Mitsubishi MLZ-KA25VA User manual

No. OBH483
REVISED EDITION-D
Models
MLZ-KA25VA - E1 , E2 , E3 , E4
MLZ-KA25VA - ER3 , ER4
MLZ-KA35VA - E1 , E2 , E3 , E4
MLZ-KA35VA - ER3 , ER4
MLZ-KA50VA - E1 , E2 , E3 , E4
MLZ-KA50VA - ER3 , ER4
Please void OBH483 REVISED EDITION-C.
Revision D:
• MLZ-KA25/35/50VA- E4 , ER4 have been
added.
INDOOR UNIT
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
MLZ-KA25VA
MLZ-KA35VA
MLZ-KA50VA
SERVICE MANUAL
Outdoor unit service manual
MXZ-A VA Series (OB377)
MXZ-B VA Series (OBH554)
MXZ-8B VA Series (OCH480)
MXZ-D VA Series (OBH626)
PARTS CATALOG (OBB483)
CONTENTS
1. TECHNICAL CHANGES ···································2
2. PART NAMES AND FUNCTIONS ·····················3
3. SPECIFICATION ················································4
4. NOISE CRITERIA CURVES ······························5
5. OUTLINES AND DIMENSIONS ························6
6. WIRING DIAGRAM ············································7
7. REFRIGERANT SYSTEM DIAGRAM ··············11
8. SERVICE FUNCTIONS ···································12
9. MICROPROCESSOR CONTROL ···················15
10. TROUBLESHOOTING ·····································21
11. DISASSEMBLY INSTRUCTIONS ····················36

2
Revision A :
• MLZ-KA25/35/50VA- E2 have been added.
1TECHNICAL CHANGES
MLZ-KA25VA- E1
MLZ-KA35VA- E1
MLZ-KA50VA- E1
1. New model
MLZ-KA25VA- E1 MLZ-KA25VA- E2
MLZ-KA35VA- E1 MLZ-KA35VA- E2
MLZ-KA50VA- E1 MLZ-KA50VA- E2
1. Fan motor has been changed (RC0J30-KC RC0J30-KK).
2. Control of auto fan speed has been changed. (When indoor units are connected with a multi type outdoor
unit, and operated in heat mode.)
Air flow in auto fan speed is changed depending on air outlet temperature of indoor unit.
3. Electronic control P.C. board has been changed.
MLZ-KA25VA- E2 MLZ-KA25VA- E3
MLZ-KA35VA- E2 MLZ-KA35VA- E3
MLZ-KA50VA- E2 MLZ-KA50VA- E3
1. Software has been changed for ERP.
MLZ-KA25VA- ER3
MLZ-KA35VA- ER3
MLZ-KA50VA- ER3
1. New model
MLZ-KA25VA- E3 MLZ-KA25VA- E4
MLZ-KA35VA- E3 MLZ-KA35VA- E4
MLZ-KA50VA- E3 MLZ-KA50VA- E4
MLZ-KA25VA- ER3 MLZ-KA25VA- ER4
MLZ-KA35VA- ER3 MLZ-KA35VA- ER4
MLZ-KA50VA- ER3 MLZ-KA50VA- ER4
1. Remote controller has been changed.
2. Electronic control P.C. board and display receiver P.C. board have been changed.
3. Vane motor (horizontal) has been changed.
Revision B :
• MLZ-KA25/35/50VA- E3 have been added.
Revision C :
• MLZ-KA25/35/50VA- ER3 have been added.
Revision D :
• MLZ-KA25/35/50VA- E4 , ER4 have been added.
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.
OBH483D

3
2PART NAMES AND FUNCTIONS
ACCESSORIES
Alkaline battery (AAA) for remote controller
Drain hose (with insulation)
Special washer (with cushion, 4pcs)
Installation template
Fixing screw for M5 х 30 mm
Band
Fixing screw for 4 х 16 mm
Remote controller
Remote controller holder
Fixing screw for 3.5 x 16 mm (Black)
MLZ-KA25VA
MLZ-KA35VA
2
1
8
1
4
1
2
1
1
2
MLZ-KA50VA
INDOOR UNIT
MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA
MLZ-KA25/35/50VA- E1 , E2 , E3 , ER3
Vertical vane
Air outlet
Horizontal vane
Air filter
(Catechin air filter, option)
Air cleaning filter
(Anti-Allergy Enzyme
Filter, option)
Safety string
Intake grille
Remote control
receiving section
Display and operation section (When the intake grille is opened)
Operation indicator lamp
Emergency operation switch
Air inlet
Display section
Operation indicator
lamp
Remote control
receiving section
Emergency
operation switch
Horizontal vane
Vertical vane
Air outlet
Air fi lter
(Air purifying
filter, option)
Air inlet
Air cleaning filter
(Silver-ionized air
purifier filter, option)
Intake grille
Safety strings Spec name plate
MLZ-KA25/35/50VA- E4 , ER4
OBH483D

4
SPECIFICATION
3
T3.15AL 250V
12V 300Ω
12V 300Ω
ERZV14D471
230V 6.4W
DC 12V
Item Model
Fuse
Horizontal vane motor
Vertical vane motor
Varistor
DRAIN PUMP
FLOAT SENSOR
MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA
(F11)
(MV1)
(MV2)
(NR11)
(DP)
(FS)
Specifications and rated conditions of main electric parts
Cooling
528/ 480/ 432
35/ 32/ 29
1,120/1,030/950
MLZ-KA35VAMLZ-KA25VA MLZ-KA50VA
Indoor model
Function
Power supply Single phase
230V,50Hz
0.3
40
—
58
0.3
RC0J30-KC
1,102 x 175 x 360
15
5
3
Heating
552/ 492/ 420
36/ 32/ 28
1,160/ 1,060/ 930
Air flow (High/Med./Low)
Running current 1
Power input 1
Auxiliary heater
Power factor 1
Fan motor current 1
Dimensions W x H x D
Weight
Air direction
Sound level (High/Med./Low)
Fan speed (High/Med./Low)
Fan speed regulator
Remote controller model
m
3
/h
A
W
A(kW)
%
A
mm
kg
dB(A)
rpm
Electrical data
Capacity
Fan motor
Special
remarks
Cooling
564/ 504/ 438
37/ 34/ 31
1,180/ 1,080/ 960
Single phase
230V,50Hz
0.3
40
—
58
0.3
RC0J30-KC
1,102 x 175 x 360
15
5
3
Heating
594/ 528/ 462
38/ 35/ 31
1,230/ 1,120/ 1,000
Cooling
684/ 588/ 498
43/ 38/ 34
1,380/1,220/1,070
Single phase
230V,50Hz
0.3
40
—
58
0.3
RC0J30-KC
1,102 x 175 x 360
15
5
3
Heating
708/ 618/ 528
43/ 39/ 34
1,420/ 1,270/ 1,120
Model RC0J30-KK
RC0J30-KT
RC0J30-KK
RC0J30-KT
RC0J30-KK
RC0J30-KT
KM152 (MLZ-KA·VA- , )/KM07E (Other models)
E1 E1 E1
E2
ER3
ER4
E3
E4
E2
ER3
ER4
ER4
E3
E4
E4
E2
ER3
ER4
E3
E4
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 Wet-bulb temperature 24°C
Heating: Indoor Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
Refrigerant piping length (one way): 5m
1 Measured under rated operating frequency.
OBH483D

5
4NOISE CRITERIA CURVES
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
Test conditions,
Cooling: Dry-bulb temperature 27ºC Wet-bulb temperature 19ºC
COOLING
FUNCTION
43
43
SPL(dB(A)) LINE
High
FAN SPEED
HEATING
Heating: Dry-bulb temperature 20ºC
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
Test conditions,
Cooling: Dry-bulb temperature 27ºC Wet-bulb temperature 19ºC
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
COOLING
FUNCTION
35
36
SPL(dB(A)) LINE
High
FAN SPEED
HEATING
Heating: Dry-bulb temperature 20ºC 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
Test conditions,
Cooling: Dry-bulb temperature 27ºC Wet-bulb temperature 19ºC
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
COOLING
FUNCTION
37
38
SPL(dB(A)) LINE
High
FAN SPEED
HEATING
Heating: Dry-bulb temperature 20ºC
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
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
MLZ-KA25VA MLZ-KA35VA
MLZ-KA50VA
INDOOR UNIT
CEILING
GRILLE
MICROPHONE
1.4m
OBH483D

6
OUTLINES AND DIMENSIONS
5
Unit : mm
INDOOR UNIT
MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA
Center of ceiling opening, suspension bolt pitch
and grille are located in one position.
Air outlet
(Front)
Refrigerant
Pipe
Length of drain hose 480
Drain pipe
NOTE: Drain hose can be used by cutting it.
VP20
Liquid Ø6.35
Ø9.52 (MLZ-KA25/35)
Ø12.7 (MLZ-KA50)
Gas
Ceiling surface Ceiling surface
Drain hose
500mm or less(12)
Hole position for the
installation of grille
Decline 1/100
Drain pipe VP20
How to connect drain pipe on indoor
unit by lifting drain hose.
Drain hose can be used by cutting it.
Suspension bolt M10 Suspension bolt M10
Grille
(Top)
414 Outer side of grille
384 Ceiling opening
308 Suspension bolt pitch
1051 Suspension bolt pitch
Electrical
box
Air outlet
(Top) Wireless
remote controller
(Front) (Right side)
Grille
[MLP-443PW: MLZ-KA·VA- , /MLP-440W: Other models]
Electrical box
Receiving section
E4 ER4
Ceiling
surface
Gas pipe
MLZ-KA25/35: Ø9.52
MLZ-KA50 : Ø12.7
(Flared)
Drain hose
connecting
part (drain pipe
VP20)
Pipe cover
Drain pan
Outlet opening area
Center of ceiling opening, suspension bolt pitch
and grille are located in one position.
Drain hose
connecting part
308
Suspension bolt pitch
Drain hose
Display and
receiving section
No gaps between
the ceiling surface and grille
Liquid pipe
Ø6.35
(Flared)
R6
0.04m2
175
244 170
110
175
180 or more
(31)
60
360
0
110
0
116 175
48
Ø58
1051 Suspension bolt pitch
1160 Ceiling opening
960
1200 Outer side of grille
Outlet
20
54.5
100
20
54.5
100
38
38
15
15
16
(51.6) 180
960 78
1102
CL
1200
1138
414 374
34 15
16
26
26
58
230
2
2
15
58 18
158
13 12
CL
R6
10
0
466.5
466.5
166.5
0
172.4
81.8
173
166.5
112
OBH483D

7
6WIRING DIAGRAM
MLZ-KA25VA- E1
MLZ-KA35VA- E1
INDOOR UNIT
MLZ-KA25VA- E2
MLZ-KA35VA- E2
OBH483D

8
MLZ-KA25VA- E3 , ER3
MLZ-KA35VA- E3 , ER3
MLZ-KA25VA- E4 , ER4
MLZ-KA35VA- E4 , ER4
OBH483D

9
MLZ-KA50VA- E1
MLZ-KA50VA- E2
OBH483D

10
MLZ-KA50VA- E3 , ER3
MLZ-KA50VA- E4 , ER4
OBH483D

11
REFRIGERANT SYSTEM DIAGRAM
7
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13 (sub)
Flared connection
Refrigerant pipe Ø9.52
(with heat insulator)
Refrigerant pipe Ø6.35
(with heat insulator)
Indoor coil
thermistor
RT12 (main)
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13 (sub)
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,RT14,
RT15 (main)
INDOOR UNIT
Unit : mm
MLZ-KA25VA
MLZ-KA35VA
MLZ-KA50VA
OBH483D

12
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
JR05
No modification
Cut off JR05
No modification
Cut off JR05
JR06
No modification
No modification
Cut off JR06
Cut off JR06
Indoor electronic
control P.C. Board
IC101
C111
JR06
JR05
IC101
C111
JR06
JR05
Indoor electronic
control P.C. Board
8SERVICE FUNCTIONS
8-1. TIMER SHORT MODE
• For service, the following set time can be shortened by bridging the JPG and JPS (MLZ-KA·VA- E1 , E2 , E3 , ER3 ) /
timer short mode point (MLZ-KA·VA- E4 , ER4 ) on the electronic control P.C. board. (Refer to 10-7.)
• The set time for the ON/OFF timer can be reduced to 1 second for each minute.
• After the breaker is turned on, the time for starting the compressor, which normally takes 3 minutes, can be reduced to 3
seconds. Restarting the compressor, which takes 3 minutes, cannot be reduced.
MLZ-KA25VA
MLZ-KA35VA
MLZ-KA50VA
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, both the P.C. boards of remote controller
and the electronic control P.C. boards must be modified according to the number of the indoor unit.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below:
NOTE: For modification, take out the batter-
ies and press the STOP/OPERATE
(OFF/ON) (MLZ-KA·VA- E4 , ER4 )/
OPERATE/STOP (ON/OFF) (MLZ-
KA·VA- E1 , E2 , E3 , ER3 ) button
2 or 3 times at first.
After modification, put back the
batteries then press the RESET
button.
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.
How to modify the electronic control P.C. board
Turn OFF the power supply before modification. Cut off “JR05” and “JR06” on the electronic control P.C. board according
to the number of indoor unit as shown in Table 2. (Refer to 10-7.)
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
1 unit operation
No modification
–
–
–
2 units operation
Same as at left
Solder J1
–
–
3 units operation
Same as at left
Same as at left
Solder J2
–
4 units operation
Same as at left
Same as at left
Same as at left
Solder both J1 and J2
Table 1
Table 2
J2
J1
NOTE: After modification, turn ON the power sup-
ply and with the remote controller headed
towards the indoor unit, press the STOP/
OPERATE (OFF/ON) (MLZ-KA·VA- E4
, ER4 )/OPERATE/STOP (ON/OFF) (MLZ-
KA·VA- E1 , E2 , E3 , ER3 ) button.
If 1 or 2 beeps is heard from the indoor
unit, modification is completed correctly.
MLZ-KA·VA- E4 , ER4
MLZ-KA·VA- E1 , E2 , E3 , ER3
OBH483D

13
JR07
C111
IC101
C111
JR77
IC101
NOTE:
• The operation settings are memorized when 10 seconds has 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 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 breaker tripping 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.
How to disable “AUTO RESTART FUNCTION”
Turn off the main power for the unit.
MLZ-KA·VA- E1 , E2 , E3 , ER3
Solder the Jumper wire to JR07 on the indoor electronic control P.C. board. (Refer to 10-7.)
MLZ-KA·VA- E4 , ER4
Cut the jumper wire to JR77 on the indoor electronic control P.C. board. (Refer to 10-7.)
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.)
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.
MLZ-KA·VA- E4 , ER4
MLZ-KA·VA- E1 , E2 , E3 , ER3
OBH483D

14
Change dip switch SW3 setting according to the height of ceiling.
Dip switch SW3
Ceiling height
Normal
2.4 m or below
Increase airflow volume
above 2.4 m and 2.7 m or below
How to change Dip switch (SW3) setting (Default setting is Normal)
1. Turn OFF the power supply for the air conditioner.
2. Remove electrical cover (1) and (2).
3. Slide out electronic control P.C. board, and slide Dip switch (SW3) up or down (MLZ-KA·VA- )/
to the left or right (MLZ-KA·VA- , ).
4. Put electronic control P.C. board back to the original position, and install electrical cover (1) and (2).
NOTE:
To prevent damage of P.C. board due to static electricity, make sure to perform static elimination before setting.
Normal Increase
airflow volume
Dip switch SW3
Electronic control P.C. board
Electrical
cover (2)
Electrical
cover (1)
NOTE: When the ceiling is above 2.7 m, airflow volume may be insufficient even with the Dip switch (SW3) set to
"increase airflow".
Electrical
cover (1)
Electrical
cover (2)
Electronic
control P.C.
board Dip switch SW3
Normal Increase airflow
volume
E4 ER4
E1 , E2 , E3 , ER3
8-4. P.C. BOARD MODIFICATION FOR CHANGING AIRFLOW VOLUME
MLZ-KA·VA- E4 , ER4
MLZ-KA·VA- E1 , E2 , E3 , ER3
OBH483D

15
9MICROPROCESSOR CONTROL
WIRELESS REMOTE CONTROLLER
MLZ-KA25VA
MLZ-KA35VA
MLZ-KA50VA·
ON-TIMER button
CLOCK SET button
TIME SET buttons
FORWARD button
BACKWARD button
OFF-TIMER button
WIDE VANE button
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
ECONO COOL button
Indication of
remote controller
model is on back
r
Open the front lid.
NOTE:
• The 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.
MLZ-KA25/35/50VA-
OBH483D

16
ON-TIMER button
CLOCK SET button
TIME SET buttons
FORWARD button
BACKWARD button
OFF-TIMER button
WIDE VANE button
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
ECONO COOL button
Indication of
remote controller
model is on back
r
Open the front lid.
NOTE:
• The 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.
MLZ-KA25/35/50VA- E4 , ER4
OBH483D

17
Operation Indicator lamp
The operation indicator at the left side of the indoor unit indicates the operation state.
INDOOR UNIT DISPLAY SECTION
Approximate
2ºC or more
Difference between target
temperature and
room temperature
Approximate
2ºC or less
This shows that the air conditioner is
operating to reach the target temperature.
Please wait until the target temperature is obtained.
This shows that the room temperature is
approaching the target temperature.
This shows a state of standby for operation.
(For multi system air conditioner)
Operation stateIndication
Lighted
Not lighted
Blinking
1. Coil frost prevention
Coil frost prevention works the same way as that in COOL mode. (9-1.1.)
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
temperature is low or when defrosting is being done, the indoor fan will stop or rotate in Very Low speed.
9-2. DRY ( ) OPERATION
(1) Press STOP/OPERATE (OFF/ON) (MLZ-KA·VA-
E4
,
ER4
)/OPERATE/STOP (ON/OFF) (MLZ-KA·VA-
E1
,
E2
,
E3
,
ER3
)
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.
9-3. HEAT ( ) OPERATION
(1) Press STOP/OPERATE (OFF/ON) (MLZ-KA·VA-
E4
,
ER4
)/OPERATE/STOP (ON/OFF) (MLZ-KA·VA-
E1
,
E2
,
E3
,
ER3
)
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. Coil frost prevention
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.
9-1. COOL ( ) OPERATION
(1) Press STOP/OPERATE (OFF/ON) (MLZ-KA·VA-
E4
,
ER4
)/OPERATE/STOP (ON/OFF) (MLZ-KA·VA-
E1
,
E2
,
E3
,
ER3
)
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.
9-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
Mode selection
(1) Initial mode
When unit starts the operation with AUTO operation from off;
• If the room temperature is higher than the set temperature, operation starts in COOL mode.
• If the room temperature is equal to or lower than the set temperature, operation starts in HEAT mode.
(2) Mode change
COOL mode changes to HEAT mode when about 15 minutes have passed with the room temperature 2 degrees
below the set temperature.
HEAT mode changes to COOL mode when about 15 minutes have passed with the room temperature 2 degrees
above the set temperature.
NOTE:
If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is operating
in (AUTO), cannot change over to the other operating mode (COOL HEAT) and becomes a state of standby.
OBH483D

18
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the desired
angle.
Confirming of standard position is performed in the following cases:
(a) When the power supply turns on.
(b) When the operation starts or finishes (including timer operation).
(c) When the test run starts.
(d) When multi-standby starts or finishes.
(e) When the swing operation finishes.
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9-5. 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 12V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.
(4) VANE AUTO ( ) mode
In VANE AUTO mode, the microprocessor automatically determines the vane angle and operation to make the optimum
room-temperature distribution.
1
5
Vane angle is fixed to Angle 1.
Vane angle is fixed to Angle 5.
(5) STOP (operation OFF) and ON-TIMER standby
In the following cases, the horizontal vane returns to the closed position.
(a) When STOP/OPERATE (OFF/ON) (MLZ-KA·VA- E4 , ER4 )/OPERATE/STOP (ON/OFF) (MLZ-KA·VA- E1 , E2 , E3 ,
ER3 ) button is pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When ON-TIMER is ON standby.
(7) Cold air prevention in HEAT operation
The horizontal vane position is set to Upward.
(6) SWING MODE ( )
By selecting SWING mode with VANE CONTROL button, the horizontal vane swings vertically. The remote controller
displays “ ”. SWING mode is cancelled when VANE CONTROL button is pressed once again.
(1) In COOL and DRY operation
(2) In HEAT operation
(8) 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.
To cancel this operation, select a different mode or press one of the following buttons in ECONO COOL operation:
ECONO COOL or VANE CONTROL button.
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9-7. TIMER OPERATION
1. How to set the time
(1) Press STOP/OPERATE (OFF/ON) (MLZ-KA·VA- E4 , ER4 )/OPERATE/STOP (ON/OFF) (MLZ-KA·VA- E1 , E2 , E3 ,
ER3 ) button to start the air conditioner.
(2) Check that the current time is set correctly.
NOTE: Timer operation will not work without setting the current time. Initially “AM0:00” blinks at the current time display
of TIME MONITOR, so set the current time correctly with CLOCK SET button.
How to set the current time
(1) Press the CLOCK set button.
(2) Press the TIME SET buttons ( and ) to set the current time.
• Each time FORWARD button ( ) is pressed, the set time increases by 1 minute, and each time BACKWARD button
( ) is pressed, the set time decreases by 1 minute.
• Pressing those buttons longer increases/decreases the set time by 10 minutes.
Press the CLOCK set button.
2. Vertical vane
(1) Press WIDE VANE button to change horizontal airflow direction.
•The vertical vane moves for about 30 seconds.
(After 30 seconds, the vertical vane moves to its original position. In this case, press WIDE VANE button again.)
(2) Press WIDE VANE button again to set horizontal airflow direction.
•The vertical vane stops and the airflow direction is set.
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane set to the desired
angle.
Confirming of standard position is performed in the following cases:
(a) When STOP/OPERATE (OFF/ON) (MLZ-KA·VA- E4 , ER4 )/OPERATE/STOP (ON/OFF) (MLZ-KA·VA- E1 , E2 , E3 ,
ER3 ) button is pressed (POWER ON).
(b) When SWING is started.
9-6. DRAIN PUMP/ FLOAT SENSOR CONTROL
1. Drain pump
Operating condition:
1. During COOL, DRY, or emergency COOL operation
2. When float sensor detects water level above fixed point during:
(a) HEAT operation.
(b) emergency HEAT operation.
(c) standby when during multi system operation.
(d) standby when ON timer is set.
(e) operation STOP.
Drain pump operates in conditions 1 or 2.
Operation stop condition:
Condition other than 1 or 2 indicated above.
2. Float sensor
Float moves with the up and down of water surface inside the drain pan, and judges water level.
(Fixed point differs at raised and lowered water levels.)
Float sensor
Water surface
Fixed point, when water level rises
Fixed point, when water level lowers
ON timer setting
(1) Press ON-TIMER button ( ) during operation.
(2) Set the time of the timer using TIME SET buttons ( and ) .
OFF timer setting
(1) Press OFF-TIMER button ( ) during operation.
(2) Set the time of the timer using TIME SET buttons ( and ).
Each time FORWARD button ( ) is pressed, the set time increases by 10 minutes; each time BACKWARD button
( ) is pressed, the set time decreases by 10 minutes.
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EMERGENCY
OPERATION switch
Operation indicator lamp
Operation mode COOL HEAT
Set temperature 24ºC 24ºC
Fan speed Medium Medium
Horizontal vane Auto Auto
The operation mode is indicated by the Operation
indicator lamp on the indoor unit as follows
Not lighted
Lighted
Operation Indicator lamp
Press again <HEAT>
Press once <COOL>
Press once again <STOP>
9-8. EMERGENCY/TEST OPERATION
In the case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the front of the
indoor unit. Emergency operation is available when the remote controller is missing or has failed, or 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, and defrosting too.
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.
(Example 1) The current time is 8:00 PM.
The unit turns OFF at 11:00 PM, and ON at 6:00 AM.
• OFF timer and ON timer can be used in combination. The time that is reached first will operate first.
• “ ” and “ ” display show the order of OFF timer and ON timer operation.
PROGRAM TIMER
(Example 2) The current time is 11:00 AM.
The unit turns ON at 5:00 PM, and OFF at 9:00 PM.
NOTE: If the main power is turned off or a power failure occurs while AUTO START/STOP timer is active, the timer setting
is cancelled. As these models are equipped with an auto restart function, the air conditioner starts operating with
timer cancelled when power is restored.
2. Cancel
To cancel ON timer, press ON-TIMER button ( ).
To cancel OFF timer, press OFF-TIMER button ( ).
TIMER is cancelled and the display of set time disappears.
9-9. 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.
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