Mitsubishi Electric Mr. Slim MS-A09WA, Mr. Slim MS-A09WA-1, Mr. Slim MS-A12WA, Mr. Slim MS-A12WA-1 Service Manual

INDOOR UNIT

SERVICE MANUAL

Models

MS-A09WA

Revision C:

• TEST POINT DIAGRAM AND VOLTAGE has
been corrected. (8-7)

Please void OB448 REVISED EDITION-B.

No. OB448

REVISED EDITION-C

MS-A09WA ­MS-A12WA
MS-A12WA -

1

1

Outdoor unit service manual

MU-A•WA Series (OB449)

CONTENTS

1. TECHNICAL CHANGES ··································· 2

2. PART NAMES AND FUNCTIONS ····················· 3

3. SPECIFICATION ················································ 5

4. OUTLINES AND DIMENSIONS ························ 6

5. WIRING DIAGRAM ············································ 7

6. REFRIGERANT SYSTEM DIAGRAM ··············· 7

7. SERVICE FUNCTIONS ····································· 8

8. TROUBLESHOOTING ······································· 9

9. DISASSEMBLY INSTRUCTIONS ···················· 21

10. PARTS LIST ····················································· 24
10-1. PARTS LIST ············································· 24
10-2. RoHS PARTS LIST ·································· 27

11. MICROPROCESSOR CONTROL ···················· 30

NOTE:

RoHS compliant products have <G> mark on the spec name plate.
For servicing of RoHS compliant products, refer to the RoHS PARTS
LIST (RoHS compliant).

Revision A :

• MS-A•WA- 1 have been added.
Remote controller has been changed.

Revision B :

• SPECIFICATION has been corrected.
Powerful has been added. (Airflow ,Sound level)

Revision C:

• TEST POINT DIAGRAM AND VOLTAGE has been corrected. (8-7)

1

TECHNICAL CHANGES

MS09TW MS-A09WA
MS12TN

1.Indoor fan motor has been changed.

2.Signal of remote controller has been changed. (It is not available for conventional models.)

MS-A09WA MS-A09WA -
MS-A12WA MS-A12WA -

1. Remote controller has been changed.

• Temperature indication function (°F/°C) has been added. (Refer to 11-8.)

Models Remote controller Temperature indication

MS-A09/12WA KM06C °F

MS-A09/12WA-

• Timer indication has been changed. (AM/PM indication)

2. Conduit plate has been removed.

3. Conduit cover, terminal block cover and terminal block holder have been changed.

MS-A12WA

1

1

1

KM07L °F/°C

2

2

PART NAMES AND FUNCTIONS

MS-A09WA
MS-A12WA

Heat exchanger

Panel

Air cleaning filter
(Anti-Allergy Enzyme
Filter, Blue bellows
type)

Catechin air filter

Air outlet
Vertical vane

Air inlet
Front panel

Horizontal vane

Operation section

(When the front panel is opened)

Line flow fan

Emergency operation switch

Remote controller

Display section

Operation Indicator
lamp

Remote control
receiving section

3

MS-A09WA
MS-A12WA

ACCESSORIES

MS-A09/12WA MS-A09/12WA-

Installation plate 1 1
Installation plate fi xing screw 4 × 25 mm 8 5
Remote controller holder 1 1
Fixing screw for 3.5 × 1.6 mm (Black) 2 2
Battery (AAA) for remote controller 2 2
Wireless remote controller 1 1
Felt tape (Used for left or left-rear piping) 1 1
Conduit plate 1 —

1

4

3

Model MS-A09WA MS-A12WA
Indoor unit model MS-A09WA MS-A12WA
External fi nish White
Power supply V, phase, Hz 115, 1, 60
Max.-fuse size (time delay) /

Disconnect switch
Min. circuit ampacity A 1.2
Fan motor F.L.A 0.95
Airfl ow

Low–Med.–High–Powerful
Moisture removal pt./h 2.7 3.2
Sound level

Low–Med.–High–Powerful
Cond. drain connection O.D. in. 5/8

Dimensions

Weight Ib. 23
Remote controller Wireless type
Control voltage (by built-in transformer) 115 VAC

NOTE : Test conditions are based on ARI 210/240

1 : Rating conditions (cooling) — Indoor : 80˚FDB, 67˚FWB, Outdoor : 95˚FDB, (75˚FWB) Rated frequency : 60Hz

SPECIFICATION

COOL
Dry (Wet)

W

D 8-1/4
H 11/-3/4

CFM

dB(A) 26 - 32 - 40 - 42 33 - 38 - 45 - 47

in.

A15

183 - 261 - 335 - 367

(162 - 233 - 300 - 328)

30-11/16

222 - 286 - 406 - 446

(198 - 254 - 363 - 399)

Operating Range

Cooling

Maximum 95˚FDB, 71˚FWB 115˚FDB
Minimum 67˚FDB, 57˚FWB 67˚FDB

Indoor intake air temperature Outdoor intake air temperature

5

4

OUTLINES AND DIMENSIONS

MS-A09WA
MS-A12WA

11-3/4

30-11/16

7/16x1 Oblong hole

Installation plate

Indoor unit

Conduit plate(MS-A•WA- is excluded.)

7/16x13/16

2-3/16 2-3/16

10-1/8

1-5/8 8-7/16

2-3/16

13-3/16 12-5/8

Air in

8-1/4

Oblong hole

8-7/8 8-7/8

7/8

6-1/8 6-1/8

3/16

Installation plate

hole

1-3/4

Liquid line 1/4 19-11/16
Gas line 3/8 16-15/16
Insulation 1-3/8 O.D

{

Unit : inch

9/1610-3/4

7/8

8-7/16

9-3/16

11-5/16

2-3/4

Wall hole 2-9/16

3/4 I.D

1/8

1-11/16

2-1/8

2-5/16

6-1/4

3/4

Drain hose 5/8

424-9/16

Air out

(Connected part O.D)
Insulation 1-1/8

6

5

WIRING DIAGRAM

MS-A09WA
MS-A12WA

6

REFRIGERANT SYSTEM DIAGRAM

MS-A09WA
MS-A12WA

Indoor
heat
exchanger

Room temperature
thermistor
RT11

Indoor coil
thermistor
RT12

Unit : inch

Refrigerant pipe 3/8 (MS-A09)

1/2 (MS-A12)

(with heat insulator)

Flared connection

Flared connection

Refrigerant flow in cooling

7

Refrigerant pipe 1/4
(with heat insulator)

7

SERVICE FUNCTIONS

MS-A09WA
MS-A12WA

7-1. TIMER SHORT MODE

For service, set time can be shortened by short circuit of JPG and JPS the electronic control P.C. board.
The time will be shortened as follows. (Refer to 8-7.)
Set time : 1-minute 1-second

Set time : 3-minute 3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is

shortened by short circuit-of JPG and JPS.)

7-2. 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.

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 batteries and press
the OPERATE/STOP(ON/
OFF)button twice or 3
times at first.

After finish modification,

put back the batteries then
press the RESET button.

J1

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.

J2

Table 1

1 unit operation 2 units operation 3 units operation 4 units operation

No. 1 unit No modifi cation 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 has turned off, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.

8

7-3. 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. The “AUTO RESTART FUNCTION” sets to work the moment
power has restored after power failure. Then, the unit will restart automatically.

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 release “AUTO RESTART FUNCTION”

Turn off the main power for the unit.

Solder the Jumper wire JR07 on the indoor electronic control P.C. board. (Refer to 8-7.)

JR07

BZ

CN151 CN211CN112 CN1R1

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

cancelled.

• 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 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.

8

TROUBLESHOOTING

MS-A09WA MS-A12WA

8-1. 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 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 electronic
control P.C. board.

3) When removing the electronic control 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 housing of the connector. DO NOT pull the lead wires.

Lead wiring

Housing point

9

3. Troubleshooting procedure

1) First, 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 abnormality indication is flashing on and off before starting service work.

2) Before servicing check that the connector and terminal are connected properly.

3) When the electronic control 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 8-2., 8-3. and 8-4.

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.

Remove the front lid and insert batteries.

Then reattach the front lid.

Insert the negative pole of the
batteries first. Check if the polarity
of the batteries is correct.

Press RESET button with tip end of ball point pen

or the like, and then use the remote controller.

RESET button

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.

10

8-2. FAILURE MODE RECALL FUNCTION

Outline of the function
This air conditioner can memorize the abnormal condition which has occurred once.
Even though LED indication listed on the troubleshooting check table (8-4.) disappears, the memorized failure details can
be recalled.

1. Flow chart of failure mode recall function for the indoor/outdoor unit

Operational procedure

The cause of abnormality cannot be found because the abnormality doesn't recur.

Setting up the failure mode recall function

Turn ON the power supply.
<Preparation of the remote controller>

While pressing both OPERATION SELECT button and TOO COOL button on the

remote controller at the same time, press RESET button.

First, release RESET button.

And release the other two buttons after all LCD except the set temperature in opera-

tion display section of the remote controller is displayed after 3 seconds.

Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature
is displayed) with the remote controller headed towards the indoor unit.

Does the left lamp of OPERATION INDICATOR lamp on the
indoor unit blink at the interval of 0.5 seconds?
Blinks: Either indoor or outdoor unit is abnormal. Beep is emit-

ted at the same timing as the blinking of the left lamp
of OPERATION INDICATOR lamp. 2

Yes
(Blinks)

The indoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the indoor unit
failure mode table. (8-2.2.)
Make sure to check at least two consecutive blinking cycles. 2

Releasing the failure mode recall function

Deleting the memorized abnormal condition

Release the failure mode recall function by the following procedures.

• Turn OFF the power supply and turn it ON again.

• Press RESET button of the remote controller.

Repair the defective parts.

After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall

function" mentioned above.

Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed)

with the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function"

mentioned above.

NOTE: 1. Make sure to release the failure mode recall function once it's set up, otherwise the unit cannot operate properly.

2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.

2. Blinking pattern when the indoor unit is abnormal:

Blinking at 0.5-

2.5-second OFF

second interval

2.5-second OFF

1

No
(OFF)

Blinking at 0.5-

second interval

1. Regardless of normal or abnormal condition, a short
beep is emitted once the signal is received.

Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnor­malities that can't be recalled with this way.

ON

OFF

Repeated cycle Repeated cycle

Beeps

Beeps

Repeated cycle

Beeps

11

2. Indoor unit failure mode table

Left lamp of OPERATION
INDICATOR lamp

Not lighted Normal — —

1-time fl ash every

0.5-second

2-time fl ash

2.5-second OFF

11-time fl ash

2.5-second OFF

12-time fl ash

2.5-second OFF

Abnormal point

(Failure mode)

Room temperature
thermistor

Indoor coil ther­mistor

Indoor fan motor

Indoor control
system

Condition Correspondence

The room temperature thermistor short or
open circuit is detected every 8 seconds dur­ing operation.

The indoor coil thermistor short or open circuit
is detected every 8 seconds during operation.

The rotational frequency feedback signal is
not emit during the 12 seconds the indoor fan
operation.

It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.

Refer to the characteristics of the room temperature
thermistor (8-7.).

Refer to the characteristics of the main indoor coil ther­mistor, the sub indoor coil thermistor (8-7.).

Refer to 8-6. "Check of indoor fan motor".

Replace the indoor electronic control P.C. board.

NOTE : Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (8-4.).

12

8-3. INSTRUCTION OF TROUBLESHOOTING

Start

Indoor unit oper­ates.
Outdoor unit
doesn't operate.

Outdoor unit
operates only
in Test Run
operation.

Check room
temperature
thermistor.
Refer to 8-7.
"Test point
diagram and
voltage".

Outdoor
unit doesn't
operate even
in Test Run
operation.

• Check the
wiring diagram
of the outdoor
unit.

• Check
outdoor fuse.

Indoor unit
doesn't receive
the signal from
remote controller.

Indoor unit
operates, when
EMERGENCY
OPERATION
switch is pressed.

Refer to 8-6.
"Check of remote
controller and
receiver P.C.
board".

OPERATION INDICATOR
lamp on the indoor unit is
fl ashing on and off.

Indoor unit
doesn't operate,
when EMER­GENCY OPERA­TION switch is
pressed.

1. Check indoor/outdoor
connecting wire.

2. Refer to 8-6. "Check
of indoor electronic
control P.C. board and
indoor fan motor".

If blinking of OPERATION INDI­CATOR lamp cannot be checked,
it can be checked with failure
mode recall function.

"Test Run operation" means

the operation within 30 minutes
after EMERGENCY OPERA­TION switch is pressed.

Left

lamp

2-time fl ash
Cause:
Indoor unit

• Trouble of room
temperature /
indoor coil ther­mistor

Check room
temperature
thermistor and
indoor coil ther­mistor. Refer to
8-7. "Test point
diagram and
voltage".

Left

lamp

3-time fl ash
Cause:
Indoor unit

• Trouble of in­door fan motor

Refer to 8-6.
"Check of indoor
fan motor".

Left

lamp

4-time fl ash
Cause:
Indoor unit

• Trouble of
indoor unit con­trol system

Replace the
indoor electronic
control P.C.
board.

13

8-4. TROUBLESHOOTING CHECK TABLE

Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and detected an abnormality of the following condition (the first detection after the
power ON), the indoor fan motor turns OFF and OPERATION INDICATOR lamp flashes.

OPERATION INDICATOR

Lighted
Blinking
Not lighted

Indoor unit and
outdoor unit do
not operate.

The indoor coil or the room temperature ther­mistor is short or open circuit.

The rotational frequency feedback signal is
not emitted during the indoor fan operation.

It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.

Refer to the characteristics of

•
indoor coil thermistor, and the
room temperature thermistor
(8-7).

Refer to 8-6. "Check of in-

•
door fan motor".

Replace the indoor electronic

•
control P.C. board.

No.

1

2

3

Abnormal

point

Indoor coil
thermistor

Room tem­perature
thermistor

Indoor fan
motor

Indoor con­trol system

Operation indicator lamp Symptom Condition Correspondence

Left lamp fl ashes.
2-time fl ash

2.5-second OFF

Left lamp fl ashes.
3-time fl ash

2.5-second OFF

Left lamp fl ashes.
4-time fl ash

2.5-second OFF

14

8-5. TROUBLE CRITERION OF MAIN PARTS

MS-A09WA MS-A12WA

Part name Check method and criterion Figure

Room temperature
thermistor
(RT11)

Measure the resistance with a tester. (Part temperature 50 ~ 86°F)

Indoor coil thermistor
(RT12)

Indoor fan motor
(MF)

Horizontal vane motor
(MV)

Refer to 8-7. "Test point diagram and voltage", the chart of thermistor.

Check 8-6.

.

Measure the resistance between the terminals with a tester.
(Part temperature 50 ~ 86°F)

Color of the lead wire Normal

BRN - other one 235 ~ 255 Ω

RED

YLW
BRN

ROTOR

ORN

GRN

15

8-6. TROUBLESHOOTING FLOW

A Check of indoor fan motor

The indoor fan motor error has occurred, and the indoor fan doesn't operate.

Turn OFF the power supply.

Is there any foreign matter that interferes
the rotation of the line fl ow fan?

Yes

Remove the foreign matter and
adjust the line fl ow fan.

Is there 162 VDC between CN211
(+) and (-), and does the voltage
between CN211
to the range of 3 to 6 VDC within 12
seconds after EMERGENCY OPERA­TION switch is pressed?

Replace the indoor electronic control P.C. board.

(+) and (-) rise

No

No

Pay careful attention to the high voltage on the fan motor connector CN211.

Turn ON the power supply, wait 5 seconds or more, and then press
EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds after EMER­GENCY OPERATION switch is pressed.
If more than 12 seconds passes by, turn OFF the power supply and
turn ON it again, then measure the voltage.

1. Measure the voltage between CN211 (+) and

2. Measure the voltage between CN211

If more than 12 seconds passes after EMERGENCY OPERATION switch

is pressed, the voltage mentioned above 2 goes 0 VDC although the
indoor electronic control P.C. board is normal

Indoor electronic

Yes

Replace the indoor fan motor.

control P.C. board

(-).

(+) and (-).

CN211

The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.

Measure the voltage between CN211

(+) and (-) while the fan motor is

rotating.

Is it unchanged holding
0 or 15 VDC?

Yes
(Unchanged)

Replace the indoor fan motor.

No
(Changed)

Replace the indoor electronic control P.C. board.

16

B Check of remote controller and indoor electronic control P.C. board

Check if the remote controller is exclusive for this air conditioner.

Press OPERATE/STOP (ON/OFF)

button on the remote controller.

Is LCD display on the remote controller
visible?

Yes

Remove the batteries, then set them back
and press RESET button. (Refer to 8-1.4.)
Check if the unit operates with the remote
controller.

Does the unit operate with the remote
controller?

Yes

OK

No
(Not clear)

No

Replace the batteries. (Refer to 8-1.4.)

Turn ON a radio to AM and press OP­ERATE/STOP (ON/OFF) button on the
remote controller.

Is noise heard from radio?

Yes

Are there any fl uorescent lights of
inverter or rapid-start type within the
range of 3.28 ft.?

No

Replace the indoor electronic control
P.C. board. (Including the receiver)

No

Yes

Replace the remote controller.

Reinstall the unit away from lights.

•

Attach a fi lter on receiving part.

•

17

C Check of indoor electronic control P.C. board and indoor fan motor

Turn OFF the power supply.
Remove indoor fan motor connector CN211
and vane motor connector CN151 from the
indoor electronic control P.C. board and turn
ON the power supply.

Measure the resistance between
CN211 and of the indoor fan motor
connector.

Yes

Short/open circuit:
Replace the indoor fan motor.

Does the unit operate with the remote
controller? Does OPERATION INDICATOR
lamp light up by pressing EMERGENCY
OPERATION switch?

Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor electronic control
P.C. board visually.

No

Measure the resistance of the horizon­tal vane motor coil.
(Refer to 8-5.)

Replace the indoor
electronic control P.C. board.

Yes

Are the varistor (NR11)
burnt and the fuse (F11)
blown?

Be sure to check both the fuse
and the varistor in any case.

Is the fuse (F11) blown
only?

Yes

Measure the resistance between
(+) and (-) of the indoor fan motor
connector (to CN211 on the indoor
electronic control P.C. board).

Is the resistance 1 MΩ
or more?

Yes

1, 2

No

No

No

Short/open circuit:
Replace the horizontal vane motor and the
indoor electronic control P.C. board.

1. The fan motor connector's lead wire is red, whereas is
black.

2. Connect "+" of the tester to fan motor connector's lead
wire, and "-" to lead wire, otherwise the resistance can­not be measured properly.

Replace indoor electronic control P.C. board
and the indoor fan motor.

Replace indoor electronic control
P.C. board.

Measure the resistance of
resistor (R111) on the indoor
electronic control P.C. board.

Indoor electronic
control P.C.Board

Varistor(NR11)
Fuse(F11)
CN211

Is the resistance approx.
2 Ω?

Yes

Replace the indoor electronic control P.C. board.

No

18

Replace the indoor electronic control P.C.
board and the indoor fan motor.

D Electromagnetic noise enters into TV sets or radios

Is the unit grounded?

Yes

Is the distance between the antennas
and the indoor unit within 9.91 ft., or is
the distance between the antennas and
the outdoor unit within 9.91 ft.?

No

Is the distance between the TV sets or
radios and the indoor unit within 3.28
ft., or is the distance between the TV
sets or radios and the outdoor unit
within 9.91 ft.?

No

Are the antennas damaged?
Is the coaxial cable damaged?
Is there any poor contact in the anten­na wiring?

No

Is the indoor/outdoor connecting wire of
the air conditioner and the wiring of the
antennas close?

No

Yes

Yes

Yes

Yes

Ground the unit.

Extend the distance between the antennas and
the indoor unit, and/or the antennas and the
outdoor unit.

Extend the distance between the TV sets and/or
radios and the indoor unit, or the TV sets or
radios and the outdoor unit.

Replace or repair the antenna.
Replace or repair the coaxial cable.

Extend the distance between the indoor/outdoor
connecting wire of the air conditioner and the wir­ing of the antennas.

No

Even if all of the above conditions are fulfi lled, the electromagnetic noise may enter, depending on the electric fi eld strength
or the installation condition (combination of specifi c conditions such as antennas or wiring).
Check the followings before asking for service.

1. Devices affected by the electromagnetic noise
TV sets, radios (FM/AM broadcast, shortwave)

2. Channel, frequency, broadcast station affected by the electromagnetic noise

3. Channel, frequency, broadcast station unaffected by the electromagnetic noise

4. Layout of ;
indoor/outdoor unit of the air conditioner, indoor/outdoor wiring, grounding wire, antennas, wiring from antennas, receiver

5. Electric fi eld intensity of the broadcast station affected by the electromagnetic noise

6. Presence or absence of amplifi er such as booster

7. Operation condition of air conditioner when the electromagnetic noise enters in

1) Turn OFF the power supply once, and then turn ON the power supply. In this situation, check for the electromagnetic
noise.

2) Within 3 minutes after turning ON the power supply, press OPERATE/STOP (ON/OFF) button on the remote controller for
power ON, and check for the electromagnetic noise.

3) After a short time (3 minutes later after turning ON), the outdoor unit starts running. During operation, check for the elec­tromagnetic noise.

4) Press OPERATE/STOP (ON/OFF) button on the remote controller for power OFF, when the outdoor unit stops but the
indoor/outdoor communication still runs on. In this situation, check for the electromagnetic noise.

19

8-7. TEST POINT DIAGRAM AND VOLTAGE

MS-A09WA MS-A12WA

Indoor electronic control P.C. board

Resistor
(R 111)

Release of Auto restart
function
Solder the Jumper wire
to JR07
(Refer to 7-3.)

Varistor (NR11)

Power supply input
115 VAC Fuse (F11)

}

250 V 3.15 A

Indoor fan motor
(CN211)

162 VDC

(-) Fiducial terminal of
cathode side on measur­ing high-voltage DC

15

VDC

(+)3-6 VDC

(+)0 or 15 VDC

Power monitor
receiver P.C.
board

Emergency
operation switch

SW P.C. board

12 VDC

5 VDC

Indoor coil thermistor
RT12
(CN112)

Horizontal vane
motor (CN151)

Room temperature
thermistor (RT11)

Timer short mode

}

point JPG, JPS
(Refer to 7-1.)

Indoor coil thermistor [RT12]
Room temperature thermistor (RT11)

20

Resistance (k )

32 50 68 86

Temperature (°F)

104 122 140

9

DISASSEMBLY INSTRUCTIONS

<"Terminal with locking mechanism" Detaching points>

The terminal which has the locking mechanism can be detached as shown below.
There are two types (refer to (1) and (2)) of the terminal with locking mechanism.
The terminal without locking mechanism can be detached by pulling it out.
Check the shape of the terminal before detaching.

(1) Slide the sleeve and check if there is a locking lever or not.

Sleeve

(2) The terminal with this connector has the
locking mechanism.

Slide the sleeve.
Pull the terminal while

Locking lever

pushing the locking
lever.

MS-A09WA MS-A12WA

OPERATING PROCEDURE PHOTOS

1. Removing the panel

(1) Remove the horizontal vane.
(2) Remove the screw caps of the panel. Remove the

screws. (Photo 1)

(3)

Hold the lower part of both ends on the panel and pull
it

slightly toward you, and then remove the panel by push-

ing

it upward.

Photo 3

Screw of the
conduit cover

Terminal block
cover

Hold the sleeve, and
pull out the terminal
slowly.

Connector

Photo 1

Screws of the panel

Horizontal vane

MS-A09/12WA -

1

Conduit cover

Photo 2

Terminal block
cover

Conduit cover

Screw of the
conduit cover

Conduit plate

MS-A09/12WA

21

OPERATING PROCEDURE

PHOTOS

2. Removing the electronic control P.C. board, the
power monitor receiver P.C. board, SW P.C. board
and the terminal block

(1) Remove the horizontal vane, the panel (refer to 1.) and the

corner box.

(2)

Remove the screw of the conduit cover, and conduit cover.

(Photo 2 or Photo 3)
(3) Remove the indoor/outdoor connecting wire.
(4) Remove the switch holder from the electrical cover. (Photo

4)

(5) Remove the screw of the electrical cover, and then the

electrical cover. (Photo 4)
(6) Remove the ground wire connected to the indoor electronic

control P.C. board from the electrical box. (Photo 5)
(7) Unhook the power monitor receiver P.C. board holder from

the catch. (Photo 4)
(8) Open the rear cover of the power monitor receiver P.C.

board holder and pull out the power monitor receiver P.C.

board.
(9) Open the switch holder and pull out SW P.C. board.
(10)

Pull the electronic control P.C. board slightly toward you

from the electrical box, and disconnect TAB3, TAB4 and all

the connectors on the electronic control P.C. board. (LD101

and LD105 are direct-mounted to the electronic control P.C.

board.)
(11)

Pull out the electronic control P.C. board from the electrical

box.
(12)

Remove the ground wire connected to the heat exchanger

from the electrical box. (Photo 5)
(13)

Unhook the catches of the electrical box, and pull out the

electrical box.
(14)

Remove the screw of the terminal block cover, and then

remove the terminal block cover and the terminal block

holder. (Photo 6)
(15)

Remove the terminal block by sliding it.

Photo 4

Photo 5

Switch holder

Screw of the
electrical cover.

Power monitor
receiver
P.C. board holder

Ground wire

Indoor fan motor
connector (CN211)

Indoor coil thermistor
connector (CN112)

Vane motor
connector (CN151)

3. Removing the electrical box

(1) Remove the horizontal vane, the panel (refer to 1.) and the

corner box.

(2) Remove the screw of Conduit cover, and then the indoor/

outdoor connecting wire. (Photo 2 or Photo 3)
(3) Remove the switch holder and the electrical cover. (Photo 4)
(4) Remove the ground wire connected to the heat exchanger

from the electrical box. (Photo 5)
(5) Disconnect the following connectors on the electronic

control P.C. board; the fan motor connector <CN211>, the

indoor coil thermistor connector <CN112>, the vane motor

connector <CN151>. (Photo 5)
(6) Unhook the catches of the electrical box, and pull out the

electrical box.

Photo 6

Screw

22

OPERATING PROCEDURE

PHOTOS

4. Removing the horizontal vane motor unit

(1) Remove the horizontal vane and the panel. (Refer to 1.)
(2) Remove the screws of the horizontal vane motor unit, and

pull out the horizontal vane motor unit. (Photo 7)

(3) Disconnect the connector from the horizontal vane motor

unit.

5. Removing the indoor fan motor and the line flow fan

(1) Remove the horizontal vane, the panel (Refer to 1.) and the

corner box.

Remove the switch holder and the electrical box. (Refer to 3.)

(2)
(3) Pull out the drain hose from the nozzle assembly, and

remove the nozzle assembly.
(4) Remove the screws fixing the motor bed.
(5) Loosen the screw fixing the line flow fan.
(6) Remove the motor bed together with fan motor and motor

band.
(7) Release the hooks of the motor band, and remove the

motor band then pull out the indoor fan motor.
(8) Remove the screws fixing the left side of the heat exchang-

er.

(Photo 10)

(9) Lift the heat exchanger, and pull out the line flow fan to the

lower-left.

(Photo 8)

(Photo 9)

Photo 7

Photo 8

Screws of
the motor
bed

Screws of the
horizontal vane
motor unit

Motor band

Photo 9

Screw of
the line flow
fan

Photo 10

Screws of the
left side of the
heat exchanger

23

10 PARTS LIST

10-1. PARTS LIST (non-RoHS compliant)
MS-A09WA
MS-A12WA

1. INDOOR UNIT STRUCTURAL PARTS

2. ACCESSORY AND REMOTE
CONTROLLER

1

2

3

4

5

6

9

10

8

7
(See 10-1.5.)

11

12

1. INDOOR UNIT STRUCTURAL PARTS

Symbol

No. Part No. Part name

1 E02 A32 234 BOX 1 1
2 E02 A49 000 PANEL ASSEMBLY 1 1 Including No.3,4
3 E02 913 067 SCREW CAP 2 2 2 PC/SET
4 E02 915 010 FRONT PANEL 1 1
5 E02 915 100 CATECHIN AIR FILTER (LEFT) 1 1
6 E02 916 100 CATECHIN AIR FILTER (RIGHT) 1 1
7
8 E02 A32 975 CORNER BOX (RIGHT) 1 1
9 E02 913 970 INSTALLATION PLATE 1 1

10 E02 A49 978 CONDUIT PLATE 1 1

—

AIR CLEANING FILTER 1 1 MAC-415FT-E

in Wiring

Diagram

MS-A09WA MS-A12WA

Q'ty/unit

Remarks

2. ACCESSORY AND REMOTE CONTROLLER

11 E02 A49 426 REMOTE CONTROLLER 1 1 KM06C

12 E02 527 083 REMOTE CONTROLLER HOLDER 1 1

24

MS-A09WA
MS-A12WA

3. INDOOR UNIT ELECTRICAL PARTS AND FUNCTIONAL PARTS

1

18

17

16

15

14

2

3

4

5

6

11

10

9

7

8

12

13

No. Part No. Part name

1 E02 751 509 BEARING MOUNT 1 1
2 E02 001 504 SLEEVE BEARING 1 1
3 E02 897 702 DRAIN HOSE 1 1
4 E02 A49 235 NOZZLE ASSEMBLY 1 1
5 E02 897 303 VANE MOTOR UNIT (HORIZONTAL) MV 1 1 UP & DOWN
6 E02 913 040 HORIZONTAL VANE 1 1

7 E02 913 095

8 E02 A49 979 CONDUIT COVER 1 1
9 E02 A49 780 TERMINAL BLOCK COVER 1 1

10 E02 A49 779 TERMINAL BLOCK HOLDER 1 1

11 E02 A49 375 TERMINAL BLOCK TB 1 1

E02 A49 452

12

E02 A50 452 1
13 E02 897 308 ROOM TEMPERATURE THERMISTOR RT11 1 1
14 E02 897 307 INDOOR COIL THERMISTOR RT12 1 1
15 E02 915 782 SWITCH HOLDER 1 1
16 E02 A49 300 INDOOR FAN MOTOR
17 E02 897 333 MOTOR BAND 1 1
18 E02 897 302 LINE FLOW FAN 1 1

1 Including SW P.C. BOARD and POWER MONITOR RECEIVER P.C. BOARD
2 Including FAN MOTOR RUBBER MOUNT (2 PC/SET)

POWER MONITOR RECEIVER P.C.
BOARD HOLDER

ELECTRONIC CONTROL P.C. BOARD

1

2 MF 1 1 RC0H30-□□

Symbol

in Wiring

Diagram

MS-A09WA MS-A12WA

Q'ty/unit

Remarks

11

1

25

MS-A09WA
MS-A12WA

4. INDOOR UNIT HEAT EXCHANGER

2

3

1

Symbol

No. Part No. Part name

E02 A49 620

1

E02 A50 620
E02 151 666

2

E02 155 666
E02 151 667

3

INDOOR HEAT EXCHANGER

UNION (GAS)

UNION (LIQUID) 1 1

in Wiring

Diagram

MS-A09WA MS-A12WA

1

1

5. AIR CLEANING FILTER (ANTI-ALLERGY ENZYME FILTER)

● AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity.

● Normal life of AIR CLEANING FILTER is 1 year.

If AIR CLEANING FILTER is to be washed, soak AIR CLEANING FILTER in water (when showing dirt, in lukewarm

water) and rinse it delicately, without removing the filter from the frame about once every 3 months.

● Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet.

● Do not remove or attach AIR CLEANING FILTER during unit operation.

Model Part No.

MS-A09WA
MS-A12WA

MAC-415FT-E

Q'ty/unit

Remarks

1

1

ø3/8
ø1/2
ø1/4

Replacement of the air cleaning filter

(1) Remove the catechin air filter (left one).

The air cleaning filter is not attached to
the right side catechin air filter.

(2) Remove the air cleaning filter (Blue bel-

lows type) from the catechin air filter.

Air cleaning filter
(Blue bellows type)

26

10-2. RoHS PARTS LIST (RoHS compliant)
MS-A09WA
MS-A12WA

1. INDOOR UNIT STRUCTURAL PARTS

2. ACCESSORY AND REMOTE
CONTROLLER

1

9

11

12

10

8

2

7
(See 10-2.5.)

3

4

5

6

1. INDOOR UNIT STRUCTURAL PARTS

Symbol

No.

1 G E12 A32 234 BOX 1 1 1 1
2 G E12 A49 000 PANEL ASSEMBLY 1 1 1 1 Including No.3,4
3 G E12 913 067 SCREW CAP 2 2 2 2 2 PC/SET
4 G E12 915 010 FRONT PANEL 1 1 1 1
5 G E12 915 100 CATECHIN AIR FILTER (LEFT) 1 1 1 1
6 G E12 916 100 CATECHIN AIR FILTER (RIGHT) 1 1 1 1
7G
8 G E12 A32 975 CORNER BOX (RIGHT) 1 1 1 1
9 G E12 913 970 INSTALLATION PLATE 1 1 1 1

10 G E12 A49 978 CONDUIT PLATE 1 1

Part No. Part name

RoHS

—

AIR CLEANING FILTER 1 1 1 1 MAC-415FT-E

in Wiring

Diagram

MS-A09WA MS-A12WA

Q'ty/unit

1

-

Remarks

1

-

2. ACCESSORY AND REMOTE CONTROLLER

G E12 A49 426

11

G E12 C30 426 1 1 KM07L

12 G E12 527 083 REMOTE CONTROLLER HOLDER 1 1 1 1

REMOTE CONTROLLER

1 1 KM06C

27

MS-A09WA
MS-A12WA

3. INDOOR UNIT ELECTRICAL PARTS AND FUNCTIONAL PARTS

1

19

18

17

16

15

2

3

4

5

6

12

11

7

10

8

No.

1 G E12 751 509 BEARING MOUNT 1 1 1 1
2 G E12 001 504 SLEEVE BEARING 1 1 1 1
3 G E12 897 702 DRAIN HOSE 1 1 1 1
4 G E12 A49 235 NOZZLE ASSEMBLY 1 1 1 1
5 G E12 897 303 VANE MOTOR UNIT (HORIZONTAL) MV 1 1 1 1 UP & DOWN
6 G E12 913 040 HORIZONTAL VANE 1 1 1 1

7 G E12 915 095

8 G E12 A49 979 CONDUIT COVER 1 1
9 G E12 C30 979 CONDUIT COVER 1 1

10

11

12 G E12 A49 375 TERMINAL BLOCK TB 1 1 1 1

13

14 G E12 897 308

15 G E12 897 307 INDOOR COIL THERMISTOR RT12 1 1 1 1
16 G E12 915 782 SWITCH HOLDER 1 1 1 1
17 G E12 A49 300 INDOOR FAN MOTOR 2 MF 1 1 1 1 RC0H30­18 G E12 897 333 MOTOR BAND 1 1 1 1
19 G E12 897 302 LINE FLOW FAN 1 1 1 1

1 Including SW P.C. BOARD and POWER MONITOR RECEIVER P.C. BOARD
2 Including FAN MOTOR RUBBER MOUNT (2 PC/SET)

Part No. Part name

RoHS

POWER MONITOR RECEIVER P.C.
BOARD HOLDER

G E12 A49 780
G E12 C30 780 1 1
G E12 A49 779
G E12 C30 779 1 1

G E12 A49 452
G E12 A50 452 11

TERMINAL BLOCK COVER

TERMINAL BLOCK HOLDER

ELECTRONIC CONTROL P.C.
BOARD 1

ROOM TEMPERATURE
THERMISTOR

Symbol

in Wiring

Diagram

RT11 1 1 1 1

13

9

MS-A09WA MS-A12WA

1111

11

11

11

14

Q'ty/unit

1

-

Remarks

1

-

□□

28

MS-A09WA
MS-A12WA

4. INDOOR UNIT HEAT EXCHANGER

2

3

1

No.

1

2

3 G E12 151 667 UNION (LIQUID) 1

Part No. Part name

RoHS

G E12 A49 620
G E12 A50 620 11
G E12 151 666
G E12 155 666 11ø1/2

INDOOR HEAT EXCHANGER

UNION (GAS)

Symbol

in Wiring

Diagram

MS-A09WA MS-A12WA

1

1

Q'ty/unit

1

-

1

1

1

1

5. AIR CLEANING FILTER (ANTI-ALLERGY ENZYME FILTER)

● AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity.

● Normal life of AIR CLEANING FILTER is 1 year.

If AIR CLEANING FILTER is to be washed, soak AIR CLEANING FILTER in water (when showing dirt, in lukewarm

water) and rinse it delicately, without removing the filter from the frame about once every 3 months.

● Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet.

● Do not remove or attach AIR CLEANING FILTER during unit operation.

Model Part No.

MS-A09WA
MS-A12WA

MAC-415FT-E

Remarks

1

-

ø3/8

ø1/4

1

Replacement of the air cleaning filter

(1) Remove the catechin air filter (left one).

The air cleaning filter is not attached to
the right side catechin air filter.

(2) Remove the air cleaning filter (Blue bel-

lows type) from the catechin air filter.

Air cleaning filter
(Blue bellows type)

29

11

MICROPROCESSOR CONTROL

MS-A09WA
MS-A12WA

WIRELESS REMOTE CONTROLLER

Signal transmitting section

Operation display section

ON/OFF (operate/

stop) button

Temperature buttons

Indication of
remote controller
model is on back

NOTE

Use the remote controller
provided with the unit only.
Do not use other remote
controller.

VANE button
(Horizontal vane button)

Operation select button

ECONO COOL button

POWERFUL button

RESET button

Fan speed control button

Off-timer button

On-timer button

TIME set buttons
Forward button
Backward button

CLOCK set button

(This diagram shows an overall view.)

(This diagram shows an overall view.)

Once the operation mode is set, the same operation mode can be repeated by simply turning OPERATE/STOP
(ON/OFF) button ON.
Indoor unit receives the signal with a beep tone.
When the system turns off, 3-minute time delay will operate to protect system from overload and compressor will not

restart for 3 minutes.

INDOOR UNIT DISPLAY SECTION

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

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.

Difference between target
temperature and room
temperature

Approx. 4°F or more

Approx. 4°F or less

Lighted

Blinking

Not lighted

30

11-1. COOL ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) 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 61 ~ 88°F.

1. Coil forest 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.

2. Low outside temperature operation

When the outside temperature lowers during cool mode operation, low outside temperature operation starts, and the out­door fan slows or stops.

11-2. DRY ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) 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 is as same as COOL mode. (11-1.1.)

2. Low outside temperature operation

Low outside temperature operation is as same as COOL mode. (11-1.2.)

11-3. FAN ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns ON with a beep tone.
(2) Select FAN mode with OPERATION SELECT button.
(3) Select the desired fan speed. When AUTO, it becomes Low.
Only indoor fan operates. Outdoor unit does not operate.

11-4. “I FEEL CONTROL” ( ) OPERATION

(1) Press OPERATE/STOP (ON/OFF) button on the remote controller. OPERATION INDICATOR lamp of the indoor unit

turns on with a beep tone.
(2) Select “I FEEL CONTROL” mode with OPERATION SELECT button.
(3) The operation mode is determined by the room temperature at start-up of the operation.

• Once the mode is fixed, the mode does not change by room temperature afterwards.

• Under the ON-TIMER (
ation.

(4) The initial set temperature is decided by the initial room temperature.

Initial room temperature Model Initial set temperature

79°F or more

77 to 79°F Initial room temperature minus 4°F

Less than 77°F DRY mode of "I FEEL CONTROL" Initial room temperature minus 4°F

) operation, mode is determined according to the room temperature at the start-up of oper-

75°F

COOL mode of "I FEEL CONTROL"

31

(5) TEMPERATURE buttons

In “I FEEL CONTROL” ( ) mode, set temperature is decided by the microprocessor based on the room temperature.
In addition, set temperature can be controlled by TOO WARM or TOO COOL buttons when you feel too cool or too warm.
Each time the TOO WARM or TOO COOL button is pressed, the indoor unit receives the signal and emits a beep tone.

• Fuzzy control

When the TOO COOL or TOO WARM button is pressed, the microprocessor changes the set temperature, considering
the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or
cool. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” mode.
In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.

TOO

COOL

…To raise the set temperature 2 ~ 4°F

TOO

WARM

…To lower the set temperature 2 ~ 4°F

11-5. 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 (approx. 12 V) transmitted from indoor microprocessor.

(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.

(3) Positioning
The vane is once pressed to the vane stopper to confirm the standard position and then set to the desired angle.
Confirming 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 multi-standby starts or finishes.

(4) VANE AUTO ( ) mode

In VANE AUTO mode, the microprocessor automatically determines the vane angle and operation to make the optimum
room-temperature distribution.

In COOL, DRY and FAN operation
Vane angle is fixed to Horizontal position.

Upward

(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) 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 2 ~ 4 when the compressor cumulative operation time
exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention.

(7) SWING MODE ( )

By selecting SWING mode with VANE CONTROL button, the horizontal vane swings vertically. The remote controller
displays “ ”.

32

(8) To change the airfl ow direction not to blow directly onto your body.

To change

the airfl ow direction

Pressing and holding VANE
CONTROL button for 2 sec­onds or more, the horizontal
vane reverses and moves
horizontal position.

When to use this function? COOL/DRY

Use this function if you don’t
want the air from the indoor unit
to blow directly onto your body.

• Depending on the shape of
the room, the air may blow
directly onto your body.

The air conditioner starts the
cooling or drying operation ap­prox. 3 minutes after the vane
has moved to the horizontal
position.

• When VANE CONTROL but­ton is pressed again, the vane

Horizontal

position

• Press VANE CONTROL but­ton again to return the vane
to the previously-set position.

returns to the previously-set
position and the air conditioner
starts the cool or dry operation
in approx. 3 minutes.

NOTE : • If you make the airfl ow not to blow directly onto your body by pressing VANE CONTROL button,

the compressor stops for 3 minutes even during the operation of the air conditioner.

• The air conditioner operates with Very Low speed until the compressor turns on again.

(9) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 3.6°F higher than that in

COOL mode.
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 than that

in COOL mode, 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. Plessing VANE CONTROL

button or POWERFUL button, or changing to other operation mode also cancels ECONO COOL operation.

10

) POWERFUL ( ) operation

(
The air conditioner automatically adjusts the fan speed and the set temperature, and operates the POWERFUL mode.

The POWERFUL mode is automatically released 15 minutes after operation starts, and the operation mode returns to

the mode prior to POWERFUL operation.

33

11-6. TIMER OPERATION

1. How to set the timer

(1) Press OPERATE/STOP (ON/OFF) 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 “0:00” 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 (

• Each time FORWARD button (
( ) is press, the set time decreases by 1 minute.

• Pressing those buttons longer increases / decreases the set time by 10 minutes.
Press the CLOCK set button.

ON timer setting

(1) Press ON-TIMER button(
(2) Set the time of the timer using TIME SET buttons (

OFF timer setting

(1) Press OFF-TIMER button ( ) during operation.
(2) Set the time of the timer using TIME SET buttons ( and ).

and ) to set the current time.

) is press, the set time increases by 1 minute, and each time BACKWARD button

) during operation.

and ).

Each time FORWARD button ( ) is pressed, the set time increases by 10 minutes; each time BACKWARD

( ) is pressed, the set time decreases by 10 minutes.

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.

button

PROGRAM TIMER

• OFF timer and ON timer can be used in combination. The timer of the set time that is reached first will operate first.
” and “ ” display shows the order of OFF timer and ON timer operation.

• “

(Example 1) The current time is 8:00 PM.

The unit turns off at 11:00 PM, and on at 6:00 AM.

NOTE : If the main power is turned off or a power failure occurs while AUTO START/STOP timer is active, the timer set-

ting is cancelled. As these models are equipped with an auto restart function, the air conditioner starts operating
with timer cancelled when power is restored.

(Example 2) The current time is 11:00 AM.

The unit turns on at 5:00 PM, and off at 9:00 PM.

34

11-7. EMERGENCY/TEST OPERATION

In 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, has failed or the batteries of the remote
controller run down. The unit will start and OPERATION INDICATOR lamp will light.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The Indoor fan speed runs at
High speed and the system is in continuous operation (with thermostat ON).
After 30 minutes of test run operation the system shifts to EMERGENCY COOL with a set temperature of 75°F. The fan
speed shifts to Med..
All protective operations such as the coil frost prevention works even in emergency operation.
In the test run or emergency operation, the horizontal vane operates in VANE AUTO (
Emergency operation continues until EMERGENCY OPERATION switch is pressed once or twice or the unit receives any
signal from the remote controller. In case of latter normal operation will start.

NOTE : Do not press EMERGENCY OPERATION switch during normal operation.

Operation mode COOL
Set temperature 75°F

Fan speed Med.

E.O.

SW

EMERGENCY OPERATION switch

Horizontal vane Auto

The operation mode is indicated by the
Operation Indicator lamp as following

Operation Indicator lamp

EMERGENCY COOL

STOP

) mode.

Lighted

Not lighted

11-8. CHANGING TEMPERATURE INDICATION (°F/°C)

MS-A•WA-

The preset unit is °F.
Press RESET button while
the temperature buttons
are pressed.

1

Press RESET button gently
using a thin stick.

35

TM

HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN

Copyright 2006 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD

Distributed in Oct. 2008. No. OB448 REVISED EDITION-C 5
Distributed in Jun. 2008. No. OB448 REVISED EDITION-B 6
Distributed in May 2007. No. OB448 REVISED EDITION-A 7
Distributed in Mar. 2006. No. OB448 7
Made in Japan

New publication, effective Oct. 2008
Specifications subject to change without notice.