Mitsubishi Electric MS-GD08ND User manual

1
SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ................................... 2
2. PART NAMES AND FUNCTIONS ..................... 3
3. SPECIFICATION ................................................ 4
4. OUTLINES AND DIMENSIONS ........................ 5
5. WIRING DIAGRAM ............................................ 6
6. REFRIGERANT SYSTEM DIAGRAM ............... 7
7. SERVICE FUNCTIONS ..................................... 8
8. TROUBLESHOOTING ..................................... 10
9. DISASSEMBLY INSTRUCTIONS ................... 19
Wireless type
Models
INDOOR UNIT
Outdoor unit service manual
MU-GD•ND Series (TBH016)
SPLIT-TYPE, AIR CONDITIONERS
MS-GD08ND- C1
MS-GD10ND- C1
MS-GD12ND- C1
PARTS CATALOG (TBB014)
No. TBH014
NOTE:
• RoHS compliant products have <G> mark on the spec name plate.
TM
MS-GD08ND-
MS-GD10ND-
MS-GD12ND-
C1
C1
C1

2
1 TECHNICAL CHANGES
MS-A08ND- C1 ➔ MS-GD08ND- C1
MS-A12ND- C1 ➔ MS-GD12ND- C1
1. Indoor unit has been changed.
• Front panel has been changed. (Flat Flat Shining)
2. Terminal block has been changed. 3P (L~, N~, 2~) 4P (L~, N~, 2~, Earth)
MS-A10ND- C1 ➔ MS-GD10ND- C1
1. Indoor unit has been changed.
• Front panel has been changed. (Flat Flat Shining)

3
2
ACCESSORIES
PART NAMES AND FUNCTIONS
INDOOR UNIT
MS-GD08ND- C1
MS-GD10ND- C1
MS-GD12ND- C1
Emergency operation switch
Fan
Air outlet
Vertical vanes
Air inlet
Remote control
receiving section
Display section
Air cleaning filter
(white bellows type)
Catechin air filter
(with deodorizing)
Front panel
Panel
Horizontal vane
Operation section
(When the front panel is opened)
Remote controller
Operation indicator lamp
Remote control
receiving section
MS-GD08ND- C1
MS-GD10ND- C1
MS-GD12ND- C1
1 Installation plate 1
2 Installation plate fixing screw 4 x 25 mm 5
3 Remote controller holder 1
4 Fixing screw for 3 3.5 x 16 mm (Black) 2
5 Battery (AAA) for remote controller 2
6 Wireless remote controller 1
7 Felt tape (Used for left or left-rear piping) 1
8 Air cleaning filter 2

4
SPECIFICATION
3
REMOTE CONTROLLER
ON/OFF
RESET
TOO
WARM
TOO
COOL
ECONO COOL
POWERFUL COOL
SELECT
FAN
VANE
TIME
MODE
I FEEL COOL
DRY
FAN
h
Signal transmitting section
Operation display section
TEMPERATURE buttons
VANE CONTROL button
TIME SET button
RESET button
ECONO COOL button
POWERFUL COOL button
OPERATION SELECT button
TIMER MODE SELECT button
OPERATE/STOP (ON/OFF) button
FAN SPEED CONTROL button
Indication of remote controller
model is on back.
These buttons are able to store the light
from nature, fluorescent lamp, etc and
shine in the dark.
Indoor model
MS-GD08ND-
C1
MS-GD10ND-
C1
MS-GD12ND-
C1
Function Cooling
Power supply Single phase 220-230V, 60Hz
Capacity Air flow (High/Med/Low) K/h 588/456/372 630/498/336 666/498/336
Electrical data
Power outlet A 10
Running current A 0.19
Power input W 40
Auxiliary heater A (kW) —
Power factor % 96-92
Fan motor current A 0.19
Fan
motor
Model RC4N19-BA
Winding
resistance (at 20ºC) " WHT-BLK 312 BLK-RED 255
Dimensions WoHoD mm 815o278o244
Weight kg 9 10
Special
remarks
Air direction 5
Sound level (High/Med/Low) dB 39/32/26 39/32/26 42/36/29
Fan speed (High/Med/Low) rpm 1030/800/650 960/800/650 1000/800/650
Fan speed regulator 3
Thermistor RT11 (at 25ºC) kΩ 10
Thermistor RT12 (at 25ºC) kΩ 10
Remote controller model MP2B
NOTE: Test conditions are based on CNS 14464
Cooling : Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C Wet-bulb temperature 24°C
Refrigerant piping length (one way) 7.5 m
MS-GD08ND- C1
MS-GD10ND- C1
MS-GD12ND- C1

5
[9.52-0.43m
244
242 5
erom ro
7
90
110
0
3
149
606
8
7
2
60
815
783
Air out
Installation plate
Insulation [28
Drain hose [16
(Connected part O.D)
Liquid line [6.35-0.5m
Gas line [9.52-0.43m
Insulation [37 O.D
[21 I.D
{
Wireless remote controller
81.5
81.5
14
5
.
2
24
172
5.132
5.
4
81.5 133.5
326326
Wall hole [65
Indoor unit
Installation plate
57
04
1
17.5
Air in
244
242
5.812
8
5
2
81.581.5
14
24
5.2
5.71
161.5161.5
326326
5
erom ro 7
90
110
0
3
149
606
872
60
815
783
Air out
Indoor unit
Installation plate
Wall hole [65
Installation plate
Insulation [28
Drain hose [16
(Connected part O.D)
Air in
Liquid line [6.35-0.5m
Gas line
Insulation[37 O.D
[21 I.D
{
Wireless remote controller
57
041
17.5
Unit : mm
INDOOR UNIT
OUTLINES AND DIMENSIONS4
MS-GD08ND- C1
INDOOR UNIT
MS-GD10ND- C1
MS-GD12ND- C1

6
MS-GD08ND- C1
MS-GD12ND- C1
WIRING DIAGRAM
5
INDOOR UNIT
MS-GD10ND- C1

7
REFRIGERANT SYSTEM DIAGRAM
6
MS-GD08ND- C1
MS-GD10ND- C1
INDOOR UNIT
Room
temperature
thermistor
Indoor
heat
exchanger
RT11
Indoor coil
thermistor
RT12
Refrigerant pipe
(Option){6.35
(with heat insulator)
Flared
connection
Flared
connection
Refrigerant pipe
(Option){12.7
(with heat insulator)
Refrigerant flow in cooling
Room
temperature
thermistor
Indoor
heat
exchanger
RT11
Indoor coil
thermistor
RT12
Refrigerant pipe
(Option){6.35
(with heat insulator)
Flared
connection
Flared
connection
Refrigerant pipe
(Option){9.52
(with heat insulator)
MS-GD12ND- C1
INDOOR UNIT

8
Table 1
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 accepts 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.
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.
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 8-6.)
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.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
NOTE : For remodelling, take out the bat-
teries and push the OPERATE/
STOP(ON/OFF)button twice or 3
times at first.
After finish remodelling, put back
the batteries then press the
RESET button.
Remote controller model : MP2B
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
J1
SERVICE FUNCTIONS
7
MS-GD08ND- C1
MS-GD10ND- C1
MS-GD12ND- C1
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

9
When the indoor unit is controlled with the remote controller, the operation mode, 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. However if the unit is operated in “I FEEL
CONTROL” mode before power failure, the operation is not memorized. In “I FEEL CONTROL” mode, the operation is
decided by the initial room temperature.
How to release “AUTO RESTART FUNCTION”
1 Turn off the main power for the unit.
2 Pull out the indoor electronic control P.C. board and the power monitor, receiver
P.C. board. (Refer to 9-1.)
3 Solder the Jumper wire to the JR07 on the indoor electronic control P.C.board.
(Refer to 8-6.)
7-3. AUTO RESTART FUNCTION
NOTE:
• The operation settings are memorized when 10 seconds have passed after the indoor unit was operated with the remote
controller.
• If the 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 appliances 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.
Operation
1 If the main power has been cut, the operation settings remain.
2 After the power is restored, the unit automatically resumes the same operation
as the memory has recorded.
However, it takes the compressor at least 3 minutes to get started.
JR07
IC101
CN151
SW1
CN112
CN111
CN201
52C/X10
C11
CN211
CN1V1
CN1R1 CN121

10
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 mis-wiring.
2. Take care 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 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
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 that the connector and terminal are connected properly.
3) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the
components for bursting and discolouration.
4) When troubleshooting, refer to 8-2. and 8-3.
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.
2 Press the RESET button with tip end of ball point
pen or the like, and then use the remote controller.
NOTE : 1. If the 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.
1 Remove the back lid and insert batteries.
Then reattach the back lid.
Insert the negative pole
of the batteries first.
Check if the polarity of
the batteries are correct.
RESET button
TROUBLESHOOTING8
MS-GD08ND- C1
MS-GD10ND- C1
MS-GD12ND- C1