Fujitsu ABU18RULX Original operating manual

SPLIT TYPE
ROOM AIR CONDITIONER
Universal Floor / Ceiling
& Large Ceiling
type
Models Indoor unit Outdoor unit
ABU18RULX
ABU24RULX
ABU36RSLX
AOU18RLX
AOU24RLX
AOU36RLX
INVERTER
SERVICE
INSTRUCTION
R410A

CONTENTS
1. DESCRIPTION OF EACH CONTROL OPERATION
1. COOLING OPERATION..............................................................................................
3. DRY OPERATION......................................................................................................
2. HEATING OPERATION..............................................................................................
5. INDOOR FAN CONTROL...........................................................................................
4. AUTO CHANGEOVER OPERATION.........................................................................
7. LOUVER CONTROL...................................................................................................
6. OUTDOOR FAN CONTROL.......................................................................................
9. TIMER OPERATION CONTROL................................................................................
8. COMPRESSOR CONTROL........................................................................................
11. TEST OPERATION CONTROL..................................................................................
10. ELECTRONIC EXPANSION VALVE CONTROL........................................................
13. 4-WAY VALVE EXTENSION SELECT.......................................................................
12. PREVENT TO RESTART FOR 3 MINUTES ( 3 MINUTES ST )................................
15. PUMP DOWN ( Refrigerant collecting operation )......................................................
14. AUTO RESTART........................................................................................................
17. DEFROST OPERATION CONTROL..........................................................................
16. COMPRESSOR PREHEATING..................................................................................
18. MANUAL AUTO OPERATION....................................................................................
20. VARIOUS PROTECTIONS.........................................................................................
19. ENERGY SAVE FUNCTION.......................................................................................
01-01
01-02
01-03
01-04
01-05
01-07
01-08
01-10
01-11
01-15
01-15
01-15
01-15
01-16
01-16
01-16
01-18
01-18
01-19
01-15
2-1-3 WIRED REMOTE CONTROLLER DISPLAY......................................................
2-1-2 OUTDOOR UNIT DISPLAY................................................................................
2-1 ERROR DISPLAY......................................................................................................
2. TROUBLE SHOOTING
2-2 TROUBLE SHOOTING WITH ERROR CODE..........................................................
2-3 TROUBLE SHOOTING WITH NO ERROR CODE....................................................
2-4 SERVICE PARTS INFORMATION............................................................................
02-01
02-02
2-1-1 INDOOR UNIT DISPLAY.................................................................................... 02-01
02-03
02-24
02-05
02-29
1-1-1 PARTS LAYOUT DRAWING...............................................................................
1-1-2 WIRING................................................................................................................
1-1-3 DISASSEMBLY PROCESS.................................................................................
1-1-4 ASSEMBLY PROCESS of INVERTER UNIT......................................................
1-1 For AOU18/ 24/ 36RLX...........................................................................................
1 REPLACEMENT PARTS ( For OUTDOOR UNIT ).......................................................
3. REPLACEMENT PARTS
03-01
03-01
03-01
03-04
03-03
03-09
2-1 PARTS LAYOUT DRAWING (For ABU18/ 24RULX)..............................................
2 REPLACEMENT PARTS ( For INDOOR UNIT )........................................................... 03-15
03-15
2-2 PARTS LAYOUT DRAWING (For ABU36RSLX).................................................... 03-20

1 . DESCRIPTION OF EACH
CONTROL OPERATION
R410A
Universal Floor / Ceiling &
Large Ceiling type
INVERTER

1. COOLING OPERATION
1-1 COOLING CAPACITY CONTROL
A sensor (room temperature thermistor) built in the indoor unit will usually perceive
difference or variation between a set temperature and present room temperature, and
controls the operation frequency of the compressor.
* If the room temperature is 3.6 degF(2 degC) higher than a set temperature,
the compressor operation frequency will attain to maximum performance.
* If the room temperature is 3.6 degF(2 degC) lower than a set temperature, the compressor
will be stopped.
* When the room temperature is between +3.6 degF(+2 degC) to -3.6 degF(-2 degC) of
the setting temperature, the compressor frequency is controlled within the range shown in Table1.
However, the maximum frequency is limited in the range shown in Figure 1 based on the
fan speed mode and the outdoor temperature.
minimum
frequency
maximum
frequency
ABU18RULX 20Hz
20Hz
20Hz
63Hz
80Hz
90Hz
ABU24RULX
ABU36RSLX
Outdoor air
temperature
A zone
87.8°F
(31°C) B zone
C zone
D zone
Hi Me Lo
A zone 63Hz
45Hz
35Hz
35Hz
80Hz
55Hz
45Hz
45Hz
90Hz
75Hz
70Hz
63Hz
45Hz
35Hz
45Hz
35Hz
35Hz 35Hz
35Hz
75Hz
70Hz
63Hz
55Hz
35Hz
75Hz
70Hz
63Hz
30Hz
55Hz
45Hz
30Hz
55Hz
55Hz
45Hz
45Hz 45Hz
B zone
C zone
ABU18RULX
D zone
A zone
B zone
C zone
ABU24RULX
D zone
A zone
B zone
C zone
ABU36RSLX
D zone
66.2°F
(19°C)
51.8°F
(11°C)
( Table 1 : Compressor Frequency Range )
( Fig. 1 : Limit of Maximum Frequency based on Outdoor Temperature )
01-01
Fan speed mode

2. HEATING OPERATION
2-1 HEATING CAPACITY CONTROL
A sensor (room temperature thermistor) built in the indoor unit will usually perceive
difference or variation between a set temperature and present room temperature, and
controls the operation frequency of the compressor.
* If the room temperature is lower 5.4 degF(3 degC) than a set temperature,
the compressor operation frequency will attain to maximum performance.
* If the room temperature is higher 3.6 degF(2 degC) than a set temperature, the compressor
will be stopped.
* When the room temperature is between +3.6 degF(+2 degC) to -5.4 degF(-3 degC) of
the setting temperature, the compressor frequency is controlled within the range shown in Table2.
However, the maximum frequency is limited in the range shown in Figure 2 based on
the outdoor temperature.
( Table 2 : Compressor Frequency Range )
( Fig.2 : Limit of Maximum Frequency based on Outdoor Temperature )
01-02
minimum
frequency
maximum
frequency
20Hz
20Hz
20Hz
87Hz
87Hz
95Hz
Outdoor air
temperature
E zone
68°F
(20°C) D zone
C zone
B zone
A zone
A zone 87Hz
85Hz
70Hz
70Hz
60Hz
87Hz
85Hz
70Hz
70Hz
90Hz
80Hz
80Hz
60Hz
95Hz
95Hz
B zone
C zone
ABU18RULX
D zone
E zone
A zone
B zone
ABU24RULX
C zone
D zone
E zone
A zone
B zone
C zone
D zone
E zone
ABU36RSLX
60.8°F
(16°C)
53.6°F
(12°C)
41°F
(5°C)
Limit of Maximum
Frequency
ABU18RULX
ABU24RULX
ABU36RSLX

3. DRY OPERATION
3-1 INDOOR UNIT CONTROL
The compressor rotation frequency shall change according to set temperature and room
temperature variation which the room temperature sensor of the indoor unit has detected
as shown in the Table 3.
Room
temperature Room temperature
Compressor ON
Ts+2.7 degF
(1.5 degC)
Ts+1.8 degF
(1 degC) Compressor OFF
Compressor
ON
ON
OFF
Indoor fan
air flow mode
Air flow mode : Lo
OFF
30 5 30 120 5 (sec)
180 180
( Table 3 : Compressor frequency )
( Fig.3 : Compressor Control based on Room Temperature )
( Fig.4 : Indoor Fan Control )
01-03
Operating frequency
ABU18RULX 25Hz
30Hz
45Hz
ABU24RULX
ABU36RSLX
Ts : Setting temperature

4. AUTO CHANGEOVER OPERATION
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 64°F(18°C) and 88°F(30°C) in 2 degF(1 degC) steps.
When operation starts, only the indoor fan is operated for 1 minute. (Air flow mode: S- Lo)
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 4 : Operation mode selection table )
When COOLING was selected at , the same operation as COOLING OPERATION is performed.
When HEATING was selected at , the same operation as HEATING OPERATION is performed.
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
2
31
4
1
01-04
Room temperature :TR Operation mode
TR > Ts +3.6 degF
(2 degC)
Ts +3.6 degF > TR
(2 degC)
=
=
Ts +3.6 degF > TR > Ts-3.6 degF
(2 degC) (2 degC)
Cooling
Monitoring
Heating
Ts : Setting temperature

5. INDOOR FAN CONTROL
1. Fan speed
( Table 5 : Indoor Fan Speed )
Operation mode Air flow mode Speed (rpm)
Hi 1060
890
770
250
Me
Lo
Heating
S-Lo
2. FAN OPERATION
The airflow can be switched in 4 steps such as AUTO, LOW, MED, HIGH, while the indoor
fan only runs.
01-05
Hi 1060
890
770
250
Me
Lo
Cooling
S-Lo
Operation mode Air flow mode Speed (rpm)
Hi 1100
1000
900
250
Me
Lo
Heating
S-Lo
Hi 1180
1000
900
250
Me
Lo
Cooling
S-Lo
Operation mode Air flow mode Speed (rpm)
Hi 1100
900
700
200
Me
Lo
Heating
S-Lo
Hi 1100
1000
850
200
Me
Lo
Cooling
S-Lo
3. COOLING OPERATION
Switch the airflow [AUTO], and the indoor fan motor will run according to a room temperature,
as shown in Figure 5.
On the other hand, if switched in [HIGH] [LOW], the indoor motor will run at a constant airflow of [COOL]
operation modes LOW, MED, HIGH,as shown in Table 5.
( Fig.5 : Airflow change - over ( Cooling : AUTO ) )
When the room
temperature rises
When the room
temperature drops
TR : Room temperature
Ts : Setting temperature
TR-Ts > 3.6 degF
(2 degC)
=
1.8 degF > TR-Ts
(1 degC)
3.6 degF > TR-Ts > 1.8 degF
(2 degC) (1 degC)
=
TR-Ts > 5.4 degF
(3 degC)
=
3.6 degF > TR-Ts
(2 degC)
5.4 degF > TR-Ts > 3.6 degF
(3 degC) (2 degC)
=
HIGH mode
MED mode
LOW mode
*1
*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.
When [AUTO] is selected, the indoor fan motor runs LO and OFF at 1 minute intervals.
ABU18RULX ABU24RULX
ABU36RSLX

4. HEATING OPERATION
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 6.
On the other hand, if switched in [HIGH] [LOW],
the indoor motor will run at a constant airflow
of [COOL] operation modes LOW, MED, HIGH,
as shown in Table 5.
5. COOL AIR PREVENTION CONTROL (Heating mode)
6. DRY OPERATION
Refer to the Figure 4.
During the dry mode operation, the fan speed setting can not be changed.
01-06
116.6°F
(47°C)
105.8°F
(41°C)
SETTING
FAN MODE
LO mode
S-LOW mode
91.4°F
(33°C)
86°F
(30°C)
86°F
(30°C)
Indoor heat exchanger
temperature
Indoor heat exchanger
temperature
Indoor heat exchanger
temperature
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.
( Fig.6 : Airflow change - over ( Heating : AUTO ) )
( Fig.7 : Cool Air Prevention Control )
Hold
Go down one-step
Go up one-step

6. OUTDOOR FAN CONTROL
1. Outdoor Fan Motor
Following table shows the fan speed of the outdoor unit.
*The outdoor fan speed changs in the range mentioned avobe depending on the compressor
frequency and outdoor temperature.
(When the compressor frequency and outdoor temperature increase, the outdoor fan speed
also changes to the higher speed.
When the compressor frequency and outdoor temperature decrease, the outdoor fan
speed also changes to the lower speed.)
*For ABU18RULX
It runs at 250rpm for 20 seconds after starting up the outdoor fan.
When the outdoor heat exchanger tenperature is lower than 35.6°F (2°C),
the fan speed switches to 780rpm on heating mode.
For ABU24RULX / ABU36RSLX
It runs at 250rpm for 20 seconds after starting up the outdoor fan.
When the outdoor heat exchanger tenperature is lower than 35.6°F (2°C),
the fan speed switches to 900rpm on heating mode.
*
01-07
( Table 6 : Fan speed of the outdoor unit )
780/ 400/ 250/ 220/ 200 rpm
900/ 850/ 780/ 400/ 250/ 220/ 200 rpm 900/ 780/ 400/ 250/ 220/ 200 rpm
780/ 400/ 250/ 220/ 200 rpm
Cooling Heating
ABU18RULX
ABU24RULX
ABU36RSLX

7. LOUVER CONTROL
1. VERTICAL LOUVER CONTROL
Each time the button is pressed, the air direction range will
change as follows:
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.
Cooling / Dry / Fan mode Horizontal flow
Heating mode Downward flow
(Function Range) (Fig.8 : Air Direction Range)
(Operation Range)
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.
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
The indoor fan motor starts after the louver reaches to the setting position.
At the start of operation if the setting louver position is or ,the setting position is set to or
after the louver moves from totally-enclosed position to . (Positioning Control)
( Stop mode means Operation stop.)
1
2
3
4
1
4
5
6
7
3
2
ABU18/ 24RULX
(UNIVERSAL FLOOR/ CEILING TYPE)
ABU36RSLX
(LARGE CEILING TYPE)
12 34
1234
567
1234567
1
2
1
3
1
2
3
6
4
5
3
4
5
6
7
1
7
4
For ABU18/ 24RULX
For ABU18/ 24RULX
For ABU36RSLX
For ABU36RSLX
Cooling / Dry mode
Heating mode
Fan mode
123
1
12
2
3
4
(For ABU18/ 24RULX)
(For ABU36RSLX)
(Swinging Range)
Airflow direction set Range of swing
to
to
to
to
1
4
5
7
7
7
to
to
to
1
1
2
2
3
4
4
4
to
to
to
to
ABU36RSLX
ABU18/ 24RULX

2. HORIZONTAL LOUVER CONTROL
Each time the button is pressed, the air direction range will
change as follows:
Cooling / Dry mode
Heating mode
Fan mode
Use the air direction adjustments within the ranges shown above.
The horizontal airflow direction is set automatically on
after initialization.
(Function Range) (Fig.9 : Air Direction Range)
(Operation Range)
2-1. SWING OPERATION
When the swing signal is received from the remote controller, the horizontal louver starts to swing.
The range of swing depends on the set airflow direction.
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.
01-09
( Stop mode means Operation stop.)
ABU18/ 24RULX
(UNIVERSAL FLOOR/ CEILING TYPE)
ABU36RSLX
(LARGE CEILING TYPE)
12 345
123
3
45
1
345
2
1345
2
1
2
1
3
1
2
5
5
3
4
3
4
5
(Swinging Range)
Airflow direction set Range of swing
to
to
to
to
1 5
to

8. COMPRESSOR CONTROL
1. OPERATION FREQUENCY RANGE
The operation frequency of the compressor is different based on the operation mode as
shown in Table 7.
Cooling Heating
Min Max Min Max Dry
(Table 7 : Compressor Operation Frequency Range)
2. OPERATION FREQUENCY CONTROL AT START UP
The compressor frequency soon after the start-up is controlled as shown in Figure 10.
(Fig.10 : Compressor Control at Start-up)
(Frequency)
(Time)
Frequency
Frequency
Frequency Frequency
01-10
ABU18RULX 20Hz
20Hz
20Hz
63Hz
80Hz
90Hz
ABU24RULX
ABU36RSLX
ABU18RULX
ABU24RULX
ABU36RSLX
ABU18RULX
ABU24RULX
ABU36RSLX
20Hz
20Hz
20Hz
87Hz
87Hz
95Hz
25Hz
30Hz
45Hz
180sec 60sec 120sec 120sec 720sec
40Hz 56Hz
Time A Time B Time C
Time E
Time D
Time A Time B Time C Time D Time E
Hold 1
2
1 Discharge pipe temp. > 50°F (10°C) (Cooling)
86°F (30°C) (Heating)
2 Discharge pipe temp. < 50°F (10°C) (Cooling)
86°F (30°C) (Heating)
=

9. TIMER OPERATION CONTROL
1. ON / OFF TIMER
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
01-11
AR- JW5
9-1 Wireless Remote Controller (accessory parts)
ON / TIMER
OFF / TIMER
PROGRAM TIMER
SLEEP TIMER
The program timer allows the OFF timer and ON timer to be used in combination one time.
Operation 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.
Stop mode Stop mode Stop mode
Operation mode Operation mode
Set time Set time Set time Set time

01-12
3. SLEEP TIMER
If the sleep timer 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.
Set temperature rises
( Ts : Set temperature )
Stop of operation
Set temperature lowers
( Ts : Set temperature )
Ts
Stop of operation
In the cooling operation mode
When the sleep timer is set, the setting temperature is increased 1.8 degF (1 degC).
It increases the setting temperature another 1.8 degF (1 degC) after 1 hour.
After that, the setting temperature is not changed and the operation is stopped at the time
of timer setting.
Ts
+1.8degF(+1degC)
+3.6degF(+2degC)
-3.6degF(-2degC)
-1.8degF(-1degC)
-7.2degF(-4degC)
-5.4degF(-3degC)
Set 60min
In the heating operation mode
When the sleep timer is set, the setting temperature is decreased 1.8 degF (1 degC).
It decreases the setting temperature another 1.8 degF (1 degC) every 30 minutes.
Upon lowering 7.2 degF (4 degC), the setting temperature is not changed and the operation stops
at the time of timer setting.
Set 30min 30min 30min

1. ON / OFF TIMER
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
The weekly timer allows up to two ON and OFF time to set up per day.
Use this timer function to set operating time for each day of the week.
Operation mode
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.
2. WEEKLY TIMER
2-1. WEEKLY TIMER
Stop mode Stop mode Stop mode
Operation mode Operation mode
Set time Set time Set time Set time
01-13
UTB- UUB
9-2 Wired Remote Controller (optional parts)
ON / TIMER
OFF / TIMER
WEEKLY TIMER
TEMPERATURE SET BACK TIMER

01-14
The DAY OFF setting is only available for days for which weekly settings already exist.
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 64°F(18°C) even if
the SET BACK temperature is set to 62°F(17°C) or lower.
The DAY OFF setting can only be set one time. The DAY OFF setting is cancelled automatically
after the set day has passed.
Normal
Next day setting
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.
2-2. DAY OFF setting
3. TEMPERATURE SET BACK TIMER
Stop mode Stop mode
Operation mode
Stop mode
Operation mode
Preceding day Next day
DAY OFF
Stop mode Stop mode
Operation mode
Stop mode
Operation mode
DAY OFF
Setting day
Preceding day Next daySetting day
Case of SET BACK timer on the Cooling operation.
( Setting temperature :72°F(22°C), SET BACK temperature :80°F(26°C))
SET BACK setting
Operation
temperature
Operation
temperature
80°F(26°C)
72°F(22°C)
80°F(26°C)
72°F(22°C)
76°F(24°C)
*1
ON OFF OFFON
*1: During the SET BACK function,
the setting temperature is changed. Chenge the setting temperature:
72°F(22°C) 76°F(24°C)

10. 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 50 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).
11. TEST OPERATION CONTROL
Under the condition where the air conditioner stops, press the MASTER CONTROL button and
the FAN CONTROL button simultaneously for 5 seconds or more, and the test operation control
mode will appear.
During test running, " " will display on the remote controller display.
Set the test operation mode, and the compressor will continue to run regardless of whatever
the room temperature sensor detects.
The test operation mode is released if 60 minutes have passed after setting up the test operation.
The compressor won't enter operation status for 3 minutes after the compressor is stopped,
even if any operation is given.
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.
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 resumed with
the memorized operation contents.
When the power is interrupted and recovered during timer operation, timer operation is canceled,
but only setting time is memorized.
[Operation contents memorized when the power is interrupted]
Operation mode
Set temperature
Set air flow
Timer mode and timer time
Air flow Direction
Swing
Thermistor detected position
12. PREVENT TO RESTART FOR 3 MINUTES ( 3 MINUTES ST )
13. 4-WAY VALVE EXTENSION SELECT
14. AUTO RESTART
01-15
With Wired Remote Controller
With Wireless Remote Controller
Under the condition where the air conditioner runs, short two metal contacts under the battery
compartment lid, 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.

When the outdoor heat exchanger temperature is lower than Operation temperature (Refer to Table 8) and the heating
operation has
been stopped for 3 hours, power is applied to the compressor and 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.
16. COMPRESSOR PREHEATING
(Table 8 : Preheating Operation / Release Temperature)
01-16
Before 24 hour After 24 hour
Operation
temperature
Operation
temperature
Release
temperature
Release
temperature
ABU18RULX
ABU24RULX
ABU36RSLX
ABU18RULX
ABU24RULX
ABU36RSLX
ABU18RULX
ABU24RULX
ABU36RSLX
37.4°F
(3°C)
44.6°F
(7°C)
32°F
(0°C)
39.2°F
(4°C)
17. 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)
Less than 6 min. *1
or 10min. *2
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)
Release Condition
Outdoor heat exchanger temperature sensor value is higher than 53.6°F(12°C) or
Compressor operation time has passed 15 minutes.
*3. Outdoor temp. > 30.2°F (-1°C)
*4. Outdoor temp. < 30.2°F (-1°C)
*2. Compressor stop time: Below 20min. Select 6min.
Above 20min. Select 10min.
After 6 min. *1
or 10min. *2
Compressor integrating
operation :Less than 45min.
Compressor integrating
operation :45min and over
17.6°F(-8°C) *3
14°F (-10°C) *4
Does not operate
=
15. PUMP DOWN ( Refrigerant collecting operation )
*1. It means contiguous operation time.
When the product is stopped:
1. Press the PUMP DOWN switch (SW2) on the outdoor unit.
(The LED on the outdoor unit circuit board flickers every 1second.)
2. The pump down operation (cooling operation) begins right away.
After operation starts, close the 3-way valve (liquid).
3. After 2-3minutes, operation stops. Close the 3-way valve (gas) within 1minute after operations stops.
4. The LED will go out 3minutes after it stops. Disconnect the power supply after confirming that the LED has gone out.
When the product is operating:
1. Press the PUMP DOWN switch (SW2) on the outdoor unit. The LED on the outdoor unit circuit board flickers
every 1second, and operation stops.
At this point, recovery has not been completed, so do not close the 2 and 3-way valves.
2. The pump down operation (cooling operation) begins after 3minutes.
Close the 3-way valve (liquid) after operation starts.
3. After 2-3minutes, operation stops. Close the 3-way valve (gas) within 1minute after operations stops.
4. The LED will go out 3minutes after it stops. Disconnect the power supply after confirming that the LED has gone out.
Perform the following procedures to collect the refrigerant when moving the indoor unit or the outdoor unit.

3. Defrost Flow Chart
The defrosting shall proceed by the integrating operation time and
outdoor heat exchanger temperature as follows.
(Not defrosted for 6 or 10 minutes)
3 sec later Compressor OFF
3 sec later Outdoor fan motor OFF
28 sec later 4-way valve OFF
34 sec later compressor ON
(Frequency : 92 Hz)
Heating operation start : Compressor ON
Defrost Indicator:
[Operation lamp]
9 sec ON / 1 sec OFF
Outdoor heat exchanger temperature: Over 53.6°F (12°C)
or
Compressor ON time: Over 15 minutes
Defrost end
01-17
Compressor integrating operation: 45 minutes and over
Outdoor heat exchanger temperarure:
Below 14°F (-10°C)
Outdoor heat exchanger temperarure:
Below 17.6°F (-8°C)
Defrost start
Outdoor temp. > 30.2°F (-1°C)
=Outdoor temp. < 30.2°F (-1°C)