t it fallen off the holder?
Is there a cable pinched?

>> Check characteristics of thermistor
If defective, replace the thermistor

OKOK

Check Point 3 : Check the solenoid coil and 4-way valve

[ Solenoid coil ]

Remove CN30 from PCB and check the resistance value of coil.
Resistance value is about 1.4k

>>If it is Open or abnormal resistance value, replace Solenoid Coil.

[ 4-way valve ]

Check each piping temperature,
and the location of the valve by the temperature difference.

>>If the value location is not proper, replace 4-way valve.

OKOK

Check Point 4 : Replace Main PCB

If Check Point 1- 3 do not improve the symptom, replace Main PCB.

02-39

2-3 TROUBLE SHOOTING WITH NO ERROR CODE

Trouble shooting 36

Indoor Unit - No Power

Forecast of Cause:

1. Power Supply failure 2. External cause

3. Electrical Components defective

Check Point 1 : Check Installation Condition

Isn’t the breaker down?

Check loose or removed connection cable.

>>If abnormal condition is found, correct it by referring
to Installation Manual or Data & Technical Manual.

OKOK

Check Point 2 : Check external cause at Indoor and Outdoor (Voltage drop or Noise)

Instant drop ----- Check if there is a large load electric apparatus in the same circuit.

Momentary power failure ----- Check if there is a defective contact or leak current in
the power supply circuit.

Noise ----- Check if there is any equipment causing harmonic wave near electric line.
(Neon bulb or electric equipment that may cause harmonic wave)
Check the complete insulation of grounding.

OKOK

Check Point 3 : Check Electrical Components

Check Fuse(250V 10A) for the indoor unit power supply line
in the outdoor unit.

>> If Fuse is open, check AC208 - 230V appears at outdoor Unit Terminal L - N
and Power Supply PCB in outdoor unit, and replace Fuse.

OK

Check Voltage of power supply.

>> Check AC208 - 230V appears at Indoor Unit Terminal L - N (Power Supply).

YES

Check Fuse (F101) in Filter PCB. (AR)

>> If Fuse is open, check if the wiring between Terminal and Filter PCB
is loose, and replace Fuse.

Check Fuse (F101) in Power PCB. (AU)

>> If Fuse is open, check if the wiring between Terminal and Power PCB
and Main PCB is loose, and replace Fuse.

Check Fuse (F1) in Control PCB. (AS

>> If Fuse is open, check if the wiring between Terminal and Control PCB
is loose, and replace Fuse.

Check Varistor (VA101, VA102) in Filter PCB. (AS,AR)
Control PCB. (AU)

>> If Varistor is defective, there is a possibility of an abnormal power supply.
Check the correct power supply and replace Varistor.

NO

OK

If the symptom does not change by above Check3, replace Filter PCB. (AR)
, replace Control PCB. (AS)
, replace Power PCB. (AU)

02-40

Trouble shooting 37

Outdoor Unit - No Power

Forecast of Cause:

1. Power Supply failure 2. External cause

3. Electrical Components defective

Check Point 1 : Check Installation Condition

Isn’t the breaker down?
Check loose or removed connection cable.

>>If abnormal condition is found, correct it by referring
to Installation Manual or Data & Technical Manual.

OKOK

Check Point 2 : Check external cause at Indoor and Outdoor (Voltage drop or Noise)

Instant drop ----- Check if there is a large load electric apparatus in the same circuit.

Momentary power failure ----- Check if there is a defective contact or leak current in the power supply circuit.

Noise ----- Check if there is any equipment causing harmonic wave near electric line.
(Neon bulb or electric equipment that may cause harmonic wave)
Check the complete insulation of grounding.

OKOK

Check Point 3 : Check Electrical Components

Check the voltage of power supply.

>> Check if AC208 - 230V appears at Outdoor Unit Terminal L - N.

YESYES

Check Fuse (F2, F4) in Main PCB.

>> If Fuse is open, check loose terminal or removed connector (C

Check Varistor in Main PCB (VA103).

>> If Varistor is defective, there is a possibility of an abnormal power supply.
Check the correct power supply and replace Varistor.
Upon checking the normal power supply, replace Varistor.

N1) , and replace Fuse.

YESYES

Check Active Filter Module. (PARTS INFORMATION 3)

>>If Active Filter Module is abnormal, replace it.

OK

If the symptom does not change by above Check 3, replace Main PCB.

NO

02-41

Trouble shooting 38

Forecast of Cause:

1. Setting/ Connection failure 2. External cause

No Operation (Power is ON)

3. Electrical Component defective

Check Point 1 : Check indoor and outdoor installation condition

Indoor Unit - Check incorrect wiring between Indoor Unit - Remote Control, or terminals between Indoor Units.
Or, check if there is an open cable connection.
Are these Indoor Unit, Outdoor Unit, and Remote Control suitable model numbers to connect?

>> If there is some abnormal condition, correct it by referring to Installation manual and
Data & Technical Manual.

OK

Turn off Power and check/ correct followings.

Is there loose or removed communication line of Indoor Unit and Outdoor Unit?

OK

Check Point 2 : Check external cause at Indoor and Outdoor (Voltage drop or Noise)

Instant drop ----- Check if there is a large load electric apparatus in the same circuit.

Momentary power failure ----- Check if there is a defective contact or leak current in the power supply circuit.

Noise ----- Check if there is any equipment causing harmonic wave near electric line.
(Neon bulb or electric equipment that may cause harmonic wave)
Check the complete insulation of grounding.

OKOK

Check Point 3 : Check Electrical Components at Indoor and Outdoor

Check Voltage at CN10 of Control PCB. < Power supply to Remote Control > (AS)

>> If it is DC12V, Remote Control is failure. (Control PCB is normal) >> Replace Remote Control
>> If it is DC 0V, Control PCB is failure. (Check Remote Control once again) >> Replace Control PCB

>> If the symptom does not change by above Check 1, 2, 3, replace Main PCB of Outdoor unit.

Check Voltage at CN17 of Control PCB. < Power supply to Remote Control > (AR)

>> If it is DC12V, Remote Control is failure. (Control PCB is normal) >> Replace Remote Control
>> If it is DC 0V, Control PCB is failure. (Check Remote Control once again) >> Replace Control PCB

>> If the symptom does not change by above Check 1, 2, 3, replace Main PCB of Outdoor unit.

Check Voltage at CN14 of Power PCB. < Power supply to Remote Control > (AU)

>> If it is DC12V, Remote Control is failure. (Power PCB is normal) >> Replace Remote Control
>> If it is DC 0V, Power PCB is failure. (Check Remote Control once again) >> Replace Power PCB

>> If the symptom does not change by above Check 1, 2, 3, replace Main PCB of Outdoor unit.

02-42

Trouble shooting 39

No Cooling / No Heating

Forecast of Cause:

1. Indoor Unit error 2. Outdoor Unit error

3. Effect by Surrounding environment

4. Connection Pipe / Connection Wire failure 5. Refrigeration cycle failure

Check Point 1 : Check Indoor Unit

Does Indoor Unit FAN run on HIGH FAN?

Is Air Filter dirty?
Is Heat Exchanger clogged?

Check if Energy save function is operated.

OKOK

Check Point 2 : Check Outdoor Unit Operation

Check if Outdoor Unit is operating
(If not, refer to Trouble shooting 30)

Check any objects that obstruct the air flow route.

Check clogged Heat Exchanger.

Is the Valve open?

OKOK

Check Point 3 : Check Site Condition

Is capacity of Indoor Unit fitted to Room size?

Any windows open? Or direct sunlight ?

OKOK

Check Point 4 :
Check Indoor/ Outdoor Installation Condition

Check connection pipe
(specified pipe length & Pipe diameter?)

Check any loose or removed communication line.

>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data & Technical
Manual.

OKOK

psi psi

Check Point 5 : Check Refrigeration Cycle

Check if Strainer is clogged (Refer to the figure at right).

Measure Gas Pressure and if there is a leakage, correct it.

>> When recharging the refrigerant, make sure to perform
vacuuming, and recharge the specified amount.

Check EEV (PARTS INFORMATION 4)

Check Compressor (PARTS INFORMATION 1,2)

Attention

Strainer normally does not have temperature difference
between inlet and outlet as shown in , but if there is a
difference like shown in , there is a possibility of inside
clogged. In this case, replace Strainer.

Pipe (In) Pipe (Out)

Pipe (In) Pipe (Out)

02-43

Trouble shooting 40

Abnormal Noise

Forecast of Cause :

1. Abnormal installation (Indoor/ Outdoor) 2. Fan failure(Indoor/ Outdoor)

3. Compressor failure (Outdoor)

Diagnosis method when Abnormal Noise is occurred

Abnormal noise is coming from Indoor Unit.
(Check and correct followings)

Abnormal noise is coming from Outdoor Unit.
(Check and correct followings)

Is Main Unit installed in stable condition?
Is the installation of Air suction grille and
front panel normal?

OK

Is Fan broken or deformed?
Is the screw of Fan loose?
Is there any object which obstruct the Fan rotation?

Trouble shooting 41

Forecast of Cause:

Water Leaking

Diagnosis method when water leak occurs

Is Main Unit installed in stable condition?
Is Fan Guard installed normally?

OK

Is Fan broken or deformed?
Is the screw of Fan loose?
Is there any object which obstruct the Fan rotation?

OK

Check if vibration noise by loose bolt or contact noise
of piping is happening.

OK

Is Compressor locked?

>> Check Compressor (PARTS INFORMATION 1,2)

1. Erroneous installation 2. Drain hose failure

Diagnosis method when water is spitting out.

Is Main Unit installed in stable condition?
Is Main Unit broken or deformed at the time of
transportation or maintenance?

OKOK

Is Drain Hose connection loose?
Is there a trap in Drain Hose?
Is Drain Hose clogged?

OKOK

Is Fan rotating?

>> Check Fan Motor (PARTS INFORMATION 5)

Is the filter clogged?

OKOK

psi psi

Check Gas Pressure and correct it
if there was a gas leak.

02-44

2-4 SERVICE PARTS INFORMATION

SERVICE PARTS INFORMATION 1

Compressor

Diagnosis method of Compressor ( If Outdoor Unit LED displays Error, refer to Trouble shooting )

Does not start up

Is there open or loose connection
cable?

Check Filter PCB, Main PCB,
connection of Compressor,and winding
resistance. (Refer to the next page).

>> If there is no failure, the defect of
Compressor is considered (Locked
compressor due to clogged dirt or
less oil)

Replace Compressor

Stops soon after starting up

Is there open or loose connection
cable?

Is Gas Pipe Valve open?
(Low Pressure is too low)

psi psi

Check if Refrigerant is leaking.
(Recharge Refrigerant)

Abnormal noise

Check if vibration noise by
loose bolt or contact noise
of piping is happening.

Defective Compressor
can be considered.
(due to inside dirt clogging
or broken component)

Replace Compressor

Check if Strainer is clogged.
(PARTS INFORMATION 4)

Check Filter PCB, Main PCB,
connection of Compressor,and winding
resistance. (Refer to the next page).

>> If there is no failure, the defect of Compressor can be
considered. (Compression part broken or valve defective.)

Replace Compressor

02-45

SERVICE PARTS INFORMATION 2

Inverter Compressor

Check Point 1 : Check Connection

Check terminal connection of Compressor
(loose or incorrect wiring)

Terminal cover opened

UU(RED)(RED)

V V (WHITE)(WHITE)WW

(BLACK)(BLACK)

Check Point 2 : Check Winding Resistance

Check winding resistance of each terminal

If the resistance value is 0 or infinite, replace Compressor.

U

Check connection of Main PCB
(Loose or incorrect wiring)

MAIN PCB

RED

WHITE

W304

W305 W303

Compressor

BLACK

Resistance Value : 0.88
at 68°F(20°C)

W

V

Check Point 3 : Replace Main PCB

If the symptom does not change with above Check 1, 2, replace Main PCB.

02-46

SERVICE PARTS INFORMATION 3

Active Filter Module

Check Point 1 : Check Open or Short-circuit and Diode (D1)

Remove connector, check the open or short-circuit and the diode in the module

(+)

( )

L2L1

Power factor control

D1

P

N1

N2

Io

Check the open or short-circuit

Terminal

Tester(+) Tester(-)

(+)

( )

P

L1

P

L1,L2

L2

( )

N1

(+)

L2

N1

Control Box

N2

1.01M /

(Ref. value 1)

1.65M /

(Ref. value 1)

Check the diode

Terminal

Tester(+) Tester(-)

L2

P

P

L2

1.32M /

(Ref. value 1)

1.01M /

(Ref. value 1)

Resistance value

360k

+

-

20%

0

720k

360k

+

20%

-

761k

(Ref. value 2)

+

20%

-

1.14M

(Ref. value 2)

Resistance value

663k

(Ref. value 2)

762k

(Ref. value 2)

If it is abnormal,replace ACTIVE FILTER MODULE

Check Point 2 : Check the Output DC voltage (between P and N1)

Check the Output DC voltage (between P and N1) of compressor stopping and operating.

>> If the output voltage of compressor operating is less than the output voltage of compressor stopping,
Active Filter Module is detective. >> Replace Active Filter Module

02-47

Ref. value 1
Specifications for Multimeter
Manufacturer : FLUKE
Model name : FLUKE11
Power source : DC9V.

Ref. value 2
Specifications for Multimeter
Manufacturer : Sanwa
Model name : PM3
Power source : DC3V.

SERVICE PARTS INFORMATION 4

Outdoor unit Electronic Expansion Valve
( EEV )

Check Point 1 : Check Connections

Check connection of connector
( Loose connector or open cable )

AOU24RML AOU36RML

CN27

CN50

1
2
3
4
5
6

1
2
4
5
6
7

RED

BROWN

BLUE
ORANGE
YELLOW

WHITE

BLACK
WHITE
WHITE
WHITE
WHITE
WHITE

1
2
3
4
5
6

WHITE

1
2
3
4
5
6

EXPANSION
VALVE COIL

E V

RED
BROWN
BLUE

ORANGE

YELLOW
WHITE

E V

CN27

CN50

CN51

CN52

RED

1

BROWN

2

BLUE

3

ORANGE

4

YELLOW

5

WHITE

6

BLACK

1

WHITE

2

WHITE

4

WHITE

5

WHITE

6

WHITE

7

BLACK

1

GREEN

3

GREEN

4

GREEN

5

GREEN

6

GREEN

7

BLACK

1

BLUE

2

BLUE

5

BLUE

6

BLUE

7

BLUE

8

1
2
3
4
5
6

WHITE

1

2
3
4
5
6

GREEN

1
2
3
4
5
6

BLUE

EXPANSION
VALVE COIL

E V

RED

1

BROWN

2

BLUE

3

ORANGE

4

YELLOW

5

WHITE

6

RED

1

BROWN

2

BLUE

3

ORANGE

4

YELLOW

5

WHITE

6

RED

1

BROWN

2

BLUE

3

ORANGE

4

YELLOW

5

WHITE

6

E V

E V

E V

Check Point 2 : Check Coil of EEV

Remove connector, check each winding
resistance of Coil.

Read wire

Resistance value

White - Red

Yellow - Brown

Orange - Red

46

4

at 68°F(20°C)

Blue - Brown

If Resistance value is abnormal, replace EEV.

Check Point 3 : Check Voltage from Main PCB.

Remove Connector and check Voltage (DC12V)

DC

If it does not appear, replace Main PCB.

Check Point 4 : Check Noise at start up

Turn on Power and check operation noise.

If an abnormal noise does not show, replace Main PCB.

02-48

Check Point 5 : Check Opening and Closing Operation of Valve

When Valve is closed,
it has a temp. difference between Inlet and Outlet.

CLOSE
Example : Hot Gas

If it is open,
it has no temp. difference between Inlet and Outlet.

OPEN
Example : Hot Gas

Pipe (In)

Hi TEMP.

Pipe (Out)

Normal TEMP.

Pipe (In)

Hi TEMP.

Pipe (Out)

Hi TEMP.

Check Point 6 : Check Strainer

Strainer normally does not have temperature difference between inlet and outlet as shown in ,
but if there is a difference as shown in , there is a possibility of inside clogged. In this case, replace Strainer.

Pipe (In) Pipe (Out)

Pipe (In) Pipe (Out)

02-49

R410A

WALL MOUNTED / DUCT /
CASSETTE type

INVERTER (MULTI)

3 . REPLACEMENT PARTS

Models :
ASU9RMLQ
ASU12RMLQ
ASU18RMLQ

REPLACEMENT PARTS

INVERTER

03-01

Models :
ASU9RMLQ
ASU12RMLQ
ASU18RMLQ

REPLACEMENT PARTS

03-02

Model :
ARU9RML

REPLACEMENT PARTS

03-03

Model :
ARU9RML

REPLACEMENT PARTS

03-04

Models :
ARU12RML
ARU18RML

REPLACEMENT PARTS

03-05

Models :
ARU12RML
ARU18RML

REPLACEMENT PARTS

03-06

Models :
ARU9RML
ARU12RML
ARU18RML

REPLACEMENT PARTS

03-07

Models: AUU9RML
AUU12RML
AUU18RML

REPLACEMENT PARTS

40

REPLACEMENT PARTS

Models : AUU9RML
AUU12RML
AUU18RML

CONTROL UNIT

41

CASSETTE TYPE
DECORATION PANEL
UTG-UFUB-W

REPLACEMENT PARTS

38

REPLACEMENT PARTS

CASSETTE TYPE
DECORATION PANEL
UTG-UFUB-W
Flap total assy
Motor holder assy

(connector : white)

(connector : red)

39

Model : AOU24RML
AOU24RML1

REPLACEMENT PARTS

03-08

Model : AOU24RML
AOU24RML1

REPLACEMENT PARTS

03-09

Model : AOU24RML
AOU24RML1

REPLACEMENT PARTS

03-10

Model : AOU24RML
AOU24RML1

REPLACEMENT PARTS

Connector : BLACK

GREEN

BLUE

RED

YELLOW

03-11

Connector : RED

WHITE

Model : AOU36RML
AOU36RML1

REPLACEMENT PARTS

03-12

Model : AOU36RML
AOU36RML1

REPLACEMENT PARTS

03-13

Model : AOU36RML
AOU36RML1

REPLACEMENT PARTS

03-14

Model : AOU36RML
AOU36RML1

REPLACEMENT PARTS

Connector : BLACK

GREEN

BLUE

RED

YELLOW

03-15

Connector : RED

WHITE

REPLACEMENT PARTS

MODEL : AOU24RML

PROCESS

Assemble PWB ASSY
(FILTER PCB)

USED
PARTS

1

INVERTER BOX A

2

FILTER PCB
SCREW,TAPPING

3

REGULATION

As shown in Fig.1, assemble PWB ASSY to INVERTER BOX A.
As shown in Fig.2, pull out the wires of PWB ASSY.

Don't sandwich ARRESTER (SA100) between PWB and INVERTER BOX A.

FILTER PCB

1

INVERTER BOX A

2

Hook

Don't sandwich ARRESTER

between PWB and

INVERTER BOX A.

Fig.1

Pull out the wires of PWB ASSY
this way.

Fig.2

3

SCREW, TAPPING

03-16

REPLACEMENT PARTS

MODEL : AOU24RML

PROCESS

Assemble PCB ASSY

USED
PARTS

(MAIN PWB)

REGULATIONS

Certainly set PWB ASSY under the 3 hooks of INVERTER BOX A.

Before it is temporary fix of PCB ASSY, As shown in the Fig.2-5, pull out the wires of PCB ASSY.

After it is temporary fix of PCB ASSY, As shown in the Fig.6-10, pull out the wires of PCB ASSY.

Don't forget to take a cushion D101(DIODE BRIDGE).

Don't bend foot D101(DIODE BRIDGE).

1

INVERTER BOX A

2

MAIN PCB

3

SCREW, TAPPING

W12 YELLOW,W13 BLUE

(MAIN PWB)

WIRE WITH TERMINAL

Don't forget to take a cushion.

Don't bend foot.

Fig.6

1

INVERTER BOX A

Hook

Fig.8-10

Fig.7

Through this hole.

SCREW, TAPPING

3

MAIN PCB

2

Temporarily fix!

Fig.1

03-17

REPLACEMENT PARTS

MODEL : AOU24RML

REGULATIONS

As shown in Fig.2, pull out the wires.

2

MAIN PCB

W12 YELLOW,W13 BLUE
(MAIN PCB)
WIRE WITH TERMINAL

Through this hole.

Fig.2

W10 BLACK,W11 WHITE
(MAIN PCB)
WIRE WITH TERMINAL

2

INVERTER BOX A

Through this hole.

03-18

REPLACEMENT PARTS

MODEL : AOU24RML

REGULATIONS

As shown in Fig.3, pull out the wires.

W16 RED (MAIN PCB)

WIRE WITH TERMINAL

W200 RED (MAIN PCB)
WIRE WITH TERMINAL

W17 BLACK (MAIN PCB)
WIRE WITH TERMINAL

W201 YELLOW(MAIN PCB)

WIRE WITH TERMINAL

CN1 (MAIN PCB)
WIRE WITH CONNECTOR

Fig.3

W303 BLACK,W304 WHITE,
W305 RED(MAIN PCB)

WIRE WITH CONNECTOR

CN407(MAIN PCB)

WIRE WITH CONNECTOR

HEATSINK THERMISTOR

CN50(MAIN PCB)
WIRE WITH CONNECTOR

CN39(MAIN PCB)
WIRE WITH CONNECTOR

03-19

REPLACEMENT PARTS

MODEL : AOU24RML

REGULATIONS
As shown in Fig.4-5, pull out the wires.

W17 BLACK (MAIN PCB)

WIRE WITH TERMINAL

W16 RED (MAIN PCB)
WIRE WITH TERMINAL

W303 BLACK,
W304 WHITE,W305 RED
(MAIN PCB)

WIRE WITH CONNECTOR

CN407(MAIN PCB)
WIRE WITH CONNECTOR

HEATSINK THERMISTOR

Through this hole.

Fig.4

W200 RED (MAIN PCB)

WIRE WITH TERMINAL

W201 YELLOW(MAIN PCB)
WIRE WITH TERMINAL

CN50(MAIN PCB)

WIRE WITH CONNECTOR

CN39(MAIN PCB)
WIRE WITH CONNECTOR

CN1 (MAIN PCB)
WIRE WITH CONNECTOR

Fig.5

03-20