Mitsubishi Electric MSZ-HJ25VA User manual

CONTENTS
1. TECHNICAL CHANGES ······························3
2. PART NAMES AND FUNCTIONS··················4
3. SPECIFICATION ········································5
4. NOISE CRITERIA CURVES··························7
5. OUTLINES AND DIMENSIONS·····················9
6. WIRING DIAGRAM···································10
7. REFRIGERANT SYSTEM DIAGRAM···········12
8. SERVICE FUNCTIONS······························14
9. MICROPROCESSOR CONTROL ················16
10. TROUBLESHOOTING·······························20
11. DISASSEMBLY INSTRUCTIONS·················34
MSZ-HJ25VA -E1 , E2 , ER1 , ER2
MSZ-HJ35VA -E1 , E2 , ER1 , ER2
MSZ-HJ50VA -E1 , E2 , ER1 , ER2
MSZ-HJ60VA -E1 , E2 , ER1
MSZ-HJ71VA -E1 , E2 , ER1
Outdoor unit service manual
MUZ-HJ·VA Series (OBH648)
MXZ-HJ•VA Series (OBH709)
SERVICE MANUAL No. OBH647
REVISED EDITION-D
PARTS CATALOG (OBB647)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
Models
Revision D:
• MSZ-HJ25/35/50/60/71VA- E2 and MSZ-
HJ25/35/50VA- ER2 have been added.
Please void OBH647 REVISED EDITION-C.
MSZ-HJ25VA
MSZ-HJ35VA
MSZ-HJ50VA
INDOOR UNIT

2
<Preparation before the repair service>
Prepare the proper tools.
Prepare the proper protectors.
Provide adequate ventilation.
After stopping the operation of the air conditioner, turn off the power-supply breaker and remove the power plug.
Discharge the capacitor before the work involving the electric parts.
<Precautions during the repair service>
Do not perform the work involving the electric parts with wet hands.
Do not pour water into the electric parts.
Do not touch the refrigerant.
Do not touch the hot or cold areas in the refrigeration cycle.
When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to
touch the live parts.
Use the specified refrigerant only
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by
failure to follow the instructions.
Revision A:
• MSZ-HJ50V A- E1 has been added.
Revision B:
• MSZ-HJ25VA- ER1 , MSZ-HJ35VA- ER1 and MSZ-HJ50VA- ER1 have been added.
Revision C:
• MSZ-HJ60VA- E1 , ER1 and MSZ-HJ71VA- E1 , ER1 have been added.
Revision D:
• MSZ-HJ25/35/50/60/71VA- E2 and MSZ-HJ25/35/50VA- ER2 have been added.
OBH647D

3
1TECHNICAL CHANGES
MSZ-HJ25VA - E1 , ER1
MSZ-HJ35VA - E1 , ER1
MSZ-HJ50VA - E1 , ER1
1. New model
MSZ-HJ60VA - E1 , ER1
MSZ-HJ71VA - E1 , ER1
1. New model
MSZ-HJ25VA -E1 MSZ-HJ25VA -E2
MSZ-HJ35VA -E1 MSZ-HJ35VA -E2
MSZ-HJ50VA -E1 MSZ-HJ50VA -E2
MSZ-HJ60VA -E1 MSZ-HJ60VA -E2
MSZ-HJ71VA -E1 MSZ-HJ71VA -E2
1. Optional air cleaning filter has been added.
MSZ-HJ25VA - ER1 MSZ-HJ25VA - ER2
MSZ-HJ35VA - ER1 MSZ-HJ35VA - ER2
MSZ-HJ50VA - ER1 MSZ-HJ50VA - ER2
1. Optional air cleaning filter has been added.
OBH647D

4
Operation indicator lamp
Remote control
receiving section
Emergency
operation switch
Horizontal vane
Air inlet
Air ¿lter
Front panel
Air outlet Heat exchanger
Emergency operation switch
Remote controller
Air cleaning ¿lter
(Silver-ionized air
purifier filter, option)
(HJ25/35/50VA- E2 , ER2 )
Operation indicator lamp
Remote control
receiving section
Emergency
operation switch
Horizontal vane
Air inlet
Air ¿lter
Front panel
Air outlet Heat exchanger
Emergency operation switch
Remote controller
Air cleaning ¿lter
(Silver-ionized air purifier
filter, option) (HJ60/71VA- E2 )
ACCESSORIES
MSZ-HJ25VA MSZ-HJ35VA MSZ-HJ50VA
MSZ-HJ60VA MSZ-HJ71VA
Installation plate 1
Installation plate fixing screw 4 ×25 mm 5
Battery (AAA) for remote controller 2
Wireless remote controller 1
Felt tape (Used for left or left-rear piping) 1
2PART NAMES AND FUNCTIONS
OBH647D

5
3SPECIFICATION
Indoor model MSZ-HJ25VA MSZ-HJ35VA MSZ-HJ50VA
Power supply Single phase 230 V, 50 Hz
Breaker Capacity A 10 12
Electrical data
Power input 1 (Total) Cooling W730 1,040 2,050
Heating 870 995 1,480
Running current 1
(Total) Cooling A3.7 4.9 9.0
Heating 4.2 4.8 6.6
Power factor 1 (Total) Cooling %85 92 99
Heating 90 97
Starting current 1 (Total) A 4.2 4.9 9.0
Fan motor
Model RC0J40-EF
Current 1 Cooling A0.19 0.24 0.27
Heating 0.20 0.22 0.34
Dimensions W × H × D mm 799 × 290 × 232
Weight kg 9
Special remarks
Air direction 5
Airflow
Cooling
Super High
m3/h
571 654 772
High 438 470 667
Med. 328 341 547
Low 227 380
Heating
Super High
m3/h
598 619 861
High 451 667
Med. 328 497
Low 208 364
Sound level
Cooling
Super High
dB(A)
43 45
High 37 38 40
Med. 30 31 36
Low 22 28
Heating
Super High
dB(A)
43 44 47
High 37 41
Med. 30 34
Low 23 27
Fan speed
Cooling
Super High
rpm
1,080 1,200 1,120
High 880 930 1,000
Med. 710 730 860
Low 550 660
Heating
Super High
rpm
1,120 1,150 1,220
High 900 1,000
Med. 710 800
Low 520 640
Fan speed regulator 4
Remote controller model MP13A ( E1 , ER1 ) / MS16B ( E2 , ER2 )
NOTE : Test conditions are based on ISO 5151.
Cooling : Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C
Heating : Indoor Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
1 Measured under rated operating frequency.
Specifications and rated conditions of main electric parts
Fuse (F11) T3.15AL250V
Horizontal vane motor (MV) 12 VDC
Varistor
(NR11) S10K300E2K1 (ERZV10D471)
Terminal block (TB) 5P
OBH647D

6
Indoor model MSZ-HJ60VA MSZ-HJ71VA
Power supply Single phase 230 V, 50 Hz
Breaker Capacity A 16
Electrical data
Power input 1 (Total) Cooling W1,900 2,330
Heating 1,970 2,440
Running current 1
(Total) Cooling A8.4 10.3
Heating 8.7 10.8
Power factor 1 (Total) Cooling %98
Heating 98
Starting current 1 (Total) A 8.7 10.8
Fan motor
Model RC0J30-MD
Current 1 Cooling A0.49
Heating 0.49
Dimensions W × H × D mm 923 × 305 × 250
Weight kg 13
Special remarks
Air direction 5
Airflow
Cooling
Super High
m3/h
1,192
High 900
Med. 729
Low 555 598
Heating
Super High
m3/h
1,192
High 957 981
Med. 752 763
Low 565 619
Sound level
Cooling
Super High
dB(A)
50
High 44
Med. 38
Low 31 33
Heating
Super High
dB(A)
49
High 44
Med. 38
Low 31 33
Fan speed
Cooling
Super High
rpm
1,250
High 1,000
Med. 850
Low 690 730
Heating
Super High
rpm
1,250
High 1,050 1,070
Med. 870 880
Low 700 750
Fan speed regulator 4
Remote controller model MP14B ( E1 ) / MS16B ( E2 )
NOTE : Test conditions are based on ISO 5151.
Cooling : Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C
Heating : Indoor Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
1 Measured under rated operating frequency.
Specifications and rated conditions of main electric parts
Fuse (F11) T3.15AL250V
Horizontal vane motor (MV) 12 VDC
Varistor
(NR11) S10K300E2K1 (ERZV14D471)
Terminal block (TB) 5P
OBH647D

7
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
43
43
NC-10
MSZ-HJ25VA
INDOOR UNIT WALL
MICROPHONE
0.8m
1m
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
Test conditions
Cooling : Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Heating : Dry-bulb temperature 20°C
44
45
NC-10
MSZ-HJ35VA
4NOISE CRITERIA CURVES
MSZ-HJ50VA
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
45
47
NC-10
OBH647D

8
MSZ-HJ60VA MSZ-HJ71VA
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
50
49
NC-10
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
50
49
NC-10
INDOOR UNIT WALL
MICROPHONE
0.8m
1m
Test conditions
Cooling : Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Heating : Dry-bulb temperature 20°C
OBH647D

9
MSZ-HJ25VA MSZ-HJ35VA MSZ-HJ50VA Unit : mm
5OUTLINES AND DIMENSIONS
2325
69
41
799
785 7
290
12063049
57
80
42
43
69
57
42
7
103
130
100
(57°)
225 225 80.5 80.5
61.5 59.5340338
41
42
249
248 21.5
3
167 157
207.5
206.5
172
14
140
57 18
46
Air in
Installation plate
Piping
Drain hose
Air out
11×26 Oblong hole 11×20 Oblong hole
Installation plate
Indoor unit
Wall hole Ø65
Piping
Insulation Ø35 O.D
Liquid line Ø7 - 0.39m (Flared connection Ø6.35)
Gas line Ø9.52 - 0.34m (Flared connection Ø9.52)
Drain hose
Insulation Connected part Ø16 O.D active length 370
MSZ-HJ25/35VA
MSZ-HJ50VA
Piping
Insulation Ø37 O.D
Liquid line Ø7 - 0.39m (Flared connection Ø6.35)
Gas line Ø9.52 - 0.34m (Flared connection Ø12.7)
Drain hose
InsulationØ28 Connected part Ø16 O.D active length 370
Piping
Insulation Ø50 O.D
Liquid line Ø8 - 0.39m (Flared connection Ø6.35)
Gas line Ø12 - 0.34m (Flared connection Ø15.88)
Drain hose
Insulation Connected part Ø16 O.D
MSZ-HJ60VA
MSZ-HJ71VA
Piping
Insulation Ø50 O.D
Liquid line Ø8 - 0.39m (Flared connection Ø9.52)
Gas line Ø12 - 0.34m (Flared connection Ø15.88)
Drain hose
Insulation Connected part Ø16 O.D
MSZ-HJ60VA MSZ-HJ71VA
OBH647D

10
MSZ-HJ25VA - E1 ,ER1 MSZ-HJ35VA - E1 ,ER1 MSZ-HJ50VA - E1 ,ER1
6WIRING DIAGRAM
MSZ-HJ25VA - E2 ,ER2 MSZ-HJ35VA - E2 ,ER2 MSZ-HJ50VA - E2 ,ER2
OBH647D

11
MSZ-HJ60VA - E1 , ER1 MSZ-HJ71VA - E1 , ER1
MSZ-HJ60VA - E2 MSZ-HJ71VA - E2
OBH647D

12
MSZ-HJ25VA MSZ-HJ35VA
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Flared connection
Refrigerant flow in cooling
Refrigerant flow in heating
Refrigerant pipe ø9.52
(with heat insulator)
Refrigerant pipe ø6.35
(with heat insulator)
Indoor coil
thermistor
RT12
Indoor coil
thermistor
RT13
Unit : mm
MSZ-HJ50VA
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Flared connection
Refrigerant flow in cooling
Refrigerant flow in heating
Refrigerant pipe ø12.7
(with heat insulator)
Refrigerant pipe ø6.35
(with heat insulator)
Indoor coil
thermistor
RT12
Indoor coil
thermistor
RT13
7REFRIGERANT SYSTEM DIAGRAM
OBH647D

13
MSZ-HJ60VA MSZ-HJ71VA
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Flared connection
Refrigerant flow in cooling
Refrigerant flow in heating
Refrigerant pipe ø15.88
(with heat insulator)
Refrigerant pipe ø6.35 (MSZ-HJ60VA)
ø9.52 (MSZ-HJ71VA)
(with heat insulator)
Indoor coil
thermistor
RT12
Indoor coil
thermistor
RT13
Unit : mm
OBH647D

14
8-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, P.C. boards of remote controller must be
modified according to the number of the indoor unit.
8-1. TIMER SHORT MODE
For service, the following set time can be shortened by bridging the timer short mode point on the electronic control P.C.
board. (Refer to 10-7.)
Set time : 3-minute →3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is
shortened by bridging the timer short mode point.)
NOTE: While the relay 52C is ON, the compressor starting time cannot be shortened.
Table 1 1 unit operation 2 units operation 3 units operation 4 units operation
No. 1 unit No modification Same as at left Same as at left Same as at left
No. 2 unit – Solder J1 Same as at left Same as at left
No. 3 unit – – Solder J2 Same as at left
No. 4 unit – – – Solder both J1 and J2
How to set the remote controller exclusively for particular indoor unit
After you turn the breaker ON, the first remote controller that sends the signal to the indoor unit will be regarded as the remote
controller for the indoor unit.
The indoor unit will only accept the signal from the remote controller that has been assigned to the indoor unit once they are
set.
The setting will be cancelled if the breaker is turned OFF, or the power supply is shut down.
Please conduct the above setting once again after the power has been restored.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.
MSZ-HJ25VA MSZ-HJ35VA MSZ-HJ50VA MSZ-HJ60VA MSZ-HJ71VA
J2
J1
8SERVICE FUNCTIONS
NOTE : For modification, take out the batteries
and press the OPERATE/STOP (ON/
OFF) (HJ·VA- E1 , ER1 ) / STOP/
OPERATE (OFF/ON) (HJ·VA- E2 , ER2 )
button 2 or 3 times at first.
After finish modification, put back the
batteries then press the RESET button.
OBH647D

15
NOTE:
• The operation settings are memorized when 10 seconds have passed after the indoor unit was operated with the remote
controller.
• If main power is turned OFF or a power failure occurs while AUTO START/STOP timer is active, the timer setting is can-
celled.
• If the unit has been turned OFF with the remote controller before power failure, the auto restart function does not work
as the power button of the remote controller is off.
• To prevent the breaker from tripping OFF due to the rush of starting current, systematize other home appliance not to
turn ON at the same time.
• When some air conditioners are connected to the same supply system, if they are operated before power failure, the
starting current of all the compressors may flow simultaneously at restart.
Therefore, the special counter measures are required to prevent the main voltage-drop or the rush of the starting current
by adding to the system that allows the units to start one by one.
JR77
Indoor electronic
control P.C. board
CN10ACN111
CN151
CN112
CN110
8-3. AUTO RESTART FUNCTION
When the indoor unit is controlled with the remote controller, the operation mode, the set temperature, and the fan speed
are memorized by the indoor electronic control P.C. board. “AUTO RESTART FUNCTION” automatically starts operation in
the same mode just before the shutoff of the main power.
Operation
If the main power has been cut, the operation settings remain.
After the power is restored, the unit restarts automatically according to the memory.
(However, it takes at least 3 minutes for the compressor to start running.)
How to disable “AUTO RESTART FUNCTION”
Turn off the main power for the unit.
Cut the Jumper wire to JR77 on the indoor electronic control P.C. board. (Refer to 10-7.)
OBH647D

16
NOTE: Last setting will be stored after the unit is turned OFF with the remote controller. Indoor unit receives the signal of the
remote controller with beeps.
WIRELESS REMOTE CONTROLLER
MSZ-HJ25VA MSZ-HJ35VA MSZ-HJ50VA MSZ-HJ60VA MSZ-HJ71VA
Time set buttons
RESET button
Vane control button
Signal transmitting section
Operation display section
Temperature buttons
OPERATE/STOP (ON/OFF) button
Fan speed control button
Operation select button
Timer mode select button
ECONO COOL button
9MICROPROCESSOR CONTROL
MSZ-HJ25/35/50VA- E1 , ER1
MSZ-HJ60/71VA- E1 , ER1
Time set buttons
RESET button
Vane control button
Signal transmitting section
Operation display section
Temperature buttons
OPERATE/STOP (ON/OFF) button
Fan speed control button
Operation select button
Timer mode select button
ECONO COOL button
OBH647D

17
NOTE: Last setting will be stored after the unit is turned OFF with the remote controller. Indoor unit receives the signal of the
remote controller with beeps.
Operation Indicator lamp
The operation indicator at the right side of the indoor unit indicates the operation state.
•The following indication applies regardless of shape of the indication.
Indication Operation state Room temperature
The unit is operating to
reach the set temperature. About 2°C or more away from set temperature
The room temperature is
approaching the set tem-
perature. About 1 to 2°C from set
temperature
Standby mode
(Only during multi system
operation)
-
Lighted
Blinking
Not lighted
9-1. COOL ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) (HJ·VA- E1 , ER1 ) / STOP/OPERATE (OFF/ON) (HJ·VA- E2 , ER2 ) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select COOL mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 16 ~ 31°C.
1. Coil frost prevention
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the coil
from frosting.
When the temperature of indoor heat exchanger becomes too low, the coil frost prevention mode works. The indoor fan
operates at the set speed and the compressor stops. This mode continues until the temperature of indoor heat exchanger
rises.
INDOOR UNIT DISPLAY SECTION
MSZ-HJ25/35/50VA- E2 , ER2 MSZ-HJ60/71VA- E2
Time set buttons
RESET button
Vane control button
Signal transmitting section
Operation display section
Temperature buttons
STOP/OPERATE (OFF/ON) button
Fan speed control button
Operation select button
Timer mode select button
ECONO COOL button
9-2. DRY ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) (HJ·VA- E1 , ER1 ) / STOP/OPERATE (OFF/ON) (HJ·VA- E2 , ER2 ) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select DRY mode with OPERATION SELECT button.
(3) The set temperature is determined from the initial room temperature.
1. Coil frost prevention
Coil frost prevention works the same way as that in COOL mode. (9-1.1.)
OBH647D

18
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the selected
angle.
Confirmation of standard position is performed in the following cases:
(a) When the operation starts or finishes (including timer operation).
(b) When the test run starts.
(c) When standby mode (only during multi system operation) starts or finishes.
(4) VANE AUTO ( ) mode
In VANE AUTO mode, the microprocessor automatically determines the vane angle to make the optimum room tempera-
ture distribution.
9-4. AUTO VANE OPERATION
1. Horizontal vane
(1) Vane motor drive
These models are equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of
the motor are controlled by pulse signals (approximately 12 V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.
Horizontal
position
In COOL and DRY operation
Vane angle is fixed to Horizontal position. In HEAT operation Vane angle is fixed to Angle 4.
AUTO 1 2 3 4 5 SWING
(5) STOP (operation OFF) and ON TIMER standby
In the following cases, the horizontal vane returns to the closed position.
(a) When OPERATE/STOP (ON/OFF) (HJ·VA- E1 , ER1 ) / STOP/OPERATE (OFF/ON) (HJ·VA- E2 , ER2 ) button is
pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When ON TIMER is ON standby.
(6) Dew prevention
During COOL or DRY operation with the vane angle at Angle 3 ~ 5 when the compressor cumulative operation time
exceeds 1 hour, the vane angle automatically changes to Angle 2 for dew prevention.
(7) SWING ( ) mode
By selecting SWING mode with VANE CONTROL button, the horizontal vane swings vertically.
9-3. HEAT ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) (HJ·VA- E1 , ER1 ) / STOP/OPERATE (OFF/ON) (HJ·VA- E2 , ER2 ) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select HEAT mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 16 ~ 31°C.
1. Cold air prevention control
When the compressor is not operating or is starting, and the temperature of indoor heat exchanger and/or the room tem-
perature is low or when defrosting is being done, the indoor fan will stop or rotate in Very Low speed.
2. High pressure protection
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the con-
densing pressure from increasing excessively.
When the temperature of indoor heat exchanger becomes too high, the high pressure protection works.
The indoor fan operates following the cold air prevention control. This mode continues until the temperature of indoor
heat exchanger falls.
3. Defrosting
Defrosting starts when the temperature of outdoor heat exchanger becomes too low.
The compressor stops once, the indoor/outdoor fans stop, the 4-way valve reverses, and the compressor re-starts.
This mode continues until the temperature of outdoor heat exchanger rises or the fixed time passes.
OBH647D

19
(8) Cold air prevention in HEAT operation.
The horizontal vane position is set to Upward.
NOTE: When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat off,
this control does not work in the indoor unit.
(9) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher.
Also the horizontal vane swings in various cycle.
SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher, the air
conditioner can keep comfort. As a result, energy can be saved.
ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE CONTROL button is
pressed or change to other operation mode.
9-5. TIMER OPERATION (ON/OFF TIMER)
1. How to set the timer
(1) Press OPERATE/STOP (ON/OFF) (HJ·VA- E1 , ER1 ) / STOP/OPERATE (OFF/ON) (HJ·VA- E2 , ER2 ) button to start
the air conditioner.
(2) Select the timer mode by pressing the button during operation.
Each time this button is pressed, the timer mode is changed in sequence:
(OFF TIMER) →(ON TIMER) →TIMER RELEASE
(3) Set the time of the timer using the button.
Each time this button is pressed, the set time increase or decrease by 1 hour to 12 hours.
2. To release the timer
Press the button until (OFF TIMER) and (ON TIMER) are not displayed.
NOTE :
• The OFF TIMER and the ON TIMER cannot be set at the same time.
• The displayed time is the time remaining and will decrease in 1-hour increments as time passes.
EMERGENCY OPERATION switch
9-6. EMERGENCY/TEST OPERATION
In the case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the right side of the
indoor unit. Emergency operation is available when the remote controller is missing or has failed, or when the batteries in
the remote controller are running down. The unit will start and OPERATION INDICATOR lamp will light up.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan runs at High
speed and the temperature control does not work.
After 30 minutes of test run operation, the system shifts to EMERGENCY COOL/HEAT MODE with a set temperature of
24°C. The fan speed shifts to Med.
The coil frost prevention works even in the test run or the emergency operation.
In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode.
Emergency operation continues until EMERGENCY OPERATION switch is pressed once or twice or the unit receives any
signal from the remote controller. In the latter case, normal operation will start.
NOTE: Do not press EMERGENCY OPERATION switch during normal operation.
Operation mode COOL HEAT
Set temperature 24°C 24°C
Fan speed Med. Med.
Horizontal vane Auto Auto
The operation mode is indicated by the
Operation Indicator lamp as follows:
Operation Indicator lamp
EMERGENCY COOL
↓
EMERGENCY HEAT
↓
STOP
Lighted
Not lighted
9-7. 3-MINUTE TIME DELAY OPERATION
When the system turns OFF, compressor will not restart for 3 minutes as 3-minute time delay function operates to protect
compressor from overload.
OBH647D

20
3. Troubleshooting procedure
1) Check if the OPERATION INDICATOR lamp on the indoor unit is flashing ON and OFF to indicate an abnormality.
To make sure, check how many times the OPERATION INDICATOR lamp is flashing ON and OFF before starting
service work.
2) Before servicing, check that the connector and terminal are connected properly.
3) When the P.C. board seems to be defective, check the copper foil pattern for disconnection and the components for
bursting and discoloration.
4) When troubleshooting, Refer to 10-2, 10-3 and 10-4.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
Insert the minus pole of the
batteries first. Check if the polarity
of the batteries is correct.
NOTE: 1. If RESET button is not pressed, the remote controller may not operate correctly.
2. This remote controller has a circuit to automatically reset the microcomputer when batteries are replaced.
This function is equipped to prevent the microcomputer from malfunctioning due to the voltage drop caused by the
battery replacement.
3. Do not use the leaking batteries.
Press RESET button with a thin instrument, and
then use the remote controller.
Remove the back lid and insert batteries.
Then reattach the back lid.
10-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following:
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and then after
confirming the horizontal vane is closed, turn OFF the breaker and/or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the P.C. board.
3) When removing the P.C. board, hold the edge of the board with care NOT to apply stress on the components.
4) When connecting or disconnecting the connectors, hold the connector housing. DO NOT pull the lead wires.
MSZ-HJ25VA MSZ-HJ35VA MSZ-HJ50VA MSZ-HJ60VA MSZ-HJ71VA
10 TROUBLESHOOTING
Lead wiring Connector housing
<Incorrect> <Correct>
OBH647D