INDOOR UNIT OUTDOOR UNIT

service manual no. obh733 revised edition-f indoor unit service manual msz-gl•na, msy-gl•na series (obh732) muz-gl18/24na muz-gl18/24nah muy-gl18/24na parts catalog (obb733) models muz-gl09na - u1 muz-gl09nah - u1 muy-gl09na - u1 muz-gl09na - u8 muz-gl09nah - u8 muz-gl12na - u1 muz-gl12nah - u1 muy-gl12na - u1 muz-gl15na - u1 muz-gl15nah ...

SERVICE MANUAL No. OBH733 REVISED EDITION-F Indoor unit service manual MSZ-GL•NA, MSY-GL•NA Series (OBH732) MUZ-GL18/24NA MUZ-GL18/24NAH MUY-GL18/24NA PARTS ...

DISASSEMBLY INSTRUCTIONS ···················· 64 OUTDOOR UNIT. 2 1 TECHNICAL CHANGES Use the specifi ed refrigerant only Never use any refrigerant other than that specified. Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.

PDF mitsubishi muz-gl24na-u2 article 680253997332191 en sm
Revision F:
· MUZ-GL24NA- U2 has been added.
OBH733 REVISED EDITION-E is void.

IONUDTODOOROURNUITNIT

SERVICE MANUAL

HFC
utilized
R410A

No. OBH733
REVISED EDITION-F

Models
MUZ-GL09NA - U1 MUZ-GL09NAH - U1 MUY-GL09NA - U1 MUZ-GL09NA - U8 MUZ-GL09NAH - U8 MUZ-GL12NA - U1 MUZ-GL12NAH - U1 MUY-GL12NA - U1 MUZ-GL15NA - U1 MUZ-GL15NAH - U1 MUY-GL15NA - U1 MUZ-GL18NA - U1 MUZ-GL18NAH - U1 MUY-GL18NA - U1 MUZ-GL24NA - ,U1 U2 MUZ-GL24NAH - U1 MUY-GL24NA - U1

MUZ-GL18/24NA MUZ-GL18/24NAH MUY-GL18/24NA

Indoor unit service manual MSZ-GL·NA, MSY-GL·NA Series (OBH732)
CONTENTS
1. TECHNICAL CHANGES ··································· 2 2. PART NAMES AND FUNCTIONS····················· 3 3. SPECIFICATION················································ 4 4. OUTLINES AND DIMENSIONS ························ 7 5. WIRING DIAGRAM············································ 9 6. REFRIGERANT SYSTEM DIAGRAM ············· 21 7. DATA································································ 24 8. ACTUATOR CONTROL··································· 39 9. SERVICE FUNCTIONS ··································· 40 10. TROUBLESHOOTING····································· 41 11. DISASSEMBLY INSTRUCTIONS ···················· 64
PARTS CATALOG (OBB733)

Use the specified refrigerant only
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of. Correct refrigerant is specified in the manuals and on the spec labels provided with our products. We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by failure to follow the instructions.

Revision A:
· MUZ-GL12/15NA- U1 , MUZ-GL12/15NAH- U1 and MUY-GL09/12/15NA- U1 have been added.
Revision B:
· MUZ-GL09NA- U8 and MUZ-GL09NAH- U8 have been added.
Revision C:
· MUZ-GL09NA- U1 and MUZ-GL09NAH- U1 have been added.
Revision D:
· MUZ-GL24NAH- U1 has been added.
Revision E:
· Capacity corrections have been corrected [7-1. 2), 3)].
Revision F:
· MUZ-GL24NA- U2 has been added.
1 TECHNICAL CHANGES

MUZ-GL09NA - U1 MUZ-GL09NAH - U1 MUZ-GL09NA - U8 MUZ-GL09NAH - U8 MUZ-GL12NA - U1 MUZ-GL12NAH - U1 MUZ-GL15NA - U1 MUZ-GL15NAH - U1 MUZ-GL18NA - U1 MUZ-GL18NAH - U1 MUZ-GL24NA - U1 , U2 MUZ-GL24NAH - U1
1. New model

MUY-GL09NA - U1
MUY-GL12NA - U1 MUY-GL15NA - U1 MUY-GL18NA - U1 MUY-GL24NA - U1

OBH733F

2

2 PART NAMES AND FUNCTIONS
MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA
Air inlet (back and side)
Piping
Air outlet Drain hose
Drain outlet

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA
Air inlet (back and side)
Piping Drain hose
Air outlet
Drain outlet

OBH733F

3

3 SPECIFICATION

Outdoor unit model

MUZ-

MUZ-

GL09NA- U1 GL09NA- U8

MUZ-

MUZ-

GL09NAH- U1 GL09NAH- U8

MUYGL09NA

MUZGL12NA
MUZGL12NAH

MUYGL12NA

Capacity
Rated (Minimum~Maximum)

Cooling 1

Btu/h

Heating 47 1 (MUZ) Btu/h

Capacity
Rated (Maximum)

Heating 17 2 (MUZ) Btu/h

9,000 (3,600 - 12,200)

10,900

10,900

(4,500 - 15,900) (4,500 - 14,100)

-

6,700 (10,200)

7,000 (9,400)

-

12,000 (1,500 - 13,600)

14,400 (2,000 - 18,100)

-

9,200 (12,000)

-

Power consumption
Rated (Minimum~Maximum)

Cooling 1

W

Heating 47 1 (MUZ) W

585 (240 - 1,050)

720

720

(230 - 1,250) (230 - 1,070)

-

920 (100 - 1,300)

1,100 (110 - 1,620)

-

Power consumption Heating 17 2 (MUZ) W
Rated (Maximum)

630 (1,060)

620 (790)

-

870 (1,240)

-

EER 1 [SEER] 3 Cooling

HSPF IV 4

Heating (MUZ)

15.4 [24.6]

13.0 [23.1]

NA: 12.8

-

NA: 12.5

-

NAH: 11.8

-

NAH: 11.5

-

COP

Heating 1 (MUZ)

4.44

-

3.84

-

Power factor

Cooling (208/230) % Heating (MUZ) (208/230) %

86/86 90/90

92/92 95/95

87/87 -

95/95 96/96

Power supply

V , phase , Hz

208/230, 1 , 60

Max. fuse size (time delay)

A

15

Min. circuit ampacity

A

9

7

9

7

Fan motor

F.L.A

A

0.50

Model

KNB073FRVMC SNB092FQAMT KNB073FRVMC

SNB092FQAMT

Compressor

R.L.A L.R.A

A A

6.2 7.7

4.9

6.6

4.9

6.1

8.2

6.1

Refrigeration oil fl oz. (L) (Model) 9.1 (0.27)/(FV50S) 11.8 (0.35)/(FV50S) 9.1 (0.27)/(FV50S)

11.8 (0.35)/(FV50S)

Refrigerant control

Linear expansion valve

Sound level 1

Cooling Heating (MUZ)

dB(A) dB(A)

48

49

49

50

-

51

-

Airflow High - Med. - Low

Cooling Heating (MUZ)

CFM CFM

1,186 - 1,116 - 1,045

1,102 - 639

-

1,186 - 1,116 - 1,045

-

Fan speed

Cooling

rpm

High - Med. - Low Heating (MUZ) rpm

870 - 820 - 770

810 - 490

-

870 - 820 - 770

-

Defrost method

Reverse cycle

W

in.

31-1/2

Dimensions

D

in.

11-1/4

H

in.

21-5/8

Weight

Ib.

81

External finish

Munsell 3Y 7.8/1.1

Remote controller

Wireless type

Control voltage (by built-in transformer) V DC

12 - 24

Refrigerant piping

Not supplied

Refrigerant pipe size Liquid

in.

(Min. wall thickness) Gas

in.

1/4 (0.0315) 3/8 (0.0315)

Connection method

Indoor Outdoor

Flared Flared

Between the indoor Height difference ft.

40

& outdoor units

Piping length

ft.

65

Refrigerant charge (R410A)

2 lb. 5 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)

(Heating) -- Indoor: 70°FDB, 60°FWB, Outdoor: 47°FDB, 43°FWB

2:

(Heating) -- Indoor: 70°FDB, 60°FWB, Outdoor: 17°FDB, 15°FWB

3: Test condition (Refer to page 6.)

4: Test condition (Refer to page 6.)

OBH733F

4

Outdoor unit model

MUZGL15NA
MUZGL15NAH

MUYGL15NA

MUZGL18NA
MUZGL18NAH

MUYGL18NA

MUZGL24NA
MUZGL24NAH

MUYGL24NA

Capacity
Rated (Minimum~Maximum)

Cooling 1

Btu/h

Heating 47 1 (MUZ) Btu/h

14,000 (3,100 - 18,200) 18,000 (5,800 ~ 22,000) 22,500 (8,200 ~ 31,400)

18,000 (4,800 - 20,900)

-

21,600 (5,400 ~ 25,000)

-

27,600 (7,500 ~ 36,900)

-

Capacity
Rated (Maximum)

Heating 17 2 (MUZ) Btu/h

12,200 (16,400)

-

13,800 (18,200)

-

16,000 (24,600)

-

Cooling 1

W

Power consumption

Rated (Minimum~Maximum) Heating 47 1 (MUZ) W

1,080 (210 - 2,000)

1,600 (200 ~ 2,010)

-

1,340 (330 ~ 2,150) 1,680 (320 ~ 2,500)

1,800 (570 ~ 3,580) 2,340 (520 ~ 3,650)

Power consumption Heating 17 2 (MUZ) W
Rated (Maximum)

1,190 (1,850)

-

1,480 (2,150)

-

1,770 (3,290)

-

EER 1 [SEER] 3 Cooling

HSPF IV 4

Heating (MUZ)

13.0 [21.6]

NA: 11.7

-

NAH: 10.8

-

13.4 [20.5]

NA: 11.2

-

NAH: 10.2

-

12.5 [20.5]

NA: 10.0

-

NAH: 10.0

-

COP

Heating 1 (MUZ)

3.30

-

3.77

-

3.46

-

Power factor

Cooling (208/230) % Heating (MUZ) (208/230) %

97/97 98/98

99/99

99/99

-

99/99

99/99

-

Power supply

V , phase , Hz

208/230, 1 , 60

Max. fuse size (time delay)

A

15

20

Min. circuit ampacity

A

10

9

14

17.1

Fan motor

F.L.A

0.50

0.93

0.93

Model

SNB130FQBMT

SNB130FQBMT

SNB172FQKMT

R.L.A

A

7.4

6.8

10

12.9

Compressor

L.R.A

A

9.3

8.5

12.5

16.1

Refrigeration oil fl oz. (L) (Model) 11.8 (0.35)/(FV50S) 11.8 (0.35)/(FV50S) 11.8 (0.35)/(FV50S)

13.5 (0.40)/(FV50S)

Refrigerant control

Linear expansion valve

Cooling

dB(A)

49

49

Sound level 1

Heating (MUZ)

dB(A)

51

-

54

55

-

55

55

-

Airflow

COOL

High - Med. - Low HEAT

CFM

1,102-639

CFM 1,186 - 1,045 - 1,045

-

1,742 - 922

1,691 - 1,691 - 1,372

-

2,016 - 1,769 - 890

1,701 - 1,701 - 1,341

-

Fan speed

Cooling

High - Med. - Low Heating (MUZ)

rpm

810 - 490

rpm 870 - 770 - 770

-

840 - 450

810 - 810 - 650

-

950 - 840 - 450

810 - 810 - 650

-

Defrost method

Reverse cycle

W

in.

31-1/2

33-1/16

Dimensions

D

in.

11-1/4

13

H

in.

21-5/8

34-5/8

Weight

Ib.

81

121

119

External finish

Munsell 3Y 7.8/1.1

Remote controller

Wireless type

Control voltage (by built-in transformer) V DC

12 - 24

Refrigerant piping

Not supplied

Refrigerant pipe size Liquid

in.

(Min. wall thickness) Gas

in.

1/4 (0.0315) 1/2 (0.0315)

3/8 (0.0315) 5/8 (0.0315)

Indoor Connection method
Outdoor

Flared Flared

Between the indoor Height difference ft.

40

50

& outdoor units

Piping length

ft.

65

100

Refrigerant charge (R410A)

2 lb. 9 oz.

3 lb. 9 oz.

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)

(Heating) -- Indoor: 70°FDB, 60°FWB, Outdoor: 47°FDB, 43°FWB

2:

(Heating) -- Indoor: 70°FDB, 60°FWB, Outdoor: 17°FDB, 15°FWB

3: Test condition (Refer to page 6.)

4: Test condition (Refer to page 6.)

OBH733F

5

Test condition

3, 4

ARI Mode

Test

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

Indoor air condition (°F)

Dry bulb

Wet bulb

80

67

Outdoor air condition (°F)

Dry bulb

Wet bulb

95

(75)

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

80

67

82

(65)

SEER "B-1" Cooling Steady State (Cooling) at minimum compressor Speed

80

67

82

(65)

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

80

67

67

(53.5)

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

80

67

87

(69)

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

70

60

47

43

"H3-2" Heating at rated compressor Speed

70

60

17

15

HSPF "H0-1" Heating Steady State (Heating) at minimum compressor Speed

70

60

62

56.5

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

70

60

47

43

"H2-V" Heating at intermediate compressor Speed 5

70

60

35

33

NOTE: 5: At intermediate compressor Speed = ("Rated compressor speed" - "minimum compressor speed") / 3 + "minimum compressor speed".

OPERATING RANGE (1) POWER SUPPLY
Rated voltage

Guaranteed voltage (V)

Outdoor unit

208/230 V 1 phase 60 Hz

Min. 187 208 230 Max. 253

(2) OPERATION

Mode

Condition

Standard temperature

Cooling

Maximum temperature Minimum temperature

Maximum humidity

Standard temperature

Heating Maximum temperature

Minimum temperature

Intake air temperature (°F)

Indoor

Outdoor

DB

WB

DB

WB

80

67

95

--

90

73

115

--

67

57

14

--

78 %

--

70

60

47

43

80

67

75

65

70

60

-4

-5

OBH733F

6

4 OUTLINES AND DIMENSIONS

MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA

REQUIRED SPACE
*1 4 in. (100 mm) or more when front and sides of the unit are clear

4

in. or

(m1o0r0emm)

clear *1

Unit: inch
4 in. o(1r0m0omrem)

(GL09/12/15NA) (GL09/12/15NAH)
holes

8 ino.r(m20o0rem*m2)

14 ionr. m(3o5r0e mm)

*2 When any 2 sides of left, right and rear of the unit are clear

Liquid refrigerant pipe joint Refrigerant pipe (flared) Ø 1/4
Gas refrigerant pipe joint Refrigerant pipe (flared) Ø 3/8 (GL09/12)
Ø 1/2 (GL15)

OBH733F

7

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

Unit: inch

13 2

16-7/16 Air in

Air in

6-7/8

Air out 19-11/16
33-1/16 4-5/16

14-3/16 Clear *1

REQUIRED SPACE
*1 20 in. (500 mm) or more when front and sides of the unit are clear

Drain hole 1-5/8 1-9/16

4 or

mino. r(e100

mm)

4 oinr.m(1o0r0e mm)

2-holes 13/32 13/16 3-3/16

20orinm. (o5r0e0*2mm)

o1r 4mionr.e(350 mm)

*2 When any 2 sides of left, right and rear of the unit are clear

Service panel

Liquid refrigerant pipe joint Refrigerant pipe (flared) Ø 1/4 (GL18) Refrigerant pipe (flared) Ø 3/8 (GL24)

34-5/8

17-25/32

35 44

6-1/2 3-29/32

7-11/16

Gas refrigerant pipe joint Refrigerant pipe (flared) Ø 1/2 (GL18) Refrigerant pipe (flared) Ø 5/8 (GL24)

OBH733F

8

5 WIRING DIAGRAM
MUZ-GL09NA MUZ-GL12NA

OBH733F

9

MUZ-GL09NAH MUZ-GL12NAH

OBH733F

10

MUY-GL09NA MUY-GL12NA

OBH733F

11

MUZ-GL15NA

OBH733F

12

MUZ-GL15NAH

OBH733F

13

MUY-GL15NA

OBH733F

14

MUZ-GL18NA

OBH733F

15

MUZ-GL18NAH

OBH733F

16

MUY-GL18NA

OBH733F

17

MUZ-GL24NA

OBH733F

18

MUZ-GL24NAH

OBH733F

19

MUY-GL24NA

OBH733F

20

6 REFRIGERANT SYSTEM DIAGRAM

MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA

Refrigerant pipe ø3/8 (ø9.52) (GL09/12) ø1/2 (ø12.7) (GL15)

4-way valve

(with heat insulator) Flared connection

Muffler

Stop valve (with service port)
Service port

Discharge temperature thermistor RT62

Flared connection

Capillary tube O.D. 0.118 × I.D. 0.079 × 9-7/16 (ø3.0 × ø2.0 × 240) (MUZ-GL09NA/H - U1 )

Capillary tube

O.D. 0.157 ×

I.D. 0.094 × 9-7/16 (ø4.0 × ø2.4 × 240)

LEV

(Other models )

Stop valve (with strainar) Refrigerant pipe ø1/4 (ø6.35)
(with heat insulator)

Muffler
Service port

Outdoor heat exchanger

Outdoor heat exchanger temperature thermistor RT68

Compressor
Defrost thermistor RT61 (MUZ)
Capillary tube O.D. 0.118 × I.D. 0.079 × 8-9/32 (ø3.0 × ø2.0 × 210)

Ambient temperature thermistor RT65
Strainer #100

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

Refrigerant flow in cooling Refrigerant flow in heating (MUZ)

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA

Refrigerant pipe ø1/2 (ø12.7) (with heat insulator)

4-way valve

Muffler with #100 mesh strainer

Flared connection

Stop valve (with service port)

Service port

Discharge temperature thermistor RT62

Service port

Defrost thermistor RT61 (MUZ)

Outdoor heat exchanger

Unit: Inch (mm)

Flared connection

Strainer #100

Stop valve

Refrigerant pipe ø1/4 (ø6.35) (with heat insulator)

Muffler

Compressor

Capillary tube

O.D. 0.118×

I.D. 0.079× 7-7/8

(ø3.0×ø2.0×200(×4))

LEV

Strainer

#100

Capillary tube O.D. 0.157× I.D. 0.094× 3-15/16
(ø4.0×ø2.4×100)

Capillary tube O.D. 0.157× I.D. 0.094×7-7/8
(ø4.0×ø2.4×200)

Outdoor heat exchanger temperature thermistor RT68 R.V. coil (MUZ) heating ON cooling OFF
Refrigerant flow in cooling Refrigerant flow in heating (MUZ)

OBH733F

21

MUZ-GL24NA - U1 MUY-GL24NA

Refrigerant pipe ø5/8 (ø15.88) (with heat insulator)

4-way valve

Muffler with #100 mesh strainer
Service port

Flared connection

Stop valve (with service port)
Service port

Discharge temperature thermistor RT62

Defrost thermistor RT61 (MUZ)

Outdoor heat exchanger

Ambient temperature thermistor RT65

Unit: inch

Flared connection

Strainer #100

Stop valve

Refrigerant pipe ø3/8 (ø9.52) (with heat insulator)

Compressor

Outdoor heat exchanger temperature thermistor RT68

LEV Strainer #100

R.V. coil (MUZ)

heating ON

Capillary tube

cooling OFF

O.D.0.157 × I.D.0.094

× 3-15/16

Refrigerant flow in cooling

(ø4.0×ø2.4×100)

Refrigerant flow in heating (MUZ)

MUZ-GL24NA - U2 MUZ-GL24NAH

Refrigerant pipe ø5/8 (ø15.88) (with heat insulator)

Muffler 4-way valve #100

Service port

Flared connection

Stop valve (with service port)

Discharge

temperature

Service port

thermistor RT62

Defrost thermistor RT61

Outdoor heat exchanger

Ambient temperature thermistor RT65

Flared connection

Strainer #100

CHECK VALVE

Stop valve

Refrigerant pipe ø3/8 (ø9.52) Capillary tube

(with heat insulator)

O.D.0.118 × I.D.0.071

× 21-21/32

(ø3.0×ø1.8×550)

Compressor
LEV Strainer #100
Capillary tube O.D.0.157 × I.D.0.094 × 3-15/16 (ø4.0×ø2.4×100)

Outdoor heat exchanger temperature thermistor RT68
R.V. coil heating ON cooling OFF
Refrigerant flow in cooling Refrigerant flow in heating

OBH733F

22

MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE

Model
MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

Refrigerant piping: ft.

Max. Length A

Max. Height difference B

65

40

100

50

Piping size O.D: in.

Gas

Liquid

3/8 1/4
1/2

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

Outdoor unit

precharged

25

Refrigerant piping length (one way): ft.

30

40

50

60

65

MUZ-GL09NA - U1 MUZ-GL09NAH - U1

2 lb. 5 oz.

MUZ-GL09NA - U8

MUZ-GL09NAH - U8

MUY-GL09NA MUZ-GL12NA

0

MUZ-GL12NAH

2 lb. 9 oz.

MUY-GL12NA

MUZ-GL15NA

MUZ-GL15NAH

MUY-GL15NA

1.08

3.24

5.40

7.56

8.64

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

OBH733F

23

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

Model

Outdoor unit precharged 25

MUZ-GL18NA

MUZ-GL18NAH 3 lb. 9 oz.

0

MUY-GL18NA

Refrigerant piping length (one way): ft.

30

40

50

60

70

80

90

100

1.08

3.24

5.40

7.56

9.72 11.88 14.04 16.20

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

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

Model

Outdoor unit

precharged

33

MUZ-GL24NA

MUZ-GL24NAH 4 lb. 3 oz.

0

MUY-GL24NA

Refrigerant piping length (one way): ft.

40

50

60

70

80

90

100

4.14

10.06

15.98

21.90

27.82

33.74

39.66

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

7 DATA

MUZ-GL09NA MUZ-GL12NA MUZ-GL15NA MUZ-GL18NA MUZ-GL24NA

MUZ-GL09NAH MUZ-GL12NAH MUZ-GL15NAH MUZ-GL18NAH MUZ-GL24NAH

MUY-GL09NA MUY-GL12NA MUY-GL15NA MUY-GL18NA MUY-GL24NA

7-1. PERFORMANCE DATA 1) COOLING CAPACITY

Indoor air

Outdoor intake air DB temperature (°F)

Model

75

85

95

105

115

IWB (°F)

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

MUZ-GL09NA

71 11.0 7.6 0.52 10.3 7.1 0.57 9.7 6.6 0.61 9.0 6.2 0.65 8.3 5.7 0.67

MUZ-GL09NAH 67 10.4 8.6 0.49 9.7 8.0 0.54 9.0 7.4 0.59 8.4 6.9 0.62 7.7 6.3 0.65

MUY-GL09NA

63 9.8 9.4 0.47 9.1 8.7 0.52 8.5 8.1 0.56 7.7 7.3 0.60 7.0 6.7 0.62

MUZ-GL12NA

71 14.7 9.4 0.82 13.7 8.7 0.90 12.9 8.2 0.97 12.0 7.6 1.02 11.0 7.0 1.06

MUZ-GL12NAH 67 13.9 10.7 0.77 13.0 10.0 0.85 12.0 9.2 0.92 11.2 8.6 0.98 10.3 7.9 1.02

MUY-GL12NA

63 13.1 11.8 0.74 12.1 10.9 0.81 11.3 10.2 0.88 10.3 9.3 0.94 9.4 8.5 0.98

MUZ-GL15NA

71 17.2 9.7 0.96 16.0 9.1 1.05 15.1 8.5 1.13 14.0 7.9 1.19 12.9 7.3 1.24

MUZ-GL15NAH 67 16.2 11.4 0.91 15.1 10.6 1.00 14.0 9.8 1.08 13.0 9.1 1.14 12.0 8.4 1.20

MUY-GL15NA

63 15.3 12.7 0.86 14.1 11.8 0.96 13.2 11.0 1.03 12.0 10.0 1.10 10.9 9.1 1.14

MUZ-GL18NA

71 22.1 16.2 1.19 20.6 15.2 1.31 19.4 14.3 1.41 18.0 13.3 1.48 16.6 12.2 1.54

MUZ-GL18NAH 67 20.9 18.2 1.13 19.4 16.9 1.24 18.0 15.7 1.34 16.7 14.6 1.42 15.4 13.4 1.49

MUY-GL18NA

63 19.6 19.7 1.07 18.2 18.2 1.19 16.9 17.0 1.28 15.4 15.4 1.37 14.0 14.1 1.42

MUZ-GL24NA

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

MUZ-GL24NAH 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

MUY-GL24NA

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

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

TC : Total Capacity (x103 Btu/h)

SHC : Sensible Heat Capacity (x103 Btu/h) TPC : Total Power Consumption (kW)

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

OBH733F

24

2) COOLING CAPACITY CORRECTIONS

Refrigerant piping length (one way: ft.)

25 (std.)

40

65

MUZ-GL09NA

MUZ-GL09NAH

MUY-GL09NA

MUZ-GL12NA

MUZ-GL12NAH

1.0

MUY-GL12NA

MUZ-GL15NA

MUZ-GL15NAH

MUY-GL15NA

0.988

0.967

MUZ-GL18NA

MUZ-GL18NAH

1.0

MUY-GL18NA

0.985

0.963

MUZ-GL24NA

MUZ-GL24NAH

1.0

MUY-GL24NA

0.983

0.956

3) HEATING CAPACITY CORRECTIONS

Refrigerant piping length (one way: ft.)

MUZ-GL09NA MUZ-GL09NAH MUZ-GL12NA MUZ-GL12NAH MUZ-GL15NA MUZ-GL15NAH

25 (std.) 1.0

40 0.997

65 0.993

MUZ-GL18NA

MUZ-GL18NAH MUZ-GL24NA

1.0

MUZ-GL24NAH

0.997

0.993

100 -
0.933 0.921 100
0.987

OBH733F

25

4) HEATING CAPACITY (MUZ)

Indoor air

Outdoor intake air WB temperature (°F)

Model

5

15

25

35

43

IDB (°F)

TC TPC TC TPC TC TPC TC TPC TC TPC

MUZ-GL09NA

75 4.8 0.42 6.3 0.54 7.9 0.63 9.4 0.70 10.6 0.74 70 5.2 0.41 6.7 0.52 8.2 0.62 9.6 0.68 10.9 0.72

65 5.5 0.39 6.9 0.50 8.6 0.59 10.0 0.67 11.2 0.70

MUZ-GL12NA

75 6.3 0.65 8.4 0.82 10.4 0.96 12.5 1.07 14.0 1.13 70 6.8 0.62 8.9 0.79 10.8 0.94 12.7 1.05 14.4 1.10

65 7.2 0.59 9.1 0.76 11.3 0.91 13.2 1.02 14.8 1.07

75 MUZ-GL09NAH 70

4.8 0.55 6.3 0.67 7.9 0.76 9.4 0.70 10.6 0.74 5.2 0.54 6.7 0.65 8.2 0.75 9.6 0.68 10.9 0.72

65 5.5 0.52 6.9 0.63 8.6 0.72 10.0 0.67 11.2 0.70

75 MUZ-GL12NAH 70

6.3 0.78 8.4 0.95 10.4 1.09 12.5 1.07 14.0 1.13 6.8 0.75 8.9 0.92 10.8 1.07 12.7 1.05 14.4 1.10

65 7.2 0.72 9.1 0.89 11.3 1.04 13.2 1.02 14.8 1.07

MUZ-GL15NA

75 7.9 0.94 10.4 1.19 13.1 1.40 15.6 1.56 17.6 1.64 70 8.6 0.90 11.1 1.15 13.5 1.37 15.9 1.52 18.0 1.60

65 9.0 0.86 11.3 1.10 14.1 1.32 16.5 1.48 18.5 1.56

75 MUZ-GL15NAH 70

7.9 1.07 10.4 1.32 13.1 1.53 15.6 1.56 17.6 1.64 8.6 1.03 11.1 1.28 13.5 1.50 15.9 1.52 18.0 1.60

65 9.0 0.99 11.3 1.23 14.1 1.45 16.5 1.48 18.5 1.56

MUZ-GL18NA

75 9.5 0.99 12.5 1.25 15.7 1.47 18.7 1.64 21.1 1.72 70 10.3 0.95 13.3 1.21 16.2 1.44 19.1 1.60 21.6 1.68

65 10.8 0.91 13.6 1.16 17.0 1.39 19.8 1.55 22.2 1.64

75 9.5 1.12 12.5 1.38 15.7 1.60 18.7 1.64 21.1 1.72 MUZ-GL18NAH 70 10.3 1.08 13.3 1.34 16.2 1.57 19.1 1.60 21.6 1.68

65 10.8 1.04 13.6 1.29 17.0 1.52 19.8 1.55 22.2 1.64

MUZ-GL24NA

75 12.1 1.38 16.0 1.74 20.0 2.05 23.9 2.28 26.9 2.40 70 13.1 1.32 17.0 1.68 20.7 2.00 24.4 2.22 27.6 2.34

65 13.8 1.26 17.4 1.61 21.7 1.93 25.3 2.16 28.4 2.28

75 12.1 1.38 16.0 1.74 20.0 2.05 23.9 2.28 26.9 2.40 MUZ-GL24NAH 70 13.1 1.32 17.0 1.68 20.7 2.00 24.4 2.22 27.6 2.34

65 13.8 1.26 17.4 1.61 21.7 1.93 25.3 2.16 28.4 2.28

NOTE: 1. IDB : Intake air dry-bulb temperature

TC : Total Capacity (x103 Btu/h)

TPC : Total Power Consumption (kW)

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

45 TC TPC 11.0 0.75 11.2 0.73 11.6 0.71 14.5 1.14 14.8 1.12 15.3 1.09 11.0 0.75 11.2 0.73 11.6 0.71 14.5 1.14 14.8 1.12 15.3 1.09 18.1 1.66 18.5 1.63 19.1 1.58 18.1 1.66 18.5 1.63 19.1 1.58 21.7 1.75 22.2 1.71 22.9 1.66 21.7 1.75 22.2 1.71 22.9 1.66 27.7 2.43 28.4 2.39 29.3 2.32 27.7 2.43 28.4 2.39 29.3 2.32

55 TC TPC 12.4 0.78 12.7 0.76 13.0 0.75 16.4 1.19 16.8 1.17 17.1 1.14 12.4 0.78 12.7 0.76 13.0 0.75 16.4 1.19 16.8 1.17 17.1 1.14 20.5 1.73 21.0 1.70 21.4 1.66 20.5 1.73 21.0 1.70 21.4 1.66 24.6 1.81 25.2 1.78 25.7 1.75 24.6 1.81 25.2 1.78 25.7 1.75 31.5 2.53 32.2 2.48 32.8 2.43 31.5 2.53 32.2 2.48 32.8 2.43

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 or press any button on the remote controller.

OBH733F

26

7-2. PERFORMANCE CURVE Cooling

Cooling capacity (at Rated frequency)
1.5

1.4

Indoor intake air Wet-bulb temperature( F)

1.3

Capacity correction factors

1.2

79

1.1 75

1.0

0.9

72

68

64

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

Outdoor intake air DB temperature(°F)

MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA

Total power consumption (kW)

0.7 0.6 0.5 0.4 0.3 0.2
65

SHF at rating condition = 0.82
Airflow = 399 CFM 71 67 63

Indoor intake air WB temperature (°F)

75

85

95

105

115

Outdoor intake air DB temperature (°F)

MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA

Total power consumption (kW)

1.1 1.0 0.9 0.8 0.7 0.6
65

SHF at rating condition = 0.77
Airflow = 399 CFM 71 67 63

Indoor intake air WB temperature (°F)

75

85

95

105

115

Outdoor intake air DB temperature (°F)

MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA

Total power consumption (kW)

1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7
65

SHF at rating condition = 0.78 Airflow = 533 CFM

71 67 63
Indoor intake air WB temperature (°F)

75

85

95

105

115

Outdoor intake air DB temperature (°F)

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA

Total power consumption (kW)

1.6 1.5 1.4 1.3 1.2 1.1 1.0 0.965

SHF at rating condition = 0.87
Airflow = 646 CFM 71 67 63

Indoor intake air WB temperature (°F)

75

85

95

105

115

Outdoor intake air DB temperature (°F)

MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

Total power consumption (kW)

2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3
65

SHF at rating condition = 0.75 Airflow = 634 CFM
71 67 63

Indoor intake air WB temperature (°F)

75

85

95

105

115

Outdoor intake air DB 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.

OBH733F

27

Heating

Capacity correction factor

Heating capacity (at Rated frequency)

1.3

59

68

1.2 1.1 1.0 0.9 0.8 0.7

Indoor intake air Dry-bulb temperature ( F)

79

0.6

0.5

0.4

-4

5

14

23

32

41

50

59

Outdoor intake air WB temperature (°F)

MUZ-GL09NA

Total power consumption (kW)

1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0
-5

Airflow = 406 CFM 75 70 65
Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

MUZ-GL09NAH
1.0

Airflow = 406 CFM

Total power consumption (kW)

0.8

75

70

65

0.6

0.4

Indoor intake air DB temperature (°F)

0.2-5

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

MUZ-GL12NA

Total power consumption (kW)

1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3
-5

Airflow = 406 CFM 75 70 65

Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

MUZ-GL15NA

Total power consumption (kW)

2.0 1.7 1.4 1.1 0.8 0.5
-5

Airflow = 463 CFM 75 70 65

Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

MUZ-GL12NAH
1.6

Airflow = 406 CFM

Total power consumption (kW)

1.3

75

70

65

1.0

0.7

Indoor intake air DB temperature (°F)

0.4-5

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

MUZ-GL15NAH

Total power consumption (kW)

Airflow = 463 CFM

1.8

75

70

65

1.5

1.2 0.9 0.6 -5

Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

OBH733F

28

MUZ-GL18NA

Total power consumption (kW)

2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6-5

Airflow = 646 CFM 75 70 65

Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

MUZ-GL18NAH
1.9 1.6

Airflow = 646 CFM 75 70 65

Total power consumption (kW)

1.3 1.0 0.7
-5

Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

Outdoor intake air WB temperature (°F)

Total power consumption (kW)

MUZ-GL24NA
3.0 2.6 2.2

Airflow = 738 CFM 75 70 65

1.8

1.4

Indoor intake air DB temperature (°F)

1.0 0

10

20

30

40

50

60

70

Outdoor intake air WB temperature (°F)

MUZ-GL24NAH
2.8 2.3

Airflow = 738 CFM 75 70 65

Total power consumption (kW)

1.8 1.3 0.8-5

Indoor intake air DB temperature (°F)

5

15

25

35

45

55

65

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.

OBH733F

29

7-3. CONDENSING PRESSURE Cooling
Data are based on the condition of indoor humidity 50 %.
Air flow should be set to High speed.

MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA

(PSIG)

450

86

400 350

Indoor DB temperature (°F)

80 75 70

(PSIG) 180
160

Suction pressure

Condensing pressure

140

300

120

100 250
80

20065 70 75 80 85 90 95 100 105 (°F) 6065 Outdoor ambient temperature

86 80 75 70
Indoor DB temperature (°F) 70 75 80 85 90 95 100 105 (°F)
Outdoor ambient temperature

MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA
(PSIG) 500

Suction pressure

Condensing pressure

450 400

Indoor DB temperature (°F)

350

86

80 (PSIG)

75 70

180

160

140

300

120

100 250
80

20065 70 75 80 85 90 95 100 105 (°F) 6065 Outdoor ambient temperature

86 80 75 70
Indoor DB temperature (°F) 70 75 80 85 90 95 100 105 (°F)
Outdoor ambient temperature

MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA
(PSIG) 500

450 400

Indoor DB temperature (°F)

86

80

75 70

(PSIG)

180

160

350

140

Suction pressure

Condensing pressure

300

120

100 250
80

20065 70 75 80 85 90 95 100 105 (°F) 6065 Outdoor ambient temperature

86 80 75 70
Indoor DB temperature (°F) 70 75 80 85 90 95 100 105 (°F)
Outdoor ambient temperature

OBH733F

30

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA

(PSIG) 500

Suction pressure

Condensing pressure

450 400

Indoor DB temperature (°F)

350

300

86

80 75

(PSIG)

70 180

160

140

120

250

100

86 80 75 70
Indoor DB temperature (°F)

20065 70 75 80 85 90 95 100 105 (°F) 8065 70 75 80 85 90 95 100 105 (°F)

Outdoor ambient temperature

Outdoor ambient temperature

MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

(PSIG)

480

86

80

450

75 70

420 390 360

Indoor DB temperature (°F)

Condensing pressure

330

300

270 68 70

75 80 85 90 95 Outdoor ambient temperature

100 105(°F)

Suction pressure

(PSIG) 180
86 170

160

80

150

75

140

70

130 Indoor DB temperature (°F)
120

110 68 70

75 80 85 90 95 Outdoor ambient temperature

100 105(°F)

OBH733F

31

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

MUZ-GL09NA - U1 MUZ-GL09NAH - U1

(PSIG)

450

(PSIG)

200

75

70

400 350

Indoor DB temperature (°F)

75 70 150 65

Indoor DB temperature (°F)

65

100 300

Suction pressure

Condensing pressure

50 250

58Hz

58Hz

200 5

0

15

25

35

45

55

65

75 (°F)

5

Outdoor ambient temperature

15

25

35

45

55

65

Outdoor ambient temperature

MUZ-GL09NA - U8 MUZ-GL09NAH - U8 MUZ-GL12NA MUZ-GL12NAH

(PSIG) 500

(PSIG) 190

450

400 350

Indoor DB temperature (°F)

300

Suction pressure

165 75 70 140 65
115
90

Indoor DB temperature (°F)

75 (°F) 75 70 65

Condensing pressure

250 200
5

65 58Hz

40

15

25

35

45

55

65

75 (°F)

5

Outdoor ambient temperature

58Hz

15

25

35

45

55

65

75 (°F)

Outdoor ambient temperature

OBH733F

32

MUZ-GL15NA MUZ-GL15NAH
(PSIG) 500

450

Indoor DB temperature (°F)

400

Condensing pressure

350

300 250
5

58Hz

15

25

35

45

55

65

Outdoor ambient temperature

75 70 65

(PSIG) 190

165

Suction pressure

140

115

90

65

40

75 (°F)

5

75 70 65 Indoor DB temperature (°F)

58Hz

15

25

35

45

55

65

75 (°F)

Outdoor ambient temperature

MUZ-GL18NA MUZ-GL18NAH

(PSIG) 550
500

(PSIG)

200

75

70

65

175

450 400

Indoor DB temperature (°F)

350

Suction pressure

75 70 65 150
125 100

Indoor DB temperature (°F)

Condensing pressure

300 250
5

75 81Hz

50

15

25

35

45

55

65

75 (°F)

5

Outdoor ambient temperature

81Hz

15

25

35

45

55

65

75 (°F)

Outdoor ambient temperature

MUZ-GL24NA MUZ-GL24NAH

(PSIG) 450

75

425

70

400 375 350

Indoor DB temperature (°F)

65

Condensing pressure

325

300 58Hz
275

250 5

15 25 35 45 55 65 75(°F) Outdoor ambient temperature

Suction pressure

(PSIG) 210 190 170 150 130 110 90 70 50 5

75 70 65
Indoor DB temperature (°F)
58Hz
15 25 35 45 55 65 75(°F) Outdoor ambient temperature

OBH733F

33

7-4. STANDARD OPERATION DATA

Model

MSZ-GL09NA - U1

Total

Item Capacity SHF Input Rated frequency
Indoor unit

Unit Btu/h
-- kW Hz

Cooling 9,000 0.82 0.585
59

Heating 10,900
-- 0.72 73

MSZ-GL09NA

Power supply
Input Fan motor current

V, phase,
Hz
kW
A

0.022 0.24/0.22

0.023 0.25/0.23

Outdoor unit

MUZ-GL09NA - U1 MUZ-GL09NAH - U1

MSZ-GL09NA - U8

Cooling 9,000 0.82 0.585
48

Heating 10,900
-- 0.72 59

MSZ-GL09NA

208/230, 1, 60

0.022 0.24/0.22

0.023 0.25/0.23

MUZ-GL09NA - U8 MUZ-GL09NAH - U8

MSY-GL09NA Cooling 9,000 0.82 0.585 59.5
MSY-GL09NA
0.022 0.24/0.22
MUY-GL09NA

Electrical circuit

Refrigerant circuit

Power supply

V, phase,
Hz

Input

kW

Comp. current

A

Fan motor current

A

Condensing pressure

PSIG

Suction pressure

PSIG

Discharge temperature

°F

Condensing temperature

°F

Suction temperature

°F

Comp. shell bottom temperature °F

Ref. pipe length

ft.

Refrigerant charge (R410A)

Intake air temperature

DB °F WB °F

DB °F Discharge air temperature
WB °F

Fan speed (High)

rpm

Airflow (High)

CFM

Intake air temperature

DB °F WB °F

Fan speed

rpm

Airflow

CFM

0.563 2.67/2.41 0.36/0.33
357 151 146 108 61 144

0.697 3.25/2.94 0.34/0.31
345 107 156 102 44 154

2 lb 5 oz.

80

70

67

60

59

99

56

--

1,020

1,040

367 (Wet)

413

95

47

--

--

900

860

1,229

1,172

208/230, 1, 60

0.563

0.697

2.45/2.21 3.05/2.76

0.36/0.33 0.34/0.31

358

349

149

108

148

155

108

104

63

44

140

144

25

2 lb 9 oz.

80

70

67

60

59

99

56

--

1,020

1,040

367 (Wet)

413

95

47

--

--

900

860

1,229

1,172

0.563 2.63/2.37 0.36/0.33
358 149 154 108 66 152
80 67 59 56 1,020 367 (Wet) 95 -- 900 1,229

Indoor unit

Outdoor unit

OBH733F

34

Total

Electrical circuit

Model Item Capacity SHF Input Rated frequency Indoor unit
Power supply
Input Fan motor current

Unit Btu/h
-- kW Hz
V, phase,
Hz kW A

Outdoor unit

Power supply

V, phase,
Hz

Input

kW

Comp. current

A

Fan motor current

A

Condensing pressure

PSIG

Suction pressure

PSIG

Discharge temperature

°F

Condensing temperature

°F

Suction temperature

°F

Comp. shell bottom temperature °F

Ref. pipe length

ft.

Refrigerant charge (R410A)

Intake air temperature

DB °F WB °F

DB °F Discharge air temperature
WB °F

Fan speed (High)

rpm

Airflow (High)

CFM

Intake air temperature

DB °F WB °F

Fan speed

rpm

Airflow

CFM

MSZ-GL12NA MSY-GL12NA

Cooling

Heating

12,000

14,400

0.77

--

0.920

1.10

70

77

MSZ-GL12NA MSY-GL12NA

MSZ-GL15NA MSY-GL15NA

Cooling

Heating

14,000

18,000

0.78

--

1.080

1.60

56.5

74

MSZ-GL15NA MSY-GL15NA

208/230, 1, 60

0.022

0.023

0.24/0.22

0.25/0.23

MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA

0.043

0.030

0.43/0.39

0.34/0.31

MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA

208/230, 1, 60

0.898 4.01/3.62 0.41/0.37
380 133 166 112 60 152
80 67 57 55 1,020 367 (Wet) 95 -- 900 1,229

1.077

1.037

4.86/4.39

4.51/4.08

0.40/0.36

0.41/0.37

402

396

106

138

167

168

115

115

35

61

150

152

25

2 lb 9 oz.

70

80

60

67

110

58

--

56

1,040

1,280

413

498 (Wet)

47

95

43

--

860

910

1,172

1,243

1.570 7.11/6.43 0.40/0.36
427 98 178 120 31 158
70 60 114 -- 1,140 463 47 43 900 1,229

Refrigerant circuit

Indoor unit

Outdoor unit

OBH733F

35

Total

Electrical circuit

Model Item Capacity SHF Input Rated frequency Indoor unit
Power supply
Input Fan motor current

Unit Btu/h
-- kW Hz
V, phase,
Hz kW A

Outdoor unit

Power supply

V, phase,
Hz

Input

kW

Comp. current

A

Fan motor current

A

Condensing pressure

PSIG

Suction pressure

PSIG

Discharge temperature

°F

Condensing temperature

°F

Suction temperature

°F

Comp. shell bottom temperature °F

Ref. pipe length

ft.

Refrigerant charge (R410A)

Intake air temperature

DB °F WB °F

DB °F Discharge air temperature
WB °F

Fan speed (High)

rpm

Airflow (High)

CFM

Intake air temperature

DB °F WB °F

Fan speed

rpm

Airflow

CFM

MSZ-GL18NA MSY-GL18NA

Cooling

Heating

18,000

21,600

0.87

--

1.34

1.68

69

81

MSZ-GL18NA MSY-GL18NA

MSZ-GL24NA MSY-GL24NA

Cooling

Heating

22,500

27,600

0.75

--

1.80

2.34

67.5

82.0

MSZ-GL24NA MSY-GL24NA

208/230, 1, 60

0.045 0.46/0.42 MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA

0.058 0.56/0.51 MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

208/230, 1, 60

1.295

1.635

1.742

2.282

5.01/4.53

6.67/6.03

7.01/6.34

9.59/8.67

1.05/0.95

1.05/0.95

1.16/1.05

1.13/1.02

377

391

395

405

144

103

141

102

149

178

158

171

111

111

115

115

51

43

52

33

134

160

140

148

25

3 lb 9 oz.

4 lb 3 oz.

80

70

80

70

67

60

67

60

52

111

56

111

51

--

53

--

1,170

1,170

1,300

1,300

581 (Wet)

646

634 (Wet)

738

95

47

95

47

--

43

--

43

810

810

840

810

1,691

1,691

1,769

1,701

Refrigerant circuit

Indoor unit

Outdoor unit

OBH733F

36

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

Capacity correction factors

Capacity correction factors Input correction factors

Input correction factors

MUZ-GL09NA - U1 MUZ-GL09NAH- U1

Correction of Cooling capacity 2.0

Correction of Cooling total input 2.0

Correction of Heating capacity 2.0

Correction of Heating total input
2.0

1.5

1.5

1.5

1.5

1.0

1.0

1.0

1.0

0.5

0.5

0.5

0.5

0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz) 0

50

100

150(Hz) 0

50

100

150 (Hz)

The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor

MUY-GL09NA

Correction of Cooling capacity 2.0

Correction of Cooling total input 2.0

1.5

1.5

1.0

1.0

0.5

0.5

Input correction factors

Capacity correction factors

Input correction factors

Capacity correction factors

Input correction factors

Capacity correction factors

0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz)

The operational frequency of compressor The operational frequency of compressor

MUZ-GL09NA - U8 MUZ-GL09NAH - U8

Correction of Cooling capacity 2.0

Correction of Cooling total input 2.0

Correction of Heating capacity 2.0

Correction of Heating total input
2.0

1.5

1.5

1.5

1.5

1.0

1.0

1.0

1.0

0.5

0.5

0.5

0.5

Input correction factors

Capacity correction factors

Input correction factors

Capacity correction factors

0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz) 0

25

50

75

100(Hz)

The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor

MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA

Correction of Cooling capacity 2.0

Correction of Cooling total input 2.0

Correction of Heating capacity 2.0

Correction of Heating total input
2.0

1.5

1.5

1.5

1.5

1.0

1.0

1.0

1.0

0.5

0.5

0.5

0.5

0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz) 0

25

50

75

100(Hz)

The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor

OBH733F

37

Capacity correction factors

Capacity correction factors

Input correction factors

Capacity correction factors

Input correction factors

MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA

Correction of Cooling capacity 2.0

Correction of Cooling total input 2.0

Correction of Heating capacity 2.0

Correction of Heating total input
2.0

1.5

1.5

1.5

1.5

1.0

1.0

1.0

1.0

0.5

0.5

0.5

0.5

0

25

50

75

100 (Hz) 0

25

50

75

100 (Hz) 0

50

100

150 (Hz) 0

50

100

150(Hz)

The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor

Input correction factors

Capacity correction factors

Input correction factors

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA

Correction of Cooling capacity 2.0

Correction of Cooling total input 2.0

2.0 Correction of Heating capacity

Correction of Heating total input
2.0

1.5

1.5

1.5

1.5

1.0

1.0

1.0

1.0

0.5

0.5

0.5

0.5

Th0e

30 60 90 operational frequency

120 150 (Hz) of compressor

0 The

30 60 90 operational frequency

120 150 (Hz) 0

30 60 90 120 150 (Hz)

of compressor The operational frequency of compressor

0

30 60 90 120 150(Hz)

The operational frequency of compressor

Input correction factors

Capacity correction factors

Input correction factors

MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

Correction of Cooling capacity 1.5

Correction of Cooling total input 2.5

2.0 1.0
1.5

1.0 0.5
0.5

1.5 Correction of Heating capacity 1.0 0.5

Correction of Heating total input 2.0 1.5 1.0 0.5

0

50

100

150(Hz)

0

50

100

150(Hz)

0

50

100

150(Hz)

The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor

0

50

100

150(Hz)

The operational frequency of compressor

Capacity correction factors

7-6. HOW TO OPERATE FIXED-FREQUENCY OPERATION (Test run operation) 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 var-
ies). 6. To cancel test run operation (EMERGENCY OPERATION), press EMERGENCY OPERATION switch or any button on the
remote controller.

OBH733F

38

8 ACTUATOR CONTROL

MUZ-GL09NA MUZ-GL12NA MUZ-GL15NA MUZ-GL18NA MUZ-GL24NA

MUZ-GL09NAH MUZ-GL12NAH MUZ-GL15NAH MUZ-GL18NAH MUZ-GL24NAH

MUY-GL09NA MUY-GL12NA MUY-GL15NA MUY-GL18NA MUY-GL24NA

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 ON

15 seconds

Compressor

OFF

ON

Outdoor fan motor

OFF
8-2. R.V. COIL CONTROL (MUZ) Heating . . . . . . . . . . . . . . . . . ON Cooling . . . . . . . . . . . . . . . . . OFF Dry . . . . . . . . . . . . . . . . . . . . OFF NOTE: The 4-way valve reverses for 5 seconds right before start-up of the compressor.

<COOL>

<HEAT>

5 seconds

5 seconds

ON Compressor OFF

R.V.coil

ON OFF

Outdoor fan ON

motor

OFF

8-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR

Sensor

Purpose

Actuator

Compressor

LEV

Outdoor fan motor

R.V.coil

Indoor fan motor

Defrost heater *

Discharge temperature thermistor

Protection

Indoor coil temperature thermistor
Defrost thermistor (MUZ)

Cooling: Coil frost prevention Heating: High pressure protection Heating: Defrosting

Fin temperature thermistor Protection

Ambient temperature thermistor

Cooling: Low ambient temperature operation Heating: Defrosting (Heater)

Outdoor heat exchanger temperature thermistor
*. MUZ-GL·NAH only.

Cooling: Low ambient temperature operation Cooling: High pressure protection















 

 

OBH733F

39

9 SERVICE FUNCTIONS

MUZ-GL09NA MUZ-GL12NA MUZ-GL15NA MUZ-GL18NA MUZ-GL24NA

MUZ-GL09NAH MUZ-GL12NAH MUZ-GL15NAH MUZ-GL18NAH MUZ-GL24NAH

MUY-GL09NA MUY-GL12NA MUY-GL15NA MUY-GL18NA MUY-GL24NA

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.).

Defrost finish temperature

Jumper

MUZ-GL09/12/15NA MUZ-GL09/12/15NAH

MUZ-GL18/24NA MUZ-GL18/24NAH

Soldered (Initial setting)
JS
None (Cut)

41°F (5°C) 50°F (10°C)

50°F (10°C) 64°F (18°C)

9-2. PRE-HEAT CONTROL SETTING (MUZ) MUZ-GL09/12/15/18 When moisture gets into the refrigerant cycle, it may interfere with the start-up of the compressor at low outside temperature. The pre-heat control prevents this interference. The pre-heat control turns ON when the discharge temperature thermistor is 68°F (20°C) or below. When the pre-heat control turns ON, the compressor is energized. (About 50 W)
MUZ-GL24 Prolonged low load operation, in which the thermostat is OFF for a long time, at low outside temperature [32°F (0°C) or less] may cause the following troubles. The pre-heat control prevents those troubles. 1) If moisture gets into the refrigerant cycle and freezes, it may interfere the start-up of the compressor. 2) If liquid refrigerant collects in the compressor, a failure in the compressor may occur. The pre-heat control turns ON when the compressor temperature is 68°F (20°C) or below. When the pre-heat control turns ON, the compressor is energized. (About 70 W)
Pre-heat control setting <JK> ON: To activate the pre-heat control, cut JK wire of the inverter P.C. board. OFF: To deactivate the pre-heat control, solder JK wire of the inverter P.C. board. (Refer to 10-6.1)

Jumper
Soldered JK
Cut

Pre-heat control setting

MUZ-GL09/12/15/18NA MUZ-GL09/12/15/18NAH

MUZ-GL24NA MUZ-GL24NAH

Deactivated (Factory setting)

Deactivated

Activated

Activated (Factory setting)

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

OBH733F

40

10 TROUBLESHOOTING

MUZ-GL09NA MUZ-GL12NA MUZ-GL15NA MUZ-GL18NA MUZ-GL24NA

MUZ-GL09NAH MUZ-GL12NAH MUZ-GL15NAH MUZ-GL18NAH MUZ-GL24NAH

MUY-GL09NA MUY-GL12NA MUY-GL15NA MUY-GL18NA MUY-GL24NA

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 connector housing. DO NOT pull the lead wires.

<Incorrect>

<Correct>

Lead wiring

Connector housing

3. Troubleshooting procedure 1) Check if the OPERATION INDICATOR lamp on the indoor unit is blinking on and off to indicate an abnormality. To make sure, check how many times the OPERATION INDICATOR lamp is blinking on and off before starting service work. (See the service manual of the indoor unit for a description of those failure codes.) 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.

OBH733F

41

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-GL06/09/12/15NA MSZ-GL18NA MSY-GL09/12/15NA MSY-GL18NA

MSZ-GL24NA MSY-GL24NA

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 OPERATION SELECT button and TOO COOL button on the remote controller at the same time, press RESET button. First, release RESET button. Hold down the other 2 buttons for another 3 seconds. Make sure that the indicators on the LCD screen shown in the right figure are all displayed. Then release the buttons.

Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. 1

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

Does the upper lamp of the 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 the OPERATION INDICATOR lamp. 2

No (OFF)

Indoor unit is normal. But the outdoor unit might be abnormal because there are some abnormalities that cannot be recalled with this way. Check if outdoor unit is abnormal according to the detailed outdoor unit failure mode recall function. (Refer to 10-2.2)

Judgment of indoor/outdoor abnormality

Yes (Blinks)

Before blinking, does the upper lamp of the OPERATION

INDICATOR lamp stay ON for 3 seconds?

When it stays ON for 3 seconds (without beep): The outdoor unit

Yes

is abnormal.

No

The indoor unit is abnormal. Check the blinking pattern, and identify the abnormal point by referring to the indoor unit failure recall mode table. (Refer to indoor unit service manual.) Make sure to check at least 2 consecutive blinking cycles. 2

The outdoor unit is abnormal. Check the blinking pattern, and identify the abnormal point by referring to the outdoor unit failure recall mode table. (Refer to 10-2.3) Make sure to check at least 2 consecutive blinking cycles. 3

E.g.: MSZ type

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.

Repair the failure parts.

Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall function" mentioned above. Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted. Release the failure mode recall function according to "Releasing the failure mode recall function" mentioned above.
NOTE: 1. Make sure to release the failure mode recall function after 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 the indoor unit is abnormal:

Blinking at 0.5-

Blinking at 0.5-

2.5-second OFF second interval 2.5-second OFF second interval

ON OFF

Beeps Repeated cycle

Beeps Repeated cycle

3.Blinking pattern when the outdoor unit is abnormal:

Blinking at 0.5-

2.5-second OFF 3-second ON

second interval

2.5-second OFF

ON OFF

No beep Repeated cycle

Beeps

OBH733F

42

Beeps Repeated cycle
3-second ON

Blinking at 0.5second interval

No beep Repeated cycle

Beeps

Repeated cycle

2. Flow chart of the detailed outdoor unit failure mode recall function Operational procedure
The outdoor unit might be abnormal. Check if outdoor unit is abnormal according to the following procedures.
Make sure that the remote controller is set to the failure mode recall function.

With the remote controller headed towards the indoor unit, press TOO COOL button to adjust the set temperature to 77°F (25°C). 1

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

Does the upper lamp of the 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 the OPERATION INDICATOR lamp. 2

No (OFF)

Yes (Blinks)

The outdoor unit is abnormal. Check the blinking pattern, and identify the abnormal point by referring to the outdoor unit failure recall mode table (10-2.3.). Make sure to check at least 2 consecutive blinking cycles. 2

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.

The outdoor unit is normal.
Release the failure mode recall function according to the left mentioned procedure.

Repair the failure 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 STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted. Release the failure mode recall function according to "Releasing the failure mode recall function" mentioned above.
NOTE: 1. Make sure to release the failure mode recall function after 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:

ON OFF

2.5-second OFF 3-second ON
No beep Repeated cycle

Blinking at 0.5second interval
Beeps

2.5-second OFF 3-second ON

Blinking at 0.5second interval

No beep Repeated cycle

Beeps

Repeated cycle

OBH733F

43

3. Table of outdoor unit failure mode recall function

NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.).

The upper lamp of the OPERATION INDICATOR
lamp (Indoor unit)

Abnormal point (Failure mode/protection)

OFF
1-time blink 2.5 seconds OFF

None (Normal)
Indoor/outdoor communication, receiving error

Indoor/outdoor communication, receiving error

2-time blink Outdoor power system 2.5 seconds OFF

3-time blink 2.5 seconds OFF

Discharge temperature thermistor Defrost thermistor
Fin temperature thermistor

4-time blink 2.5 seconds OFF

P.C. board temperature thermistor
Ambient temperature thermistor
Outdoor heat exchanger temperature thermistor
Overcurrent

Compressor synchronous abnormality (Compressor start-up failure protection)
5-time blink Discharge temperature 2.5 seconds OFF

6-time blink High pressure 2.5 seconds OFF
7-time blink Fin temperature/ P.C. board 2.5 seconds temperature OFF

8-time blink Outdoor fan motor 2.5 seconds OFF

9-time blink 2.5 seconds OFF

Non-volatile memory data
Power module (IC700) (MUZ-GL09/12/15/18, MUYGL09/12/15/18) IGBT module (IC700) (MUZ-GL24, MUY-GL24)

LED indication (Outdoor P.C. board)

Condition

Remedy

Indoor/outdoor unit failure mode recall function

Outdoor unit failure mode recall function

--

--

--

--

--

Any signals from the inverter P.C.

·Refer to 10-5. How

--

board cannot be received normally for to check miswiring and

3 minutes. Although the inverter P.C. board

serial signal error. ·Refer to 10-5. How





--

sends signal "0", signal "1" has been to check miswiring and

received 30 consecutive times.

serial signal error.

Overcurrent protection cut-out

· Reconnect

operates 3 consecutive times within connectors.

--

1 minute after the compressor gets started.

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





compressor".

·Check stop valve.

1-time blink every Thermistor shorts or opens during

·Refer to 10-5.

2.5 seconds

compressor running.

"Check of outdoor

thermistors".

Defective outdoor

3-time blink

thermistors can be

2.5 seconds OFF
4-time blink 2.5 seconds OFF

identified by checking the blinking pattern of





LED.

2-time blink 2.5 seconds OFF

--

11-time blink

Large current flows into the power

· Reconnect

2.5 seconds OFF module (IC700) (MUZ-GL09/12/15/18, compressor connector.

MUY-GL09/12/15/18)/ IGBT module ·Refer to 10-5. "How

(IC700) (MUZ-GL24, MUY-GL24).

to check inverter/

--



compressor".

·Check stop valve.

12-time blink

Waveform of compressor current is ·Reconnect

2.5 seconds OFF distorted.

compressor connector.

·Refer to 10-5. "How

--

to check inverter/



compressor".

Temperature of discharge temperature ·Check refrigerant

thermistor exceeds 241°F (116°C),

circuit and refrigerant

compressor stops.

amount.

--

Compressor can restart if discharge ·Refer to 10-5. "Check

--



temperature thermistor reads

of LEV".

212°F (100°C) or less 3 minutes later.

Temperature indoor coil thermistor

·Check refrigerant

--

exceeds 158°F (70°C) in HEAT

circuit and refrigerant

mode. Temperature defrost thermistor amount.

--



exceeds 158°F (70°C) in COOL mode. ·Check stop valve.

7-time blink

Temperature of the fin temperature

·Check around outdoor

2.5 seconds OFF thermistor on the inverter P.C. board

unit.

exceeds 167 - 187°F (75 - 86°C) (MUZ- ·Check outdoor unit air GL09/12/15/18, MUY-GL09/12/15/18)/167 passage.

- 176°F (75 - 80°C) (MUZ-GL24, MUY- ·Refer to 10-5. "Check

GL24), or temperature of P.C. board

of outdoor fan motor".

--

temperature thermistor on the inverter



P.C. board exceeds 162 - 185°F (72 - 85°C) (MUZ-GL09/12/15/18, MUY-

GL09/12/15/18)/158 - 167°F (70 - 75°C) (MUZ-GL24, MUY-GL24).

Outdoor fan has stopped 3 times in a ·Refer to 10-5. "Check

row within 30 seconds after outdoor of outdoor fan motor".

--

fan start-up.

Refer to 10-5. "Check

--



of inverter P.C. board".

5-time blink

Non-volatile memory data cannot be ·Replace the inverter

2.5 seconds OFF read properly.

P.C. board.

6-time blink

The interface short circuit occurs

·Refer to 10-5. "How

2.5 seconds OFF in the output of the power module

to check inverter/

(IC700) (MUZ-GL09/12/15/18, MUY- compressor".



GL09/12/15/18)/IGBT module (IC700)

(MUZ-GL24, MUY-GL24).

The compressor winding shorts circuit.

OBH733F

44

The upper lamp of the OPERATION INDICATOR
lamp (Indoor unit)

Abnormal point (Failure mode/protection)

10-time blink Discharge temperature 2.5 seconds OFF

11-time blink 2.5 seconds OFF
14-time blink or more 2.5 seconds OFF

DC voltage
Each phase current of compressor Stop valve (Closed valve)
4-way valve/ Pipe temperature

Outdoor refrigerant system abnormality

NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.).

LED indication (Outdoor P.C. board)

Condition

Remedy

Indoor/outdoor unit failure mode recall function

Outdoor unit failure mode recall function

Temperature of discharge temperature ·Refer to 10-5. "Check

thermistor has been 122°F (50°C) or of LEV".

--

less for 20 minutes.

·Check refrigerant

--

circuit and refrigerant



amount.

8-time blink

DC voltage of inverter cannot be

·Refer to 10-5. "How

2.5 seconds OFF detected normally.

9-time blink

Each phase current of compressor

to check inverter/ compressor".

--



2.5 seconds OFF cannot be detected normally.

14-time blink

Closed valve is detected by

2.5 seconds OFF compressor current.

·Check stop valve.

16-time blink

The 4-way valve does not work

2.5 seconds OFF properly.

·Check the 4-way valve.



The indoor coil thermistor detects an ·Replace the inverter

abnormal temperature.

P.C. board.

1-time blink

A closed valve and air trapped in the ·Check for a gas leak

2.5 seconds OFF refrigerant circuit are detected based in a connecting piping

on the temperature sensed by the

etc.

indoor and outdoor thermistors and the ·Check the stop valve.

current of the compressor.

·Refer to 10-5.





"Check of outdoor

refrigerant circuit".

OBH733F

45

10-3. TROUBLESHOOTING CHECK TABLE

No. Symptom Outdoor unit does not op-
1 erate.
2

LED indication
1-time blink every 2.5 seconds

Abnormal point/ Condition
Outdoor power system
Outdoor thermistors

Condition Overcurrent protection cut-out operates 3 consecutive times within 1 minute after the compressor gets started.
Discharge temperature thermistor, fin temperature thermistor, defrost thermistor, P.C. board temperature thermistor, outdoor heat exchanger temperature thermistor or ambient temperature thermistor shorts or opens during compressor running.

Remedy
·Reconnect connector of compressor. ·Refer to 10-5. "How to check inverter/compressor". ·Check stop valve. ·Refer to 10-5. "Check of outdoor thermistors".

Outdoor control sys- Nonvolatile memory data cannot be read properly.

·Replace inverter P.C. board.

3

tem (The upper lamp of the OPERATION INDICATOR lamp on the

indoor unit lights up or blinks 7-time.)

4

6-time blink

Serial signal

2.5 seconds OFF

The communication fails between the indoor and outdoor unit ·Refer to 10-5. "How to check

for 3 minutes.

miswiring and serial signal error.

5

11-time blink

Stop valve/

2.5 seconds OFF Closed valve

Closed valve is detected by compressor current.

·Check stop valve.

16-time blink

4-way valve/

The 4-way valve does not work properly.

·Refer to 10-5. "Check of R.V.

6

2.5 seconds OFF Pipe temperature The indoor coil thermistor detects an abnormal temperature. coil".

·Replace the inverter P.C. board.

17-time blink

Outdoor refrigerant A closed valve and air trapped in the refrigerant circuit are

·Check for a gas leak in a

2.5 seconds OFF system abnormality detected based on the temperature sensed by the indoor and connecting piping etc.

7

outdoor thermistors and the current of the compressor.

·Check the stop valve.

·Refer to 10-5. "Check of outdoor

refrigerant circuit".

'Outdoor unit 2-time blink

Overcurrent protec- Large current flows into the power module (IC700) (MUZ-

stops and 2.5 seconds OFF tion

GL09/12/15/18, MUY-GL09/12/15/18)/ IGBT module (IC700)

8 restarts 3

(MUZ-GL24, MUY-GL24).

· Reconnect connector of compressor. ·Refer to 10-5. "How to check inverter/compressor".

minutes later'

is repeated. 3-time blink

Discharge tem-

9

2.5 seconds OFF perature overheat protection

·Check stop valve.
Temperature of discharge temperature thermistor exceeds ·Check refrigerant circuit and refrig241°F (116°C), compressor stops. Compressor can restart if erant amount. discharge temperature thermistor reads 212°F (100°C) or less ·Refer to 10-5. "Check of LEV". 3 minutes later.

4-time blink

Fin temperature

Temperature of the fin temperature thermistor on the heat sink ·Check around outdoor unit.

2.5 seconds OFF /P.C. board tem-

exceeds 167 - 187°F (75 - 86°C) (MUZ-GL09/12/15/18, MUY- ·Check outdoor unit air passage.

perature thermistor GL09/12/15/18)/167 - 176°F (75 - 80°C) (MUZ-GL24, MUY- ·Refer to 10-5. "Check of outdoor

10

overheat protection GL24) or temperature of P.C. board temperature thermistor on fan motor".

the inverter P.C.board exceeds 162 - 185°F (72 - 85°C) (MUZ-

GL09/12/15/18, MUY-GL09/12/15/18)/158 - 167°F (70 - 75°C)

(MUZ-GL24, MUY-GL24).

5-time blink

High pressure pro- Indoor coil thermistor exceeds 158°F (70°C) in HEAT mode. ·Check refrigerant circuit and refrig-

11

2.5 seconds OFF tection

Defrost thermistor exceeds 158°F (70°C) in COOL mode.

erant amount.

·Check stop valve.

8-time blink

Compressor syn- The waveform of compressor current is distorted.

· Reconnect connector of compressor.

12

2.5 seconds OFF chronous abnormal-

·Refer to 10-5. "How to check

ity

inverter/compressor".

10-time blink

Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds ·Refer to 10-5. "Check of outdoor

13

2.5 seconds OFF

after outdoor fan start-up.

fan motor. ·Refer to 10-5. "Check of inverter

P.C. board.

14

12-time blink

Each phase current Each phase current of compressor cannot be detected nor-

2.5 seconds OFF of compressor

mally.

·Refer to 10-5. "How to check inverter/compressor".

13-time blink

DC voltage

DC voltage of inverter cannot be detected normally.

·It occurs with following case.

2.5 seconds OFF

Instantaneous power voltage drop.

(Short time power failure) (MUZ-

15

GL24, MUY-GL24) ·Refer to 10-5. "Check of power

supply". (MUZ-GL24, MUY-GL24)

·Refer to 10-5. "How to check inverter/compressor".

NOTE: 1. The location of LED is illustrated at the right figure. Refer to 10-6.1. 2. LED is lighted during normal operation. 3. Blinking patterns of this mode differ from the ones of the failure recall mode.

Inverter P.C. board MUZ-GL09/12/15/18NA(H)
MUY-GL09/12/15/18NA

MUZ-GL24NA(H) MUY-GL24NA

The blinking frequency shows the number of times the LED blinks after every 2.5-second OFF. (Example) When the blinking frequency is "2".

0.5-second ON

0.5-second ON

Blinking  LED

Blinking 
LED

ON OFF

2.5-second OFF

2.5-second OFF

OBH733F

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No. Symptom Outdoor unit operates.
16
17
18
19

LED indication
1-time blink 2.5 seconds OFF

Abnormal point/ Condition
Frequency drop by current protection

MUZ-GL09/12/15/18 MUY-GL09/12/15/18 MUZ-GL24 MUY-GL24

Condition
When the input current exceeds approximately 10.5A, compressor frequency lowers.
Current from power outlet is nearing breaker capacity.

Remedy
The unit is normal, but check the following. ·Check if indoor filters are clogged. ·Check if refrigerant is short. ·Check if indoor/outdoor unit air circulation is short cycled.

3-time blink 2.5 seconds OFF
4-time blink 2.5 seconds OFF
5-time blink 2.5 seconds OFF

Frequency drop by high pressure protection
Frequency drop by defrosting in COOL mode
Frequency drop by discharge temperature protection
Outside temperature thermistor protection

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.
When the outside temperature thermistor shorts or opens, protective operation without that thermistors is performed.

·Check refrigerant circuit and refrigerant amount. ·Refer to 10-5. "Check of LEV". ·Refer to 10-5. "Check of outdoor thermistors".
·Refer to 10-5. Check of outdoor thermistors.

Outdoor unit 20 operates.
21
22

7-time blink 2.5 seconds OFF 8-time blink 2.5 seconds OFF
9-time blink 2.5 seconds OFF

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

MUZ-GL09/12/15/18 MUY-GL09/12/15/18 PAM protection PAM: Pulse Amplitude Modulation

The overcurrent flows into PFC (Power factor correction :IC820) or the DC voltage reaches 394 V or more, PAM stops and restarts.

MUZ-GL24 MUY-GL24

Zero cross signal cannot be detected.

Zero cross detecting

circuit

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

·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.
·It occurs with following cases. 1 Instantaneous power voltage drop. (Short time power failure) 2 Distortion of primary voltage
·Refer to 10-5. "Check of power supply".
·Check if the connector of the compressor is correctly connected. Refer to 10-5. "How to check inverter/compressor".

NOTE: 1. The location of LED is illustrated at the right figure. Refer to 10-6.1. 2. LED is lighted during normal operation. 3. Blinking patterns of this mode differ from the ones of the failure recall mode.

The blinking frequency shows the number of times the LED blinks after every 2.5-second OFF. (Example) When the blinking frequency is "2".

Inverter P.C. board MUZ-GL09/12/15/18(H)
MUY-GL09/12/15/18NA

MUZ-GL24NA(H) MUY-GL24NA

ON OFF

2.5-second OFF

0.5-second ON 2.5-second OFF

0.5-second ON

Blinking  LED

Blinking 
LED

OBH733F

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10-4. TROUBLE CRITERION OF MAIN PARTS
MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

Part name
Defrost thermistor (RT61) (MUZ)

Check method and criterion

Fin temperature thermistor (RT64)
Ambient temperature thermistor (RT65)

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.

Outdoor heat exchanger temperature thermistor (RT68)

Discharge temperature thermistor (RT62)

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: 14 - 104°F (-10 - 40°C)]

Compressor

Normal ()

MUZ-GL09NA(H) - U1
MUY-GL09

MUZ-GL09NA(H) - U8
MUZ-GL12 MUY-GL12

MUZ-GL15/18 MUY-GL15/18

MUZ-GL24 MUY-GL24

U-V U-W V-W

1.26 - 1.72

1.60 - 2.17

0.82 - 1.11 0.87 - 1.18

Outdoor fan motor

Measure the resistance between lead wires using a tester. [Temperature: 14 - 104°F (-10 - 40°C)]

Color of lead wire
RED ­ BLK BLK ­ WHT WHT ­ RED

Normal () MUZ-GL09/12/15 MUZ-GL18/24 MUY-GL09/12/15 MUY-GL18/24

29 - 40

12 - 16

R. V. coil (21S4)

Measure the resistance using a tester. [Temperature: 14 - 104°F (-10 - 40°C)]
Normal (k) 0.97 - 1.38

Expansion valve coil (LEV)
Defrost heater (MUZ-GL·NAH)
OBH733F

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

Color of lead wire

Normal ()

RED ­ ORN

RED ­ WHT RED ­ BLU RED ­ YLW

37 - 54

Measure the resistance using a tester. [Temperature: 14 - 104°F (-10 - 40°C)]
Normal () 349 - 428

48

Figure

WHT RED BLK
W

V

U

WHT RED BLK
W

V

U

WHT

LEV

ORN RED (+12V)

YLW BLU

10-5. TROUBLESHOOTING FLOW A How to check inverter/compressor

Disconnect the connector between the compressor and the power module (IC700) (MUZ-GL09/12/15/18, MUY-GL09/12/15/18)/IGBT module (IC700) (MUZGL24, MUY-GL24).

Check the voltage between terminals.

See 10-5. "Check of open phase".

Are the voltages balanced? Yes
Check the compressor.

No

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 power module (IC700) (MUZ-GL09/12/15/18, MUY-GL09/12/15/18)/IGBT module (IC700) (MUZ-GL24, MUY-GL24) 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)

Measure AC voltage between the lead wires at 3 points.

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 blinks 9 times. (Refer to 10-6.1.)

C Check of compressor

Refer to 10-5. "Check of compressor

winding". Is the compressor normal?

No

Yes

Refer to 10-5. "Check of compressor

operation time". Does the compressor operate continuously?

No

Yes

OK

Replace the compressor. Refer to 10-5. "Check of compressor start failure".

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D Check of compressor winding

Disconnect the connector between the compressor and the power module (IC700) (MUZ-GL09/12/15/18, MUY-GL09/12/15/18)/ IGBT module (IC700) (MUZ-GL24, MUY-GL24), 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 [] ················Abnormal [short]

Infinite [] ·······Abnormal [open] NOTE: Be sure to zero the ohmmeter before measurement.

E Check of compressor operation time
 Connect the compressor and activate the inverter. Then measure the time until the inverter stops due to overcurrent. <<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.

<<Judgement>> 0 second 1 second 2 seconds
10 seconds

F Check of compressor start failure

10 minutes

Compressor starts Abnormal (IC700 failure) (Compressor winding short) Abnormal (Compressor lock out) (Starting defect) Abnormal (Poor contact) (Inverter P.C. board defect) (Disconnected connector) Abnormal (Refrigerant circuit defect) (Closed valve)
Normal

Confirm that ~ is normal. ·Electrical circuit check
. Contact of the compressor connector . Output voltage of inverter P.C. board and balance of them (See 10-5. ) . Direct current voltage between DB61(+) and (-) (MUZ-GL09/12/15/18,
MUY-GL09/12/15/18)/ JP715(+) and JP30(-) (MUZ-GL24, MUY-GL24), on
the inverter P.C. board . Voltage between outdoor terminal block S1-S2

Does the compressor run for 10 seconds or

Check the refrigerant circuit.

more after it starts?

Yes Check the stop valve.

No

After the compressor is heated with a drier,

does the compressor start? 1

No

Yes

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

Replace the compressor.

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50

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

G Check of outdoor thermistors

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

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

Replace the thermistor except RT64.

When RT64 is abnormal, replace the inverter P.C.

No

board.

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?

No

Yes

Replace the inverter P.C. board.

OK (Cause is poor contact.)

MUZ-GL09/12/15/18, MUY-GL09/12/15/18

Thermistor

Symbol

Connector, Pin No.

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-GL24, MUY-GL24

Thermistor Defrost (MUZ)

Symbol

Connector, Pin No.

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

Board Inverter P.C. board
Board Inverter P.C. board

OBH733F

51

H Check of R.V. coil (MUZ)

MUZ-GL09/12/15/18NA MUZ-GL09/12/15/18NAH
First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4. In case CN721 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 is connected.

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

Disconnect connector between the compressor and the power module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch twice (HEAT mode).

Is there 208/230 V AC between CN721 and on the inverter P.C. board 3 minutes after the power supply is turned No ON?
Yes

Replace the inverter P.C. board.

Replace the 4-way valve.

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

Disconnect connector between the compressor and the power module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch once (COOL mode).

Is there 208/230 V AC between CN721

and on the inverter P.C. board

Replace the inverter

3 minutes after the power supply is turned Yes P.C. board.

ON?

No

Replace the 4-way valve.

MUZ-GL24NA MUZ-GL24NAH

First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4. In case CN602 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 CN602 is connected.

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

Disconnect connector between the compressor and the IGBT module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch twice (HEAT mode).

Is there 208/230 V AC between CN602 and on the inverter P.C. board 3 minutes after the power supply is turned No ON?
Yes

Replace the inverter P.C. board.

Replace the 4-way valve.

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

Disconnect connector between the compressor and the IGBT module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch once (COOL mode).

Is there 208/230 V AC between CN602

and on the inverter P.C. board

Replace the inverter

3 minutes after the power supply is turned Yes P.C. board.

ON?

No

Replace the 4-way valve.

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I Check of outdoor fan motor
Check the connection between the connector CN931 and CN932. Disconnect the connectors CN931 and CN932 from the inverter P.C. board.

Is the resistance between each ter-

minal of outdoor fan motor normal? (Refer to 10-4.)

Yes

No

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 V DC) No
No Replace the outdoor fan motor.

Does the voltage between each terminal become 5 and 0 V DC repeatedly?
Yes
Does the outdoor fan motor rotate smoothly? Yes
Replace the inverter P.C. board.

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53

J Check of power supply

Disconnect the connector between the compressor and the power module (IC700) (MUZ-GL09/12/15/18, MUYGL09/12/15/18)/IGBT module (IC700) (MUZ-GL24, MUY-GL24). Turn ON power supply and press EMERGENCY OPERATION switch.

Does the upper lamp of the

OPERATION INDICATOR lamp on the indoor unit light up?

No

Yes

Rectify indoor/outdoor connecting wire.

No
Is there voltage 208/230 V AC between the indoor terminal block S1 and S2?

Replace the indoor

Yes

electronic control P.C. board.

Is there DC voltage 260 - 370 V DC

between DB61 (+) and DB61 (­)

(MUZ-GL09/12/15/18, MUY-

GL09/12/15/18)/294 - 370 V DC between JP715 (+) and JP30 (­)

Yes

(MUZ-GL24, MUY-GL24) on the

inverter P.C. board? (Refer to 10-6.1.)

No

Check the electric parts in main circuit.

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

No

Replace the inverter P.C. board.

Yes

If lights up, OK. If blinks, refer to 10-3.

DB61

260 - 370 V DC

Inverter P.C. board (Solder side)
MUZ-GL09/12/15/18NA MUZ-GL09/12/15/18NAH MUY-GL09/12/15/18NA

294 -370 V DC

JP715

JP30

MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

OBH733F

54

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. Hold down the other 2 buttons for another 3 seconds. Make sure that the indicators on the LCD screen shown in the right figure are all displayed. Then release the buttons.

MSZ-GL06/09/12/15NA MSZ-GL18NA MSY-GL09/12/15NA MSY-GL18NA

MSZ-GL24NA MSY-GL24NA

Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. 1

Expansion valve operates in full-opening direction.

E.g.: MSZ type

Do you hear the expansion valve "click,

click·······"? Do you feel the expansion valve vibrates Yes

OK

when touching it ?

No

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

Is LEV coil properly fixed to

the expansion valve?

No

Yes

Does the resistance of LEV

coil have the characteristics? (Refer to 10-4.)

Yes

No

Replace the LEV coil.

Properly fix 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 V AC between each? NOTE: Measure the voltage by an analog
tester.
Yes

Replace the inverter P.C. No board.

Replace the expansion valve.

NOTE: After check of LEV, do the undermentioned operations. 1. Turn OFF the power supply and turn it ON again. 2. Press RESET button on the remote controller.

OBH733F

55

L Check of inverter P.C. board
Check the outdoor fan motor. (Refer to 10-5. .)

Is the fuse (F901) blown on the in-

verter P.C. board?

Yes

No

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

Operate the outdoor unit by starting EMERGENCY OPERATION.

Check the LED indication on the in-

verter P.C. board. Does the LED blink 10 times?

No

Yes (10-time blink)

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

Replace the inverter P.C. board.

OBH733F

56

M How to check miswiring and serial signal error

MUZ-GL09/12/15NA MUZ-GL09/12/15NAH MUY-GL09/12/15NA

Turn OFF the power supply.
Is there rated voltage in the power supply? No Yes
Turn ON the power supply.

Check the power supply.

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

No

Press EMERGENCY OPERATION switch once.

Check the wiring.

Does the left lamp of OPERATION INDICATOR

lamp light up? <Confirmation of the power to

the indoor unit>

No

Yes

Is serial signal error indicated 6 minutes later? No Yes

Is there any miswiring,

poor contact, or wire

disconnection of the indoor/outdoor connect-

Yes

Correct them.

ing wire?

No

A
Turn OFF the power supply. Check once more if the indoor/outdoor B connecting wire is not miswiring. Bridge the outdoor terminal block S2 and S3. 1
Turn ON the power supply.

1. Miswiring may damage indoor electronic control P.C. board during the operation. Be sure to confirm the wiring is correct before the operation starts.
3. Be sure to check this within 3 minutes after turning ON. After 3 minutes, LED blinks 6 times. Even when the inverter P.C. board is normal, LED blinks 6 times after 3 minutes.

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

No Check of power supply.

Does the LED on the inverter P.C. board repeat "3.6-second-OFF and 0.8-second-ON quick blinking"? 3
Yes
Turn OFF the power supply. Remove the bridge between the outdoor terminal block S2 and S3. Turn ON the power supply.

No (Lighted or not lighted)

Replace the inverter P.C. board . 2
2. Be careful of the residual voltage of smoothing capacitor.

Is there rated voltage between the indoor terminal block S1 and S2? <Confirmation of power voltage>
Yes

Check the wiring

If there are any error of the indoor/outdoor connecting wire:

No

such as the damage of the wire, intermediate connection, and/or poor contact to the terminal block, replace the indoor/

outdoor connecting wire.

Is there amplitude of 10 to 20 V DC between the indoor terminal block

S2 and S3? <Confirmation of serial signal>

No

A · Turn OFF inverter-controlled lighting
equipment. · Turn OFF the power supply and then
turn ON again. · Press EMERGENCY OPERATION
switch.

Is serial signal error indicated 6 minutes later?
Yes
B

· Reinstall

either the unit

or the light

away from

each other.

No

· Attach a filter on remote

control receiv-

ing section

of the indoor

unit.

Yes

Is there 2 V DC or less between CN202 (+)

and JPG (GND)(-) on the indoor electronic

control P.C. board?

Yes

No

Is there 2 V DC or less between

CN202A (+) and JPG (GND)(-)

on the indoor electronic control P.C.

board?

No

Yes

Is there 2 V DC or less between

CN202 (+) and JPG (GND)(-) on

the indoor electronic control P.C.

Yes

board?

No

Replace the indoor power P.C. board.

Replace the indoor electronic control P.C. board.

OBH733F

57

MUZ-GL18/24NA MUZ-GL18/24NAH MUY-GL18/24NA

Turn OFF the power supply.

Is there rated voltage in the power supply? No Yes
Turn ON the power supply.

Check the power supply.

Is there rated voltage between outdoor terminal block S1 and S2? No Yes
Press EMERGENCY OPERATION switch once.

Check the wiring.

Does the OPERATION INDICATOR lamp light up? <Confirmation of the power to the indoor unit>
Yes
Is serial signal error indicated 6 minutes later?
Yes

No

Is there any miswiring,

poor contact, or wire

No

disconnection of the indoor/outdoor connect-

Yes

Correct them.

ing wire?

No

A
Turn OFF the power supply. Check once more if the indoor/outdoor B connecting wire is not miswiring. Bridge the outdoor terminal block S2 and S3. 1
Turn ON the power supply.

1. Miswiring may damage indoor electronic control P.C. board during the operation. Be sure to confirm the wiring is correct before the operation starts.
3. Be sure to check this within 3 minutes after turning ON. 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. (Except for outdoor unit of multi system type)

Is the bus-bar voltage of the inverter P.C. board or the outdoor electronic control P.C. board normal? (Refer

to "TEST POINT DIAGRAM AND VOLTAGE" in the outdoor service manual.)

No

Yes

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

No (Lighted or not lighted)

Replace the inverter P.C. board or the outdoor electronic control P.C. board. 2
2. Be careful of the residual voltage of smoothing capacitor.

Turn OFF the power supply. Remove the bridge between outdoor terminal block S2 and S3.

GL18

GL24

Turn on the power supply.

Replace the indoor electronic control P.C. board.

Is there amplitude of 10 to 20 V DC between the indoor terminal block

S2 and S3? <Confirmation of serial signal>

No

Yes A

· Turn OFF inverter-controlled lighting equipment.
· Turn OFF the power supply and then turn ON again.
· Press EMERGENCY OPERATION switch.

Is serial signal error indicated 6 minutes later?
Yes
B

· Reinstall

either the unit

or the light

away from

each other.

No

· Attach a filter on remote

control receiv-

ing section

of the indoor

unit.

Is there 2 V DC or less between CN10A (+)

and GND (-) on the indoor electronic control

P.C. board?

Yes

No

Is there 2 V DC or less between

CN10A (+) and GND (-) on

the indoor electronic control P.C.

board?

No

Yes

Is there 2 V DC or less between

CN10A (+) and GND (-) on

the indoor electronic control P.C.

Yes

board?

No

Replace the indoor power P.C. board.

Replace the indoor electronic control P.C. board.

OBH733F

58

N Check of defrost heater (base pan heater) (MUZ-GL·NAH)

MUZ-GL09/12/15/18/24NAH
Check the following points before checking electric continuity. 1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to 10-6.1. 2. Is the resistance of defrost heater normal? Refer to 10-4. 3. Does the heater protector remain conducted (not open)? 4. Are both ambient temperature thermistor and circuit of defrost heater securely connected to connectors?

In HEAT mode, for more than 5 minutes, let the ambient temperature thermistor continue to read 32°F (0°C) or below, and let the defrost thermistor continue to read 30°F (-1°C) or below.
NOTE: In case both thermistors are more than the above temperature, cool them with cold water etc...

Is there 208/230 V AC between CN601 and

(MUZ-GL24NAH)/CN722 and (Other models) on the inverter P.C. board? Refer to 10-6.1.

Yes

No

Not the problem of the inverter P.C. board.

Replace the inverter P.C. board.

O Check of outdoor refrigerant circuit

Has the operation stopped during pump down?
Yes

No

Was the operation started with the stop valve closed, and was it opened during operation?

The unit occasionally stops when the stop valve is opened or closed during Yes operation. Open the stop valve and start the cooling operation again.

No

The operation has stopped to prevent the diesel explosion caused by air trapped in the refrigerant circuit. Close the stop valve, and disconnect the power plug or turn OFF the breaker.

The refrigerant gas amount may be 60% or less than the normal amount. Identify where the gas is leaking from, and fix the leak.

CAUTION : Do not start the operation again to prevent hazards.

OBH733F

59

P Electromagnetic noise enters into TV sets or radios

Is the unit grounded?

Ground the unit.

No

Yes

Is the distance between the antennas and the indoor unit within 9.91 ft. (3m), or is the distance between the antennas Yes and the outdoor unit within 9.91 ft. (3m)?
No

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

Is the distance between the TV sets or ra-

dios and the indoor unit within 3.28 ft. (1m),

or is the distance between the TV sets or

radios and the outdoor unit within

Yes

9.91 ft. (3m)?

No

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

Are the antennas damaged? Is the coaxial cable damaged? Is there any poor contact in the anten- Yes na wiring?
No

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

Is the indoor/outdoor connecting wire

of the air conditioner and the wiring of

the antennas close?

Yes

No

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 fulfilled, the electromagnetic noise may enter, depending on the electric field strength or the installation condition (combination of specific conditions such as antennas or wiring). Check the following 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, ground wire, antennas, wiring from antennas, receiver 5. Electric field intensity of the broadcast station affected by the electromagnetic noise 6. Presence or absence of amplifier 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 STOP/OPERATE (OFF/ON) 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 STOP/OPERATE (OFF/ON) 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.

OBH733F

60

10-6. TEST POINT DIAGRAM AND VOLTAGE

1. Inverter P.C. board

MUZ-GL09/12/15NA

MUZ-GL09/12/15NAH MUY-GL09/12/15NA
Back side of unit

Smoothing capacitor (C63)

DB61

260 - 370 V DC

(-)

(+)

Smoothing capacitor (C62)

R.V.coil/21S4

(CN721)

Heater connector

Smoothing capacitor (C61)

(MUZ) 208/230

V AC

(CN722) (MUZ-GL09/ 12/15NAH)

208/230 V AC

Fuse (F801) T3.15AL250V

Fuse (F701) T3.15AL250V

Fuse (F901) T3.15AL250V
Output to drive outdoor fan motor (CN932)
Output to drive compressor (LDU, LDV, LDW)

Fin temperature thermistor/RT64 (CN642) Signal of outdoor fan motor (CN931) Ambient temperature thermistor/RT65 (CN643) Defrost thermistor /RT61(CN641)(MUZ) Discharge temperature thermistor/RT62 (CN641) Outdoor heat exchanger temperature thermistor /RT68 (CN644) Expansion valve/LEV (CN724)

LED Front side of unit

208/230 V AC Jumper wire for preheat control setting (JK)
Jumper wire for changing defrost setting (JS)

5HVLVWDQFHN

Defrost thermistor (RT61) Ambient temperature thermistor (RT65) Outdoor heat exchanger temperature thermistor (RT68) 100

90

80

Discharge temperature thermistor (RT62)

70

800

700

60

600

50

500

40

400

30

300

20

200

10

100

0 -4 14 32 50 68 86 104 Temperature (°F)

0 32 50 68 86 104 122 140 158 176 194 212 230 248 Temperature (°F)

OBH733F

61

5HVLVWDQFHN 5HVLVWDQFHN

Fin temperature thermistor (RT64) 200 180 160 140 120 100
80 60 40 20
0 32 50 68 86 104 122 140 158 176 Temperature (°F)

MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA
Back side of unit
208/230 V AC

DB61

260 - 370 V DC

(-)

(+)

Smoothing capacitor (C63)
Smoothing capacitor (C62)

Smoothing capacitor (C61)

Fuse (F801) T3.15AL250V

R.V.coil/21S4 (CN721) (MUZ) 208/230 V AC

Heater connector (CN722) (MUZ-GL18NAH)
Fuse (F701) T3.15AL250V

Fuse (F901) T3.15AL250V
Output to drive outdoor fan motor (CN932)
Output to drive compressor (LDU, LDV, LDW)

208/230 V AC

LED Front side of unit

Jumper wire for changing defrost setting (JS)

Jumper wire for pre-heat control setting (JK)

Fin temperature thermistor/RT64 (CN642) Signal of outdoor fan motor (CN931) Ambient temperature thermistor/RT65 (CN643) Defrost thermistor /RT61(CN641) (MUZ) Discharge temperature thermistor/RT62 (CN641) Outdoor heat exchanger temperature thermistor /RT68 (CN644) Expansion valve/LEV (CN724)

5HVLVWDQFHN 5HVLVWDQFHN
5HVLVWDQFHN

Defrost thermistor (RT61) Ambient temperature thermistor (RT65) Outdoor heat exchanger temperature thermistor (RT68) 100

90

80

Discharge temperature thermistor (RT62)

70

800

700 60
600

50

500

40

400

30

300

20

200

10

100

0 -4 14 32 50 68 86 104 Temperature (°F)

0 32 50 68 86 104 122 140 158 176 194 212 230 248 Temperature (°F)

Fin temperature thermistor (RT64) 200 180 160 140 120 100
80 60 40 20
0 32 50 68 86 104 122 140 158 176 Temperature (°F)

OBH733F

62

MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA
Heater connector (CN601) (MUZ-GL24NAH)

Fuse (F601) T3.15AL250V
R.V. coil/21S4 (CN602) 208/230 V AC (MUZ)

Signal of outdoor fan motor (CN931)
Fuse (F901) T3.15AL250V Output to drive outdoor fan motor (CN932) Fuse (F880) T3.15AL250V
JP715 (+) 294 - 370 V DC
JP30 (-)

Expansion valve/LEV (CN724)
LED
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)
Jumper wire for changing defrost setting (JS)
Jumper wire for pre-heat control setting (JK)

Resistance(k ) 5HVLVWDQFHN
Resistance(k )

Defrost thermistor (RT61) (MUZ) Ambient temperature thermistor (RT65) 100 Outdoor heat exchanger temperature thermistor (RT68)

90

80

Discharge temperature thermistor (RT62)

70

800

700 60
600

50

500

40

400

30

300

20

200

10

100

0-4 14 32 50 68 86 104 Temperature (°F)

0 32 50 68 86 104 122 140 158 176 194 212 230 248 Temperature (°F)

OBH733F

63

200 Fin temperature thermistor (RT64) 180 160 140 120 100
80 60 40 20
032 50 68 86 104 122 140 158 176 Temperature (°F)

11 DISASSEMBLY INSTRUCTIONS

<Detaching method of the terminals with locking mechanism>

The terminal which has the locking mechanism can be detached as shown below. There are 2 types of the terminals with locking mechanism. The terminal without locking mechanism can be detached by pulling it out. Check the shape of the terminal before detaching.

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

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

Locking lever

Slide the sleeve. Pull the terminal while pushing the locking lever.

11-1. MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA
NOTE: Turn OFF the power supply before disassembly.
OPERATING PROCEDURE

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. (Photo 4) (5) Remove the screw fixing the conduit plate. (Photo 5) (6) Remove the conduit plate. (7) Disconnect the power supply wire and indoor/outdoor connecting wire. (8) Remove the screws fixing the top panel. (9) Remove the top panel. (10) Remove the screws fixing the cabinet. (11) Remove the cabinet. (12) Remove the screws fixing the back panel. (13) Remove the back panel.

Photo 1

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

: Indicates the visible parts in the photos/figures. : Indicates the invisible parts in the photos/figures.
PHOTOS/FIGURES

Screws of the top panel

Back panel

Screws of the back panel

Photo 2

Screws of the top panel

Screws of the cabinet

Photo 3

Screw of the cabinet

Service panel
Screws of the terminal block support and the back panel

Screws of the cabinet
OBH733F

Screws of the cabinet
64

Direction to remove
Hooks

Photo 4

OPERATING PROCEDURE
Screws of the conduit cover

Photo 5

PHOTOS/FIGURES
Screw of the conduit plate

2. Removing the inverter assembly, inverter P.C. board (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C. board> CN721 (R.V. coil) (MUZ) CN722 (Defrost heater and heater protector) (MUZGL09/12/15NAH) 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 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 terminal 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.
3. Removing R.V. coil (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the following connectors: <Inverter P.C. board> CN721 (R.V. coil) (MUZ) (3) Remove the R.V. coil.

Photo 6
Screws of the heat sink support and the separator

Screws of the terminal block support and the back panel

Photo 7 Heat sink Heat sink support
P.C. board support

Screw of the Terminal block support

Terminal block support

OBH733F

Screw of the inverter P.C. board

Screw of the ground wire

65

OPERATING PROCEDURE

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 section 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C. board> CN641 (Defrost thermistor (MUZ) and discharge temperature thermistor) CN643 (Ambient temperature thermistor) CN644 (Outdoor heat exchanger temperature thermistor) (3) Pull out the discharge temperature thermistor from its holder. (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.

Photo 8

PHOTOS/FIGURES
Screw of the R.V. coil (MUZ)

Discharge temperature thermistor Photo 9

Ambient temperature thermistor
Outdoor heat exchanger temperature thermistor
Defrost thermistor (MUZ)

OBH733F

66

OPERATING PROCEDURE
5. Removing outdoor fan motor (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the following connectors: <Inverter P.C. board> CN931, CN932 (Fan motor) (3) Remove the propeller fan nut. (4) Remove the propeller fan. (5) Remove the screws fixing the fan motor. (6) Remove the fan motor. NOTE: The propeller fan nut is a reverse thread.

Photo 10

PHOTOS/FIGURES
Screws of the outdoor fan motor

Propeller fan

6. Removing the compressor and 4-way valve (1) Remove the cabinet and panels. (Refer to section 1.) (2) Remove the inverter assembly. (Refer to section 2.) (3) Remove the screws fixing the reactor. (4) Remove the reactor. (5) Remove the soundproof felt. (6) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 PSIG. (7) Detach the brazed part of the suction and the discharge pipe connected with compressor. (8) Remove the nuts fixing the compressor. (9) Remove the compressor. (10) Detach the brazed part of pipes connected with 4-way valve.

Photo 11
Screws of the reactor

Propeller fan nut

Photo 12

Discharge pipe brazed part
OBH733F

Soundproof felt

Suction pipe brazed part

Brazed parts of 4-way valve
67

11-2. MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA

NOTE: Turn OFF the power supply before disassembly.

OPERATING PROCEDURE

PHOTOS/FIGURES

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 screw of fixing the conduit plate. (8) Remove the conduit plate. (9) Remove the top panel. (10) Remove the valve cover. (11) Disconnect the power supply and indoor/outdoor connecting wire. (12) Remove the screws of the cabinet. (13) Remove the cabinet. (14) Remove the screws of the back panel. (15) Remove the back panel.

Photo 1 Screws of the top panel
Screws of the cabinet

Photo 3 Screws of the conduit cover

Screws of the cabinet

Screws of the cabinet

Photo 4 Screw of the conduit plate

Photo 2
Screw of the back panel Screws of the cabinet
Screws of the top panel Screw of the valve cover

OBH733F

Screws of the cabinet

Screws of the back panel
Screws of the service panel

68

OPERATING PROCEDURE

PHOTOS/FIGURES

2. Removing the inverter assembly, inverter P.C. board (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C. board> CN721 (R.V. coil) (MUZ) CN722 (Defrost heater) (MUZ-GL18NAH) 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. (4) Remove the screw 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, screw of the P.C. board cover and screws of the terminal 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 the inverter P.C. board from the P.C. board support.

Photo 5
Screw of the heat sink support and the separator

Screws of the terminal block support and the back panel

Photo 6

Heat sink

Heat sink support

3. Removing R.V. coil (MUZ) (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the following connector: <Inverter P.C. board> CN721 (R.V. coil) (MUZ) (3) Remove the R.V. coil.

P.C. board support

Screw of the P.C. board cover

Photo 7

Screw of the inverter P.C. board

Screw of the R.V. coil (MUZ)

Screw of the ground wire

Screws of the terminal block support

Brazed parts of 4-way valve

OBH733F

69

OPERATING PROCEDURE
4. Removing the discharge temperature thermistor, defrost thermistor (MUZ), outdoor heat exchanger temperature thermistor and ambient temperature thermistor (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C. board> CN641 (Defrost thermistor (MUZ) and discharge temperature thermistor) CN643 (Ambient temperature thermistor) CN644 (Outdoor heat exchanger temperature thermistor) (3) Pull out the discharge temperature thermistor from its holder. (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.

Photo 8

PHOTOS/FIGURES

Outdoor heat exchanger temperature thermistor

Ambient temperature thermistor

5. Removing outdoor fan motor (1) Remove the top panel, cabinet and service panel. (Refer to section 1.) (2) Disconnect the following connectors: <Inverter P.C. board> CN931 and CN932 (Fan motor) (3) Remove the propeller fan nut. (4) Remove the propeller fan. (5) Remove the screws fixing the fan motor. (6) Remove the fan motor. NOTE: The propeller fan nut is a reverse thread.

Photo 9

Defrost thermistor (MUZ) Propeller fan nut

6. Removing the compressor and 4-way valve (1) Remove the top panel, cabinet and service panel. (Refer to section 1.) (2) Remove the back panel. (Refer to section 1.) (3) Remove the inverter assembly. (Refer to section 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 pipe connected with compressor.
(6) Remove the compressor nuts. (7) Remove the compressor. (8) Detach the brazed part of 4-way valve and pipe. (Photo 7)

OBH733F

70

Photo 10

Screws of the outdoor fan motor

Brazed part of the discharge pipe

Discharge temperature thermistor

Brazed part of the suction pipe

11-3. MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA

NOTE: Turn OFF the power supply before disassembly.

OPERATING PROCEDURE

PHOTOS/FIGURES

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 connecting 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 1 Screws of the top panel
Screws of the cabinet

Photo 2

Screws of the top panel
Screws of the back panel

Screws of the back panel

Screws of the back panel

Screws of the cabinet

Screws of the cabinet

Photo 3

Screws of the conduit cover

Photo 4

Screw of the conduit plate

Screws of the cabinet

Screws of the back panel

Screws of the back panel

Screws of the service panel
Screw of the valve cover

OBH733F

71

OPERATING PROCEDURE

PHOTOS/FIGURES

2. Removing the inverter assembly, inverter P.C. board and relay P.C. board (1) Remove the cabinet and panels. (Refer to section 1.)
(2) Disconnect the lead wire to the reactor and the following con-
nectors:
<Inverter P.C. board> CN601 (Defrost heater) (MUZ-GL24NAH) CN602 (R.V. coil) (MUZ)
CN931, CN932 (Fan motor) CN671 (Defrost thermistor (MUZ), discharge temperature
thermistor and outdoor heat exchanger temperature
thermistor)
CN672 (Ambient temperature thermistor)
CN724 (LEV)

Photo 5
Inverter P.C. board

Screw of the relay panel
Ground wires

Screws of the P.B. support

(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 screws of the P.B. support. (8) Remove the inverter P.C. board from the P.B. support.

Screws of the P.B. support

Screw of the relay panel

Screw of the relay panel

3. Removing R.V. coil (MUZ) (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the following connector: <Inverter P.C. board> CN602 (R.V. coil) (MUZ) (3) Remove the R.V. coil.

Photo 6

Screw of the R.V. coil (MUZ)

Brazed parts of 4-way valve

OBH733F

72

OPERATING PROCEDURE

PHOTOS/FIGURES

4. Removing the discharge temperature thermistor, defrost thermistor (MUZ), outdoor heat exchanger temperature thermistor and ambient temperature thermistor (1) Remove the cabinet and panels. (Refer to section 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 heat exchanger temperature thermistor) CN672 (Ambient temperature thermistor) (3) Pull out the discharge temperature thermistor from its holder. (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.

Photo 7
Outdoor heat exchanger temperature thermistor

Ambient temperature thermistor

5. Removing outdoor fan motor (1) Remove the top panel, cabinet and service panel. (Refer to section 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. NOTE: The propeller fan nut is a reverse thread.

Photo 8

Defrost thermistor (MUZ)

Screws of the outdoor fan motor

6. Removing the compressor and 4-way valve (1) Remove the top panel, cabinet and service panel. (Refer to section 1.) (2) Remove the back panel. (Refer to section 1.) (3) Remove the inverter assembly. (Refer to section 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 6)

Photo 9
Brazed part of the discharge pipe

Discharge temperature thermistor

OBH733F

Brazed part of the suction pipe
73

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

© Copyright 2015 MITSUBISHI ELECTRIC CORPORATION Issued: Nov. 2018. No.OBH733 REVISED EDITION-F Issued: Jul. 2017. No. OBH733 REVISED EDITION-E Issued: Mar. 2017. No. OBH733 REVISED EDITION-D Issued: Sep. 2016. No. OBH733 REVISED EDITION-C Issued: Jan. 2016. No. OBH733 REVISED EDITION-B Issued: Nov. 2015. No. OBH733 REVISED EDITION-A Published: Sep. 2015. No. OBH733 Made in Japan

Specifications are subject to change without notice.


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