Mitsubishi Electric MUZ-GL09NA-U8 User manual

HFC
utilized
R410A
INDOOR UNIT
SERVICE MANUAL
No. OBH733
REVISED EDITION-G
Indoor unit service manual
MSZ-GL•NA, MSY-GL•NA Series (OBH732)
MUZ-GL18/24NA
MUZ-GL18/24NAH
MUY-GL18/24NA
PARTS CATALOG (OBB733)
OBH733 REVISED EDITION-F is void.
Revision G:
• MUZ-GL09/12/15NA(H)- U2 and
MUY-GL09/12/15NA- U2 have been added.
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 ···················· 65
OUTDOOR UNIT
Models
MUZ-GL09NA -
U1
,
U2
,
U8
MUZ-GL09NAH -
U1
,
U2
,
U8
MUY-GL09NA -
U1
,
U2
MUZ-GL12NA -
U1
,
U2
MUZ-GL12NAH -
U1
,
U2
MUY-GL12NA -
U1
,
U2
MUZ-GL15NA -
U1
,
U2
MUZ-GL15NAH -
U1
,
U2
MUY-GL15NA -
U1
,
U2
MUZ-GL18NA -
U1
MUZ-GL18NAH -
U1
MUY-GL18NA -
U1
MUZ-GL24NA -
U1
,
U2
MUZ-GL24NAH -
U1
MUY-GL24NA -
U1

2
1TECHNICAL CHANGES
Use the speci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.
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.
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
1. New model
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.
Revision G:
• MUZ-GL09/12/15NA(H)- U2 and MUY-GL09/12/15NA- U2 have been added.
MUZ-GL09NA - U1 MUZ-GL09NA - U2
MUZ-GL09NAH - U1 MUZ-GL09NAH - U2
1. Fan motor has been changed.
2. INVERTER P.C.BOARD has been changed.
3. EXPANSION VALVE has been changed.
4. 4-WAY VALVE has been changed.
5. R.V. COIL has been changed.
6. Compressor has been changed.
MUZ-GL12NA - U1 MUZ-GL12NA - U2
MUZ-GL12NAH - U1 MUZ-GL12NAH - U2
1. Fan motor has been changed.
2. INVERTER P.C.BOARD has been changed.
3. EXPANSION VALVE has been changed.
4. 4-WAY VALVE has been changed.
5. R.V. COIL has been changed.
MUY-GL09NA - U1 MUY-GL09NA - U2
1. Fan motor has been changed.
2. INVERTER P.C.BOARD has been changed.
3. EXPANSION VALVE has been changed.
4. 4-WAY VALVE has been changed.
5. Compressor has been changed.
6. Refrigerant charge has been changed.
MUY-GL12NA - U1 MUY-GL12NA - U2
1. Fan motor has been changed.
2. INVERTER P.C.BOARD has been changed.
3. EXPANSION VALVE has been changed.
4. 4-WAY VALVE has been changed.
MUZ-GL15NA - U1 MUZ-GL15NA - U2
MUZ-GL15NAH - U1 MUZ-GL15NAH - U2
MUY-GL15NA - U1 MUY-GL15NA - U2
1. Fan motor has been changed.
2. INVERTER P.C.BOARD has been changed.
3. EXPANSION VALVE has been changed.
OBH733G

3
MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA
MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA
Piping
Air outlet
Drain outlet
Air inlet
(back and side)
Drain hose
PART NAMES AND FUNCTIONS
2
MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA
MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA
MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA
Air outlet
Drain outlet
Piping
Drain hose
Air inlet
(back and side)
OBH733G

8
Unit: inch
16-7/16
1-9/16
1-5/8
Drain hole
6-7/8 19-11/16
13
2
Air in
Air in
Air out
2-holes 13/32 13/16
14-3/16
33-1/16
4-5/16
3-3/16
34-5/8
17-25/32
Service panel
3-29/32
6-1/2
7-11/16
35
44
Liquid refrigerant pipe joint
Refrigerant pipe (flared) Ø 1/4 (GL18)
Refrigerant pipe (flared) Ø 3/8 (GL24)
Gas refrigerant pipe joint
Refrigerant pipe (flared) Ø 1/2 (GL18)
Refrigerant pipe (flared) Ø 5/8 (GL24)
*1 20 in. (500 mm) or more when front
and sides of the unit are clear
14 in. (350 mm)
or more
4 in. (100 mm)
or more
REQUIRED SPACE
Clear *1
4 in. (100 mm)
or more
20 in. (500 mm)
or more *2
*2 When any 2 sides of left, right
and rear of the unit are clear
MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA
MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA
OBH733G

15
MUZ-GL18NA
OBH733G

16
MUZ-GL18NAH
OBH733G

21
6REFRIGERANT SYSTEM DIAGRAM
Unit: Inch (mm)
MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
(MUZ)
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
Capillary tube
O.D. 0.157×
I.D. 0.094×
3-15/16
(ø 4.0 × ø 2.4 × 100)
Capillary tube
O.D. 0.157×
I.D. 0.094×7-7/8
(ø 4.0 × ø 2.4 × 200)
Refrigerant flow in cooling
Compressor
4-way
valve
Refrigerant flow in heating (MUZ)
Refrigerant pipe
ø1/2 ( ø 12.7)
(with heat insulator)
Refrigerant pipe ø1/4 ( ø 6.35)
(with heat insulator)
LEV
R.V. coil (MUZ)
heating ON
cooling OFF
Muffler
with #100 mesh strainer
Strainer
#100
Outdoor heat
exchanger
temperature
thermistor
RT68
Strainer
#100
Muffler
Capillary tube
O.D. 0.118×
I.D. 0.079× 7-7/8
(ø3.0×ø2.0×200(×4))
Stop valve
(with service port)
Service
port
Service port
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
(MUZ)
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainar)
Refrigerant flow in cooling
Compressor
4-way valve
Refrigerant flow in heating
(MUZ)
Refrigerant pipe ø1/4 (ø6.35)
(with heat insulator)
R.V. coil (MUZ)
heating ON
cooling OFF
Strainer
#100
LEV
Ambient
temperature
thermistor
RT65
Muffler
Capillary tube
O.D. 0.118 ×
I.D. 0.079 × 9-7/16
(
ø3.0 × ø2.0 × 240 )
(MUZ-GL09NA(H)- U1 , U2
MUY-GL09NA- U2 )
Outdoor heat
exchanger
temperature
thermistor
RT68
Capillary tube
O.D. 0.118 ×
I.D. 0.079 × 8-9/32
(ø3.0 × ø2.0 × 210)
Service
port
Service
port
Refrigerant pipe ø3/8 (ø9.52) (GL09/12)
(with heat insulator)
ø1/2 (ø12.7) (GL15)
Stop valve
(with service port)
Capillary tube
O.D. 0.157 ×
I.D. 0.094 × 9-7/16
(
ø4.0 × ø2.4 × 240 )
(Other models )
Muffler
MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA
MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA
MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA
OBH733G

23
Max. Length
A
Max. Height
difference
B
Indoor
unit
Outdoor unit
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE
Model
Refrigerant piping: ft. Piping size O.D: in.
Max. Length
A
Max. Height difference
B Gas Liquid
MUZ-GL09NA
MUZ-GL09NAH
MUY-GL09NA
MUZ-GL12NA
MUZ-GL12NAH
MUY-GL12NA
65 40 3/8 1/4
MUZ-GL15NA
MUZ-GL15NAH
MUY-GL15NA
65 40 1/2 1/4
MUZ-GL18NA
MUZ-GL18NAH
MUY-GL18NA
100 50 1/2 1/4
MUZ-GL24NA
MUZ-GL24NAH
MUY-GL24NA
100 50 5/8 3/8
ADDITIONAL REFRIGERANT CHARGE (R410A: oz.)
NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.
Model Outdoor unit
precharged
Refrigerant piping length (one way): ft.
25 30 40 50 60 65
MUZ-GL09NA
-
U1
MUZ-GL09NA -
U2
MUZ-GL09NAH -
U1
MUZ-GL09NAH -
U2
MUY-GL09NA -
U2
2 lb. 5 oz.
0 1.08 3.24 5.40 7.56 8.64
MUZ-GL09NA
-
U8
MUZ-GL09NAH -
U8
MUY-GL09NA -
U1
MUZ-GL12NA
MUZ-GL12NAH
MUY-GL12NA
MUZ-GL15NA
MUZ-GL15NAH
MUY-GL15NA
2 lb. 9 oz.
Calculation: X oz. = 1.08/5 oz./ft. × (Refrigerant piping length (ft.) - 25)
OBH733G

24
NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.
Model Outdoor unit
precharged
Refrigerant piping length (one way): ft.
25 30 40 50 60 70 80 90 100
MUZ-GL18NA
MUZ-GL18NAH
MUY-GL18NA
3 lb. 9 oz. 0 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
Refrigerant piping length (one way): ft.
33 40 50 60 70 80 90 100
MUZ-GL24NA
MUZ-GL24NAH
MUY-GL24NA
4 lb. 3 oz. 0 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)
DATA7
7-1. PERFORMANCE DATA
1) COOLING CAPACITY
Model
Indoor air Outdoor intake air DB temperature (˚F)
IWB (˚F) 75 85 95 105 115
TC SHC TPC TC SHC TPC TC SHC TPC TC SHC TPC TC SHC TPC
MUZ-GL09NA
MUZ-GL09NAH
MUY-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
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
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
MUZ-GL12NAH
MUY-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
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
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
MUZ-GL15NAH
MUY-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
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
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
MUZ-GL18NAH
MUY-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
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
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
MUZ-GL24NAH
MUY-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
67 26.1 19.6 1.51 24.3 18.2 1.67 22.5 16.9 1.80 20.9 15.7 1.91 19.2 14.4 2.00
63 24.5 21.7 1.44 22.7 20.1 1.59 21.2 18.7 1.72 19.2 17.0 1.84 17.6 15.5 1.91
NOTE: 1. IWB : Intake air wet-bulb temperature TC : Total Capacity (x103Btu/h)
SHC : Sensible Heat Capacity (x103Btu/h) TPC : Total Power Consumption (kW)
2. SHC is based on 80˚F of indoor Intake air DB temperature.
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
OBH733G

25
2) COOLING CAPACITY CORRECTIONS
Refrigerant piping length (one way: ft.)
25 (std.) 40 65 100
MUZ-GL09NA
MUZ-GL09NAH
MUY-GL09NA
MUZ-GL12NA
MUZ-GL12NAH
MUY-GL12NA
MUZ-GL15NA
MUZ-GL15NAH
MUY-GL15NA
1.0 0.988 0.967 -
MUZ-GL18NA
MUZ-GL18NAH
MUY-GL18NA
1.0 0.985 0.963 0.933
MUZ-GL24NA
MUZ-GL24NAH
MUY-GL24NA
1.0 0.983 0.956 0.921
3) HEATING CAPACITY CORRECTIONS
Refrigerant piping length (one way: ft.)
25 (std.) 40 65 100
MUZ-GL09NA
MUZ-GL09NAH
MUZ-GL12NA
MUZ-GL12NAH
MUZ-GL15NA
MUZ-GL15NAH
1.0 0.997 0.993 -
MUZ-GL18NA
MUZ-GL18NAH
MUZ-GL24NA
MUZ-GL24NAH
1.0 0.997 0.993 0.987
OBH733G

26
4) HEATING CAPACITY (MUZ)
Model
Indoor air Outdoor intake air WB temperature (˚F)
IDB (˚F) 5 15 25 35 43 45 55
TC TPC TC TPC 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 11.0 0.75 12.4 0.78
70 5.2 0.41 6.7 0.52 8.2 0.62 9.6 0.68 10.9 0.72 11.2 0.73 12.7 0.76
65 5.5 0.39 6.9 0.50 8.6 0.59 10.0 0.67 11.2 0.70 11.6 0.71 13.0 0.75
MUZ-GL09NAH
75 4.8 0.55 6.3 0.67 7.9 0.76 9.4 0.70 10.6 0.74 11.0 0.75 12.4 0.78
70 5.2 0.54 6.7 0.65 8.2 0.75 9.6 0.68 10.9 0.72 11.2 0.73 12.7 0.76
65 5.5 0.52 6.9 0.63 8.6 0.72 10.0 0.67 11.2 0.70 11.6 0.71 13.0 0.75
MUZ-GL12NA
75 6.3 0.65 8.4 0.82 10.4 0.96 12.5 1.07 14.0 1.13 14.5 1.14 16.4 1.19
70 6.8 0.62 8.9 0.79 10.8 0.94 12.7 1.05 14.4 1.10 14.8 1.12 16.8 1.17
65 7.2 0.59 9.1 0.76 11.3 0.91 13.2 1.02 14.8 1.07 15.3 1.09 17.1 1.14
MUZ-GL12NAH
75 6.3 0.78 8.4 0.95 10.4 1.09 12.5 1.07 14.0 1.13 14.5 1.14 16.4 1.19
70 6.8 0.75 8.9 0.92 10.8 1.07 12.7 1.05 14.4 1.10 14.8 1.12 16.8 1.17
65 7.2 0.72 9.1 0.89 11.3 1.04 13.2 1.02 14.8 1.07 15.3 1.09 17.1 1.14
MUZ-GL15NA
75 7.9 0.94 10.4 1.19 13.1 1.40 15.6 1.56 17.6 1.64 18.1 1.66 20.5 1.73
70 8.6 0.90 11.1 1.15 13.5 1.37 15.9 1.52 18.0 1.60 18.5 1.63 21.0 1.70
65 9.0 0.86 11.3 1.10 14.1 1.32 16.5 1.48 18.5 1.56 19.1 1.58 21.4 1.66
MUZ-GL15NAH
75 7.9 1.07 10.4 1.32 13.1 1.53 15.6 1.56 17.6 1.64 18.1 1.66 20.5 1.73
70 8.6 1.03 11.1 1.28 13.5 1.50 15.9 1.52 18.0 1.60 18.5 1.63 21.0 1.70
65 9.0 0.99 11.3 1.23 14.1 1.45 16.5 1.48 18.5 1.56 19.1 1.58 21.4 1.66
MUZ-GL18NA
75 9.5 0.99 12.5 1.25 15.7 1.47 18.7 1.64 21.1 1.72 21.7 1.75 24.6 1.81
70 10.3 0.95 13.3 1.21 16.2 1.44 19.1 1.60 21.6 1.68 22.2 1.71 25.2 1.78
65 10.8 0.91 13.6 1.16 17.0 1.39 19.8 1.55 22.2 1.64 22.9 1.66 25.7 1.75
MUZ-GL18NAH
75 9.5 1.12 12.5 1.38 15.7 1.60 18.7 1.64 21.1 1.72 21.7 1.75 24.6 1.81
70 10.3 1.08 13.3 1.34 16.2 1.57 19.1 1.60 21.6 1.68 22.2 1.71 25.2 1.78
65 10.8 1.04 13.6 1.29 17.0 1.52 19.8 1.55 22.2 1.64 22.9 1.66 25.7 1.75
MUZ-GL24NA
75 12.1 1.38 16.0 1.74 20.0 2.05 23.9 2.28 26.9 2.40 27.7 2.43 31.5 2.53
70 13.1 1.32 17.0 1.68 20.7 2.00 24.4 2.22 27.6 2.34 28.4 2.39 32.2 2.48
65 13.8 1.26 17.4 1.61 21.7 1.93 25.3 2.16 28.4 2.28 29.3 2.32 32.8 2.43
MUZ-GL24NAH
75 12.1 1.38 16.0 1.74 20.0 2.05 23.9 2.28 26.9 2.40 27.7 2.43 31.5 2.53
70 13.1 1.32 17.0 1.68 20.7 2.00 24.4 2.22 27.6 2.34 28.4 2.39 32.2 2.48
65 13.8 1.26 17.4 1.61 21.7 1.93 25.3 2.16 28.4 2.28 29.3 2.32 32.8 2.43
NOTE: 1. IDB : Intake air dry-bulb temperature
TC : Total Capacity (x103Btu/h) TPC : Total Power Consumption (kW)
2. Above data is for heating operation without any frost.
How to operate with fixed operational frequency of the compressor.
1. Press the EMERGENCY OPERATION switch on the front of the indoor unit, and select either EMERGENCY COOL
mode or EMERGENCY HEAT mode before starting to operate the air conditioner.
2. The compressor starts with operational frequency.
3. The fan speed of the indoor unit is High.
4. This operation continues for 30 minutes.
5. In order to release this operation, press the EMERGENCY OPERATION switch or press any button on the remote con-
troller.
OBH733G

27
7-2. PERFORMANCE CURVE
Cooling
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.
MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA
Cooling capacity ( at Rated frequency)
0.9
1.0
1.1
1.2
1.3
1.4
1.5
14 23 32 41 50 59 68 77 86 95 104 113
Outdoor intake air DB temperature(°F)
Capacity correction factors
79
75
68
64
72
Indoor intake air Wet-bulb
temperature( F)
71
67
63
65 75 85 95 105 115
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
Indoor intake air WB temperature (°F)
SHF at rating condition = 0.87
= 646 CFM
Airflow
Outdoor intake air DB temperature (°F)
Total power consumption
(kW)
71
67
63
65 75 85 95 105 115
0.6
0.7
0.8
0.9
1.0
1.1
Indoor intake air WB temperature (°F)
SHF at rating condition = 0.77
= 399 CFM
Airflow
Outdoor intake air DB temperature (°F)
Total power consumption
(kW)
71
67
63
65 75 85 95 105 115
0.2
0.3
0.4
0.5
0.6
0.7
Indoor intake air WB temperature (°F)
SHF at rating condition = 0.82
= 399 CFM
Airflow
Outdoor intake air DB temperature (°F)
Total power consumption
(kW)
71
67
63
65 75 85 95 105 115
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
Indoor intake air WB temperature (°F)
SHF at rating condition = 0.78
= 533 CFM
Airflow
Outdoor intake air DB temperature (°F)
Total power consumption
(kW)
MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA
71
67
63
65 75 85 95 105 115
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
Indoor intake air WB temperature (°F)
SHF at rating condition = 0.75
= 634 CFM
Airflow
Outdoor intake air DB temperature (°F)
Total power consumption
(kW)
MUZ-GL12NA MUZ-GL12NAH MUY-GL12NA
MUZ-GL09NA MUZ-GL09NAH MUY-GL09NA
MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA
OBH733G

29
MUZ-GL18NA
MUZ-GL24NA
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.
75
70
65
-5 5 15 25 35 45 55 65
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Indoor intake air DB temperature (°F)
= 646 CFM
Airflow
Outdoor intake air WB temperature (°F)
Total power consumption
(kW)
MUZ-GL18NAH
65
70
75
-5 5 15 25 35 45 55 65
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Indoor intake air DB temperature (°F)
= 646 CFM
Airflow
Outdoor intake air WB temperature (°F)
Total power consumption
(kW)
75
70
65
0 10 20 30 40 50 60 70
1.0
1.4
1.8
2.2
2.6
3.0
Indoor intake air DB temperature (°F)
= 738 CFM
Airflow
Outdoor intake air WB temperature (°F)
Total power consumption
(kW)
MUZ-GL24NAH
65
70
75
0 10 20 30 40 50 60 70
1.0
1.4
1.8
2.2
2.6
3.0
Indoor intake air DB temperature (°F)
= 738 CFM
Airflow
Outdoor intake air WB temperature (°F)
Total power consumption
(kW)
OBH733G

31
MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA
MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA
65 70 75 80 85 90 95 100 105
200
250
300
350
400
450
500
(°F) (°F)
65 70 75 80 85 90 95 100 105
80
100
120
140
160
180
(PSIG)
Condensing pressure
Suction pressure
Outdoor ambient temperature
Indoor DB temperature (°F)
(PSIG)
Indoor DB temperature (°F)
Outdoor ambient temperature
86
80
75
70
86
80
75
70
(PSIG)
6870 75 80 85 90 95 100 105(°F)
270
300
330
360
390
420
450
480
(PSIG)
6870 75 80 85 90 95 100 105(°F)
110
120
130
140
150
160
170
180
Condensing pressure
86
80
75
70
Suction pressure
Indoor DB temperature (°F)
Outdoor ambient temperature
86
80
75
70
Indoor DB temperature (°F)
Outdoor ambient temperature
OBH733G

33
MUZ-GL15NA MUZ-GL15NAH
75
70
65
75
70
65
(PSIG)
Condensing pressure
Outdoor ambient temperature
(°F) (°F)
(PSIG)
Suction pressure
Outdoor ambient temperature
5 15 25 35 45 55 65 75
250
300
350
400
450
500
58Hz
Indoor DB temperature (°F)
5 15 25 35 45 55 65 75
40
65
90
115
140
165
190
Indoor DB temperature (°F)
58Hz
MUZ-GL18NA MUZ-GL18NAH
MUZ-GL24NA MUZ-GL24NAH
75
70
65
75
70
65
(PSIG)
Condensing pressure
Outdoor ambient temperature
(°F) (°F)
(PSIG)
Suction pressure
Outdoor ambient temperature
5 15 25 35 45 55 65 75
250
300
350
400
450
500
550
81Hz
Indoor DB temperature (°F)
5 15 25 35 45 55 65 75
50
75
100
125
150
175
200
Indoor DB temperature (°F)
81Hz
5 15 25 35 45 55 65 75(°F) 75(°F)
250
275
300
325
350
375
400
425
450
5 15 25 35 45 55 65
50
70
90
110
130
150
170
190
210
Indoor DB temperature (°F)
Condensing pressure
Outdoor ambient temperature
(PSIG) (PSIG)
75
70
65
58Hz
Indoor DB temperature (°F)
Suction pressure
Outdoor ambient temperature
75
70
65
58Hz
OBH733G

36
Model MSZ-GL18NA MSY-GL18NA MSZ-GL24NA MSY-GL24NA
Item Unit Cooling Heating Cooling Cooling Heating Cooling
Total
Capacity Btu/h 18,000 21,600 18,000 22,500 27,600 22,500
SHF — 0.87 — 0.87 0.75 — 0.75
Input kW 1.34 1.68 1.34 1.80 2.34 1.80
Rated Hz 69 81 69 67.5 82.0 67.5
Electrical circuit
Indoor unit MSZ-GL18NA MSY-GL18NA MSZ-GL24NA MSY-GL24NA
Power supply V, phase, Hz 208/230, 1, 60 208/230, 1, 60 208/230, 1, 60 208/230, 1, 60
Input kW 0.045 0.045 0.058 0.058
Fan motor current A 0.46/0.42 0.46/0.42 0.56/0.51 0.56/0.51
Outdoor unit MUZ-GL18NA
MUZ-GL18NAH
MUY-GL18NA
MUZ-GL24NA
MUZ-GL24NAH
MUY-GL24NA
Power supply V, phase, Hz 208/230, 1, 60 208/230, 1, 60 208/230, 1, 60 208/230, 1, 60
Input kW 1.295 1.635 1.295 1.742 2.282 1.742
Comp. current A 5.01/4.53 6.67/6.03 5.01/4.53 7.01/6.34 9.59/8.67 7.01/6.34
Fan motor current A 1.05/0.95 1.05/0.95 1.05/0.95 1.16/1.05 1.13/1.02 1.16/1.05
Refrigerant circuit
Condensing pressure PSIG 377 391 377 395 405 395
Suction pressure PSIG 144 103 144 141 102 141
Discharge temperature ˚F 149 178 149 158 171 158
Condensing temperature ˚F 111 111 111 115 115 115
Suction temperature ˚F 51 43 51 52 33 52
Comp. shell bottom temperature ˚F 134 160 134 140 148 140
Ref. pipe length ft. 25 25 25 25
Refrigerant charge (R410A) 3 lb 9 oz. 3 lb 9 oz. 4 lb 3 oz. 4 lb 3 oz.
Indoor unit
Intake air temperature DB ˚F 80 70 80 80 70 80
WB ˚F 67 60 67 67 60 67
Discharge air temperature DB ˚F 52 111 52 56 111 56
WB ˚F 51 — 51 53 — 53
Fan speed (High) rpm 1,170 1,170 1,170 1,300 1,300 1,300
Airow (High) CFM 581 (Wet) 646 581 (Wet) 634 (Wet) 738 634 (Wet)
Outdoor unit
Intake air temperature DB ˚F 95 47 95 95 47 95
WB ˚F — 43 — — 43 —
Fan speed rpm 810 810 810 840 810 840
Airow CFM 1,691 1,691 1,691 1,769 1,701 1,769
OBH733G

38
MUZ-GL24NA MUZ-GL24NAH MUY-GL24NA MUZ-GL24NA MUZ-GL24NAH
Capacity correction factors Capacity correction factors
Correction of Cooling capacity
The operational frequency of compressor
Correction of Cooling total input
The operational frequency of compressor
Correction of Heating total input
The operational frequency of compressor
Correction of Heating capacity
The operational frequency of compressor
0 50 100 150(Hz)
0.5
1.0
1.5
0 50 100 150(Hz)
0.5
1.0
1.5
2.0
2.5
0 50 100 150(Hz)
0.5
1.0
1.5
0 50 100 150(Hz)
0.5
1.0
1.5
2.0
Capacity correction factors
Input correction factors
Input correction factors
Capacity correction factors
Correction of Cooling capacity
The operational frequency of compressor
Correction of Cooling total input
The operational frequency of compressor
Correction of Heating total input
The operational frequency of compressor
Correction of Heating capacity
The operational frequency of compressor
(Hz) (Hz) (Hz) (Hz)
030 60 90 120 150
0.5
1.0
1.5
2.0
030 60 90 120 150
0.5
1.0
1.5
2.0
030 60 90 120 150
0.5
1.0
1.5
2.0
030 60 90 120 150
0.5
1.0
1.5
2.0
MUZ-GL18NA MUZ-GL18NAH MUY-GL18NA MUZ-GL18NA MUZ-GL18NAH
Capacity correction factors
Input correction factors
Input correction factors Input correction factors
Input correction factors
Capacity correction factors
Correction of Cooling capacity
The operational frequency of compressor
Correction of Cooling total input
The operational frequency of compressor
Correction of Heating total input
The operational frequency of compressor
Correction of Heating capacity
The operational frequency of compressor
(Hz) (Hz) (Hz) (Hz)
0 25 50 75 100
0.5
1.0
1.5
2.0
0 25 50 75 100
0.5
1.0
1.5
2.0
0 50 100 150
0.5
1.0
1.5
2.0
0 50 100 150
0.5
1.0
1.5
2.0
MUZ-GL15NA MUZ-GL15NAH MUY-GL15NA MUZ-GL15NA MUZ-GL15NAH
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.
OBH733G

39
8ACTUATOR CONTROL
8-2. R.V. COIL CONTROL (MUZ)
Heating ................. ON
Cooling ................. OFF
Dry .................... OFF
NOTE: The 4-way valve reverses for 5 seconds right before startup of the compressor.
ON
OFF
ON
OFF
Outdoor fan
motor
Compressor
5 seconds 15 seconds
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.
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
Cooling: Coil frost prevention ○
Heating: High pressure protection ○ ○
Defrost thermistor (MUZ) Heating: Defrosting ○ ○ ○ ○ ○
Fin temperature thermistor Protection ○ ○
Ambient temperature
thermistor
Cooling: Low ambient temperature operation ○ ○ ○
Heating: Defrosting (Heater) ○
Outdoor heat exchanger tem-
perature thermistor
Cooling: Low ambient temperature operation ○ ○ ○
Cooling: High pressure protection ○ ○ ○
*. MUZ-GL•NAH only.
ON
OFF
Compressor
Outdoor fan
motor
R.V.coil ON
OFF
ON
OFF
<COOL>
5 seconds
<HEAT>
5 seconds
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
OBH733G

40
SERVICE FUNCTIONS
9
9-1. CHANGE IN DEFROST SETTING (MUZ)
Changing defrost finish temperature
<JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board (Refer to 10-6.1.).
Jumper
Defrost nish temperature
MUZ-GL09/12/15NA
MUZ-GL09/12/15NAH
MUZ-GL18/24NA
MUZ-GL18/24NAH
JS
Soldered
(Initial setting) 41°F (5°C) 50°F (10°C)
None
(Cut) 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 startup of the compressor at low outside tempera-
ture. The pre-heat control prevents this interference. The pre-heat control turns ON when the discharge temperature ther-
mistor 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 startup 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
Pre-heat control setting
MUZ-GL09/12/15/18NA
MUZ-GL09/12/15/18NAH
MUZ-GL24NA
MUZ-GL24NAH
JK
Soldered Deactivated
(Initial setting) Deactivated
Cut Activated Activated
(Initial setting)
NOTE: When the inverter P.C. board is replaced, check the JK wire, and cut/solder them if necessary.
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
OBH733G

41
10 TROUBLESHOOTING
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 con-
firming 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.
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.
Lead wiring
<Incorrect>
Connector housing
<Correct>
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
OBH733G