Mitsubishi Mr.Slim MSZ-FE09NA Service manual

Revision A:
• MUZ-FE18NA has been added.
Please void OBH543.
SPLIT-TYPE AIR CONDITIONERS
OUTDOOR UNIT
SERVICE MANUAL
HFC
utilized
No. OBH543
REVISED EDITION-A
R410A
Models
MUZ-FE09NA
MUZ-FE12NA
MUZ-FE18NA
Indoor unit service manual
MSZ-FE•NA Series (OBH542)
CONTENTS
1. TECHNICAL CHANGES ··································· 2
2. PART NAMES AND FUNCTIONS ····················· 2
3. SPECIFICATION ················································ 3
4. OUTLINES AND DIMENSIONS ························ 5
5. WIRING DIAGRAM············································ 6
6. REFRIGERANT SYSTEM DIAGRAM ··············· 7
7. DATA ·································································· 9
8. ACTUATOR CONTROL ··································· 16
9. SERVICE FUNCTIONS ··································· 17
10. TROUBLESHOOTING ····································· 17
11. DISASSEMBLY INSTRUCTIONS ···················· 36
PARTS CATALOG (OBB543)
MUZ-FE09NA
MUZ-FE12NA
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
TM
Revision A:
• MUZ-FE18NA has been added.
1
TECHNICAL CHANGES
MUZ-FE09NA
MUZ-FE12NA
MUZ-FE18NA
1. New model
2
PART NAMES AND FUNCTIONS
MUZ-FE09NA MUZ-FE12NA
Air inlet
(back and side)
Piping
Drain hose
Air outlet
Drain outlet
MUZ-FE18NA
Air inlet
(back and side)
Piping
Drain hose
Air outlet
Drain outlet
2
3
SPECIFICATION
Outdoor unit model
Cooling 1
Heating 47
Heating 17
Capacity Rated
Power consumption Cooling 1
Rated (Minimum~Maximum)
Heating 47
Power consumption Rated Heating 17
EER 1 [SEER] 3 Cooling
HSPF IV 4
Heating
Capacity
Rated (Minimum~Maximum)
COP
Heating 1
Power supply
Max. fuse size (time delay)
Min. circuit ampacity
Fan motor
Model
Compressor
Btu/h
Btu/h
Btu/h
W
W
W
1
2
1
2
MUZ-FE09NA
MUZ-FE12NA
MUZ-FE18NA
9,000 (2,800~9,000)
10,900 (3,000~18,000)
12,500
580 (160~650)
710 (150~2,250)
1,730
15.5 [26.0]
10.0
4.50
12,000 (2,800~12,000)
13,600 (3,000~21,000)
13,600
930 (160~960)
950 (150~2,250)
1,780
12.9 [23.0]
10.6
4.20
208/230, 1 , 60
18,000 (8,200~25,200)
21,600 (7,500~29,700)
19,300
1,270 (570~2,280)
1,540 (520~2,420)
2,180
14.2 [20.2]
10.3
4.11
V , phase , Hz
A
A
F.L.A
R.L.A
L.R.A
Refrigeration oil L (Model)
Refrigerant control
Sound level 1
Cooling
Heating
dB(A)
dB(A)
W
D
H
in.
in.
in.
Ib.
48
49
Defrost method
Dimensions
Weight
External finish
Remote controller
Control voltage (by built-in transformer)
Refrigerant piping
Liquid
Refrigerant pipe size
(Min. wall thickness)
Gas
Indoor
Connection method
Outdoor
Between the indoor Height difference
& outdoor units
Piping length
Refrigerant charge (R410A)
VDC
in.
in.
ft.
ft.
15
12
0.56
SNB130FQAH
8.6
10.8
0.45 (NEO22)
Linear expansion valve
48
49
Reverse cycle
31-1/2
11-1/4
21-5/8
80
Munsell 3Y 7.8/1.1
Wireless type
12 - 24
Not supplied
1/4 (0.0315)
3/8 (0.0315)
Flared
Flared
40
65
2 lb. 9 oz.
20
17.1
0.93
SNB172FQKMT
12.9
16.1
0.40 (FV50S)
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
Rated frequency
Rated frequency
Maximum frequency
55
55
33-1/16
13
34-5/8
119
3/8 (0.0315)
5/8 (0.0315)
Flared
Flared
50
100
4 lb. 3 oz.
Test condition
3, 4
ARI
Mode
Indoor air condition (°F)
Dry bulb
Wet bulb
Test
Outdoor air condition (°F)
Dry bulb
Wet bulb
"A-2" Cooling Steady State
at rated compressor Speed
80
67
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
5: At Intermediate compressor Speed
= ("Cooling rated compressor speed" - "minimum compressor speed") / 3 + "minimum compressor speed".
OPERATING RANGE
(1) POWER SUPPLY
Rated voltage
Outdoor unit
Guaranteed voltage (V)
208/230 V
1 phase
60 Hz
Min. 187
208
230
Max. 253
(2) OPERATION
Intake air temperature (°F)
Mode
Condition
Standard temperature
Maximum temperature
Cooling
Minimum temperature
Maximum humidity
Standard temperature
Heating Maximum temperature
Minimum temperature
Indoor
Outdoor
DB
80
90
67
WB
67
73
57
DB
95
115
14
60
67
60
47
75
-13
78 %
WB
—
—
—
—
70
80
70
4
43
65
-15
4
OUTLINES AND DIMENSIONS
Unit: inch
MUZ-FE09NA MUZ-FE12NA
1-3/4
15-3/4
REQUIRED SPACE
Drain hole
1-5/8
4 in
4 in
. or
re
29/32
8
11-1/4
rm
in. o
Open two sides of left,
right, or rear side.
Liquid pipe
Gas pipe
5-7/8
2
11-1/32
handle
11-29/32
5-15/16
:1/4 (flared)
:3/8 (flared)
6-23/32
19-11/16
31-1/2
2-23/32
20 in. or more
13/32
14
ore
13/16 Oval hole
REQUIRED SPACE
MUZ-FE18NA
16-7/16
Drain hole
1-9/16
1-5/8
4 in
. or
.
4 in
mo
2
13
Air out
re
or
in.
20
2-holes 13/32 13/16
6-7/8
19-11/16
33-1/16
4-5/16
re
14
mo
in.
or m
ore
3-3/16
Service panel
35
17-25/32
34-5/8
Liquid refrigerant
pipe joint
Refrigerant pipe
(flared) Ø 3/8
6-1/2
3-29/32
44
7-11/16
5
Gas refrigerant
pipe joint
Refrigerant pipe
(flared) Ø 5/8
ore
or m
14-3/16
Air in
e
mor
mo
1-9/16
2- 3/8
7/8
. or
13-9/16
11/16
Air out
12 ~ 12-3/4
Air in
Air in
21-5/8
Basically open 4 inch or more
without any obstruction in front
and on both sides of the unit.
in.
or m
ore
5
WIRING DIAGRAM
MUZ-FE09NA MUZ-FE12NA
MUZ-FE18NA
6
6
REFRIGERANT SYSTEM DIAGRAM
Unit: inch
MUZ-FE09NA MUZ-FE12NA
Refrigerant pipe ø3/8
(with heat insulator)
4-way valve
Muffler
Stop valve
(with service port)
Discharge
temperature
thermistor
RT62
Service
port
Flared connection
Outdoor
heat
exchanger
Muffler
Service
port
Outdoor heat
exchanger
temperature
thermistor
RT68
Ambient
temperature
thermistor
RT65
Compressor
Defrost
thermistor
RT61
Capillary tube
O.D. 0.118 × I.D. 0.071
× 23-5/8
(ø3.0 × ø1.8 × 600)
Expansion
valve
Flared connection
Stop valve
(with strainer)
Refrigerant pipe ø1/4
(with heat insulator)
Strainer
#100
R.V. coil
heating ON
cooling OFF
Capillary tube
O.D. 0.118 × I.D. 0.079× 9-7/16
Refrigerant flow in cooling
Refrigerant flow in heating
(ø3.0 × ø2.0 × 240)
MUZ-FE18NA
Refrigerant pipe ø5/8
(with heat insulator)
Muffler
4-way valve #100
Service
port
Stop valve
(with service port)
Flared connection
Discharge
temperature
Service thermistor
RT62
Defrost
thermistor
RT61
port
Outdoor
heat
exchanger
Ambient
temperature
thermistor
RT65
Compressor
Outdoor heat
exchanger
temperature
thermistor
RT68
Flared connection
LEV
Strainer
#100
Stop valve
Refrigerant pipe ø3/8
(with heat insulator)
Strainer
#100
Capillary tube
R.V. coil
heating ON
cooling OFF
O.D. 0.157 × I.D. 0.094× 3-15/16
(ø4.0×ø2.4×100)
7
Refrigerant flow in cooling
Refrigerant flow in heating
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE
Model
MUZ-FE09NA
MUZ-FE12NA
MUZ-FE18NA
Refrigerant piping: ft.
Max. Length
Max. Height difference
A
B
Piping size O.D: in.
Gas
Liquid
65
40
3/8
1/4
100
50
5/8
3/8
Indoor
unit
Max. Height
difference
B
Max. Length
A
Outdoor unit
ADDITIONAL REFRIGERANT CHARGE (R410A: oz.)
NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.
Model
Outdoor unit precharged
MUZ-FE09NA
MUZ-FE12NA
2 lb. 9 oz.
Refrigerant piping length (one way): ft.
30
40
50
60
25
0
1.62
4.86
8.10
11.34
65
12.96
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
MUZ-FE18NA
4 lb. 3 oz.
33
0
40
4.14
Refrigerant piping length (one way): ft.
50
60
70
80
10.06
15.98
21.90
27.82
90
33.74
100
39.66
Calculation: X oz. = 2.96/5 oz. / ft. × (Refrigerant piping length (ft.) - 33)
8
7
DATA
MUZ-FE09NA MUZ-FE12NA MUZ-FE18NA
7-1. PERFORMANCE DATA
1) COOLING CAPACITY
Indoor air
Model
MUZ-FE09NA
MUZ-FE12NA
MUZ-FE18NA
IWB (˚F)
71
67
63
71
67
63
71
67
63
TC
11.0
10.4
9.8
14.7
13.9
13.1
22.1
20.9
19.6
75
SHC
6.9
7.9
8.8
8.8
10.2
11.3
15.6
17.5
19.1
TPC
0.58
0.55
0.52
0.85
0.81
0.77
1.13
1.07
1.02
TC
10.3
9.7
9.1
13.7
13.0
12.1
20.6
19.4
18.2
Outdoor intake air DB temperature (˚F)
85
95
105
SHC TPC TC SHC TPC TC SHC
6.5 0.63 9.7
6.1 0.68 9.0
5.6
7.4 0.60 9.0
6.8 0.65 8.4
6.4
8.1 0.58 8.5
7.6 0.62 7.7
6.9
8.2 0.94 12.9 7.7 1.01 12.0 7.2
9.5 0.89 12.0 8.8 0.96 11.2 8.1
10.5 0.85 11.3 9.7 0.92 10.3 8.9
14.6 1.24 19.4 13.7 1.33 18.0 12.7
16.3 1.17 18.0 15.1 1.27 16.7 14.1
17.7 1.12 16.9 16.5 1.21 15.4 15.0
TPC
0.72
0.69
0.66
1.06
1.02
0.98
1.40
1.35
1.30
115
TC SHC TPC
8.3
5.2 0.75
7.7
5.8 0.72
7.0
6.3 0.69
11.0 6.6 1.10
10.3 7.5 1.07
9.4
8.1 1.02
16.6 11.7 1.46
15.4 12.9 1.41
14.0 13.7 1.35
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.
2) COOLING CAPACITY CORRECTIONS
Refrigerant piping length (one way: ft.)
25 (std.)
40
65
100
MUZ-FE09NA
MUZ-FE12NA
1.0
0.954
0.878
-
MUZ-FE18NA
1.0
0.954
0.878
0.771
3) HEATING CAPACITY
Indoor air
Model
MUZ-FE09NA
MUZ-FE12NA
MUZ-FE18NA
IDB (˚F)
75
70
65
75
70
65
75
70
65
5
TC
4.8
5.2
5.5
6.0
6.5
6.8
9.5
10.3
10.8
15
TPC
0.44
0.42
0.41
0.58
0.55
0.53
0.91
0.87
0.83
TC
6.3
6.7
6.9
7.9
8.4
8.6
12.5
13.3
13.6
TPC
0.56
0.54
0.52
0.73
0.71
0.68
1.15
1.11
1.06
Outdoor intake air WB temperature (˚F)
25
35
43
TC TPC TC TPC TC TPC
7.9 0.66 9.4 0.73 10.6 0.77
8.2 0.64 9.6 0.71 10.9 0.75
8.6 0.62 10.0 0.69 11.2 0.73
9.9 0.86 11.8 0.96 13.3 1.00
10.2 0.84 12.0 0.93 13.6 0.98
10.7 0.81 12.4 0.91 14.0 0.96
15.7 1.35 18.7 1.50 21.1 1.58
16.2 1.32 19.1 1.46 21.6 1.54
17.0 1.27 19.8 1.42 22.2 1.50
45
TC
11.0
11.2
11.6
13.7
14.0
14.4
21.7
22.2
22.9
55
TPC
0.78
0.77
0.74
1.02
1.00
0.97
1.60
1.57
1.52
TC
12.4
12.7
13.0
15.5
15.8
16.2
24.6
25.2
25.7
TPC
0.81
0.80
0.78
1.06
1.04
1.02
1.66
1.63
1.60
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.
How to operate with fixed operational frequency of the compressor.
1. Press the EMERGENCY OPERATION switch on the front of the indoor unit, and select either EMERGENCY COOL
mode or EMERGENCY HEAT mode before starting to operate the air conditioner.
2. The compressor starts with operational frequency.
3. The fan speed of the indoor unit is High.
4. This operation continues for 30 minutes.
5. In order to release this operation, press the EMERGENCY OPERATION switch twice or once, or press any button on
the remote controller.
9
7-2. PERFORMANCE CURVE
Cooling
Capacity correction factors
Indoor air Wet-bulb temperature
difference (°F)
Cooling capacity (at Rated frequency)
1.5
Indoor intake air Wet-bulb
temperature( F)
1.4
1.3
1.2
76
1.1
75
1.0
0.9
14
23
32
41
50
59
68
77
86
95
104
72
68
64
113
Outdoor intake air Dry-bulb temperature(°F)
MUZ-FE12NA
SHF at rating condition = 0.76
Airflow = 307 CFM
0.8
(°F)
rature
0.7
ke air
or inta
Indo
0.6
mpe
WB te
71
67
63
0.5
65
75
85
95
105
115
Outdoor intake air DB temperature (°F)
Total power consumption
(kW)
Total power consumption
(kW)
MUZ-FE09NA
1.3
SHF at rating condition = 0.73
Airflow = 350 CFM
1.2
1.0
0.9
ke air
r inta
Indoo
emp
WB t
)
re (°F
eratu
1.1
71
67
63
0.8
0.7
65
75
85
95
105
Outdoor intake air DB temperature (°F)
115
Total power consumption
(kW)
MUZ-FE18NA
SHF at rating condition = 0.84
Airflow = 634 CFM
1.5
71
67
63
1.4
1.3
1.2
r intak
Indoo
1.0
0.9
65
B te
e air W
°F)
ture (
mpera
1.1
70
75
80
85
90
95 100 105 110 115
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.
10
Heating
Heating capacity (at Rated frequency)
Capacity correction factor
Indoor air Dry-bulb temperature
difference (°F)
1.3
1.2
e(
tur
1.1
ra
pe
1.0
lb
bu
0.9
0.8
ir
ea
ak
t
r in
yDr
F)
59
68
79
tem
oo
Ind
0.7
0.6
0.5
0.4
-4
5
14
23
32
41
50
Outdoor intake air Wet-bulb temperature (°F)
MUZ-FE12NA
Airflow = 381 CFM
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
75
70
65
air
take
or in
Indo
-5
DB
per
tem
°F)
e(
atur
5
15
25
35
45
55
Outdoor intake air WB temperature (°F)
65
Total power consumption
(kW)
Total power consumption
(kW)
MUZ-FE09NA
-15
59
Airflow = 420 CFM
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
-15
-5
(°F)
ta
or in
Indo
ture
ra
mpe
B te
ir D
ke a
75
70
65
5
15
25
35
45
55
Outdoor intake air WB temperature (°F)
65
MUZ-FE18NA
Total power consumption
(kW)
Airflow = 738 CFM
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
-15
oor
Ind
-5
5
re
atu
per
tem
DB
ir
a
ke
inta
15
25
35
75
70
65
)
(°F
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.
11
7-3. CONDENSING PRESSURE
Cooling
Data is based on the condition of indoor humidity 50 %.
Air flow should be set to High speed.
MUZ-FE09NA
(PSIG)
580
500
460
420
)
(°F
ture
380
oor
Ind
340
DB
86
80
75
70
a
per
tem
300
260
68 70
75
80
85
90
95
100
105(°F)
(PSIG)
180
175
170
165
160
155
150
145
140
135
130
125
120
68 70
rature (°F)
Indoor DB tempe
86
Suction pressure
Condensing pressure
540
Outdoor ambient temperature
80
75
70
75
80
85
90
95
Outdoor ambient temperature
100
105(°F)
MUZ-FE12NA
(PSIG)
580
500
460
86
80
75
70
F)
(°
ture
era
420
B
D
oor
Ind
380
p
tem
340
300
260
68 70
75
80
85
90
95
100
105(°F)
(PSIG)
180
175
170
165
160
155
150
145
140
135
130
125
120
68 70
rature (°F)
Indoor DB tempe
Suction pressure
Condensing pressure
540
Outdoor ambient temperature
86
80
75
70
75
80
85
90
95
Outdoor ambient temperature
100
105(°F)
MUZ-FE18NA
(PSIG)
480
86
80
75
70
(PSIG)
190
360
)
oor
Ind
280
m
B te
°F
re (
atu
per
320
240
68 70
86
180
400
Suction pressure
Condensing pressure
440
D
80
170
160
75
150
70
140
rature (°F)
Indoor DB tempe
130
120
75
80
85
90
95
100 105(°F)
110
68 70
75
80
85
90
95
Outdoor ambient temperature
Outdoor ambient temperature
12
100
105(°F)
Heating
Data is based on the condition of outdoor humidity 75%.
Air flow should be set to High speed.
Data is for heating operation without any frost.
MUZ-FE09NA
(PSIG)
170
75
70
65
160
I
75
70
65
)
(°F
ture
era
p
m
B te
or D
o
d
n
150
140
Suction pressure
Condensing pressure
(PSIG)
400
380
360
340
320
300
280
260
240
220
200
180
160
140
120
-15 -10 5
58Hz
130
120
110
B
rD
oo
d
In
100
90
re
tu
ra
pe
m
te
(°F
)
58Hz
80
70
60
50
40
10 15 20 25 30 35 40 45 50 55 60 65 70(°F)
-15 -10 5
10 15 20 25 30 35 40 45 50 55 60 65 70(°F)
Outdoor ambient temperature
Outdoor ambient temperature
MUZ-FE12NA
(PSIG)
400
380
360
340
320
300
280
260
240
220
200
180
160
140
(PSIG)
170
DB
oor
Ind
p
tem
150
140
Suction pressure
era
Condensing pressure
120
-15 -10 5
75
70
65
F)
(°
ture
75
70
65
160
58Hz
130
110
100
90
°F)
e(
120
pe
em
Bt
D
or
ur
rat
o
Ind
58Hz
80
70
60
50
40
10 15 20 25 30 35 40 45 50 55 60 65 70(°F)
-15 -10 5
Outdoor ambient temperature
10 15 20 25 30 35 40 45 50 55 60 65 70(°F)
Outdoor ambient temperature
MUZ-FE18NA
(PSIG)
240
(PSIG)
480
220
440
75
420
70
180
400
65
160
Suction pressure
Condensing pressure
460
380
360
340
320
ture
a
per
300
280
260
240
-15 -10 -5 0
oor
Ind
m
B te
D
)
(°F
58Hz
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75(°F)
Outdoor ambient temperature
75
70
65
200
140
120
100
80
60
rature (°F)
Indoor DB tempe
58Hz
40
20
0
-15 -10 -5 0
13
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75(°F)
Outdoor ambient temperature
7-4. STANDARD OPERATION DATA
Model
Item
Unit
Total
Capacity
Btu/h
10,900
18,000
13,600
21,600
—
0.76
—
0.73
—
0.84
—
0.580
0.710
0.930
0.950
1.800
2.200
Rated frequency
Hz
34
42
51
52.5
50.5
62.5
MSZ-FE09NA
V,
phase,
Hz
kW
Input
Fan motor current
Outdoor unit
A
MSZ-FE12NA
MSZ-FE18NA
208/230, 1, 60
0.018
0.024
0.19/0.17
0.25/0.23
MUZ-FE09NA
0.024
0.030
0.25/0.23
0.32/0.29
MUZ-FE12NA
0.058
0.56/0.51
MUZ-FE18NA
V,
phase,
Hz
kW
0.562
0.686
0.906
0.920
1.212
1.482
Comp. current
A
2.38/2.15
2.98/2.70
4.05/3.66
4.12/3.72
4.47/4.04
5.72/5.17
Fan motor current
A
1.16/1.05
1.13/1.02
Power supply
208/230, 1, 60
0.35/0.32
Condensing pressure
PSIG
376
355
402
392
373
357
Suction pressure
PSIG
154
108
148
104
151
107
Discharge temperature
˚F
142
145
160
158
150
159
Condensing temperature
˚F
112
108
117
115
111
105
Suction temperature
˚F
53
36
53
34
58
41
Comp. shell bottom temperature
˚F
144
128
146
129
132
136
Ref. pipe length
ft.
25
Refrigerant charge (R410A)
Intake air temperature
Indoor unit
12,000
kW
Input
Discharge air temperature
2 lb. 9 oz.
˚F
80
70
80
WB
˚F
67
60
DB
˚F
59
99
WB
Fan speed (High)
Intake air temperature
4 lb 3 oz.
DB
Airflow (High)
Outdoor unit
MSZ-FE18NA
Cooling
Heating
Input
Power supply
Electrical circuit
9,000
MSZ-FE12NA
Cooling
Heating
SHF
Indoor unit
Refrigerant circuit
MSZ-FE09NA
Cooling
Heating
70
80
67
60
67
60
58
101
59
102
56
˚F
56
—
55
—
rpm
1,020
1,120
1,120
1,220
70
—
1,300
CFM
307 (Wet)
381
350 (Wet)
420
634 (Wet)
738
DB
˚F
95
47
95
47
95
47
WB
˚F
—
43
—
43
—
43
Fan speed
rpm
810
870
810
870
840
810
Airflow
CFM
1,102
1,187
1,102
1,187
1,769
1,701
14
7-5. CAPACITY AND INPUT CORRECTION BY INVERTER OUTPUT FREQUENCY
MUZ-FE09NA
Correction of Cooling total input
0.5
50
100
Capacity correction factors
Input correction factors
Capacity correction factors
1.0
0
2.0
1.5
1.0
0.5
150 (Hz)
0
50
100
1.5
1.0
0.5
0
150 (Hz)
Correction of Heating total input
Correction of Heating capacity
Input correction factors
Correction of Cooling capacity
1.5
50
100
150 (Hz)
The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor
3.0
2.0
1.0
0
50
100
150 (Hz)
The operational frequency of compressor
MUZ-FE12NA
Correction of Cooling total input
0.5
50
100
150 (Hz)
Capacity correction factors
Input correction factors
Capacity correction factors
1.0
0
1.5
1.5
1.0
0.5
0
50
100
150 (Hz)
Correction of Heating capacity
1.0
0.5
0
2.5
Input correction factors
Correction of Cooling capacity
1.5
50
100
150 (Hz)
The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor
Correction of Heating total input
2.0
1.5
1.0
0.5
0
50
100
150 (Hz)
The operational frequency of compressor
MUZ-FE18NA
Input correction factors
Capacity correction factors
1.0
0.5
0
50
100
150 (Hz)
Correction of Cooling total input
1.5
1.5
1.0
0.5
0
50
100
150 (Hz)
Correction of Heating capacity
1.0
0.5
0
2.0
Input correction factors
2.0
Capacity correction factors
Correction of Cooling capacity
1.5
50
100
150 (Hz)
The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor
Correction of Heating total input
1.5
1.0
0.5
0
50
100
150 (Hz)
The operational frequency of compressor
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 varies).
6. To cancel test run operation (EMERGENCY OPERATION), press EMERGENCY OPERATION switch or any button on
remote controller.
15
8
ACTUATOR CONTROL
MUZ-FE09NA MUZ-FE12NA MUZ-FE18NA
8-1. OUTDOOR FAN MOTOR CONTROL
The fan motor turns ON/OFF, interlocking with the compressor.
[ON] The fan motor turns ON 5 seconds before the compressor starts up.
[OFF] The fan motor turns OFF 15 seconds after the compressor has stopped running.
5 seconds
15 seconds
ON
Compressor
OFF
ON
Outdoor fan
motor
OFF
8-2. R.V. COIL CONTROL
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
Compressor
ON
OFF
R.V.coil
ON
OFF
5 seconds
Outdoor fan ON
OFF
motor
8-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR
Sensor
Discharge temperature thermistor
Indoor coil temperature thermistor
Defrost thermistor
Purpose
Protection
Cooling: Coil frost prevention
Heating: High pressure protection
Cooling: High pressure protection
Heating: Defrosting
Fin temperature thermistor
Protection
Outdoor heat exchanger temperature thermistor
High pressure protection
Ambient temperature thermistor
Low ambient temperature operation
Compressor
LEV
○
○
○
○
○
○
○
○
○
○
○
○
○
○
16
Actuator
Outdoor
fan motor
○
○
○
○
R.V. coil
Indoor fan
motor
○
○
9
SERVICE FUNCTIONS
MUZ-FE09NA MUZ-FE12NA MUZ-FE18NA
9-1. CHANGE IN DEFROST SETTING
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
JS
Defrost finish temperature
MUZ-FE09/12NA
MUZ-FE18NA
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
PRE-HEAT CONTROL
When moisture gets into the refrigerant cycle, it may interfere the start-up of the compressor at low outside temperature. The pre-heat control prevents this interference. The pre-heat control turns ON when outside temperature is 68°F (20
°C) or below. When pre-heat control is turned ON, compressor is energized. (About 50 W)
<JK> To activate the pre-heat control, cut the JK wire of the inverter P.C. board (Refer to 10-6.1.).
NOTE: When the inverter P.C. board is replaced, check the Jumper wires, and cut/solder them if necessary.
10
TROUBLESHOOTING
MUZ-FE09NA MUZ-FE12NA MUZ-FE18NA
10-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, then after confirming the horizontal vane is closed, turn off the breaker and/or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
3) When removing the electrical parts, be careful of the residual voltage of smoothing capacitor.
4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
<Incorrect>
<Correct>
Lead wiring
Housing point
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.
2) Before servicing, 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.
17
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-FE09NA
MSZ-FE12NA
MSZ-FE18NA
Operational procedure
The cause of abnormality cannot be found because the abnormality does not recur.
Setting up the failure mode recall function
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button and TOO COOL button on the
remote controller at the same time, press RESET button.
First, release RESET button.
And release the other two buttons after all LCD in operation display section of the
remote controller is displayed after 3 seconds.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is
displayed) with the remote controller headed towards the indoor unit. 1
Does POWER lamp (MSZ-FE09/12NA)/the upper lamp
of OPERATION INDICATOR lamp (MSZ-FE18NA) 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 POWER lamp (MSZ-FE09/12NA)/the upper
lamp of OPERATION INDICATOR lamp (MSZFE18NA). 2
Yes
Judgment of indoor/outdoor abnormality
(Blinks)
Before blinking, does POWER lamp (MSZ-FE09/12NA)/the
upper lamp of OPERATION INDICATOR lamp (MSZ-FE18NA)
stay ON for 3 seconds?
Stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.
No
No
(OFF)
Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnormalities that can not be recalled with this way.
Confirm if outdoor unit is abnormal according to the detailed outdoor
unit failure mode recall function. (Refer to 10-2.2)
1. Regardless of normal or abnormal
condition, a short beep is emitted
once the signal is received.
Yes
The indoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the indoor unit
failure mode table. (Refer to indoor unit service manual.)
Make sure to check at least two consecutive blinking cycles. 2
The outdoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the
outdoor unit failure mode table. (Refer to 10-2.3)
Make sure to check at least two consecutive blinking cycles. 3
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 defective parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function" mentioned above.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed)
with the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function"
mentioned above.
NOTE: 1. Make sure to release the failure mode recall function once it is set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
2. Blinking pattern when the indoor unit is abnormal:
Blinking at 0.52.5-second OFF second interval
Blinking at 0.52.5-second OFF second interval
ON
OFF
Beeps
Repeated cycle
Beeps
Repeated cycle
Beeps
Repeated cycle
3.Blinking pattern when the outdoor unit is abnormal:
Blinking at 0.52.5-second OFF
3-second ON
second interval
2.5-second OFF
3-second ON
Blinking at 0.5second interval
ON
OFF
No beep
Repeated cycle
No beep
Repeated cycle
Beeps
18
Beeps
Repeated cycle
2. Flow chart of the detailed outdoor unit failure mode recall function
Operational procedure
The outdoor unit might be abnormal.
Confirm if outdoor unit is abnormal according to the following procedures.
Confirm that the remote controller is in the failure mode recall function.
With the remote controller headed towards the indoor unit, press TOO
COOL or TOO WARM button to adjust the set temperature to 77˚F (25˚C).
1
Does POWER lamp(MSZ-FE09/12NA)/the upper lamp of OPERATION INDICATOR lamp(MSZFE18NA) 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 POWER
lamp (MSZ-FE09/12NA)/the upper lamp of
OPERATION INDICATOR lamp (MSZ-FE18NA). 2
Yes
(Blinks)
1. Regardless of normal or abnormal condition, 2 short
beeps are emitted as the signal is received.
No
(OFF)
The outdoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the outdoor unit failure mode table (10-2.3.).
Make sure to check at least two consecutive blinking cycles. 2
The outdoor unit is normal.
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
Turn OFF the power supply and turn it ON again.
Press RESET button of the remote controller.
Release the failure mode recall function according to the left mentioned procedure.
Repair the defective parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function" (10-2.1.).
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with
the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function" mentioned above.
NOTE: 1. Make sure to release the failure mode recall function once it is set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
2.Blinking pattern when outdoor unit is abnormal:
2.5-second OFF
ON
OFF
3-second ON
No beep
Repeated cycle
Blinking at 0.5second interval
2.5-second OFF
3-second ON
No beep
Repeated cycle
Beeps
19
Blinking at 0.5second interval
Beeps
Repeated cycle
3. Outdoor unit failure mode table
OPERATION
INDICATOR
POWER lamp
Upper lamp
(Indoor unit)
Abnormal point
(Failure mode/protection)
OFF
None (Normal)
2-time flash
2.5 seconds
OFF
Outdoor power system
3-time flash
2.5 seconds
OFF
Discharge temperature
thermistor
Condition
—
—
1-time flash every
2.5 seconds
—
Overcurrent protection stop is
continuously performed 3 times within
1 minute after the compressor gets
started.
Thermistor shorts or opens during
compressor running.
Defrost thermistor
Fin temperature thermistor
4-time flash
2.5 seconds
OFF
LED indication
(Outdoor P.C. board)
P.C. board temperature
thermistor
Ambient temperature
thermistor
Overcurrent
3-time flash
2.5 seconds OFF
4-time flash
2.5 seconds OFF
2-time flash
2.5 seconds OFF
11-time flash
2.5 seconds OFF
Large current flows into intelligent
power module.
Compressor synchronous
12-time flash
abnormality (Compressor start- 2.5 seconds OFF
up failure protection)
Waveform of compressor current is
distorted.
5-time flash
2.5 seconds
OFF
Discharge temperature
6-time flash
2.5 seconds
OFF
High pressure
7-time flash
2.5 seconds
OFF
Fin temperature/ P.C. board
temperature
8-time flash
2.5 seconds
OFF
Outdoor fan motor
Temperature of discharge temperature
thermistor exceeds 241°F (116°C),
compressor stops.
Compressor can restart if discharge
temperature thermistor reads 212°F
(100°C) or less 3 minutes later.
Temperature of indoor coil thermistor
exceeds 158°F (70°C) in HEAT mode.
Temperature of defrost thermistor
exceeds 158°F (70°C) in COOL mode.
Temperature of fin temperature
thermistor on the inverter P.C. board
exceeds 167 ~ 176°F (75 ~ 80°C), or
temperature of P.C. board temperature
thermistor on the inverter P.C. board
exceeds 158 ~ 167°F (70 ~ 75°C).
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor fan
start-up.
9-time flash
2.5 seconds
OFF
Nonvolatile memory data
—
—
7-time flash
2.5 seconds OFF
—
MUZ-FE18NA
Power module
10-time flash Discharge temperature
2.5 seconds
OFF
11-time flash DC voltage
2.5 seconds
OFF
Each phase current of
compressor
12-time flash Overcurrent Compressor open2.5 seconds phase
OFF
14-time flash Stop valve (Closed valve)
2.5 seconds
OFF
5-time flash
2.5 seconds OFF
6-time flash
2.5 seconds OFF
—
8-time flash
2.5 seconds OFF
9-time flash
2.5 seconds OFF
10-time flash
2.5 seconds OFF
14-time flash
2.5 seconds OFF
Nonvolatile memory data cannot be
read properly.
The interphase short circuit occurs
in the output of the intelligent power
module (IPM).
The compressor winding shorts circuit.
Temperature of discharge temperature
thermistor has been 122°F (50°C) or
less for 20 minutes.
DC voltage of inverter cannot be
detected normally.
Each phase current of compressor
cannot be detected normally.
Large current flows into intelligent
power module (IPM).
The open-phase operation of
compressor is detected.
The interphase short circuit occurs
in the output of the intelligent power
module (IPM).
The compressor winding shorts circuit.
Remedy
—
—
—
○
○
○
○
—
○
—
○
• Check refrigerant circuit
and refrigerant amount.
• Refer to 10-5. "Check
of LEV".
—
○
• Check refrigerant circuit
and refrigerant amount.
• Check stop valve.
—
○
—
○
—
○
○
○
• Reconnect connectors.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check stop valve.
• Refer to 10-5. "Check
of outdoor thermistors".
Defective outdoor
thermistors can be
identified by checking
the blinking pattern of
LED.
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check stop valve.
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check around outdoor
unit.
• Check outdoor unit air
passage.
• Refer to 10-5. "Check
of outdoor fan motor".
• Refer to 10-5. "Check
of outdoor fan motor".
Refer to 10-5. "Check
of inverter P.C. board".
• Replace the inverter
P.C. board.
• Refer to 10-5. "How
to check inverter/
compressor".
• Refer to 10-5. "Check
of LEV".
• Check refrigerant circuit
and refrigerant amount.
• Refer to 10-5. "How
to check inverter/
compressor".
—
○
—
○
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
—
○
○
○
Closed valve is detected by compressor • Check stop valve
current.
NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-3.).
OPERATION INDICATOR
POWER lamp: MSZ-FE09/12NA
Upper lamp: MSZ-FE18NA
20
Indoor/
unit
outdoor unit Outdoor
failure mode
failure mode recall
function
recall function
10-3. TROUBLESHOOTING CHECK TABLE
No.
1
Abnormal point/ ConCondition
dition
Outdoor unit 1-time flash every Outdoor power sys- Overcurrent protection stop is continuously performed 3 times
does not oper- 2.5 seconds
tem
within 1 minute after the compressor gets started, or failure of
ate.
restart of compressor has repeated 24 times.
Symptom
LED indication
Outdoor thermistors Discharge temperature thermistor, fin temperature thermistor,
defrost thermistor, outdoor heat exchanger temperature thermistor, P.C. board temperature thermistor or ambient temperature thermistor shorts or opens during compressor running.
2
3
6-time flash
2.5 seconds OFF
11-time flash
2.5 seconds OFF
14-time flash
2.5 seconds OFF
4
5
6
7
8
'Outdoor unit 2-time flash
stops and
2.5 seconds OFF
restarts 3 minutes later' is
repeated.
3-time flash
2.5 seconds OFF
4-time flash
2.5 seconds OFF
9
10
5-time flash
2.5 seconds OFF
11
8-time flash
2.5 seconds OFF
12
10-time flash
2.5 seconds OFF
13
14
unit
15 Outdoor
operates.
12-time flash
2.5 seconds OFF
13-time flash
2.5 seconds OFF
1-time flash
2.5 seconds OFF
3-time flash
2.5 seconds OFF
16
17
4-time flash
2.5 seconds OFF
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.
tem
[POWER lamp (MSZ-FE09/12NA)/the upper lamp of OPERATION INDICATOR lamp (MSZ-FE18NA) of the indoor unit
lights up or flashes 7 times.]
Serial signal
The communication fails between the indoor and outdoor unit
for 3 minutes.
Stop valve/
Closed valve is detected by compressor current.
Closed valve
Outdoor unit
Outdoor unit is defective.
(Other abnormality)
• Replace inverter P.C. board.
Overcurrent protection
• Reconnect connector of compressor.
• Refer to 10-5. "How to check inverter/compressor".
• Check stop valve.
• Check refrigerant circuit and refrigerant amount.
• Refer to 10-5. "Check of LEV".
Large current flows into intelligent power module.
MUZ-FE09/12NA
When overcurrent protection occurs within 10 seconds after
compressor starts, compressor restarts after 15 seconds.
Discharge tempera- Temperature of discharge temperature thermistor exceeds 241
ture overheat protec- °F (116°C), compressor stops. Compressor can restart if distion
charge temperature thermistor reads 212°F (100°C) or less 3
minutes later.
Fin temperature
Temperature of fin temperature thermistor on the heat sink
/P.C. board temexceeds 167 ~ 176°F (75 ~ 80°C) or temperature of P.C. board
perature thermistor temperature thermistor on the inverter P.C. board exceeds 158
overheat protection ~ 167°F (70 ~ 75°C).
• Refer to 10-5. "How to check
miswiring and serial signal error.
• Check stop valve.
• Refer to 10-2.2. "Flow chart of the
detailed outdoor unit failure mode
recall function".
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to 10-5. "Check of outdoor
fan motor".
High pressure protection
Temperature of indoor coil thermistor exceeds 158°F (70°C) in • Check refrigerant circuit and refrigHEAT mode. Temperature of outdoor heat exchanger tempera- erant amount.
ture thermistor exceeds 158°F (70°C) in COOL mode.
• Check stop valve.
• Reconnect connector of compresCompressor synThe waveform of compressor current is distorted.
chronous abnormalsor.
• Refer to 10-5. "How to check inity
verter/compressor".
Outdoor fan motor
Outdoor fan has stopped 3 times in a row within 30 seconds
• Refer to 10-5. "Check of outdoor
after outdoor fan start-up.
fan motor.
• Refer to 10-5. "Check of inverter
P.C. board.
Each phase current Each phase current of compressor cannot be detected nor• Refer to 10-5. "How to check inof compressor
mally.
verter/compressor".
• Refer to 10-5. "How to check inDC voltage
DC voltage of inverter cannot be detected normally.
verter/compressor".
Frequency drop by Current from power outlet is nearing Max. fuse size.
The unit is normal, but check the
current protection
following.
Frequency drop by Temperature of indoor coil thermistor exceeds 131°F (55°C) in • Check if indoor filters are clogged.
•
Check if refrigerant is short.
high pressure proHEAT mode, compressor frequency lowers.
• Check if indoor/outdoor unit air cirtection
culation is short cycled.
Frequency drop by Indoor coil thermistor reads 46°F (8°C) or less in COOL mode,
defrosting in COOL compressor frequency lowers.
mode
Frequency drop by
discharge temperature protection
Temperature of discharge temperature thermistor exceeds 232 • Check refrigerant circuit and refrig°F (111°C), compressor frequency lowers.
erant amount.
• Refer to 10-5. "Check of LEV".
• Refer to 10-5. "Check of outdoor
thermistors".
NOTE: 1. The location of LED is illustrated at the right figure. Refer to 10-6.1.
2. LED is lighted during normal operation.
Inverter P.C. board (Parts side)
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF. Flashing
(Example) When the flashing frequency is “2”.
LED
Flashing →
MUZ-FE
18NA
0.5-second ON
0.5-second ON
LED
ON
OFF
2.5-second OFF
2.5-second OFF
21
MUZ-FE09
/12NA
No.
Symptom
LED indication
Outdoor unit
18 operates.
7-time flash
2.5 seconds OFF
19
20
8-time flash
2.5 seconds OFF
9-time flash
2.5 seconds OFF
Abnormal point/ ConCondition
dition
Low discharge tem- Temperature of discharge temperature thermistor has been
perature protection 122°F (50°C) or less for 20 minutes.
MUZ-FE09/12NA
PAM protection
PAM: Pulse Amplitude Modulation
MUZ-FE18NA
Zero cross detecting circuit
The overcurrent flows into IGBT (Insulated Gate Bipolar transistor: TR821) or the bus-bar voltage reaches 320 V or more,
PAM stops and restarts.
Zero cross signal for PAM control cannot be detected.
Inverter check mode The connector of compressor is disconnected, inverter check
mode starts.
22
Remedy
• Refer to 10-5. "Check of LEV".
• Check refrigerant circuit and refrigerant amount.
This is not malfunction. PAM protection will be activated in the following
cases:
1 Instantaneous power voltage drop
(Short time power failure)
2 When the power supply voltage is
high.
• Check if the connector of the compressor is correctly connected.
Refer to 10-5. "How to check
inverter/compressor".
10-4. TROUBLE CRITERION OF MAIN PARTS
MUZ-FE09NA MUZ-FE12NA MUZ-FE18NA
Part name
Defrost thermistor
(RT61)
Check method and criterion
Figure
Ambient temperature Measure the resistance with a tester.
thermistor (RT65)
Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, 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.
Fin temperature
thermistor (RT64)
Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, the chart of thermistor.
Measure the resistance between terminals using a tester.
(Winding temperature: -4 ~ 104°F (-20 ~ 40°C))
Compressor
U-V
U-W
V-W
2
Normal
MUZ-FE09/12NA
MUZ-FE18NA
1.52 ~ 2.17 Ω
0.83 ~ 1.18 Ω
Measure the resistance between lead wires using a tester.
(Part temperature: -4 ~ 104°F (-20 ~ 40°C))
Outdoor fan motor
Color of lead wire
RED – BLK
BLK – WHT
WHT – RED
WHT
RED BLK
3
1
W
V
WHT
2
U
RED BLK
3
1
W
Normal
11 ~ 16 Ω
V
U
Measure the resistance using a tester.
(Part temperature: 14 ~ 104°F (-10 ~ 40°C))
R. V. coil (21S4)
Normal
0.97 ~ 1.38 kΩ
Measure the resistance using a tester.
(Part temperature: 14 ~ 104°F (-10 ~ 40°C))
WHT
LEV
RED
37 ~ 54 Ω
23
BLU
Normal
YLW
Color of lead wire
WHT – RED
RED – ORN
YLW – BRN
BRN – BLU
BRN
Expansion valve coil
(LEV)
ORN
10-5. TROUBLESHOOTING FLOW
A How to check inverter/compressor
Disconnect the connector between compressor
and the intelligent power module (IPM).
See 10-5.
Check the voltage between terminals.
Are the voltages balanced?
Yes
No
Replace the inverter P.C. board.
See 10-5.
Check the compressor.
“Check of open phase”.
“Check of compressor”.
B Check of open phase
● With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if
the inverter is normal by measuring the voltage balance between the terminals.
Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)
<< Operation method>>
Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERATION: 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 flashes 9 times. (Refer to 10-6.1.)
C Check of compressor
Refer to 10-5. “Check of compressor
winding”.
Is the compressor normal?
Yes
Refer to 10-5. “Check of compressor
operation time”.
Does the compressor operate continuously?
Yes
No
No
Replace the compressor.
Refer to 10-5.
OK.
24
“Check of compressor start failure”.
D Check of compressor winding
● Disconnect the connector between the compressor and intelligent power module, and measure the resistance between the
compressor terminals.
<<Measurement point>>
at 3 points
BLK - WHT
Measure the resistance between the lead wires at 3 points.
BLK - RED
WHT - RED
<<Judgement>>
Refer to 10-4.
0[Ω] ················· Abnormal [short]
Infinite [Ω] ········ Abnormal [open]
NOTE: Be sure to zero the ohmmeter before measurement.
E Check of compressor operation time
<<Judgement>>
● Connect the compressor and activate the inverter. Then measure
the time until the inverter stops due to over current.
<<Operation method>>
Start heating or cooling operation by pressing EMERGENCY
OPERATION switch on the indoor unit.
(TEST RUN OPERATION: Refer to 7-6.)
<<Measurement>>
Measure the time from the start of compressor to the stop of
compressor due to overcurrent.
0 second
Compressor starts
1 second
Abnormal
(IPM failure)
(Compressor winding short)
2 seconds
Abnormal
(Compressor lock out)
(Starting defect)
10 seconds
Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)
Abnormal
(Refrigerant circuit defect)
(Closed valve)
10 minutes
Normal
F Check of compressor start failure
Confirm that 1~4 is normal.
• Electrical circuit check
1. Contact of the compressor connector
2. Output voltage of inverter P.C. board and balance of them (See 10-5. )
3. Direct current voltage between DB61(+) and (-) (MUZ-FE09/12NA)/JP715(+)
and JP30(-) (MUZ-FE18NA) on the inverter P.C. board
4. Voltage between outdoor terminal block S1-S2
Does the compressor run for 10 seconds or
more after it starts?
Yes
Check the refrigerant circuit.
Check the stop valve.
No
After the compressor is heated with a drier,
does the compressor start? 1
No
Replace the compressor.
1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Yes
Compressor start failure. Activate pre-heat control.
(Refer to 9-2. "PRE-HEAT CONTROL SETTING")
Heating part
25
G Check of outdoor thermistors
Disconnect the connector of thermistor in the outdoor P.C. board (see
below table), and measure the resistance of thermistor.
Is the thermistor normal? (Refer to 10-6.1.)
Yes
No
Replace the thermistor except RT64. When RT64 is
abnormal, replace the inverter P.C. 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
Replace the inverter P.C. board.
Yes
OK. (Cause is poor contact.)
MUZ-FE09NA MUZ-FE12NA
Thermistor
Symbol
Connector, Pin No.
Defrost
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
Board
Inverter P.C. board
MUZ-FE18NA
Thermistor
Symbol
Connector, Pin No.
Defrost
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
H Check of R.V. coil
First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4.
In case CN721 (MUZ-FE09/12NA)/CN602 (MUZ-FE18NA) is disconnected or R.V. coil is open, voltage is generated
between the terminal pins of the connector although no signal is being transmitted to R.V. coil.
Check if CN721 (MUZ-FE09/12NA)/CN602 (MUZ-FE18NA) is connected.
Unit operates COOL mode even if it is set to HEAT mode.
Disconnect connector between
the compressor and the intelligent
power module.
Turn ON the power supply and
press EMERGENCY OPERATION
switch twice (HEAT mode).
Is there 208/230 VAC between CN721 (MUZFE09/12NA)/CN602 (MUZ-FE18NA) and
on the inverter P.C. board 3 minutes after the
power supply is turned ON?
Yes
No
Replace the inverter
P.C. board.
Replace the 4-way valve.
Unit operates HEAT mode even if it is set to COOL mode.
Disconnect connector between
the compressor and the intelligent
power module.
Turn ON the power supply and
press EMERGENCY OPERATION
switch once (COOL mode).
Is there 208/230 VAC between CN721 (MUZFE09/12NA)/CN602 (MUZ-FE18NA) and
on the inverter P.C. board 3 minutes after the
power supply is turned ON?
No
Replace the 4-way valve.
26
Replace the inverter
Yes P.C. board.
I Check of outdoor fan motor
MUZ-FE09NA MUZ-FE12NA
Disconnect CN932 from the inverter P.C. board, and
measure the resistance of the outdoor fan motor.
Is the outdoor fan motor normal?
(Refer to 10-4.)
Yes
No
Replace the outdoor fan motor.
Replace the inverter P.C. board.
MUZ-FE18NA
Disconnect the connectors CN931
and CN932 from the inverter P.C.
board.
Check the connection between the
connector CN931 and CN932.
Is the resistance between each terminal of outdoor fan motor normal?
(Refer to 10-4.)
No
Yes
Disconnect CN932 from the inverter P.C. board, and turn on the
power supply.
Rotate the outdoor fan motor manually and measure the voltage
of CN931.
Between 1(+) and 5(-)
Between 2(+) and 5(-)
Between 3(+) and 5(-)
(Fixed to either 5 or 0 VDC)
No
No
Does the voltage between each terminal become 5 and 0
VDC repeatedly?
Yes
Does the outdoor fan motor rotate smoothly?
Yes
Replace the inverter P.C. board.
Replace the outdoor fan motor.
27
J Check of power supply
MUZ-FE09NA MUZ-FE12NA
Disconnect the connector (CN61)
between compressor and intelligent
power module.
Turn ON power supply and press
EMERGENCY OPERATION switch.
Does POWER lamp on the indoor
unit light up?
Yes
Is there bus-bar voltage 260-325
VDC between DB61 (+) and DB61
(–) on the inverter P.C. board?
(Refer to 10-6.1.)
No
Check the electric parts in main circuit.
Rectify indoor/outdoor
connecting wire.
No
Yes
Yes
Is there voltage 208/230 VAC
between the indoor terminal
block S1 and S2?
Does LED on the inverter P.C.
board light up or flash? (Refer
to 10-6.1.)
Yes
If light up, OK.
If flash, refer to 10-3.
No
No
Replace the indoor
electronic control P.C.
board.
Replace the inverter
P.C. board.
260-325VDC
DB61
Inverter P.C. board
(Solder side)
28
MUZ-FE18NA
Disconnect the connector between
compressor and intelligent power
module.
Turn ON power supply and press
EMERGENCY OPERATION switch.
Does the upper lamp of
OPERATION INDICATOR on the
indoor unit light up?
Yes
Is there bus-bar voltage 325 - 370
VDC between JP715 (+) and JP30
(–) on the inverter P.C. board?
(Refer to 10-6.1.)
No
Check the electric parts in main circuit.
Rectify indoor/outdoor
connecting wire.
No
Yes
Yes
Is there voltage 208/230 VAC
between the indoor terminal
block S1 and S2?
Does LED on the inverter P.C.
board light up or flash? (Refer
to 10-6.1.)
Yes
No
No
Replace the indoor
electronic control P.C.
board.
Replace the inverter
P.C. board.
If LED lights up, it is OK.
If LED flashes, refer to 10-3.
JP30 JP715
325 -370 VDC
29
MSZ-FE09NA
MSZ-FE12NA
K Check of LEV (Expansion valve)
MSZ-FE18NA
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button
and TOO COOL button on the remote controller at the
same time, press RESET button.
First, release RESET button.
And release the other two buttons after all LCD except
the set temperature in operation display section of the
remote controller is displayed after 3 seconds.
Press OPERATE/STOP (ON/OFF) button of the remote
controller (the set temperature is displayed) with the
remote controller headed towards the indoor unit. 1
1. Regardless of normal or abnormal condition, a short beep
is emitted once the signal is received.
Expansion valve operates in full-opening direction.
Do you hear the expansion valve "click,
click·······"?
Do you feel the expansion valve vibrate
on touching it ?
No
Is LEV coil properly fixed to
the expansion valve?
No
Yes
Does the resistance of LEV
coil have the characteristics? Yes
(Refer to 10-4.)
No
Replace the LEV coil.
Yes
OK.
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 VAC between each?
NOTE: Measure the voltage by an analog
tester.
Yes
Replace the expansion valve.
NOTE: After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply and turn ON it again.
2. Press RESET button on the remote controller.
30
No
Replace the inverter P.C.
board.
L Check of inverter P.C. board
Check the outdoor fan motor.
(Refer to 10-5. .)
Is the fuse (F901) blown on the inverter P.C. board?
Yes
No
Check the connection of the connectors
(CN931 , CN932) of the outdoor fan motor.
If the connection is poor, make it correct.
Only for MUZ-FE18NA
Operate the outdoor unit by starting
EMERGENCY OPERATION.
Check the LED indication on the inverter P.C. board.
Does the LED flash 10 times?
Yes
(10-time flash)
No
Check the remedy following LED
indication.
(Refer to 10-3.)
Replace the inverter P.C. board.
31
M How to check miswiring and serial signal error
Turn OFF the power supply.
Is there rated voltage in the power supply?
Yes
Check the power supply.
No
Turn ON the power supply.
Is there rated voltage between outdoor terminal block S1 and S2?
Yes
No
Check the wiring.
Press EMERGENCY OPERATION switch once.
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
A
Turn OFF the power supply.
Check once more if the indoor/outdoor
B connecting wire is not miswiring.
Short-circuit outdoor terminal block S2
and S3. 1
No
No
Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor connecting wire?
No
Yes
Correct them.
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.
Turn ON the power supply.
Is the bus-bar voltage of the inverter P.C. board normal
(Refer to "TEST POINT DIAGRAM AND VOLTAGE" in this manual.) ?
No
Yes
Does the LED on the inverter P.C. board repeat "3.6-second-OFF
and 0.8-second-ON quick blinking"? 3
Yes
No
(Lighted
or not
lighted)
Turn OFF the power supply.
Remove the short-circuit between outdoor terminal block S2 and S3.
Replace the indoor electronic control P.C. board.
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.
• Attach a filter
No on remote
control receiving section
of the indoor
unit.
32
Replace the inverter P.C. board. 2
2. Be careful of the residual voltage of smoothing
capacitor.
N Electromagnetic noise enters into TV sets or radios
Is the unit grounded?
Yes
Is the distance between the antennas
and the indoor unit within 9.91 ft., or is
the distance between the antennas and
the outdoor unit within 9.91 ft.?
Ground the unit.
No
Yes
Extend the distance between the antennas and
the indoor unit, and/or the antennas and the
outdoor unit.
Yes
Extend the distance between the TV sets and/or
radios and the indoor unit, or the TV sets or
radios and the outdoor unit.
Yes
Replace or repair the antenna.
Replace or repair the coaxial cable.
Yes
Extend the distance between the indoor/outdoor
connecting wire of the air conditioner and the wiring of the antennas.
No
Is the distance between the TV sets or
radios and the indoor unit within 3.28
ft., or is the distance between the TV
sets or radios and the outdoor unit
within 9.91 ft.?
No
Are the antennas damaged?
Is the coaxial cable damaged?
Is there any poor contact in the antenna wiring?
No
Is the indoor/outdoor connecting wire
of the air conditioner and the wiring of
the antennas close?
No
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 followings before asking for service.
1. Devices affected by the electromagnetic noise
TV sets, radios (FM/AM broadcast, shortwave)
2. Channel, frequency, broadcast station affected by the electromagnetic noise
3. Channel, frequency, broadcast station unaffected by the electromagnetic noise
4. Layout of:
indoor/outdoor unit of the air conditioner, indoor/outdoor wiring, grounding wire, antennas, wiring from antennas, receiver
5. Electric 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 OPERATE/STOP (ON/OFF) button on the remote controller
for power ON, and check for the electromagnetic noise.
3) After a short time (3 minutes later after turning ON), the outdoor unit starts running. During operation, check for the electromagnetic noise.
4) Press OPERATE/STOP (ON/OFF) button on the remote controller for power OFF, when the outdoor unit stops but the
indoor/outdoor communication still runs on. In this situation, check for the electromagnetic noise.
33
10-6. TEST POINT DIAGRAM AND VOLTAGE
1. Inverter P.C. board
MUZ-FE09NA MUZ-FE12NA
Bus-bar voltage Smoothing
capacitor
DB61
(C63)
260-325 VDC
Back side of unit
(-)
Smoothing
capacitor
(C62)
(+)
Smoothing
capacitor Fuse (F701)
(C61)
T3.15AL250V
Fuse (F801)
T3.15AL250V
208/230 VAC
R.V. coil
(CN721)
208/230 VAC
Fuse (F901)
T3.15AL250V
Output to
drive compressor
(LDU,
LDV,
LDW)
100
Discharge temperature
thermistor /RT62
(CN641)
Defrost thermistor
/RT61(CN641)
Ambient temperature
thermistor /RT65
(CN643)
Outdoor heat exchanger
temperature thermistor
/RT68(CN644)
Fin temperature
thermistor /RT64
(CN642)
Front side of unit
Output to drive outdoor
fan motor (CN932)
208/230 VAC
LED LEV
Jumper wire for
connector changing defrost
(CN724) setting (JS)
Defrost thermistor(RT61)
Ambient temperature thermistor(RT65)
Outdoor heat exchanger temperature thermistor(RT68)
200
80
160
Discharge temperature thermistor(RT62)
60
600
50
40
30
20
10
14
32 50 68 86
Temperature(°F)
104
140
Resistance(kΩ)
70
700
Resistance(kΩ)
Resistance(kΩ)
Fin temperature thermistor(RT64)
180
90
0
-4
Jumper wire
for pre-heat
control setting
(JK)
500
400
300
120
100
80
60
200
40
100
20
0
32
50
68
86 104 122 140 158 176 194 212 230 248
Temperature(°F)
34
0
32 50 68 86 104 122 140 158 176
Temperature(°F)
MUZ-FE18NA
Fuse (F62)
T2.0AL250V
Fuse (F601)
T3.15AL250V
R.V. coil (CN602)
208/230 VAC
Jumper wire for
changing defrost
setting (JS)
Jumper wire for
pre-heat control
setting (JK)
Signal of outdoor fan motor
(CN931)
Defrost thermistor
/RT61 (CN671)
Discharge temperature
thermistor/RT62
(CN671)
Outdoor heat exchanger
temperature thermistor
/RT68 (CN671)
Ambient temperature
thermistor/RT65
(CN672)
Fin temperature
thermistor/RT64
(CN673)
LED
Output to
drive outdoor
fan motor
(CN932)
Fuse (F901)
T3.15AL250V
Fuse (F880)
T3.15AL250V
LEV connector (CN724)
100
JP715 (+)
Bus-bar voltage
325 - 370 VDC
Fin temperature thermistor(RT64)
JP30 (-)
Defrost thermistor(RT61)
Ambient temperature thermistor(RT65)
Outdoor heat exchanger temperature thermistor(RT68)
200
180
90
60
600
50
40
30
20
10
14
32 50 68 86
Temperature(°F)
104
140
Resistance(k )
70
0
-4
160
Discharge temperature thermistor(RT62)
700
Resistance(k )
Resistance(k )
80
500
400
300
120
100
80
60
200
40
100
20
0
32
50
68
86 104 122 140 158 176 194 212 230 248
Temperature(°F)
35
0
32 50 68 86 104 122 140 158 176
Temperature(°F)
11
DISASSEMBLY INSTRUCTIONS
<"Terminal with locking mechanism" Detaching points>
The terminal which has the locking mechanism can be detached as shown below.
There are two types (refer to (1) and (2)) of the terminal with locking mechanism.
The terminal without locking mechanism can be detached by pulling it out.
Check the shape of the terminal before detaching.
(1) Slide the sleeve and check if there is a locking lever or not.
Sleeve
Locking lever
(2) The terminal with this connector has the
locking mechanism.
Slide the sleeve.
Pull the terminal while
pushing the locking
lever.
Hold the sleeve, and
pull out the terminal
slowly.
Connector
11-1. MUZ-FE09NA MUZ-FE12NA
NOTE: Turn OFF power supply before disassembling.
OPERATING PROCEDURE
PHOTOS
1. Removing the cabinet
Photo 1
(1)
(2)
(3)
(4)
(5)
Remove the screw fixing the service panel. (Photo 1)
Pull down the service panel and remove it. (Photo 1)
Remove the screws fixing the conduit cover. (Photo 2)
Remove the conduit cover. (Photo 2)
Disconnect the power supply wire and indoor/outdoor
connecting wire.
(6) Remove the screws fixing the top panel. (Photo 1)
(7) Remove the top panel. (Photo 1)
(8) Remove the screws fixing the cabinet.
(9) Remove the cabinet.
(10) Remove the screws fixing the back panel.
(11) Remove the back panel.
Screws
of the top
panel
Screw of the
cabinet
Screws of
the top panel
Back
panel
Screw of
the service
panel
Photo 2
Hooks
Screw of the
conduit cover
Conduit cover
Screws of
the cabinet
Conduit plate
36
Service
panel
OPERATING PROCEDURE
PHOTOS
2. Removing the inverter assembly, inverter P.C. board
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following
connectors:
<Inverter P.C. board>
CN721 (R.V.coil)
CN932 (Fan motor)
CN641 (Defrost thermistor 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 relay panel. (Photo 3)
(5) Remove the inverter assembly. (Photo 4)
(6) Remove the screw of the ground wire and screw of the
T.B.support. (Photo 4)
(7) Remove the inverter P.C. board from the inverter assembly.
Photo 3
Screws of the
relay panel
Photo 4 (Inverter assembly)
3. Removing R.V. coil
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Remove the R.V. coil. (Photo 5)
Heat sink
Inverter
P.C. board
Screw of the
T.B.support
T.B.support
4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor.
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following
connectors:
<Inverter P.C. board>
CN721 (R.V.coil)
CN932 (Fan motor)
CN641 (Defrost thermistor and discharge temperature thermistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)
(3) Pull out the discharge temperature thermistor from its holder. (Photo 5)
(4) Pull out the defrost thermistor from its holder. (Photo 6)
(5) Pull out the outdoor heat exchanger temperature thermistor
from its holder. (Photo 6)
(6) Pull out the ambient temperature thermistor from its holder.
Screw of the
ground wire
Photo 5
R.V. coil
Discharge temperature thermistor
37
OPERATING PROCEDURE
PHOTOS
Photo 6
5. Removing outdoor fan motor
(1)
(2)
(3)
(4)
(5)
(6)
Remove the cabinet and panels. (Refer to 1.)
Disconnect the connectors for outdoor fan motor.
Remove the propeller nut. (Photo 7)
Remove the propeller. (Photo 7)
Remove the screws fixing the fan motor. (Photo 7)
Remove the fan motor.
Outdoor heat
exchanger temperature thermistor
6. Removing the compressor and 4-way valve
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Remove the inverter assembly. (Refer to 2.)
(3) Recover gas from the refrigerant circuit.
NOTE: Recover gas from the pipes until the pressure
gauge shows 0 PSIG.
Defrost thermistor
(4) Detach the brazed part of the suction and the discharge
pipes connected with compressor.
(5) Remove the nuts of compressor legs.
(6) Remove the compressor.
(7) Detach the brazed part of pipes connected with 4-way
valve. (Photo 8)
Photo 7
Screws of the outdoor fan motor
Photo 8
Propeller
Brazed parts of 4-way valve
38
Propeller nut
11-2. MUZ-FE18NA
NOTE: Turn OFF power supply before disassembling.
OPERATING PROCEDURE
PHOTOS
Photo 1
1. Removing the cabinet
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
Remove the screws of the service panel.
Remove the screws of the top panel.
Remove the screw of the valve cover.
Remove the service panel.
Remove the screws fixing the conduit cover. (Photo 3)
Remove the conduit cover. (Photo 3)
Remove the top panel.
Remove the valve cover.
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.
Screws of the
back panel
Photo 2 Screws of the
top panel
Screws of the
back panel
Screws of
the back
panel
Screws of the top panel
Screws of the
cabinet
Screws of the
cabinet
Photo 3
Screws of the
conduit cover
Screws
of the
cabinet
Conduit plate
Screws of
the service
panel
Screws of the
back panel
Screws of
the back
panel
Screw of
the valve
cover
39
OPERATING PROCEDURE
PHOTOS
2. Removing the inverter assembly, inverter P.C. board
Photo 4
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following conInverter P.C
nectors:
board
<Inverter P.C. board>
CN602 (R.V. coil)
CN931, CN932 (Fan motor)
CN671 (Defrost thermistor, discharge temperature thermistor
and outdoor heat exchanger temperature thermistor)
CN672 (Ambient temperature thermistor)
CN724 (LEV)
(3) Remove the compressor connector.
(4) Remove the screws fixing the relay panel.
(5) Remove the relay panel.
(6) Remove the earth wires and the lead wires of the inverter P.C.
board.
(7) Remove the screw of the PB support.
Screws
(8) Remove the inverter P.C. board from the relay panel.
of the PB
support
Screw of the
relay panel
Earth wires
Screws of the
PB support
Screws of the
relay panel
3. Removing R.V. coil
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the following connector:
<Inverter P.C. board>
CN602 (R.V. coil)
(3) Remove the R.V. coil.
Photo 5
Screw of the
R.V. coil
Brazed parts of
4-way valve
40
OPERATING PROCEDURE
PHOTOS
4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor
(1) Remove the cabinet and panels. (Refer to 1.)
(2) Disconnect the lead wire to the reactor and the following
connectors:
<Inverter P.C. board>
CN671 (Defrost thermistor, discharge temperature thermistor and outdoor heart exchanger temperature thermistor)
CN672 (Ambient temperature thermistor)
(3) Pull out the discharge temperature thermistor from its holder.
(Photo 8)
(4) Pull out the defrost thermistor from its holder.
(5) Pull out the outdoor heat exchanger temperature thermistor
from its holder.
(6) Pull out the ambient temperature thermistor from its holder.
Photo 6
Outdoor heat
exchanger temperature thermistor
Ambient temperature
thermistor
5. Removing outdoor fan motor
(1) Remove the top panel, cabinet and service panel. (Refer to 1.)
(2) Disconnect the following connectors:
<Inverter P.C. board>
CN931 and CN932 (Fan motor)
Defrost thermistor
Photo 7
(3) Remove the propeller.
(4) Remove the screws fixing the fan motor.
(5) Remove the fan motor.
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 1.)
(2) Remove the back panel. (Refer to 1.)
(3) Remove the inverter assembly. (Refer to 2.)
(4) Recover gas from the refrigerant circuit.
NOTE: Recover gas from the pipes until the pressure gauge
shows 0 kg/cm2 (0 MPa).
(5) Detach the brazed part of the suction and the discharge
pipes connected with compressor.
(6) Remove the compressor nuts.
(7) Remove the compressor.
(8) Detach the brazed parts of 4-way valve and pipes. (Photo 5)
Photo 8
Brazed part of the
discharge pipe
Discharge temperature
thermistor
Brazed part of the suction pipe
41
42
43
HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN
© Copyright 2009 MITSUBISHI ELECTRIC CO.,LTD
Distributed in Sep. 2010. No. OBH543 REVISED EDITION-A 5
Distributed in Jul. 2009. No. OBH543 5
Made in Japan
New publication, effective Sep. 2010
Specifications subject to change without notice.