Mitsubishi Electric MU-GD08ND, MU-GD10ND, MU-GD12ND 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. PERFORMANCE CURVES

································

9

8. TROUBLESHOOTING

······································

11

9. DISASSEMBLY INSTRUCTIONS

····················

12

SPLIT-TYPE, AIR CONDITIONERS

MU-GD08ND­MU-GD10ND­MU-GD12ND-

C1

C1

C1

TM

Indoor unit service manual

MS-GD•ND Series (TBH014)

No. TBH016

SERVICE MANUAL

Wireless type
Models

OUTDOOR UNIT

NOTE:

• RoHS compliant products have <G> mark on the spec name plate.

PARTS CATALOG (TBB016)

MU-GD08ND-



C1

2

TECHNICAL CHANGES1

MU-A08ND-

C2

= MU-GD08ND-

C1

1. Compressor has been changed. (2R10S3R236A-6B = KS-098NARC)

2. Outdoor fan motor has been changed. (RA6N33-AA = RA6V21-BE)

3. Outdoor heat exchanger has been changed.

4. Compressor capacitor has been changed.

5. Fan motor capacitor has been changed.

MU-A12ND- C1 = MU-GD12ND-

C1

1. Compressor has been changed. (RH174NHNT = RH189NRAT)

2. Outdoor fan motor has been changed. (RA6N30-BA = RA6V33-MC)

3. Compressor capacitor has been changed.

4. Fan motor capacitor has been changed.

MU-A10ND-

C2

= MU-GD10ND-

C1

1. Model name changed.

3

2

PART NAMES AND FUNCTIONS

Air outlet

Drain outlet

Piping

Drain hose

Air inlet
(back and side)

MU-C08VC
MU-C10VC
MU-C13VC

MU-C18VC

Air inlet
(back and side)

Piping

Drain hose

Air outlet

Drain outlet

MU-GD08ND

MU-GD10ND
MU-GD12ND

4

SPECIFICATION

3

Outdoor model

MU-GD08ND -

C1

MU-GD10ND -

C1

MU-GD12ND -

C1

Function Cooling

Power supply

Single phase

220-230V, 60Hz

Capacity

Capacity kW 2.2-2.2 2.9-2.9 3.6-3.6

Dehumidifi cation R/h 0.1 0.45 1.1

Air fl ow K /h 1896-1962 1452-1524 2106-2124

Electrical data

Power outlet A 10 10 10

Running current (Total) A 3.19-3.24 4.31-4.31 5.7-5.7

Power input (Total) W 680-685 930-930 1210-1210

Power factor (Total) % 97-92 98-94 96-92

Starting current A 19 26 40

Compressor motor current A 2.67-2.71 3.86-3.85 5.14-5.13

Fan motor current A 0.330-0.340 0.260-0.270 0.370-0.380

Coeffi cient of performance (C.O.P) 3.24-3.21 3.12-3.12 2.98-2.98

Compressor

Model KS098NARC RH145NHNT RH189NRAT

Output W 500 700 900

Winding
resistance (at 20:)

Ω

C-R 3.54
C-S 4.90

C-R 2.74
C-S 3.78

C-R 1.50
C-S 2.33

Fan

motor

Model RA6V21-BE RA6N21-AB RA6V33-MC

Winding
resistance (at 20:)

Ω

WHT-BLK 252
BLK-RED 278

WHT-BLK 384
BLK-RED 259

WHT-BLK 141
BLK-RED 175

Dimensions WxHxD mm 684x540x255 800x550x285

Weight kg 22 34 35

Special

remarks

Sound level dB 46-47 46-46 50-51

Fan speed rpm 820-830 690-720 980-990

Fan speed regulator 1

Refrigerant fi lling capacity (R22) kg 0.55 1.10

Refrigeration oil (Model) cc 300(NM56) 520(NM56)

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

5

4

OUTLINES AND DIMENSIONS

20.8

6.441
6

.
98

255

145.5

Service panel

Service port

Air out

Liquid refrigerant pipe joint
Refrigerant pipe (flared) ;6.35

Gas refrigerant pipe joint
Refrigerant pipe (flared) ;9.52

34 

04 

REQUIRED SPACE

Basically open 100mm or more
without any obstruction in front
and on both sides of the unit.

ero

m

r

o m

m0

5

3

ero

m

ro

mm0

01

erom ro

m

m00

1

erom

ro mm001

Open two sides of left,
right, or rear side.

Air in

Air in

381.5

Drain hole

;33

ro
f

hct
ip t

loB

noitalla

tsni

082~462

0
03

045

072

0
1

5.74

5.
22

17.5

243

Bolt pitch for installation

500

684

61

105

Handle

2 holes 10'16

40

Unit : mm

Unit : mm

0
1

69

800

302.5

500 Bolt pitch for installation

150

22.3

Handle

055

0
82

5.
46

1

5.9
9

170.5

23

Service panel

Service port

582

5.44

3

44

400

Air in

Air out

5.7
1

r
o

f
hct

i
p
tlo

B

no
ital

lats

n

i

52
3

~
4
03

40

Liquid refrigerant pipe joint
Refrigerant pipe (flared) ;6.35

Gas refrigerant pipe joint
Refrigerant pipe (flared)

34 

53 

2 holes 10'21

REQUIRED SPACE

Basically open 100mm or more
without any obstruction in front
and on both sides of the unit.

erom ro m

m053

erom

ro mm002

erom ro

mm

00

1

e

rom ro mm001

Open two sides of left,
right, or rear side.

Drain hole ;42

Air in

;9.52 (MU-GD10ND)
;12.7 (MU-GD12ND)

MU-GD08ND

MU-GD10ND
MU-GD12ND

6

WIRING DIAGRAM

5

MU-C08VC
MU-C10VC

MU-C13VC

MU-GD08ND

MU-GD10ND

7

MU-C18VC

REFRIGERANT SYSTEM DIAGRAM

6

Refrigerant flow in cooling

Capillary tube

X3.0 ' X 1.6 ' 650

Compressor

Stop valve
(with service port)

Stop valve

Strainer
#100

Outdoor
heat
exchanger

Refrigerant pipe
(with heat insulator)

X6.35

Refrigerant pipe

X9.52

(with heat insulator)

Flared
connection

Flared
connection

Unit : mm

MU-GD12ND

MU-GD08ND

8

MAX.REFRIGERANT PIPING LENGTH

Model

Piping size O.D : mm

Refrigerant piping : m

Gas

X9.52

Liquid

X6.35

20

10

MU-GD08ND-

Max. lengthAMax. height

B

MU-GD10ND-
MU-GD12ND-

X12.7

30

NOTE : Calculation : Xg=15g/m x (Refrigerant piping length (m)-7)

Model

Outdoor unit precharged

Refrigerant piping length (one way)

15m

120

20m

195

7m

0

10m

45

550

1100

30m

-

345

Capillary tube

X3.0 ' X1.6 ' 850
X3.0 ' X1.6 ' 450

Stop valve
(with service port)

Stop valve

Compressor

Strainer
#100

Outdoor heat
exchanger

Refrigerant pipe X6.35
(with heat insulator)

Refrigerant pipe

X9.52 (MU-GD10ND)
X12.7 (MU-GD12ND)

(with heat insulator)

Flared
connection

Flared
connection

Refrigerant flow in cooling

MU-C18VC

C1

C1

C1

MU-GD10ND-

C1

MU-GD12ND-

C1

MU-GD08ND-

C1

Indoor
unit

Max. Height
B

Outdoor unit

Refrigerant Piping

Max. Length

A

MAX.HEIGHT DIFFERENCE

ADDITIONAL REFRIGERANT CHARGE(R22 : g)

MU-GD10ND
MU-GD12ND

Model

Refrigerant piping : m Piping size O.D : mm

Max. length

A

Max. height

B

Gas Liquid

MU-GD08ND -

C1

20 10

ø9.52

ø6.35

MU-GD10ND -

C1

MU-GD12ND -

C1

ø12.7

Model

Outdoor unit

precharged

Refrigerant piping length (one way)

7m 10m 15m 20m

MU-GD08ND -

C1

550

0 45 120 195

MU-GD10ND -

C1

110 0

MU-GD12ND -

C1

(MU-GD10ND - C1)
(MU-GD12ND - C1)

9

PERFORMANCE CURVES7

The standard data contained in these specifications apply only to the operation of the air conditioner under normal conditions.
Since operating conditions vary according to the areas where these units are installed. The following information has been
provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.

(1) GUARANTEED VOLTAGE

198 ~ 253V, 60Hz

(2) AIR FLOW

Air flow should be set at MAX.

(3) MAIN READINGS

(1) Indoor intake air wet-bulb temperature : °CWB
(2) Indoor outlet air wet-bulb temperature : °CWB
(3) Outdoor intake air dry-bulb temperature : °CDB
(4) Total input: W
Indoor air wet/dry-bulb temperature difference on the left side of the chart on next page shows the difference between the
indoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for your reference at service.

MU-C08VC MU-C10VC MU-C13VC MU-C18VC

Wet and dry-bulb
thermometers

Wet and dry-bulb
thermometers

How to measure the indoor air wet/dry-bulb temperature difference

1. Attach at least 2 sets of wet and-dry-bulb thermometers to the indoor air intake as shown in the figure, and at least 2 sets
of wet and dry-bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where air
speed is high.

2. Attach at least 2 sets of wet and dry-bulb thermometers to the outdoor air intake.
Cover the thermometers to prevent direct rays of the sun.

3. Check that the air filter is cleaned.

4. Open windows and doors of the room.

5. Press the EMERGENCY OPERATION switch once to start the EMERGENCY COOL MODE.

6. When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.

7. 10 minutes later, measure temperature again and check that the temperature does not change.

INDOOR UNIT OUTDOOR UNIT

Indoor intake air WB temperature ()

Outdoor intake air DB temperature ()

Indoor intake air WB temperature ()

Outdoor intake air DB temperature ()

3.8

3.4

4.3

5.6

5.1

4.7

5.8

5.1

6.4

8.5

7.8

7.1

4.8

4.3

5.4

7.0

6.5

5.9

MS-GD08ND-

C1

MU-GD08ND-C1MS-GD12ND-

C1

MU-GD12ND-

C1

MS-GD10ND-

C1

MU-GD10ND-

C1

MU-GD08ND MU-GD10ND MU-GD12ND

10

 Both indoor and outdoor units are under the same temperature/humidity condition.

OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT
COOL operation

 Air flow should be set at MAX.

Dry-bulb temperature ()

Relative humidity (%)

20

50

25

60

30 70

 The unit of pressure has been changed to MPa on the international system of units(SI unit system).

The conversion factor is : 1(MPa [Gauge]) =10.2(kgf/C[Gauge])

15 20

50

25
60

3070 35()

(%)

0.4

0.5

0.6

0.7

0.8

4.0

5.0

6.0

7.0

8.0

9.0

0.9

15 20

50

25
60

30
70

35()
(%)

2.0

2.5

3.0

3.5

4.0

erusser

p
wol

roodtuO

)
A

(
tnerruc tinu roo

d

t
u

O

(kgf/& [Gauge])(MPa [Gauge])

Ambient temperature (˚C)/Ambient humidity (%)

Ambient temperature (˚C)/Ambient humidity (%)

230V

220V

0.4

0.5

0.6

0.7

0.8

1

2

3

4

0.8

0.7

0.6

0.5

0.4
15 20

50

25
60

3070 35()

(%)

15 20

50

25
60

3070 35()

(%)

Ambient temperature (˚C)/Ambient humidity (%)

erusserp wol roodtuO

Ambient temperature (˚C)/Ambient humidity (%)

)A( tner

r
uc tinu roodtuO

(kgf/& [Gauge])(MPa [Gauge])

230V

220V

MU-GD10ND MU-GD10ND

MU-GD08ND MU-GD08ND

0.3

0.4

0.5

0.6

0.7

4

5

6

7

0.7

0.6

0.5

0.4

0.3
15 20

50

25
60

3070 35()

(%)

15 20

50

25
60

3070 35()

(%)

Ambient temperature (˚C)/Ambient humidity (%)

erusserp wol roodtuO

Ambient temperature (˚C)/Ambient humidity (%)

)A( tnerruc tinu roo

d

tuO

(kgf/& [Gauge])(MPa [Gauge])

220V

230V
220V

230V

MU-GD12ND MU-GD12ND

11

8-2. Trouble criterion of main parts

$

$

:INNER PROTECTOR

TROUBLESHOOTING8

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 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 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.

MU-C08VC MU-C10VC MU-C13VC MU-C18VC

Lead wiring

Housing point

Outdoor fan
motor (MF)

INNER FUSE

MU-GD08/GD12ND-

126&2 OPEN

MU-GD10ND-

145 OPEN

Measure the resistance between the terminals with a tester.
(Coil wiring temperature -10oC ~ 40oC)

WHT

RED

BLK

AUX.

MAIN

FUSE

Compressor (MC)

INNER
PROTECTOR

MU-GD08ND-

155&5 OPEN
90&10 CLOSE

MU-GD10/GD12ND-

150&5 OPEN
90&10 CLOSE

Part name

Check method and criterion

Measure the resistance between the terminals with a tester.
(Coil wiring temperature -10oC ~ 40oC)

Figure

RED

WHT

BLK

P

C

SR

C1

C1

C1

C1

MU-GD08ND MU-GD10ND MU-GD12ND

MU-GD08ND
MU-GD10ND
MU-GD12ND

Color of

lead wire

Normal

MU-GD08ND-

C1

MU-GD10ND-

C1

MU-GD12ND-

C1

C-R 3.12 ~ 3.82 Ω 2.41 ~ 2.96 Ω 1.32 ~ 1.62 Ω

C-S 4.32 ~ 5.29 Ω 3.33 ~ 4.08 Ω 2.05 ~ 2.52 Ω

Color of

lead wire

Normal

MU-GD08ND -

C1

MU-GD10ND - C1 MU-GD12ND -

C1

WHT-BLK 222 ~ 272 Ω 338 ~ 415 Ω 124 ~ 153 Ω

BLK-RED 245 ~ 300 Ω 228 ~ 280 Ω 154 ~ 189 Ω

12

DISASSEMBLY INSTRUCTIONS

9

OPERATING PROCEDURE

PHOTOS

Photo 1

1. Removing the cabinet

(1) Remove the screws fixing the top panel. (See Photo 1.)
(2) Remove the top panel. (See Photo 1.)
(3) Remove the screw fixing the service panel. (See Photo 2.)
(4) Pull down the service panel and remove it. (See Photo 2.)
(5) Remove the screws fixing the cabinet.
(6) Remove the cabinet.
(7)

Disconnect the power supply and indoor/outdoor connecting wire.
(8) Remove the screws fixing the back panel.
(9) Remove the back panel.

Screws of
the cabinet

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

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

Slide the sleeve.
Pull the terminal while

pushing the locking
lever.

Hold the sleeve, and
pull out the terminal
slowly.

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.

<"Terminal with locking mechanism" Detaching points>

Connector

Sleeve

Locking lever

Photo 2

Screw of the

service panel

Direction to
remove

Hooks

Service

panel

Screw of
the top panel

Screws
of the
top panel

9-1. MU-C08VC MU-C10VC MU-C13VC

MU-GD08ND

13

3. Removing the propeller and the outdoor fan motor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the propeller nut and the propeller.
NOTE : Loose the propeller in the rotating direction for

removal.
When attaching the propeller, align the mark on the
propeller and the motor shaft cut section.
Set the propeller in position by using the cut on the shaft

and the mark on the propeller.
(3) Remove the lead clamps and outdoor fan motor lead wires.
(4) Remove the screws fixing the outdoor fan motor.
(5) Remove the outdoor fan motor.

Photo 4

Propeller

Propeller
nut

Outdoor
fan motor

Set screws of the
outdoor fan motor

Hook

Relay panel

Outdoor fan motor lead wires

Set screws of the
outdoor fan motor

OPERATING PROCEDURE PHOTOS

2. Removing the electrical parts

(1) Remove the service panel and the cabinet.(Refer to 1.)
(2) Remove the following parts.

•Compressor capacitor (C1)

•Outdoor fan capacitor (C2)

•Terminal block (TB)

•Compressor contactor (52C)

Photo 3

Outdoor fan
capacitor
(C2)

Terminal
block (TB2)

Compressor
capacitor
(C1)

Lead clamp

Connector

Terminal
block(TB1)

Compressor
contactor
(52C)

x

xx

x

x

x

xx

x

xx

xx

xxx

x

x

x

x

xx

xx

xx

xxx

xx

xxx

xx

x

x

x

x

x

x

x

x

x

x

xxxx

x

x

xx

x

x

xx

x

x

x

x

x

x

x

xx

x

x

xx

x

x

x

x

xx

0

8

2

1

Model and type name
OMRON
G7L-1A-TUB-07

NOTE : When attaching compressor contactor (52C)
to relay panel, make sure that the side with
printed letters is facing upward.

4

6

0

1

Earth screw of
indoor/

outdoor

connecting wire

Earth screw of
power supply

14

OPERATING PROCEDURE PHOTOS

4. Removing the compressor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the soundproof felt.
(3) Remove the screws fixing the relay panel.
(4) Remove the terminal cover.
(5) Pull out the lead wires from the glass terminal of the com-

pressor.

(6) Recover gas from the refrigerant circuit.

NOTE : Recover gas from the pipes until the pressure gauge

shows 0 kg/cm

2

(0MPa).

(7) Disconnect the welded part of the suction pipe and

discharge pipe.
(8) Remove the nuts fixing the compressor.
(9) Remove the compressor.

Photo 5

Compressor

Discharge
pipe

Compressor set nuts
(3 places)

Terminal

cover

Suction
pipe

MU-C08/10VC

Photo 6

Compressor

Discharge
pipe

Compressor set nuts
(3 places)

Terminal

cover

Suction
pipe

MU-C13VC

15

2. Removing the electrical parts

(1) Remove the service panel and the cabinet. (Refer to 1.)
(2) Remove the following parts.

•Compressor capacitor (C1)

•Outdoor fan capacitor (C2)

•Terminal block (TB)

•Compressor contactor (52C)

OPERATING PROCEDURE PHOTOS

9-2. MU-C18VC

Photo 4

1. Removing the cabinet

(1) Remove the screws fixing the top panel. (See Photo 2 and

3.)
(2) Remove the top panel. (See Photo 3.)
(3) Remove the screw fixing the service panel. (See Photo 3.)
(4) Pull down the service panel and remove it. (See Photo 3.)
(5) Remove the screws fixing the cabinet.
(6) Remove the cabinet.
(7) Disconnect the indoor/outdoor connecting wire.
(8) Remove the screws fixing the back panel.
(9) Remove the back panel.

Photo 1

Screws of the cabinet

Screws of the front panel and motor support

Photo 3

Screws of the
top panel

Service
panel

Screw of the
cabinet

Direction
to remove

Hooks

Screw of the
service panel

Screws of
the cabinet

Photo 2

Screws of the
top panel

MU-GD10ND MU-GD12ND

MU-GD10ND

Lead clamp

Compressor
capacitor (C1)

Outdoor fan
capacitor (C2)

Connector

Terminal
block(TB1)

Earth screw of
power supply

Terminal
block (TB2)

Earth screw of indoor/
outdoor connecting wire

16

PHOTOS

OPERATING PROCEDURE

3. Removing propeller and the outdoor fan motor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the propeller nut and remove the propeller.

NOTE : Loose the propeller in the rotating direction for

removal.
When attaching the propeller, align the mark on the
propeller and the motor shaft cut section.
Set the propeller in position by using the cut on the
shaft and the mark on the propeller.

(3) Disconnect the connector and remove the lead clamps and

outdoor fan motor lead wires.
(4) Remove the screws fixing the outdoor fan motor.
(5) Remove the outdoor fan motor.

Photo 5

MU-GD12ND

MU-GD10ND

MU-GD12ND

Relay panel

Hook

Outdoor fan motor

lead wires
Set screws of the
outdoor fan motor

Propeller

Set screws of the
outdoor fan motor

Propeller nut

Outdoor
fan motor

Set screws of the
outdoor fan motor

Propeller nut

Relay panel

Hook

Outdoor fan motor
lead wires

Set screws of the
outdoor fan motor

Propeller

Outdoor
fan motor

Lead clamp

Compressor
capacitor (C1)

Outdoor fan
capacitor (C2)

Connector

Terminal
block(TB1)

Terminal
block (TB2)

Compressor
contactor
(52C)

17

PHOTOS

OPERATING PROCEDURE

4. Removing the compressor

(1) Remove the cabinet. (Refer to 1.)
(2) Remove the relay panel.
(3) Remove the soundproof felt.
(4) Remove the terminal cover.
(5) Pull out the lead wires from the glass terminal of the com-

pressor.

(6) Recover gas from the refrigerant circuit.

NOTE : Recover gas from the pipes until the pressure gauge

shows 0 kg/cm

2

(0MPa).

(7) Disconnect the welded part of the suction pipe and dis-

charge pipe.

(8) Remove the nuts fixing the compressor and the compres-

sor.

Glass
terminal

Compressor

Suction pipe

Discharge pipe

Compressor
nuts

Photo 6

MU-GD10ND

Glass
terminal

Discharge
pipe

Suction
pipe

Compressor nuts

(3 places)

Compressor

MU-GD12ND

MITSUBISHI ELECTRIC CONSUMER PRODUCTS (THAILAND) CO., LTD.
AMATA NAKORN INDUSTRIAL ESTATE
700/406 MOO 7, TAMBON DON HUA ROH,
AMPHUR MUANG, CHONBURI 20000 THAILAND
Made in Thailand

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

HEAD OFFICE: TOKYO DENKI BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO100-8310, JAPAN

TM