Mitsubishi MUZ-GE24NA, MUZ-GE12NA, MUY-GE09NA, MUY-GE12NA, MUY-GE15NA Service Manual

SPLIT-TYPE AIR CONDITIONERS

OUTDOOR UNIT

Revision B:

• Descriptions regarding the outdoor fan motor

have been corrected.

Please void OBH549 REVISED EDITION-A.

SERVICE MANUAL

Models

MUZ-GE09NA
MUZ-GE12NA
MUZ-GE15NA
MUZ-GE18NA
MUZ-GE24NA
MUY-GE09NA
MUY-GE12NA
MUY-GE15NA
MUY-GE18NA
MUY-GE24NA

HFC

utilized

R410A

Indoor unit service manual

MSZ-GE•NA MSY-GE•NA Series (OBH548)

No. OBH549

REVISED EDITION-B

MUZ-GE09/12/15NA
MUY-GE09/12/15NA

NOTE:

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

CONTENTS

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

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

3. SPECIFICATION ················································ 4

4. OUTLINES AND DIMENSIONS ························ 8

5. WIRING DIAGRAM ·········································· 10

6. REFRIGERANT SYSTEM DIAGRAM ············· 15

7. DATA ································································ 18

8. ACTUATOR CONTROL ··································· 30

9. SERVICE FUNCTIONS ··································· 31

10. TROUBLESHOOTING ····································· 31

11. DISASSEMBLY INSTRUCTIONS ···················· 49

PARTS CATALOG (OBB549)

TM

Revision A:

• MUZ-GE24NA and MUY-GE24NA have been added.

Revision B:

• Descriptions regarding the outdoor fan motor have been corrected.

1

MUZ-GE09NA
MUZ-GE12NA
MUZ-GE15NA
MUZ-GE18NA
MUZ-GE24NA
MUY-GE09NA
MUY-GE12NA
MUY-GE15NA
MUY-GE18NA
MUY-GE24NA

1. New model

TECHNICAL CHANGES

2

Piping

Air outlet

Drain hose

Drain outlet

Air inlet

(back and side)

2

PART NAMES AND FUNCTIONS

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA

Air inlet

(back and side)

Piping

Drain hose

Air outlet

Drain outlet

MUZ-GE18NA MUY-GE18NA

MUZ-GE24NA MUY-GE24NA

Air inlet

(back and side)

Piping

Drain hose

Air outlet

Drain outlet

3

3

Outdoor unit model MUZ-GE09NA MUY-GE09NA MUZ-GE12NA MUY-GE12NA

Capacity

Rated (Minimum~Maximum)

Capacity Heating 17 2 Btu/h 8,700 —

Power consumption

Rated (Minimum~Maximum)

Power consumption Heating 17
EER
HSPF IV
COP Heating
Power supply V , phase , Hz 208/230 , 1 , 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 12 12 12 12
Fan motor F.L.A 0.50

Compressor

Refrigerant control Linear expansion valve

Sound level

Defrost method Reverse cycle

Dimensions

Weight Ib. 66 77
External fi nish Munsell 3Y 7.8/1.1
Remote controller Wireless type
Control voltage
Refrigerant piping Not supplied

Refrigerant pipe size
(Min. wall thickness)

Connection method

Between the indoor &
outdoor units

Refrigerant charge (R410A) 1 lb. 12 oz. 2 lb. 9 oz.

NOTE: Test conditions are based on AHRI 210/240.

1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB) Rated frequency
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB Rated frequency
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB Maximum frequency

SPECIFICATION

Cooling

Heating 47

Cooling 1 W
Heating 47 1 W

1

[SEER] 3 Cooling 13.6 [ 21.0 ] 13.6 [ 21.0 ] 12.5 [ 20.5 ] 12.5 [ 20.5 ]

4 Heating 10.0 — 10.0 —

Model KNB073FQDHC

Refrigeration oil
(Model)

1

Cooling dB(A) 46 46 49 49
Heating dB(A) 50 — 51 —

W in. 31-1/2
D in. 11-1/4
H in. 21-5/8

(by built-in transformer)

Liquid in. 1/4 (0.0315)
Gas in. 3/8 (0.0315)
Indoor Flared
Outdoor Flared
Height difference ft. 40
Piping length ft. 65

1 Btu/h

1 Btu/h

2 W 950 — 1,200 —

1 4.20 — 3.61 —

R.L.A 6.6 4.9 6.6 4.9
L.R.A 8.2 6.1 8.2 6.1

L 0.32 (NEO22)

VDC 12 - 24

9,000

( 3,800 ~ 12,200 )

10,900

( 4,500 ~ 14,100 )

660 (205~1,200) 660 (205~1,200) 960 (205~1,300) 960 (205~1,300)
760 (255~1,200)

9,000

( 3,800 ~ 12,200 )

—

—

12,000

( 3,800 ~ 13,600 )

14,400

( 5,500 ~ 18,100 )

11,200

1,170 (340~1,660)

KNB092FQAHC

12,000

( 3,800 ~ 13,600 )

—

—

—

4

Outdoor unit model MUZ-GE15NA MUY-GE15NA MUZ-GE18NA MUY-GE18NA

Capacity

Rated (Minimum~Maximum)

Cooling 1 Btu/h

Heating 47 1 Btu/h

Capacity Heating 17

Power consumption

Rated (Minimum~Maximum)

Cooling 1 W
Heating 47 1 W

Power consumption Heating 17

1

EER

[SEER] 3 Cooling 13.0 [ 21.0 ] 13.0 [ 21.0 ] 10.5 [19.2] 10.5 [19.2]

14,000

( 3,100 ~ 18,200 )

18,000

( 4,800 ~ 20,900 )

2 Btu/h 15,900 —

1,080 (160 ~ 2,000) 1,080 (160 ~ 2,000) 1,640 (240 ~ 2,070) 1,640 (240 ~ 2,070)
1,600 (270 ~ 2,010)

2 W 1,950 — 2,080 —

14,000

( 3,100 ~ 18,200 )

—

—

17,200

( 3,700 ~ 18,700 )

21,600

( 3,500 ~ 25,200 )

17,200

1,900 (230 ~ 2,680)

17,200

( 3,700 ~ 18,700 )

—

—

—

HSPF IV 4 Heating 10.0 — 10.0 —
COP Heating

1 3.30 — 3.33 —
Power supply V , phase , Hz 208/230 , 1 , 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 12 14
Fan motor F.L.A 0.50 0.93

Model SNB130FQBH

R.L.A 7.4 6.8 10.0 10.0

Compressor

Refrigeration oil
(Model)

L.R.A 9.3 8.5 12.5 12.5

L 0.45 (NEO22)

Refrigerant control Linear expansion valve

Sound level

1

Cooling dB(A) 49 49 54 54
Heating dB(A) 51 — 56 —

Defrost method Reverse cycle

W in. 31-1/2 33-1/16

Dimensions

D in. 11-1/4 13
H in. 21-5/8 33-7/16

Weight Ib. 80 119
External fi nish Munsell 3Y 7.8/1.1
Remote controller Wireless type
Control voltage

(by built-in transformer)

VDC 12 - 24

Refrigerant piping Not supplied

Refrigerant pipe size
(Min. wall thickness)

Connection method

Between the indoor &
outdoor units

Liquid in. 1/4 (0.0315)
Gas in. 1/2 (0.0315)
Indoor Flared
Outdoor Flared
Height difference ft. 40 50
Piping length ft. 65 100

Refrigerant charge (R410A) 2 lb. 9 oz. 3 lb. 7 oz.

NOTE: Test conditions are based on AHRI 210/240.

1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB) Rated frequency
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB Rated frequency
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB Maximum frequency

5

Outdoor unit model MUZ-GE24NA MUY-GE24NA

Capacity

Rated (Minimum~Maximum)

Cooling 1 Btu/h

Heating 47 1 Btu/h

Capacity Heating 17

Power consumption

Rated (Minimum~Maximum)

Cooling 1W
Heating 47 1 W

22,500

(8,200 ~ 31,400)

27,600

(7,500 ~ 36,900)

2 Btu/h 24,600 —

1,800 (570
2,340 (520

~ 3,580)
~ 3,650) —

22,500

(8,200 ~ 31,400)

—

1,800 (570

~ 3,580)

Power consumption Heating 17 2 W 3,290 —

1

EER

[SEER] 3 Cooling 12.5 [19.0] 12.5 [19.0]
HSPF IV 4 Heating 10.0 —
COP Heating

1 3.46 —
Power supply V , phase , Hz 208/230 , 1 , 60
Max. fuse size (time delay) A 20
Min. circuit ampacity A 17.1
Fan motor F.L.A 0.93

Model SNB172FQKMT

R.L.A 12.9

Compressor

Refrigeration oil
(Model)

L.R.A 16.1

L 0.40 (FV50S)

Refrigerant control Linear expansion valve

Sound level

1

Cooling dB(A) 55 55
Heating dB(A) 55 —

Defrost method Reverse cycle

W in. 33-1/16

Dimensions

D in. 13
H in. 34-5/8

Weight Ib. 119
External fi nish Munsell 3Y 7.8/1.1
Remote controller Wireless type
Control voltage

(by built-in transformer)

VDC 12-24

Refrigerant piping Not supplied

Refrigerant pipe size
(Min. wall thickness)

Connection method

Between the indoor &
outdoor units

Liquid in. 3/8 (0.0315)
Gas in. 5/8 (0.0315)
Indoor Flared
Outdoor Flared
Height difference ft. 50
Piping length ft. 100

Refrigerant charge (R410A) 4 lb. 3 oz.

NOTE: Test conditions are based on AHRI 210/240.

1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB) Rated frequency
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB Rated frequency
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB Maximum frequency

6

7

Test condition

3, 4

Mode Test

ARI

"A-2" Cooling Steady State
at rated compressor Speed

"B-2" Cooling Steady State
at rated compressor Speed

SEER

(Cooling)

HSPF

(Heating)

(MUZ)

5

: At Intermediate compressor Speed

"B-1" Cooling Steady State
at minimum compressor Speed

"F-1" Cooling Steady State
at minimum compressor Speed

"E-V" Cooling Steady State
at Intermediate compressor Speed 5

"H1-2" Heating Steady State
at rated compressor Speed

"H3-2" Heating
at rated compressor Speed

"H0-1" Heating Steady State
at minimum compressor Speed

"H1-1" Heating Steady State
at minimum compressor Speed

"H2-V" Heating
at Intermediate compressor Speed

5

= ("Cooling rated compressor speed" - "minimum compressor speed") / 3 + "minimum compressor speed".

Indoor air condition (°F) Outdoor air condition (°F)

Dry bulb Wet bulb Dry bulb Wet bulb

80 67 95 (75)

80 67 82 (65)

80 67 82 (65)

80 67 67 (53.5)

80 67 87 (69)

70 60 47 43

70 60 17 15

70 60 62 56.5

70 60 47 43

70 60 35 33

3-1. OPERATING RANGE

(1) POWER SUPPLY

Outdoor unit

(2) OPERATION

Mode Condition

Standard temperature 80 67 95 —

Cooling

Heating

(MUZ)

Maximum temperature 90 73 115 —
Minimum temperature 67 57 14 —
Maximum humidity 78 % —
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 -4 -5

Rated voltage Guaranteed voltage (V)

208/230 V

1 phase

60 Hz

Min. 187

Indoor Outdoor

DB WB DB WB

208 230 Max. 253

Intake air temperature (°F)

4

OUTLINES AND DIMENSIONS

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA

21-5/8

1-3/4

Air in

handle

11-1/32

7/8

13/32

15-3/4

Air in

11-29/32

5-15/16

Air out

19-11/16

31-1/2

Drain hole 1-5/8

1-9/16

2- 3/8 13/16 Oval hole

11/ 16

2

2-23/32

13-9/16

12 ~ 12-3/4

5-7/8

REQUIRED SPACE

4 i

n. or more

17/3229/32 11-1/4

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

Liquid pipe :1/4 (flared)
Gas pipe :3/8 (flared) (GE09/12)

6-23/32

1/2 (flared) (GE15)

8 in. or

Basically open 4 inch or more
without any obstruction in front
and on both sides of the unit.

4 in. or more

re

mo

Unit: inch

14 in. or more

MUZ-GE18NA MUY-GE18NA

Drain 3 holes
(ø1

-5/16)

2

Air in

13

33-7/16

11-25/32

2-19/32

20-9/32

Air out

4-25/32

Air in

1-11/32

19-11/16

33-1/16

1-9/16

4-3/8

×

13/16 slot

3-3/16

REQUIRED SPACE

4 in. or more

14-3/16

Open as a rule
20 inch or more if the back,
both sides and top are open

Open as a rule
20 inch or more if
the front and both
sides are open

4 inch or more/
8 inch or more if
there are obstacles
to both sides

14 in. or more

16-15/16

2-9/16

30°

35°

8-11/32

Liquid:1/4(flared)
Gas :1/2(flared)

3-9/16

8

16-7/16

1-9/16

1-5/8

Drain ho

le

6-7/8

19-11/16

13

2

Air in

Air out

2-holes 13/32 13/16

14-3/16

33-1/16

4-5/16

3-3/16

34-5/8

17-25/32

Service panel

3-29/32

6-1/2

7-11/16

35

44

Liquid refrigerant
pipe joint
Refrigerant pipe
(flared)

Ø 3/8

Gas refrigerant
pipe joint
Refrigerant pipe
(flared)

Ø 5/8

14 in. or more

4 in. or

more

REQUIRED SPACE

20 in. or more

4 in. or more

20 in. or more

MUZ-GE24NA
MUY-GE24NA

Unit: inch

9

5

MUZ-GE09NA MUZ-GE12NA

WIRING DIAGRAM

MUY-GE09NA MUY-GE12NA

10

MUZ-GE15NA

MUY-GE15NA

11

MUZ-GE18NA

MUY-GE18NA

12

13

MUZ-GE24NA

MUY-GE24NA

14

Outdoor
heat
exchanger

Flared connection

Defrost
thermistor
RT61
(MUZ)

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve
(with strainar)

Stop valve
(with service port)

Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

(MUZ)

Refrigerant pipe ø3/8
(with heat insulator)

Refrigerant pipe ø1/4
(with heat insulator)

R.V. coil

(MUZ)
heating ON
cooling OFF

Strainer
#100

LEV

Ambient
temperature
thermistor
RT65

Muffler

Capillary tube

O.D. 0.118 × I.D. 0.079

× 9-7/16

(ø3.0 × ø2.0 × 240)

Outdoor heat
exchanger
temperature
thermistor
RT68

Service port

Service port

Muffler

Outdoor
heat
exchanger

Flared connection

Defrost
thermistor
RT61
(MUZ)

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve
(with strainar)

Stop valve
(with service port)

Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

(MUZ)

Refrigerant pipe ø3/8 (GE12NA)
Refrigerant pipe ø1/2 (GE15NA)
(with heat insulator)

Refrigerant pipe ø1/4
(with heat insulator)

R.V. coil

(MUZ)
heating ON
cooling OFF

Strainer
#100

Capillary tube

O.D. 0.118 × I.D. 0.071

× 23-5/8

(ø

3.0

× ø

1.8×600

)

(×2)

LEV

Ambient
temperature
thermistor
RT65

Muffler

Capillary tube

O.D. 0.118 × I.D. 0.079

× 9-7/16

(ø3.0 × ø2.0 × 240)

Outdoor heat
exchanger
temperature
thermistor
RT68

Muffler

Service port

Service port

6

REFRIGERANT SYSTEM DIAGRAM

MUZ-GE09NA MUY-GE09NA

Unit: inch

MUZ-GE12NA MUZ-GE15NA MUY-GE12NA MUY-GE15NA

15

MUZ-GE18NA MUY-GE18NA

Outdoor
heat
exchanger

Flared connection

Defrost
thermistor
RT61

(MUZ)

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve
(with strainar)

Stop valve
(with service port)

Capillary tube

O.D. 0.142 × I.D. 0.094

× 1-31/32

(ø

3.6

×

ø

2.4×50)

Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

(MUZ)

Refrigerant pipe ø1/2
(with heat insulator)

Refrigerant pipe ø1/4
(with heat insulator)

LEV

R.V. coil

(MUZ)

heating ON
cooling OFF

Muffler

#100

Receiver

Outdoor heat
exchanger
temperature
thermistor
RT68

Ambient
temperature
thermistor
RT65

Strainer

#100

Service port

Service port

Unit: inch

MUZ-GE24NA MUY-GE24NA

Refrigerant pipe
(with heat insulator)

Flared connection

Refrigerant pipe ø3/8
(with heat insulator)

Flared connection

ø

5/8

Stop valve
(with service port)

4-way valve

Service

Stop valve

port

Strainer

#100

Discharge
temperature
thermistor
RT62

Capillary tube
O.D.0.157

×

3-15/16

(ø

4.0

Muffler

#100

Service
port

Defrost
thermistor
RT61
(MUZ)

Compressor

LEV

Strainer

#100

×

I.D.0.094

×

ø

2.4×100)

16

Outdoor
heat
exchanger

Outdoor heat
exchanger
temperature
thermistor
RT68

R.V. coil (MUZ)
heating ON
cooling OFF

Refrigerant flow in cooling
Refrigerant flow in heating (MUZ)

Ambient
temperature
thermistor
RT65

17

MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE

Refrigerant piping: ft. Piping size O.D: in.

Model

MUZ-GE09/12/15NA
MUY-GE09/12/15NA

MUZ-GE18NA
MUY-GE18NA

MUZ-GE24NA
MUY-GE24NA

Max. Length

A

65 40

Max. Height difference

B

Gas Liquid

3/8 (GE09/12)

1/2 (GE15)

100 50 1/2

100 50 5/8 3/8

Indoor
unit

Max. Height

difference

B

Max. Length
A

Outdoor unit

ADDITIONAL REFRIGERANT CHARGE (R410A: oz.)

NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.

Model

MUZ-GE09NA
MUY-GE09NA

MUZ-GE12NA
MUY-GE12NA

MUZ-GE15NA
MUY-GE15NA

Model

MUZ-GE18NA
MUY-GE18NA

Outdoor unit

precharged

25 30 40 50 60 65

1 lb. 12 oz.

0 1.62 4.86 8.10 11.34 12.96

2 lb. 9 oz.

Outdoor unit

precharged

25 30 40 50 60 70 80 90 100

3 lb. 7 oz. 0 1.08 3.24 5.40 7.56 9.72 11.88 14.04 16.20

Refrigerant piping length (one way): ft.

Calculation: X oz. = 1.62/5 oz. / ft. × (Refrigerant piping length (ft.) - 25)

Refrigerant piping length (one way): ft.

Calculation: X oz. = 1.08/5 oz. / ft. × (Refrigerant piping length (ft.) - 25)

1/4

NOTE: Refrigerant piping exceeding 33 ft. requires additional refrigerant charge according to the calculation.

Model

MUZ-GE24NA
MUY-GE24NA

Outdoor unit

precharged

33 40 50 60 70 80 90 100

4 lb. 3 oz. 0 4.14 10.06 15.98 21.90 27.82 33.74 39.66

Refrigerant piping length (one way): ft.

Calculation: X oz. = 2.96/5 oz. / ft. × (Refrigerant piping length (ft.) - 33)

7

DATA

7-1. PERFORMANCE DATA

1) COOLING CAPACITY

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUZ-GE18NA MUZ-GE24NA
MUY-GE09NA MUY-GE12VA MUY-GE15VA MUY-GE18VA MUY-GE24VA

Indoor air Outdoor intake air DB temperature (˚F)

Model

MUZ-GE09NA
MUY-GE09NA

MUZ-GE12NA
MUY-GE12NA

MUZ-GE15NA
MUY-GE15NA

MUZ-GE18NA
MUY-GE18NA

MUZ-GE24NA
MUY-GE24NA

NOTE: 1. IWB: Intake air wet-bulb temperature

2. SHC is based on 80˚F of indoor Intake air DB temperature.

IWB (˚F)

71 11.0 7.6 0.59 10.3 7.1 0.64 9.7 6.6 0.69 9.0 6.2 0.73 8.3 5.7 0.76
67 10.4 8.6 0.55 9.7 8.0 0.61 9.0 7.4 0.66 8.4 6.9 0.70 7.7 6.3 0.73
63 9.8 9.4 0.53 9.1 8.7 0.58 8.5 8.1 0.63 7.7 7.3 0.67 7.0 6.7 0.70
71 14.7 8.9 0.85 13.7 8.3 0.94 12.9 7.8 1.01 12.0 7.3 1.06 11.0 6.7 1.10
67 13.9 10.3 0.81 13.0 9.6 0.89 12.0 8.9 0.96 11.2 8.3 1.02 10.3 7.6 1.07
63 13.1 11.4 0.77 12.1 10.6 0.85 11.3 9.9 0.92 10.3 9.0 0.98 9.4 8.2 1.02
71 17.2 11.4 0.96 16.0 10.7 1.05 15.1 10.0 1.13 14.0 9.3 1.19 12.9 8.6 1.24
67 16.2 13.0 0.91 15.1 12.1 1.00 14.0 11.2 1.08 13.0 10.4 1.14 12.0 9.6 1.20
63 15.3 14.2 0.86 14.1 13.2 0.96 13.2 12.3 1.03 12.0 11.2 1.10 10.9 10.2 1.14
71 21.1 12.2 1.46 19.7 11.4 1.60 18.5 10.7 1.72 17.2 9.9 1.81 15.8 9.1 1.89
67 20.0 14.2 1.38 18.6 13.2 1.52 17.2 12.2 1.64 16.0 11.4 1.74 14.7 10.4 1.82
63 18.7 15.8 1.31 17.4 14.7 1.45 16.2 13.6 1.57 14.7 12.4 1.67 13.4 11.3 1.74
71 27.6 17.0 1.60 25.8 15.9 1.76 24.2 14.9 1.89 22.5 13.9 1.99 20.7 12.8 2.07
67 26.1 19.6 1.51 24.3 18.2 1.67 22.5 16.9 1.80 20.9 15.7 1.91 19.2 14.4 2.00
63 24.5 21.7 1.44 22.7 20.1 1.59 21.2 18.7 1.72 19.2 17.0 1.84 17.6 15.5 1.91

TC: Total Capacity (×10
SHC: Sensible Heat Capacity (×10
TPC: Total Power Consumption (kW)

75 85 95 105 115

TC SHC TPC TC SHC TPC TC SHC TPC TC SHC TPC TC SHC TPC

3

Btu/h)

3

Btu/h)

2) COOLING CAPACITY CORRECTIONS

Refrigerant piping length (one way: ft.)

25 (std.) 40 65 100

MUZ-GE09NA
MUY-GE09NA
MUZ-GE12NA
MUY-GE12NA
MUZ-GE15NA
MUY-GE15NA
MUZ-GE18NA
MUY-GE18NA

MUZ-GE24NA
MUY-GE24NA

1.0 0.954 0.878 —

1.0 0.954 0.878 0.771

18

3) HEATING CAPACITY (MUZ)

Indoor air Outdoor intake air WB temperature (˚F)

Model

IDB (˚F)

5 152535434555

TC TPC TC TPC TC TPC TC TPC TC TPC TC TPC TC TPC

75 4.8 0.45 6.3 0.57 7.9 0.67 9.4 0.74 10.6 0.78 11.0 0.79 12.4 0.82

MUZ-GE09NA

70 5.2 0.43 6.7 0.55 8.2 0.65 9.6 0.72 10.9 0.76 11.2 0.78 12.7 0.81
65 5.5 0.41 6.9 0.52 8.6 0.63 10.0 0.70 11.2 0.74 11.6 0.75 13.0 0.79
75 6.3 0.69 8.4 0.87 10.4 1.02 12.5 1.14 14.0 1.20 14.5 1.22 16.4 1.26

MUZ-GE12NA

70 6.8 0.66 8.9 0.84 10.8 1.00 12.7 1.11 14.4 1.17 14.8 1.19 16.8 1.24
65 7.2 0.63 9.1 0.81 11.3 0.97 13.2 1.08 14.8 1.14 15.3 1.16 17.1 1.22
75 7.9 0.63 10.4 0.79 13.1 0.93 1.56 1.03 17.6 1.09 18.1 1.10 20.5 1.14

MUZ-GE15NA

70 8.6 0.60 11.1 0.76 13.5 0.91 15.9 1.01 18.0 1.06 18.5 1.08 21.0 1.12
65 9.0 0.57 11.3 0.73 14.1 0.87 16.5 0.98 18.5 1.03 19.1 1.05 21.4 1.10
75 9.1 0.64 11.9 0.81 14.9 0.95 17.8 1.06 20.1 1.12 20.7 1.13 23.5 1.18

MUZ-GE18NA

70 9.8 0.62 12.7 0.78 15.5 0.93 18.2 1.04 20.6 1.09 21.2 1.11 24.0 1.16
65 10.3 0.59 13.0 0.75 16.2 0.90 18.8 1.01 21.2 1.06 21.8 1.08 24.5 1.13
75 12.1 1.38 16.0 1.74 20.0 2.05 23.9 2.28 26.9 2.40 27.7 2.43 31.5 2.53

MUZ-GE24NA

70 13.1 1.32 17.0 1.68 20.7 2.00 24.4 2.22 27.6 2.34 28.4 2.39 32.2 2.48
65 13.8 1.26 17.4 1.61 21.7 1.93 25.3 2.16 28.4 2.28 29.3 2.32 32.8 2.43

NOTE: 1. IDB: Intake air dry-bulb temperature
TC: Total Capacity (x10

3

Btu/h)

TPC: Total Power Consumption (kW)

2. Above data is for heating operation without any frost.

How to operate with fixed operational frequency of the compressor.

1. Press the EMERGENCY OPERATION switch on the front of the indoor unit, and select either EMERGENCY COOL
mode or EMERGENCY HEAT mode before starting to operate the air conditioner.

2. The compressor starts with operational frequency.

3. The fan speed of the indoor unit is High.

4. This operation continues for 30 minutes.

5. In order to release this operation, press the EMERGENCY OPERATION switch twice or once, or press any button on
the remote controller.

7-2. PERFORMANCE CURVE
Cooling

1.5

1.4

1.3

1.2

1.1

difference (°F)

1.0

Capacity correction factors

0.9

Indoor air Wet-bulb temperature

14 23 32 41 50 59 68 77 86 95 104 113

Cooling capacity (

Outdoor intake air Dry-bulb temperature(°F)

at Rated frequency)

Indoor intake air Wet-bulb
temperature( F)

79

75

72
68
64

MUZ-GE09NA
MUY-GE09NA

SHF at rating condition = 0.76

0.8

0.7

Indoor

(kW)

0.6

0.5

Total power consumption

65 75 85 95 105 115

Outdoor intake air DB temperature (°F)

e air WB temperat

intak

Airflow

= 307 CFM

ure (°F)

MUZ-GE12NA
MUY-GE12NA

SHF at rating condition = 0.73

1.3

71
67
63

1.2

1.1

1.0

(kW)

0.9

0.8

0.7

Total power consumption

oor intake air WB temperature (°F)

Ind

65 75 85 95 105 115

Outdoor intake air DB temperature (°F)

19

Airflow

= 350 CFM

71
67
63

75
70
65

Indoor intake air DB temperature (°F)

= 413 CFM

Airflow

155253545556570

Outdoor intake air WB temperature (°F)

0.4

0.6

0.8

1.0

1.1

Total power consumption

(kW)

Indoor air Dry-bulb temperature

difference (°F)

Outdoor intake air Wet-bulb temperature (°F)

-4 5 142332415059

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

Heating capacity (

at Rated frequency)

Capacity correction factor

59

68

79

Indoor intake air Dry-bulb temperature

( F)

MUZ-GE15NA
MUY-GE15NA

1.4

1.3

1.2

1.1

(kW)

1.0

0.9

0.8

Total power consumption

SHF at rating condition = 0.80

Indoor intake air WB temperature (°F)

65 75 85 95 105 115

Outdoor intake air DB temperature (°F)

Airflow

= 498 CFM

MUZ-GE24NA
MUY-GE24NA

SHF at rating condition = 0.75

2.2

2.1

2.0

1.9

1.8

1.7

(kW)

1.6

1.5

1.4

Total power consumption

1.3
65 75 85 95 105 115

Indoor intake air WB temperature (°F)

Outdoor intake air DB temperature (°F)

Airflow

= 634 CFM

Heating (MUZ)

MUZ-GE18NA
MUY-GE18NA

SHF at rating condition = 0.71

2.0

71
67
63

71
67
63

1.9

1.8

1.7

1.6

(kW)

1.5

1.4

1.3

Total power consumption

65 75 85 95 105 115

Indoor intake air WB temperature (°F)

Outdoor intake air DB temperature (°F)

Airflow

= 498 CFM

71
67

63

MUZ-GE09NA

MUZ-GE12NA

1.4

1.3

1.2

1.1

1.0

0.9

(kW)

0.8

0.7

0.6

Total power consumption

0.5

This value of frequency is not the same as the actual frequency in operating. Refer to 7-5 and 7-6 for the relationships
between frequency and capacity.

155253545556570

= 413 CFM

Airflow

Indoor intake air DB temperature (°F)

Outdoor intake air WB temperature (°F)

MUZ-GE15NA

= 463 CFM

1.9

75
70
65

1.8

1.5

1.2

(kW)

0.9

Total power consumption

0.6
155253545556570

Outdoor intake air WB temperature (°F)

20

Airflow

oor intake air DB temperature (°F)

Ind

75
70
65

21

68 70 75 80 85 90 95 100 105

(°F)

120

140

160

180

200

(PSIG)(PSIG)

6870 75 80 85 90

95

100 105

(°F)

280

320

360

400

440

Condensing pressure

86
80
75
70

Suction pressure

Outdoor ambient temperature

Indoor DB temperature (°F)

Outdoor ambient temperature

Indoor DB temperature (°F)

86

80

75

70

MUZ-GE18NA

2.1

1.9

1.7

1.5

1.3

(kW)

1.1

0.9

0.7

Total power consumption

0.5
155253545556570

= 463 CFM

Airflow

Indoor intake air DB temperature (°F)

Outdoor intake air WB temperature (°F)

75
70
65

MUZ-GE24NA

2.8

2.5

2.2

1.9

(kW)

1.6

1.3

Total power consumption

1.0
5 15253545556570

= 738 CFM

Airflow

Outdoor intake air WB temperature (°F)

This value of frequency is not the same as the actual frequency in operating. Refer to 7-5 and 7-6 for the relationships
between frequency and capacity.

7-3. CONDENSING PRESSURE
Cooling

Data is based on the condition of indoor humidity 50 %.
Air flow should be set to High speed.

MUZ-GE09NA MUY-GE09NA

75
70
65

MUZ-GE12NA MUY-GE12NA

(PSIG)

420

380

340

Condensing pressure

300

260

Indoor DB temperature (°F)

6870 75 80 85 90

Outdoor ambient temperature

95

100 105

(PSIG)

86
80
75
70

190

170

150

Suction pressure

Indoor DB temperature (°F)

130

(°F)

110

6870 75 80 85 90

Outdoor ambient temperature

95

100 105

86

80

75

70

(°F)

MUZ-GE15NA MUY-GE15NA

(PSIG) (PSIG)

68 70 75 80 85 90 95 100

105

(°F)

120

140

160

180

200

6870 75 80 85 90

95

100 105(°F)

280

320

360

400

440

Condensing pressure

86
80
75
70

Suction pressure

Outdoor ambient temperature

Indoor DB temperature (°F)

Outdoor ambient temperature

Indoor DB temperature (°F)

86

80

75

70

(PSIG)

6870 75 80 85 90

95

100

105

(°F)

270

310

350

390

430

(PSIG)

6870 75 80 85 90

95

100

105

(°F)

100

115

130

145

160

Condensing pressure

86
80

75
70

Suction pressure

Indoor DB temperature (°F)

Outdoor ambient temperature

86

80

75
70

Indoor DB temperature (°F)

Outdoor ambient temperature

MUZ-GE18NA MUY-GE18NA

MUZ-GE24NA MUY-GE24NA

(PSIG)

480

450

420

390

360

330

Condensing pressure

300

270

6870 75 80 85 90

Indoor DB temperature (°F)

Outdoor ambient temperature

95

100 105

86
80
75

(°F)

(PSIG)

180

70

170

160

150

140

Suction pressure

130

120

110

6870 75 80 85 90

Outdoor ambient temperature

Indoor DB temperature (°F)

22

95

100 105

86

80

75

70

(°F)

23

Heating (MUZ)

5 15253545556575(°F) 5 15253545556575(°F)

60

85

110

135

160

185

210

260

300

340

380

420

460

Indoor DB temperature (°F)

Condensing pressure

Outdoor ambient temperature

(PSIG) (PSIG)

75
70

65

58Hz

Indoor DB temperature (°F)

Suction pressure

Outdoor ambient temperature

75
70

65

58Hz

Data is based on the condition of outdoor humidity 75%.
Air flow should be set to High speed.
Data is for heating operation without any frost.

MUZ-GE09NA

(PSIG) (PSIG)

370

345

75
70
65

210

185

75
70
65

320

295

270

Condensing pressure

245

220

5 15253545556575(°F) 5 15253545556575(°F)

MUZ-GE12NA

Indoor DB temperature (°F)

Outdoor ambient temperature

58Hz

160

135

110

Suction pressure

85

60

Indoor DB temperature (°F)

58Hz

Outdoor ambient temperature

MUZ-GE15NA

(PSIG) (PSIG)

440

404

368

332

Condensing pressure

296

260

Indoor DB temperature (°F)

5 15253545556575(°F) 5 15253545556575(°F)

Outdoor ambient temperature

54Hz

75
70
65

210

185

160

135

110

Suction pressure

85

60

Indoor DB temperature (°F)

Outdoor ambient temperature

54Hz

75
70
65

MUZ-GE18NA

5 15253545556575(°F) 75(°F)

250

275

300

325

350

375

400

425

450

5 152535455565

50

70

90

110

130

150

170

190

210

Ind

oor DB temperature (°F)

Condensing pressure

Outdoor ambient temperature

(PSIG) (PSIG)

75
70
65

58Hz

Indoor DB temperature (°F)

Suction pressure

Outdoor ambient temperature

75
70

65

58Hz

(PSIG) (PSIG)

500

475

450

425

75

65

70

210

185

160

75
70
65

400

375

Condensing pressure

350

325

300

5 15253545556575

MUZ-GE24NA

Indoor DB temperature (°F)

Outdoor ambient temperature

58Hz

(°F)

135

oor DB temperature (°F)

110

Suction pressure

85

60

5 15253545556575(°F)

Ind

58Hz

Outdoor ambient temperature

24

25

7-4. STANDARD OPERATION DATA

Model

Item Unit Cooling Heating Cooling Heating

Capacity Btu/h 9,000 10,900 12,000 14,400

SHF - 0.82 — 0.74 —

Total

Input kW 0.660 0.760 0.960 1.170

Rated frequency Hz 59.5 77.5 69.0 77.0

Indoor unit MSZ-GE09NA, MSY-GE09NA MSZ-GE12NA, MSY-GE12NA

Power supply (V, Phase, Hz) 208 / 230, 1, 60

Input kW 0.022 0.023 0.022 0.023

Fan motor current A 0.24/0.22 0.25/0.23 0.24/0.22 0.25/0.23

Outdoor unit

Power supply (V, phase, Hz) 208/230, 1, 60

Electrical circuit

Input kW 0.638 0.737 0.938 1.147

Comp. current A 3.32/3.00 3.66/3.31 4.39/3.97 5.41/4.89

Fan motor current A 0.27/0.24 0.30/0.27 0.34/0.31 0.31/0.28

Condensing pressure

Suction pressure

Discharge temperature °F 154 152 163 162

Condensing temperature °F 115 103 115 116

Suction temperature °F 59 39 56 35

Comp. shell bottom temp °F 151 149 158 158

Refrigerant circuit

Ref. pipe length ft. 25

Refrigerant charge (R410A) - 1 lb. 12 oz. 2 lb. 9 oz.

Intake air temperature

Discharge air temperature

Indoor unit

Fan speed (High) rpm 1,020 1,040 1,020 1,040

Airfl ow (High)

Intake air temperature

Fan speed rpm 800 850 900 860

Airfl ow

Outdoor unit

PSIG

PSIG

DB °F 80 70 80 70

WB °F 67 60 67 60

DB °F 60 97 56 108

WB °F 58 — 55 —

CFM

DB °F 95 47 95 47

WB °F — 43 — 43

CFM

MSZ-GE09NA
MSY-GE09NA

MUZ-GE09NA
MUY-GE09NA

389 331 389 397

151 103 133 104

367 (Wet) 413 367 (Wet) 413

1151 1225 1229 1172

MSZ-GE09NA

MUZ-GE09NA

MSZ-GE12NA
MSY-GE12NA

MUZ-GE12NA
MUY-GE12NA

MSZ-GE12NA

MUZ-GE12NA

Model

Item Unit Cooling Heating Cooling Heating

Capacity Btu/h 14,000 18,000 17,200 21,600

SHF - 0.80 — 0.71 —

Total

Input kW 1.080 1.600 1.640 1.900

Rated frequency Hz 55.5 74.0 83.0 84.0

Indoor unit MSZ-GE15NA, MSY-GE15NA MSZ-GE18NA, MSY-GE18NA

Power supply (V, Phase, Hz) 208/230, 1, 60

Input kW 0.045 0.031 0.043 0.037

Fan motor current A 0.50/0.45 0.35/0.32 0.43/0.39 0.40/0.36

Outdoor unit

Power supply (V, phase, Hz) 208/ 230, 1, 60

Electrical circuit

Input kW 1,035 1,569 1,595 1,860

Comp. current A 4.86/4.40 7.38/6.67 6.97/6.29 8.36/7.55

Fan motor current A 0.33/0.30 0.34/0.31 0.80/0.72 0.64/0.59

Condensing pressure

Suction pressure

Discharge temperature °F 164 179 177 184

Condensing temperature °F 117 122 112 127

Suction temperature °F 57 31 59 33

Comp. shell bottom temp °F 148 165 164 170

Refrigerant circuit

Ref. pipe length ft. 25

Refrigerant charge (R410A) - 2 lb. 9 oz. 3 lb. 7 oz.

Intake air temperature

Discharge air temperature

Indoor unit

Fan speed (High) rpm 1,280 1,140 1,280 1,240

Airfl ow (High)

Intake air temperature

Fan speed rpm 910 900 780 740

Airfl ow

Outdoor unit

PSIG

PSIG

DB °F 80 70 80 70

WB °F 67 60 67 60

DB °F 60 114 56 117

WB °F 57 — 54 —

CFM

DB °F 95 47 95 47

WB °F — 43 — 43

CFM

MSZ-GE15NA
MSY-GE15NA

MUZ-GE15NA
MUY-GE15NA

400 431 376 458

139 99 117 102

498 (Wet) 463 498 (Wet) 512

1,243 1,229 1,730 1,659

MSZ-GE15NA

MUZ-GE15NA

MSZ-GE18NA
MSY-GE18NA

MUZ-GE18NA
MUY-GE18NA

MSZ-GE18NA

MUZ-GE18NA

26

27

Model

Item Unit Cooling Heating

Capacity Btu/h 22,500 27,600

SHF - 0.75 —

Total

Input kW 1.800 2.340

Rated frequency Hz 66.5 82.0

Indoor unit MSZ-GE24NA, MSY-GE24NA

Power supply (V, Phase, Hz) 208/230, 1, 60

Input kW 0.058

Fan motor current A 0.56/0.51

Outdoor unit

Power supply (V, phase, Hz) 208/230, 1, 60

Electrical circuit

Input kW 1.742 2.282

Comp. current A 7.01/6.34 9.59/8.67

Fan motor current A 1.61/1.05 1.13/1.02

Condensing pressure

Suction pressure

Discharge temperature °F 158 171

Condensing temperature °F 115

Suction temperature °F 52 33

Comp. shell bottom temp °F 140 148

Refrigerant circuit

Ref. pipe length ft. 25

Refrigerant charge (R410A) - 4 lb. 3 oz.

Intake air temperature

Discharge air temperature

Indoor unit

Fan speed (High) rpm 1,300

Airfl ow (High)

Intake air temperature

Fan speed rpm 840 810

Airfl ow

Outdoor unit

PSIG

PSIG

DB °F 80 70

WB °F 67 60

DB °F 56 111

WB °F 53 —

CFM

DB °F 95 47

WB °F — 43

CFM

MSZ-GE24NA
MSY-GE24NA

MUZ-GE24NA
MUY-GE24NA

395 405

141 102

634 (Wet) 738

1,769 1,701

MSZ-GE24NA

MUZ-GE24NA

7-5. CAPACITY AND INPUT CORRECTION BY INVERTER OUTPUT FREQUENCY

Capacity correction factors

Input correction factors

Input correction factors

Capacity correction factors

Correction of Cooling capacity

The operational frequency of compressor

Correction of Cooling total input

The operational frequency of compressor

Correction of Heating total input

The operational frequency of compressor

Correction of Heating capacity

The operational frequency of compressor

MUZ-GE09NA
MUY-GE09NA

050100150

0.5

1.0

1.5

(Hz) (Hz)

0 50 100 150

0.5

1.0

2.0

1.5

(Hz) (Hz)

MUZ-GE12NA
MUY-GE12NA

Capacity correction factors

Input correction factors

Input correction factors

Capacity correction factors

Correction of Cooling capacity

The operational frequency of compressor

Correction of Cooling total input

The operational frequency of compressor

Correction of Heating total input

The operational frequency of compressor

Correction of Heating capacity

The operational frequency of compressor

0 50 100 150

0.5

1.0

1.5

(Hz)

050100150

0.5

1.0

1.5

(Hz)

0 50 100 150

0.5

1.0

1.5

(Hz) (Hz)

MUZ-GE09NA

MUZ-GE12NA

0 50 100 150

0.5

1.0

1.5

2.0

0 50 100 150

0.5

1.0

1.5

050100150

0.5

1.0

2.0

1.5

Capacity correction factors

Input correction factors

Input correction factors

Capacity correction factors

Correction of Cooling capacity

The operational frequency of compressor

Correction of Cooling total input

The operational frequency of compressor

Correction of Heating total input

The operational frequency of compressor

Correction of Heating capacity

The operational frequency of compressor

MUZ-GE15NA
MUY-GE15NA

(Hz) (Hz)

(Hz) (Hz)

MUZ-GE18NA
MUY-GE18NA

Capacity correction factors

Input correction factors

Input correction factors

Capacity correction factors

Correction of Cooling capacity

The operational frequency of compressor

Correction of Cooling total input

The operational frequency of compressor

Correction of Heating total input

The operational frequency of compressor

Correction of Heating capacity

The operational frequency of compressor

050100150

0.5

1.0

1.5

(Hz)

0 50 100 150

0.5

1.0

1.5

(Hz)

0 50 100 150

0.5

1.0

1.5

(Hz) (Hz)

MUZ-GE15NA

MUZ-GE18NA

0 50 100 150

0.5

1.0

2.0

1.5

0 50 100 150

0.5

1.0

2.0

1.5

0 50 100 150

0.5

1.0

1.5

0 50 100 150

0.5

1.0

1.5

0 50 100 150

0.5

1.0

1.5

28

29

7-6. HOW TO OPERATE FIXED-FREQUENCY OPERATION (Test run operation)

MUZ-GE24NA
MUY-GE24NA

Capacity correction factors

Correction of Cooling capacity

The operational frequency of compressor

Correction of Cooling total input

The operational frequency of compressor

Correction of Heating total input

The operational frequency of compressor

Correction of Heating capacity

The operational frequency of compressor

MUZ-GE24NA

0 50 100 150(Hz)

0.5

1.0

1.5

0 50 100 150(Hz)

0.5

1.0

1.5

2.0

2.5

0 50 100 150(Hz)

0.5

1.0

1.5

0 50 100 150(Hz)

0.5

1.0

1.5

2.0

1. Press EMERGENCY OPERATION switch to start COOL or HEAT mode (COOL: Press once, HEAT: Press twice).

2. Test run operation starts and continues to operate for 30 minutes.

3. Compressor operates at rated frequency in COOL mode or 58 Hz in HEAT mode.

4. Indoor fan operates at High speed.

5. After 30 minutes, test run operation finishes and EMERGENCY OPERATION starts (operation frequency of compressor var­ies).

6. To cancel test run operation (EMERGENCY OPERATION), press EMERGENCY OPERATION switch or any button on
remote controller.

ON

OFF

Compressor

Outdoor fan

motor

R.V.coil

ON

OFF

ON

OFF

<COOL>

5 seconds

<HEAT>

5 seconds

8

ACTUATOR CONTROL

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUZ-GE18NA MUZ-GE24NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA MUY-GE18NA MUY-GE24NA

8-1. OUTDOOR FAN MOTOR CONTROL

The fan motor turns ON/OFF, interlocking with the compressor.
[ON] The fan motor turns ON 5 seconds before the compressor starts up.
[OFF] The fan motor turns OFF 15 seconds after the compressor has stopped running.

5 seconds 15 seconds

ON

Compressor

OFF

ON

Outdoor fan
motor

OFF

8-2. R.V. COIL CONTROL (MUZ)

Heating
Cooling
Dry

NOTE: The 4-way valve reverses for 5 seconds right before start-up of the compressor.

8-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR

Discharge temperature
thermistor

Indoor coil temperature
thermistor

Defrost thermistor (MUZ) Heating: Defrosting

Fin temperature thermistor Protection

Ambient temperature
thermistor

Outdoor heat exchanger tem­perature thermistor

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . .

Sensor Purpose

ON
OFF
OFF

Protection

Cooling: Coil frost prevention

Heating: High pressure protec­tion

Cooling: Low ambient tempera­ture operation

Cooling: Low ambient tempera­ture operation

Cooling: High pressure protec­tion

Actuator

Compressor

LEV

Outdoor fan

motor

R.V.coil

(MUZ)

Indoor fan

○○
○

○○
○○○○○

○○
○○○

○○○
○○○

30

motor

31

9

SERVICE FUNCTIONS

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUZ-GE18NA MUZ-GE24NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA MUY-GE18NA MUY-GE24NA

9-1. CHANGE IN DEFROST SETTING (MUZ)
Changing defrost finish temperature

<JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board.
(Refer to 10-6.1.)

Jumper

(Initial setting)

JS

Soldered

None
(Cut)

MUZ-GE09 MUZ-GE12 MUZ-GE15 MUZ-GE18 MUZ-GE18/24

41°F (5°C) 50°F (10°C) 41°F (5°C) 48°F (9°C) 50°F (10°C)

46°F (8°C) 55°F (13°C) 50°F (10°C) 64°F (18°C) 64°F (18°C)

9-2. PRE-HEAT CONTROL SETTING

PRE-HEAT CONTROL

When moisture gets into the refrigerant cycle, it may interfere the start-up of the compressor at low outside tempera­ture. The pre-heat control prevents this interference. The pre-heat control turns ON when outside temperature is 68°F (20
°C) or below. When pre-heat control is turned ON, compressor is energized. (About 50 W)

<JK> To activate the pre-heat control, cut the JK wire of the inverter P.C. board. (Refer to 10-6.1.)

NOTE: When the inverter P.C. board is replaced, check the Jumper wires, and cut/solder them if necessary.

Defrost fi nish temperature

10

TROUBLESHOOTING

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUZ-GE18NA MUZ-GE24NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA MUY-GE18NA MUY-GE24NA

10-1. CAUTIONS ON TROUBLESHOOTING

1. Before troubleshooting, check the following

1) Check the power supply voltage.

2) Check the indoor/outdoor connecting wire for miswiring.

2. Take care of the following during servicing

1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, 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 electrical parts, be careful of the residual voltage of smoothing capacitor.

4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.

5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.

<Incorrect>

Lead wiring

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 OPERATION INDICATOR lamp is flashing ON and OFF before starting
service work.

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

3) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.

4) Refer to 10-2. and 10-3.

<Correct>

Housing point

10-2. 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 (10-3.) disappears, the memorized failure details
can be recalled.

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

MSZ-GE06/09/12/15/18NA
MSY-GE09/12/15/18NA

Operational procedure

The cause of abnormality cannot be found because the abnormality does not 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 in operation display section of the

remote controller is displayed after 3 seconds.

MSZ-GE24NA
MSY-GE24NA

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 upper 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

emitted at the same timing as the blinking of the upper
lamp of OPERATION INDICATOR lamp. 2

Yes

Judgment of indoor/outdoor abnormality

Releasing the failure mode recall function

Deleting the memorized abnormal condition

NOTE: 1. Make sure to release the failure mode recall function once it is 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.

Before blinking, does the upper lamp of OPERATION INDICA­TOR lamp stay ON for 3 seconds?
Stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.

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

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.

(Blinks)

No

1

No
(OFF)

Yes

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 not be recalled with this way.
Confi rm if outdoor unit is abnormal according to the detailed outdoor
unit failure mode recall function. (Refer to 10-2.2)

The outdoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the
outdoor unit failure mode table. (Refer to 10-2.3)
Make sure to check at least two consecutive blinking cycles. 3

2. Blinking pattern when the indoor unit is abnormal:

2.5-second OFF

Blinking at 0.5­second interval

2.5-second OFF

Blinking at 0.5­second interval

ON

OFF

Repeated cycle Repeated cycle

Beeps

3.Blinking pattern when the outdoor unit is abnormal:

2.5-second OFF 3-second ON

Blinking at 0.5­second interval

Beeps

2.5-second OFF

Repeated cycle

3-second ON

ON

OFF

No beep Beeps

Repeated cycle

No beep Beeps

Repeated cycle

Beeps

Blinking at 0.5­second interval

Repeated cycle

32

33

2. Flow chart of the detailed outdoor unit failure mode recall function

Operational procedure

The outdoor unit might be abnormal.
Confi rm if outdoor unit is abnormal according to the following procedures.

Confi rm that the remote controller is in the failure mode recall function.

With the remote controller headed towards the indoor unit, press TOO
COOL or TOO WARM button to adjust the set temperature to 77°F (25°C).

1

Does the upper lamp of OPERATION INDICATOR
lamp on the indoor unit blink at the interval of 0.5
seconds?
Blinks: The outdoor unit is abnormal. Beep is emitted

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

Yes
(Blinks

)

No
(OFF)

1. Regardless of normal or abnormal condition, 2 short
beeps are emitted as the signal is received.

The outdoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the out-
door unit failure mode table (10-2.3.).
Make sure to check at least two consecutive blinking cycles.

2

The outdoor unit is normal.

Releasing the failure mode recall function

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.

Release the failure mode recall function accord­ing to the left mentioned procedure.

Repair the defective parts.

Deleting the memorized abnormal condition

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

function" (10-2.1.).

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" men-

tioned above.

NOTE: 1. Make sure to release the failure mode recall function once it is 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 outdoor unit is abnormal:

2.5-second OFF 3-second ON

ON

OFF

No beep

Repeated cycle

Blinking at 0.5­second interval

Beeps

2.5-second OFF 3-second ON

No beep Beeps

Repeated cycle

Blinking at 0.5-

second interval

Repeated cycle

3. Outdoor unit failure mode table

OPERATION

INDICATOR

upper lamp

(Indoor unit)

OFF None (Normal)

2-time fl ash

2.5 seconds
OFF

3-time fl ash

2.5 seconds
OFF

4-time fl ash

2.5 seconds
OFF

5-time fl ash

2.5 seconds
OFF

6-time fl ash

2.5 seconds
OFF

7-time fl ash

2.5 seconds
OFF

8-time fl ash

2.5 seconds
OFF

9-time fl ash

2.5 seconds
OFF

10-time fl ash

2.5 seconds
OFF

11-time fl ash

2.5 seconds
OFF

12-time fl ash

2.5 seconds
OFF

14-time fl ash

2.5 seconds
OFF

Abnormal point

(Failure mode / protection)

Outdoor power system

Discharge temperature
thermistor

Defrost thermistor (MUZ)

Fin temperature thermistor 3-time fl ash

P.C. board temperature
thermistor

Ambient temperature
thermistor

Outdoor heat exchanger
temperature thermistor

(MUZ/MUY-GE24NA)

Overcurrent 11-time fl ash

Compressor synchronous
abnormality (Compressor start­up failure protection)

Discharge temperature

High pressure

Fin temperature/ P.C. board
temperature

Outdoor fan motor

Nonvolatile memory data 5-time fl ash

Power module

(MUZ/MUY-GE24NA)

Discharge temperature

DC voltage 8-time fl ash

Each phase current of
compressor

Overcurrent Compressor open­phase

Stop valve (Closed valve) 14-time fl ash

LED indication

(Outdoor P.C. board)

—— ———

—

1-time fl ash every

2.5 seconds

2.5 seconds OFF
4-time fl ash

2.5 seconds OFF
2-time fl ash

2.5 seconds OFF

2.5 seconds OFF

12-time fl ash

2.5 seconds OFF

—

—

7-time fl ash

2.5 seconds OFF

—

2.5 seconds OFF
6-time fl ash

2.5 seconds OFF

—

2.5 seconds OFF
9-time fl ash

2.5 seconds OFF
10-time fl ash

2.5 seconds OFF

2.5 seconds OFF

Condition Remedy

Overcurrent protection stop is
continuously performed 3 times within
1 minute after the compressor gets
started.

Thermistor shorts or opens during
compressor running.

Large current fl ows into intelligent
power module.

Waveform of compressor current is
distorted.

Temperature of discharge temperature
thermistor exceeds 241°F (116°C),
compressor stops.
Compressor can restart if discharge
temperature thermistor reads 212°F
(100°C) or less 3 minutes later.

Temperature of indoor coil thermistor
exceeds 158°F (70°C) in HEAT mode
(MUZ only). Temperature of outdoor

heat exchanger temperature thermistor
exceeds 158°F (70°C) in COOL mode.

Temperature of fi n temperature
thermistor on the inverter P.C. board
exceeds 167 ~ 176°F (75 ~ 80°C), or
temperature of P.C. board temperature
thermistor on the inverter P.C. board
exceeds 158 ~ 167°F (70 ~ 75°C).

Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor fan
start-up.

Nonvolatile memory data cannot be
read properly.

The interphase short circuit occurs
in the output of the intelligent power
module (IPM). The compressor winding
shorts circuit.

Temperature of discharge temperature
thermistor has been 122°F (50°C) or
less for 20 minutes.

DC voltage of inverter cannot be
detected normally.

Each phase current of compressor
cannot be detected normally.

Large current fl ows into intelligent
power module (IPM).
The open-phase operation of
compressor is detected.
The interphase short circuit occurs
in the output of the intelligent power
module (IPM).
The compressor winding shorts circuit.

Closed valve is detected by compressor
current.

Reconnect connectors.

•
Refer to 10-5. "How

•
to check inverter/
compressor".
Check stop valve.

•
Refer to 10-5. "Check

•
of outdoor thermistors".
Defective outdoor
thermistors can be
identifi ed by checking
the blinking pattern of
LED.

Reconnect compressor

•
connector.
Refer to 10-5. "How

•
to check inverter/
compressor".
Check stop valve.

•
Reconnect compressor

•
connector.
Refer to 10-5. "How

• —
to check inverter/
compressor".

Check refrigerant circuit

•
and refrigerant amount.
Refer to 10-5. "Check

•
of LEV".

Check refrigerant circuit

•
and refrigerant amount.
Check stop valve.

•

Check around outdoor

•
unit.
Check outdoor unit air

•
passage.
Refer to 10-5.

•
of outdoor fan motor".

Refer to 10-5. "Check

•
of outdoor fan motor".
Refer to 10-5. "Check
of inverter P.C. board".

Replace the inverter

•
P.C. board.

Refer to 10-5. "How

•
to check inverter/
compressor".

Refer to 10-5. "Check

•
of LEV".
Check refrigerant circuit

•
and refrigerant amount.

Refer to 10-5. "How

•
to check inverter/
compressor".

Reconnect compressor

•
connector.
Refer to 10-5. "How

•
to check inverter/
compressor".

Check stop valve •

NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-3.).

"Check

Indoor/
outdoor unit
failure mode

recall function

Outdoor unit
failure mode

recall function

○○

○○

—

○

○

—

—

—

—

○

○

○

○

○○

—

—

—

○

○

○

○○

34

35

10-3. TROUBLESHOOTING CHECK TABLE

No. Symptom LED indication

Outdoor
unit does

1

not oper­ate.

2

3

4

5

6

'Outdoor
unit stops

7

and re­starts 3
minutes
later' is

8

repeated.

9

10

11

12

13

14

Outdoor

15

unit oper­ates.

16

17

Outdoor

18

unit oper­ates.

19

20

NOTE: 1. The location of LED is illustrated at the right fi gure. Refer to 10-6.1.

2. LED is lighted during normal operation.
The fl ashing frequency shows the number of times the LED blinks after every 2.5-second OFF. Flashing
(Example) When the fl ashing frequency is “2”.

1-time fl ash every

2.5 seconds

6-time fl ash

2.5 seconds OFF
11-time fl ash

2.5 seconds OFF
14-time fl ash

2.5 seconds OFF

2-time fl ash

2.5 seconds OFF

3-time fl ash

2.5 seconds OFF

4-time fl ash

2.5 seconds OFF

5-time fl ash

2.5 seconds OFF

8-time fl ash

2.5 seconds OFF

10-time fl ash

2.5 seconds OFF

12-time fl ash

2.5 seconds OFF
13-time fl ash

2.5 seconds OFF
1-time fl ash

2.5 seconds OFF
3-time fl ash

2.5 seconds OFF

4-time fl ash

2.5 seconds OFF

7-time fl ash

2.5 seconds OFF

8-time fl ash

2.5 seconds OFF

9-time fl ash

2.5 seconds OFF

Abnormal point/

Condition

Outdoor power sys­tem

Outdoor thermistors Discharge temperature thermistor, fi n temperature thermistor, de-

Outdoor control sys­tem

Serial signal The communication fails between the indoor and outdoor unit for

Stop valve/
Closed valve

Outdoor unit
(Other abnormality)

Overcurrent protec­tion

Discharge tempera­ture overheat protec­tion

Fin temperature /P.C.
board temperature
thermistor overheat
protection

High pressure pro­tection

Compressor syn­chronous abnormal­ity

Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds after

Each phase current
of compressor

DC voltage DC voltage of inverter cannot be detected normally. Refer to 10-5. "How to check inverter/

Frequency drop by
current protection

Frequency drop by
high pressure protec­tion

Frequency drop by
defrosting in COOL
mode

Frequency drop by
discharge tempera­ture protection

Low discharge tem­perature protection

PAM protection PAM:
Pulse Amplitude
Modulation

Zero cross detecting
circuit

Inverter check mode The connector of compressor is disconnected, inverter check

Overcurrent protection stop is continuously performed 3 times
within 1 minute after the compressor gets started, or failure of re­start of compressor has repeated 24 times.

frost thermistor, outdoor heat exchanger temperature thermistor,
P.C. board temperature thermistor or ambient temperature therm­istor shorts or opens during compressor running.

Nonvolatile memory data cannot be read properly.
(The upper lamp of OPERATION INDICATOR of the indoor unit
lights up or fl ashes 7 times.)

3 minutes.
Closed valve is detected by compressor current. Check stop valve. •

Outdoor unit is defective. Refer to 10-2.2. "Flow chart of the de-

Large current fl ows into intelligent power module.

When overcurrent protection occurs within 10 seconds after

compressor starts, compressor restarts after 15 seconds (

GE09/12/15/18NA, MUY-GE09/12/15/18NA)

Temperature of discharge temperature thermistor exceeds 241°F
(116°C), compressor stops. Compressor can restart if discharge
temperature thermistor reads 212°F (100°C) or less 3 minutes
later.

Temperature of fi n temperature thermistor on the heat sink ex-
ceeds 167 ~ 176°F (75 ~ 80°C) or temperature of P.C. board tem­perature thermistor on the inverter P.C. board exceeds 158 ~ 167
°F (70 ~ 75°C).

Temperature of indoor coil thermistor exceeds 158°F (70°C) in
HEAT mode (MUZ only). Temperature of outdoor heat exchanger

temperature thermistor exceeds 158°F (70°C) in COOL mode.
The waveform of compressor current is distorted. Reconnect connector of compressor.

outdoor fan start-up.

Each phase current of compressor cannot be detected normally. Refer to 10-5.

Current from power outlet is nearing Max. fuse size. The unit is normal, but check the follow-

Temperature of indoor coil thermistor exceeds 131°F (55°C) in
HEAT mode, compressor frequency lowers.

Indoor coil thermistor reads 46°F (8°C) or less in COOL mode,
compressor frequency lowers.

Temperature of discharge temperature thermistor exceeds 232°F
(111°C), compressor frequency lowers.

Temperature of discharge temperature thermistor has been 122°F
(50°C) or less for 20 minutes.

The overcurrent fl ows into IGBT (Insulated Gate Bipolar transis-
tor: TR821) or the bus-bar voltage reaches 320 V or more, PAM
stops and restarts.

Zero cross signal for PAM control cannot be detected.

mode starts.

0.5-second ON

Condition Remedy

.

0.5-second ON

Reconnect connector of compressor.

•
Refer to 10-5. "How to check inverter/

•
compressor".
Check stop valve.

•
Refer to 10-5. "Check of outdoor

•
thermistors".

Replace inverter P.C. board. •

Refer to 10-5. "How to check miswir-

•
ing and serial signal error.

•
tailed outdoor unit failure mode recall
function".

Reconnect connector of compressor.

•
Refer to 10-5. "How to check inverter/

•

MUZ-

compressor".
Check stop valve.

•
Check refrigerant circuit and refrigerant

•
amount.
Refer to 10-5. "Check of LEV".

•

Check around outdoor unit.

•
Check outdoor unit air passage.

•
Refer to 10-5. "Check of outdoor fan

•
motor".

Check refrigerant circuit and refrigerant

•
amount.
Check stop valve.

•

•
Refer to 10-5. "How to check inverter/

•
compressor".

Refer to 10-5. "Check of outdoor fan

•
motor.
Refer to 10-5. "Check of inverter P.C.

•
board.

•
compressor".

•
compressor".

ing.
Check if indoor fi lters are clogged.

•
Check if refrigerant is short.

•
Check if indoor/outdoor unit air circula-

•
tion is short cycled.

Check refrigerant circuit and refrigerant

•
amount.
Refer to 10-5.

•
Refer to 10-5. "Check of outdoor

•
thermistors".

Refer to 10-5. "Check of LEV".

•
Check refrigerant circuit and refrigerant

•
amount.

This is not malfunction. PAM protection
will be activated in the following cases:

1 Instantaneous power voltage drop

(Short time power failure)

2 When the power supply voltage is high.

•

Check if the connector of the compres­sor is correctly connected. Refer to
10-5.
sor".

Inverter
P.C. board
(Parts side)

"How to check inverter/

"Check of LEV".

"How to check inverter/compres-

MUZ/MUY­GE24NA

LED

ON

OFF

2.5-second OFF

2.5-second OFF

Flashing →

LED

MUZ/MUY­GE09/12/15/
18NA

10-4. TROUBLE CRITERION OF MAIN PARTS

LEV

WHT

RED

ORN

YLW

BRN

BLU

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUZ-GE18NA MUZ-GE24NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA MUY-GE18NA MUY-GE24NA

Part name Check method and criterion Figure

Defrost thermistor (RT61)

(MUZ)

Fin temperature
thermistor (RT64)

Ambient temperature
thermistor (RT65)

Outdoor heat exchanger
temperature thermistor
(RT68)

Discharge temperature
thermistor (RT62)

Compressor

Measure the resistance with a tester.

Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, for the chart of thermistor.

Measure the resistance with a tester. Before measurement, hold the
thermistor with your hands to warm it up.

Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, for the chart of thermistor.

Measure the resistance between terminals using a tester.
(Temperature: -4 ~ 104°F (-20 ~ 40°C))

Normal (Ω)

GE09 GE12 GE15/18 GE24

U-V

U-W

1.36 ~ 1.93 1.52 ~ 2.17 0.78 ~ 1.11 0.83 ~ 1.18

V-W

WHT

V

RED BLK

W

U

Outdoor fan motor

R. V. coil (21S4)

(MUZ)

Expansion valve coil
(LEV)

Measure the resistance between lead wires using a tester.
(Temperature: -4 ~ 104°F (-20 ~ 40°C))

Color of lead wire

GE09/12 GE15 GE18/24

Normal (Ω)

RED – BLK

BLK – WHT

28 ~ 40 11 ~ 16

WHT – RED

Measure the resistance using a tester.
(Temperature: 14 ~ 104°F (-10 ~ 40°C))

Normal (kΩ)

0.97 ~ 1.38

Measure the resistance using a tester.
(Temperature: 14 ~ 104°F (-10 ~ 40°C))

Color of lead wire Normal (Ω)

WHT – RED
RED – ORN

YLW – BRN

37 ~ 54

BRN – BLU

WHT

V

RED BLK

W

U

36

37

10-5. TROUBLESHOOTING FLOW

A How to check inverter/compressor

Disconnect the connector between compressor
and the intelligent power module (IPM).

Check the voltage between terminals.

Are the voltages balanced?

Yes

Check the compressor.

No

See 10-5. “Check of open phase”.

Replace the inverter P.C. board.

See 10-5.

“Check of compressor”.

B Check of open phase

● With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if

the inverter is normal by measuring the voltage balance between the terminals.

Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)

<< Operation method>>
Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERA-

TION: Refer to 7-6.)
<<Measurement point>>
at 3 points
BLK (U) - WHT (V)
BLK (U) - RED (W)
WHT(V) - RED (W)

NOTE: 1. Output voltage varies according to power supply voltage.

2. Measure the voltage by analog type tester.

3. During this check, LED of the inverter P.C. board fl ashes 9 times. (Refer to 10-6.1.)

Measure AC voltage between the lead wires at 3 points.

C Check of compressor

Refer to 10-5. “Check of compressor
winding”.
Is the compressor normal?

Yes

Refer to 10-5. “Check of compressor
operation time”.
Does the compressor operate continuously?

Yes

OK.

No

No

Replace the compressor.

Refer to 10-5. “Check of compressor start failure”.

D Check of compressor winding

● Disconnect the connector between the compressor and intelligent power module, and measure the resistance between the

compressor terminals.
<<Measurement point>>
at 3 points
BLK - WHT
BLK - RED

Measure the resistance between the lead wires at 3 points.
WHT - RED
<<Judgement>>
Refer to 10-4.
0[Ω] ················· Abnormal [short]
Infinite [Ω] ········ Abnormal [open]
NOTE: Be sure to zero the ohmmeter before measurement.

E Check of compressor operation time

<<Judgement>>

● Connect the compressor and activate the inverter. Then measure

the time until the inverter stops due to over current.
<<Operation method>>
Start heating or cooling operation by pressing EMERGENCY

OPERATION switch on the indoor unit.
(TEST RUN OPERATION: Refer to 7-6.)
<<Measurement>>
Measure the time from the start of compressor to the stop of

compressor due to overcurrent.

0 second

1 second

2 seconds

10 seconds

Compressor starts

Abnormal
(IPM failure)
(Compressor winding short)

Abnormal
(Compressor lock out)
(Starting defect)

Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)

F Check of compressor start failure

Confi rm that 1~4 is normal.

• Electrical circuit check
Contact of the compressor connector

1.
Output voltage of inverter P.C. board and balance of them (See 10-5. )

2.
Direct current voltage between DB61(+) and (-)

3.

JP715(+) and JP30(-)

4.

Voltage between outdoor terminal block S1-S2

(MUZ/MUY-GE24NA

Does the compressor run for 10 seconds or
more after it starts?

No

After the compressor is heated with a drier,
does the compressor start?

1

Yes

Compressor start failure. Activate pre-heat control.
(Refer to 9-2. "PRE-HEAT CONTROL SETTING")

(MUZ/MUY-GE09/12/15/18NA)

) on the inverter P.C. board

Check the refrigerant circuit.

Yes

No

Check the stop valve.

Replace the compressor.

Abnormal
(Refrigerant circuit defect)
(Closed valve)

10 minutes

Normal

/

1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.

38

Heating part

39

G Check of outdoor thermistors

Disconnect the connector of thermistor in the outdoor P.C. board (see
below table), and measure the resistance of thermistor.

Is the resistance of thermistor normal? (Refer to 10-6.1.)

Yes

Reconnect the connector of thermistor.
Turn ON the power supply and press EMERGENCY OPERATION switch.

Does the unit operate for 10 minutes or more
without showing thermistor abnormality?

Yes

OK. (Cause is poor contact.)

No

Replace the thermistor except RT64. When RT64 is

No

abnormal, replace the inverter P.C. board.

Replace the inverter P.C. board.

MUZ/MUY-GE09/12/15/18NA

Thermistor Symbol Connector, Pin No. Board

Defrost (MUZ) RT61 Between CN641 pin1 and pin2
Discharge temperature RT62 Between CN641 pin3 and pin4
Fin temperature RT64 Between CN642 pin1 and pin2
Ambient temperature RT65 Between CN643 pin1 and pin2
Outdoor heat exchanger temperature RT68 Between CN644 pin1 and pin3

MUZ/MUY-GE24NA

Thermistor Symbol Connector, Pin No. Board

Defrost (MUZ) RT61 Between CN671 pin1 and pin2
Discharge temperature RT62 Between CN671 pin3 and pin4
Fin temperature RT64 Between CN673 pin1 and pin2
Ambient temperature RT65 Between CN672 pin1 and pin2
Outdoor heat exchanger temperature RT68 Between CN671 pin5 and pin6

Inverter P.C. board

Inverter P.C. board

H Check of R.V. coil

MUZ-GE09/12/15/18/24NA

First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4.
In case CN721 (MUZ-GE09/12/15/18NA)/CN602 (MUZ-GE24NA) is disconnected or R.V. coil is open, voltage is

generated between the terminal pins of the connector although no signal is being transmitted to R.V. coil.

Check if CN721 (MUZ-GE09/12/15/18NA)/CN602 (MUZ-GE24NA) is connected.

Unit operates COOL mode even if it is set to HEAT mode.

Disconnect connector between
the compressor and the intelligent
power module.
Turn ON the power supply and
press EMERGENCY OPERATION
switch twice (HEAT mode).

Is there 208/230 VAC between CN721 (MUZ-
GE09/12/15/18NA)/CN602 (MUZ-GE24NA)

and on the inverter P.C. board 3 minutes

after the power supply is turned ON?

Yes

Replace the 4-way valve.

Replace the inverter

No

P.C. board.

Unit operates HEAT mode even if it is set to COOL mode.

Disconnect connector between
the compressor and the intelligent
power module.
Turn ON the power supply and
press EMERGENCY OPERATION
switch once (COOL mode).

Is there 230 VAC between CN721 (MUZ-
GE09/12/15/18NA)/CN602 (MUZ-GE24NA)

and on the inverter P.C. board 3 minutes

after the power supply is turned ON?

No

Replace the 4-way valve.

Replace the inverter

Yes

P.C. board.

I Check of outdoor fan motor

Disconnect the connectors CN931 and CN932
from the inverter P.C. board.Check the connec­tion between the connector CN931 and CN932.

Is the resistance between each ter­minal of outdoor fan motor normal?
(Refer to 10-4.)

No

Yes

Disconnect CN932 from the inverter P.C. board, and turn on the
power supply.

Rotate the outdoor fan motor manually and measure the voltage
of CN931.
Between 1(+) and 5(-)
Between 2(+) and 5(-)
Between 3(+) and 5(-)

(Fixed to either 5 or 0 VDC)

Replace the outdoor fan motor.

Does the voltage between each terminal become 5 and 0

No

VDC repeatedly?

Yes

Does the outdoor fan motor rotate smoothly?

No

Replace the inverter P.C. board.

Yes

40

41

J Check of power supply

MUZ-GE09/12/15/18NA MUY-GE09/12/15/18NA

Disconnect the connector (CN61)
between compressor and intelligent
power module.
Turn ON power supply and press
EMERGENCY OPERATION switch.

Does The upper lamp of
OPERATION INDICATOR lamp on
the indoor unit light up?

Yes

No

Rectify indoor/outdoor
connecting wire.

Is there voltage 208/230 VAC
between the indoor terminal
block S1 and S2?

Yes

Replace the indoor
electronic control P.C.

No

board.

Is there bus-bar voltage 260-325
VDC between DB61 (+) and DB61
(–) on the inverter P.C. board?
(Refer to 10-6.1.)

No

Check the electric parts in main circuit.

MUZ-GE24NA MUY-GE24NA

Disconnect the connector between
compressor and intelligent power
module.
Turn ON power supply and press
EMERGENCY OPERATION switch.

Does the upper lamp of
OPERATION INDICATOR on the
indoor unit light up?

Yes

Yes

No

Does LED on the inverter P.C.
board light up or fl ash? (Refer
to 10-6.1.)

Yes

If LED lights up, it is OK.
If LED fl ashes, refer to 10-3.

Rectify indoor/outdoor
connecting wire.

Yes

Is there voltage 208/230 VAC
between the indoor terminal
block S1 and S2?

Replace the inverter

No

P.C. board.

DB61

Inverter P.C. board
(Solder side)

Replace the indoor
electronic control P.C.

No

board.

260-325 VDC

Is there bus-bar voltage 294 - 370
VDC between JP715 (+) and JP30
(–) on the inverter P.C. board?
(Refer to 10-6.1.)

No

Check the electric parts in main circuit.

Yes

Does LED on the inverter P.C.
board light up or fl ash? (Refer
to 10-6.1.)

Yes

If LED lights up, it is OK.
If LED fl ashes, refer to 10-3.

325 -370 VDC

Replace the inverter

No

P.C. board.

JP715

JP30

K Check of LEV (Expansion valve)

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 operation 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.

1

MSZ-GE06/09/12/15/18NA
MSY-GE09/12/15/18NA

MSZ-GE24NA
MSY-GE24NA

Expansion valve operates in full-opening direction.

Do you hear the expansion valve "click,
click·······"?
Do you feel the expansion valve vibrate
on touching it ?

No

Is LEV coil properly fi xed to
the expansion valve?

Yes

Does the resistance of LEV
coil have the characteristics?
(Refer to 10-4.)

No

Replace the LEV coil.

NOTE: After check of LEV, do the undermentioned operations.

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

2. Press RESET button on the remote controller.

No

Yes

Properly fi x the LEV coil to the expansion valve.

Measure each voltage between connector
pins of CN724 on the inverter P.C. board.

1. Pin (-) — Pin (+)

2. Pin (-) — Pin (+)

3. Pin (-) — Pin (+)

4. Pin (-) — Pin (+)
Is there about 3 ~ 5 VAC between each?
NOTE: Measure the voltage by an analog

OK.

Yes

tester.

Replace the expansion valve.

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

Replace the inverter P.C.

No

board.

Yes

42

43

L Check of inverter P.C. board

Check the outdoor fan motor.
(Refer to 10-5. .)

Is the fuse (F901) blown on the in­verter P.C. board?

No

Check the connection of the connectors
(CN931 , CN932) of the outdoor fan motor.
If the connection is poor, make it correct.

Only for MUZ/MUY-GE24NA

Operate the outdoor unit by starting
EMERGENCY OPERATION.

Check the LED indication on the in­verter P.C. board.
Does the LED fl ash 10 times?

Yes
(10-time fl ash)

Replace the inverter P.C. board.

Yes

No

Check the remedy following LED
indication.
(Refer to 10-3.)

M How to check miswiring and serial signal error

Turn OFF the power supply.

Is there rated voltage in the power supply?

Turn ON the power supply.

Is there rated voltage between outdoor terminal block S1 and S2?

Press EMERGENCY OPERATION switch once.

Does the OPERATION INDICATOR lamp light
up? <Confi rmation of the power to the indoor
unit>

Is serial signal error indicated 6 minutes later?

Turn OFF the power supply.
Check once more if the indoor/outdoor

B

connecting wire is not miswiring.
Short-circuit outdoor terminal block S2
and S3. 1

Turn ON the power supply.

Is the bus-bar voltage of the inverter P.C. board normal? (Refer to "TEST POINT DIAGRAM AND
VOLTAGE" in this manual.)

Does the LED on the inverter P.C. board repeat "3.6-second-OFF and 0.8-sec­ond-ON quick blinking"? 3

Turn OFF the power supply.
Remove the short-circuit between outdoor terminal block S2 and S3.

Yes

Yes

Yes

Yes

A

Yes

Yes

No

No

No

1. Miswiring may damage indoor electronic control P.C.

3. Be sure to check this within 3 minutes after turning ON.

No
(Lighted
or not
lighted)

Check the power supply.

Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor connect­ing wire?

board during the operation.
Be sure to confi rm the wiring is correct before the opera-
tion starts.

After 3 minutes, LED blinks 6 times. Even when the
inverter P.C. board or the outdoor electronic control P.C.
board is normal, LED blinks 6 times after 3 minutes.

Replace the inverter P.C. board . 2

No

No

2. Be careful of the residual voltage of smoothing
capacitor.

Check the wiring.

Correct them.

Yes

Check of power supply.
(Refer to 10-5. .)

No

A

Turn OFF inverter-controlled lighting

•
equipment.
Turn OFF the power supply and then

•
turn ON again.
Press EMERGENCY OPERATION

•
switch.

Reinstall

•
either the unit
or the light
away from

No

•

each other.
Attach a fi lter
on remote
control receiv­ing section
of the indoor
unit.

Is serial signal
error indicated 6
minutes later?

Yes

B

Replace the indoor elec­tronic control P.C. board.

44

45

N 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

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.

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.

-4 14 32 50 68 86 104

0

10

20

30

40

50

60

70

80

90

100

Temperature(°F)

Defrost thermistor(RT61) (MUZ)
Ambient temperature thermistor(RT65)
Outdoor heat exchanger temperature thermistor(RT68)

Temperature(°F)

Discharge temperature thermistor(RT62)

32 50 68 86 104 122 140 158 176 194 212 230 248

0

100

200

300

400

500

600

700

32 50 68 86 104 122 140 158 176

0

20

40

60

80

100

120

140

160

180

200

Temperature(°F)

Fin temperature thermistor(RT64)

Resistance(kΩ)

Resistance(kΩ)

Resistance(kΩ)

10-6. TEST POINT DIAGRAM AND VOLTAGE

1. Inverter P.C. board

MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUY-GE09NA MUY-GE12NA MUY-GE15NA

Smoothing
capacitor
(C62)

Fuse (F801)
T3.15AL250V

Smoothing
capacitor
(C61)

Fuse (F701)
T3.15AL250V

R.V.coil
(CN721)
208/230
VAC

(MUZ)

208/230
VAC

Back side of unit

208/230 VAC

Fuse (F901)
T3.15AL250V

Output to
drive
compressor
(LDU,
LDV,
LDW)

Bus-bar voltage
DB61
260-325 VDC

(-)

(+)

Smoothing
capacitor
(C63)

Front side of unit

Fin temperature

thermistor/RT64

(CN642)

Output to drive outdoor

fan motor (CN932)

Ambient temperature

thermistor/RT65

(CN643)

Defrost thermistor

Outdoor heat exchanger

temperature thermistor

/RT68 (CN644)

/RT61(CN641)(MUZ)

LED

LEV
connector
(CN724)

Signal of outdoor fan

Discharge temperature

thermistor/RT62

46

motor (CN931)

(CN641)

Jumper wire for
changing defrost
setting (JS)(MUZ)

Jumper wire
for pre-heat
control setting
(JK)

47

-4 14 32 50 68 86 104

0

10

20

30

40

50

60

70

80

90

100

Temperature(°F)

Defrost thermistor(RT61) (MUZ)
Ambient temperature thermistor(RT65)
Outdoor heat exchanger temperature thermistor(RT68)

Temperature(°F)

Discharge temperature thermistor(RT62)

32 50 68 86 104 122 140 158 176 194 212 230 248

0

100

200

300

400

500

600

700

32 50 68 86 104 122 140 158 176

0

20

40

60

80

100

120

140

160

180

200

Temperature(°F)

Fin temperature thermistor(RT64)

Resistance(kΩ)

Resistance(kΩ)

Resistance(kΩ)

MUZ-GE18NA MUY-GE18NA

Back side of unit

208/230 VAC

Fuse (F901)
T3.15AL250V

Output to
drive
compressor
(LDU,
LDV,
LDW)

Bus-bar voltage
DB61
260-325 VDC

(-)

(+)

Smoothing
capacitor
(C63)

Smoothing
capacitor
(C62)

Fuse (F801)
T3.15AL250V

Smoothing
capacitor
(C61)

Fuse (F701)
T3.15AL250V

R.V.coil
(CN721)
208/230
VAC

(MUZ)

208/230
VAC

Front side of unit

Fin temperature

thermistor /RT64

(CN642)

Outdoor heat exchanger

temperature thermistor

/RT68(CN644)

Defrost thermistor

(CN643)

/RT61(CN641)(MUZ)

Discharge temperature

thermistor /RT62

Ambient temperature

thermistor /RT65

Signal of outdoor fan

(CN641)

Output to drive outdoor

fan motor (CN932)

motor (CN931)

LEV connector (CN724)

LED

Jumper wire for changing

defrost setting (JS)(MUZ)

Jumper wire for pre-heat

control setting (JK)

-4 14 32 50 68 86 104

0

10

20

30

40

50

60

70

80

90

100

Temperature(°F)

Defrost thermistor(RT61) (MUZ)
Ambient temperature thermistor(RT65)
Outdoor heat exchanger temperature thermistor(RT68)

Temperature(°F)

Discharge temperature thermistor(RT62)

32 50 68 86 104 122 140 158 176 194 212 230 248

0

100

200

300

400

500

600

700

32 50 68 86 104 122 140 158 176

0

20

40

60

80

100

120

140

160

180

200

Temperature(°F)

Fin temperature thermistor(RT64)

Resistance(kΩ)

Resistance(kΩ)

Resistance(kΩ)

MUZ-GE24NA
MUY-GE24NA

Fuse (F62)
T2.0AL250V

Fuse (F601)
T3.15AL250V (MUZ)

R.V. coil (CN602)
208/230 VAC (MUZ)

Jumper wire for
changing defrost
setting (JS) (MUZ)

Jumper wire for
pre-heat control
setting (JK)

Signal of out­door fan motor
(CN931)

LED

Output to
drive outdoor
fan motor
(CN932)

Fuse (F901)
T3.15AL250V

Fuse (F880)
T3.15AL250V

Defrost thermistor
/RT61 (CN671) (MUZ)

Discharge temperature
thermistor/RT62
(CN671)

Outdoor heat exchanger
temperature thermistor
/RT68 (CN671)

Ambient temperature
thermistor/RT65

(CN672)

Fin temperature
thermistor/RT64
(CN673)

LEV connector (CN724)

48

JP715 (+)

Bus-bar voltage
325 - 370 VDC

JP30 (-)

11

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

Slide the sleeve.
Pull the terminal while

Locking lever

pushing the locking
lever.

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

11-1. MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA
MUY-GE09NA MUY-GE12NA MUY-GE15NA

OPERATING PROCEDURE PHOTOS

1. Removing the cabinet

(1) Remove the screw fixing the service panel.
(2) Pull down the service panel and remove it.
(3) Remove the screws fixing the conduit cover.
(4) Remove the conduit cover.
(5) Disconnect the power supply wire and indoor/outdoor

connecting wire.
(6) Remove the screws fixing the top panel.
(7) Remove the top panel.
(8) Remove the screws fixing the cabinet.
(9) Remove the cabinet.
(10)

Remove the screws fixing the back panel.

(11)

Remove the back panel.

Photo 1

Screws of the top panel

Hold the sleeve, and
pull out the terminal
slowly.

Connector

NOTE: Turn OFF power supply before disassembly.

Screws of the top panel

Back
panel

Screw
of the
back
panel

Photo 2

Screws of
the cabinet

Screw of the
cabinet

Screws of
the terminal block
support and the
back panel

Screw of the
service panel

Direction to
remove

Hooks

Screws of the cabinet

Photo 3

Conduit cover

49

Service

panel

Screw of the

conduit cover

Conduit plate

OPERATING PROCEDURE

PHOTOS

2. Removing the inverter assembly, inverter P.C. board

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following

connectors:

<Inverter P.C. board>

CN721 (R.V. coil) (MUZ)
CN931, CN932 (Fan motor)
CN641 (Defrost thermistor (MUZ) and discharge tempera-

ture thermistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)
CN724 (LEV)

(3) Remove the compressor connector (CN61).
(4) Remove the screws fixing the heat sink support and the

separator.

(5) Remove the fixing screws of the terminal block support and

the back panel.
(6) Remove the inverter assembly.
(7) Remove the screw of the ground wire and screw of the ter-

minal block support.
(8) Remove the heat sink support from the P.C. board support.
(9) Remove the screw of the inverter P.C. board and remove

the inverter P.C. board from the P.C. board support.

Photo 4

Screws of the heat sink
support and the separator

Photo 5 (Inverter assembly)

Heat sink Inverter P.C. board

Hook of the
P.C. board
support

P.C. board
support

Screws of the
terminal block
support and the
back panel

Screw of the
terminal block
support

3. Removing R.V. coil

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the following connectors:
<Inverter P.C. board>

CN721 (R.V. coil)

(3) Remove the R.V. coil.

(MUZ)

Heat sink support

Hook of the P.C.
board support

Photo 6

Discharge temperature thermistor

Terminal

block support

Screw of the

ground wire

Screw of the P.C.
board fixture

R.V. coil (MUZ)

50

51

OPERATING PROCEDURE

PHOTOS

4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger tempera­ture thermistor and ambient temperature thermistor

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following

connectors:
<Inverter P.C. board>
CN641 (Defrost thermistor (MUZ) and discharge tempera-

ture thermistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)

(3) Pull out the discharge temperature thermistor from its hold-

er. (Photo 6)
(4) Pull out the defrost thermistor from its holder.
(5) Pull out the outdoor heat exchanger temperature thermistor

from its holder.
(6) Pull out the ambient temperature thermistor from its holder.

5. Removing outdoor fan motor

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the following connectors:
<Inverter P.C. board>

CN931, CN932 (Fan motor)
(3) Remove the propeller nut.
(4) Remove the propeller.
(5) Remove the screws fixing the fan motor.
(6) Remove the fan motor.

Photo 7

Photo 8

Outdoor heat
exchanger tempera­ture thermistor

Defrost thermistor

(MUZ)

Screws of the outdoor fan motor

6. Removing the compressor and 4-way valve

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Remove the inverter assembly. (Refer to 2.)
(3) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure

gauge shows 0 PSIG.

(4) Detach the brazed part of the suction and the discharge

pipes connected with compressor.
(5) Remove the nuts of compressor legs.
(6) Remove the compressor.
(7) Detach the brazed part of the pipes connected with 4-way

valve.

Propeller

Photo 9

Propeller nut

Brazed parts of 4-way valve

11-2. MUZ-GE18NA MUY-GE18NA

NOTE: Turn OFF power supply before disassembly.

OPERATING PROCEDURE

1. Removing the cabinet

(1) Remove the screws of the service panel.
(2) Remove the screws of the top panel.
(3) Remove the screw of the valve cover.
(4) Remove the service panel.
(5) Remove the top panel.
(6) Remove the valve cover.
(7) Disconnect the power supply and indoor/outdoor connect-

ing wire.
(8) Remove the screws of the cabinet.
(9) Remove the cabinet.
(10)

Remove the screws of the back panel.

(11)

Remove the back panel.

Photo 1

Screw of the top panel

Screws
of the
back
panel

Photo 2

Screws of the top panel

PHOTOS

Screws of the cabinet

Screws
of the
cabinet

52

Screws
of the
cabinet

Screw
of the
service
panel

Screw
of the
valve
cover

Screws of
the back
panel

53

OPERATING PROCEDURE

PHOTOS

2. Removing the inverter assembly, inverter P.C. board

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following con-

nectors:
<Inverter P.C. board>
CN721 (R.V.coil) (MUZ)
CN931, CN932 (Fan motor)
CN641 (Defrost thermistor (MUZ) and discharge temperature

thermistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)
CN724 (LEV)

(3) Remove the compressor connector (CN61).
(4) Remove the screws fixing the heat sink support and the sep-

arator.

(5) Remove the fixing screws of the terminal block support and

the back panel.
(6) Remove the inverter assembly.
(7) Remove the screw of the ground wire and screw of the termi-

nal block support.
(8) Remove the heat sink support from the P.C. board support.
(9) Remove the screw of the inverter P.C. board and remove the

inverter P.C. board from the P.C. board support.

Photo 3

Screw of the heat sink
support and the separator

Photo 4 (Inverter assembly)

Heat sink

Hook of the P.C.
board support

Inverter P.C. board

P.C. board
support

Screws of
the terminal
block support
and the back
panel

Screws of
the reactor

Screw of the
terminal block
support

3. Removing R.V. coil

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the following connectors:
<Inverter P.C. board>

CN721 (R.V. coil) (MUZ)

(3) Remove the R.V. coil.

Heat sink support

Hook of the P.C.
board support

Photo5

Screw of the

ground wire

Screw of the P.C.
board fixture

R.V. coil (MUZ)

Brazed parts of 4-way valve

Terminal block
support

OPERATING PROCEDURE PHOTOS

4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger tempera­ture thermistor and ambient temperature thermistor

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following

connectors:
<Inverter P.C. board>

CN641 (Defrost thermistor (MUZ) and discharge tempera-

ture thermistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)

(3) Pull out the discharge temperature thermistor from its hold-

er. (Photo 8)
(4) Pull out the defrost thermistor from its holder.
(5) Pull out the outdoor heat exchanger temperature thermistor

from its holder.
(6) Pull out the ambient temperature thermistor from its holder.

5. Removing outdoor fan motor

(1)

Remove the top panel, cabinet and service panel. (Refer to 1.)

(2) Disconnect the following connectors:

<Inverter P.C. board>

CN931 and CN932 (Fan motor)

(3) Remove the propeller.
(4) Remove the screws fixing the fan motor.
(5) Remove the fan motor.

Photo 6

Photo 7

Screws of
the outdoor
fan motor

Outdoor heat
exchanger tempera­ture thermistor

Ambient tem-

perature

thermistor

Defrost thermistor

(MUZ)

6. Removing the compressor and 4-way valve

(1)

Remove the top panel, cabinet and service panel. (Refer to 1.)
(2) Remove the back panel. (Refer to 1.)
(3) Remove the inverter assembly. (Refer to 2.)
(4) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure gauge

shows 0 PSIG.

(5) Detach the brazed part of the suction and the discharge

pipes connected with compressor.

(6) Remove the compressor nuts.

(7) Remove the compressor.

(8) Detach the brazed parts of 4-way valve and pipes. (Photo 5)

54

Photo 8

Brazed part of the
discharge pipe

Discharge temperature
thermistor

Brazed part of the
suction pipe

55

11-3. MUZ-GE24NA MUY-GE24NA

OPERATING PROCEDURE PHOTOS

NOTE: Turn OFF power supply before disassembly.

1. Removing the cabinet

(1) Remove the screws of the service panel.
(2) Remove the screws of the top panel.
(3) Remove the screw of the valve cover.
(4) Remove the service panel.
(5) Remove the screws fixing the conduit cover.
(6) Remove the conduit cover.
(7) Remove the top panel.
(8) Remove the valve cover.
(9) Disconnect the power supply and indoor/outdoor con-

necting wire.

(

10

) Remove the screws of the cabinet.
(11) Remove the cabinet.
(12)

Remove the screws of the back panel.

(13)

Remove the back panel.

Photo 2

Screws of the

Screws of the
top panel

Screws of
the back
panel

back panel

Screws of the
back panel

Photo 1

Screws of the
cabinet

Photo 3

Screws of the top panel

Screws of the
cabinet

Screws
of the
cabinet

Screws of the
back panel

Screws of
the back
panel

Screws of the
conduit cover

Conduit plate

Screws of
the service
panel

Screw of
the valve
cover

OPERATING PROCEDURE

PHOTOS

2. Removing the inverter assembly, inverter P.C. board

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following con-

nectors:
<Inverter P.C. board>
CN602 (R.V. coil)
CN931, CN932 (Fan motor)
CN671 (Defrost thermistor, discharge temperature thermistor

and outdoor heat exchanger temperature thermistor)
CN672 (Ambient temperature thermistor)
CN724 (LEV)

(3) Remove the compressor connector.
(4) Remove the screws fixing the relay panel.
(5) Remove the relay panel.
(6) Remove the ground wires and the lead wires of the inverter

P.C. board.
(7) Remove the screw of the PB support.
(8) Remove the inverter P.C. board from the relay panel.

Photo 4

Inverter P.C
board

Screws
of the PB
support

Ground wires

Screws of the
relay panel

Screw of the
relay panel

Screws of the
PB support

3. Removing R.V. coil

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the following connector:
<Inverter P.C. board>

CN602 (R.V. coil) (MUZ)

(3) Remove the R.V. coil.

Photo 5

Screw of the
R.V. coil (MUZ)

Brazed parts of
4-way valve

56

57

OPERATING PROCEDURE PHOTOS

4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger tempera­ture thermistor and ambient temperature thermistor

(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following

connectors:
<Inverter P.C. board>

CN671 (Defrost thermistor (MUZ), discharge temperature

thermistor and outdoor heart exchanger tempera­ture thermistor)

CN672 (Ambient temperature thermistor)

(3)

Pull out the discharge temperature thermistor from its holder.

(Photo 8)
(4) Pull out the defrost thermistor from its holder.
(5) Pull out the outdoor heat exchanger temperature thermistor

from its holder.
(6) Pull out the ambient temperature thermistor from its holder.

5. Removing outdoor fan motor

(1)

Remove the top panel, cabinet and service panel. (Refer to 1.)

(2) Disconnect the following connectors:

<Inverter P.C. board>

CN931 and CN932 (Fan motor)

(3) Remove the propeller.
(4) Remove the screws fixing the fan motor.
(5) Remove the fan motor.

Photo 6

Outdoor heat
exchanger tempera­ture thermistor

Photo 7

Ambient tem­perature
thermistor

Defrost thermistor (MUZ)

6. Removing the compressor and 4-way valve

(1)

Remove the top panel, cabinet and service panel. (Refer to 1.)
(2) Remove the back panel. (Refer to 1.)
(3) Remove the inverter assembly. (Refer to 2.)
(4) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure gauge

shows 0 kg/cm2 (0 MPa).

(5) Detach the brazed part of the suction and the discharge

pipes connected with compressor.
(6) Remove the compressor nuts.
(7) Remove the compressor.
(8)

Detach the brazed parts of 4-way valve and pipes. (Photo 5)

Photo 8

Brazed part of the
discharge pipe

Screws of the
outdoor fan motor

Discharge temperature
thermistor

Brazed part of the suction pipe

TM

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

© Copyright 2009 MITSUBISHI ELECTRIC CO.,LTD
Distributed in Dec. 2010. No. OBH 549 REVISED EDITION-B
Distributed in Sep. 2010. No. OBH 549 REVISED EDITION-A 5
Distributed in Jul. 2009. No. OBH 549 5
Made in Japan

New publication, effective Dec. 2010
Specifications subject to change without notice.