Mitsubishi Electric MUZ-A09NA User manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ··································· 3
2. PART NAMES AND FUNCTIONS····················· 6
3. SPECIFICATION················································ 7
4. OUTLINES AND DIMENSIONS ·······················11
5. WIRING DIAGRAM·········································· 12
6. REFRIGERANT SYSTEM DIAGRAM ············· 20
7. DATA································································ 23
8. ACTUATOR CONTROL··································· 37
9. SERVICE FUNCTIONS ··································· 38
10. TROUBLESHOOTING····································· 38
11. DISASSEMBLY INSTRUCTIONS···················· 65
12. PARTS LIST····················································· 72
12-1. PARTS LIST ··········································· 72
12-2. RoHS PARTS LIST ································ 78
13. OPTIONAL PARTS······················ BACK COVER
Models
MUZ-A09NA,- 1,- U1 ,- U2
MUZ-A12NA,- U1
MUZ-A15NA,- U1
MUZ-A17NA,- U1
MUZ-A24NA,- 1,- U1 ,- U2
MUY-A15NA
MUY-A17NA
MUY-A24NA,- 1,- U1 ,- U2
MUZ-GA24NA,- U1
MUY-GA24NA
SPLIT-TYPE AIR CONDITIONERS
OUTDOOR UNIT
Indoor unit service manual
MSZ-A•NA Series (OB450)
MSZ-GA•NA Series (OB450)
MUZ-A09/12/15/17NA
MUY-A15/17NA
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
For servicing of RoHS compliant products, refer to the PARTS LIST
(RoHS compliant).
TM
HFC
utilized
R410A
No. OB451
REVISED EDITION-E
Revision E:
• MUZ-GA24NA and MUY-GA24NA have
been added.
Please void OB451 REVISED EDITION-D.

2
Revision A:
• MUZ-A09NA - U2 and MUZ-A09NA - 1have been added.
Revision B:
• 10-5. ”Check of outdoor thermistors” has been corrected.
Revision C:
• 10-6. ”Test point diagram and voltage” has been corrected.
10-6.3. ”Outdoor electronic control P.C. board”, the chart of thermistor has been corrected.
Revision D:
• MUZ-A24NA - 1, MUZ-A24NA - U2 and MUY-A24NA - 1have been added.
Revision E:
• MUZ-GA24NA and MUY-GA24NA have been added.

3
MUZ09UN →MUZ-A09NA MUZ12UN →MUZ-A12NA
MUH15TN →MUZ-A15NA MUH17TN →MUZ-A17NA
MUH24WN →MUZ-A24NA
MU15TN →MUY-A15NA MU17TN →MUY-A17NA
MU24WN →MUY-A24NA
1. Outdoor unit model has been changed.
2. Control method between indoor and outdoor unit has been changed.
3. Refrigerant has been changed. (R22 →R410A)
4. Fan motor has been changed. (AC →DC)
5. Compressor has been changed. (AC →DC)
MUZ-A09NA →MUZ-A09NA - 1
MUZ-A09NA - U1 →MUZ-A09NA - U2
1. Refrigerant system diagram has been changed.
MUZ-A24NA →MUZ-A24NA - 1
MUZ-A24NA - U1 →MUZ-A24NA - U2
MUY-A24NA →MUY-A24NA - 1
1. Wiring diagram has been changed.
MUZ-A24NA - 1→MUZ-GA24NA
MUZ-A24NA - U2 →MUZ-GA24NA - U1
MUY-A24NA - 1→MUY-GA24NA
1. Compressor has been changed. (SNB130FPDH →SNB130FQBH)
2. Wiring diagram has been changed.
3. Fan motor has been changed.
4. ELECTRONIC CONTROL P.C. Board has been changed.
1TECHNICAL CHANGES

4
INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT
• This room air conditioner adopts HFC refrigerant (R410A) which never destroys the ozone layer.
• Pay particular attention to the following points, though the basic installation procedure is same as that for R22 air condition-
ers.
As R410A has working pressure approximate 1.6 times as high as that of R22, some special tools and piping parts/materials
are required. Refer to the table below.
Take sufficient care not to allow water and other contaminations to enter the R410A refrigerant during storage and installa-
tion, since it is more susceptible to contaminations than R22.
For refrigerant piping, use clean, pressure-proof parts/materials specifically designed for R410A. (Refer to 2. Refrigerant pip-
ing.)
Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrigerant to prevent
composition change.
New refrigerant Previous refrigerant
Refrigerant
Refrigerant R410A R22
Composition (Ratio) HFC-32: HFC-125 (50%: 50%) R22 (100%)
Refrigerant handling Pseudo-azeotropic refrigerant Single refrigerant
Chlorine Not included Included
Safety group (ASHRAE) A1 / A1 A1
Molecular weight 72.6 86.5
Boiling point (°F) -60.5 -41.4
Steam pressure [77°F] (PSIG) 225.82 136.34
Saturated steam density [77°F] (lb./ft.3) 3.995 2.772
Combustibility Non combustible Non combustible
ODP 1 0 0.055
GWP 2 1730 1700
Refrigerant charge method From liquid phase in cylinder Gas phase
Additional charge on leakage Possible Possible
Refrigeration oil
Kind Incompatible oil Compatible oil
Color None Light yellow
Smell None None
1: Ozone Depletion Potential: based on CFC-11
2: Global Warming Potential: based on CO2
New Specification Current Specification
Compressor
The incompatible refrigeration oil easily separates from
refrigerant and is in the upper layer inside the suction
muffler.
Raising position of the oil back hole enables to back the
refrigeration oil of the upper layer to flow back to the
compressor.
Since refrigerant and refrigeration oil are compatible with
each other, refrigeration oil goes back to the compressor
through the lower position oil back hole.
Compressor
Suction muffler
Oil back hole
refrigeration oil
Refrigerant
Compressor
Suction muffler
Oil back hole
Refrigeration oil /Refrigerant

5
-22 -4 14 32 50 68 86 104 122 140
-73
0
73
145
218
290
363
435
508
580
(PSIG)
R410A
R22
Conversion chart of refrigerant temperature and pressure
Saturated liquid pressure
(°F)
1. Tools dedicated for the air conditioner with R410A refrigerant
The following tools are required for R410A refrigerant. Some R22 tools can be substituted for R410A tools.
R410A tools Can R22 tools
be used? Description
Gauge manifold No R410A has high pressures beyond the measurement range of existing gaug-
es.
Charge hose No Hose material have been changed to improve the pressure resistance.
Gas leak detector No Dedicated for HFC refrigerant.
Torque wrench Yes 1/4 in. and 3/8 in.
No 1/2 in. and 5/8 in.
Flare tool Yes Clamp bar hole has been enlarged to reinforce the spring strength in the tool.
Flare gauge New Provided for flaring work (to be used with R22 flare tool).
Vacuum pump adapter New Provided to prevent the back flow of oil. This adapter enables you to use vac-
uum pumps.
Electronic scale for refrigerant
charging New It is difficult to measure R410A with a charging cylinder because the refriger- ant bubbles due to high pressure and high-speed vaporization
No: Not Substitutable for R410A Yes: Substitutable for R410A
2. Refrigerant piping
Specifications
Use the copper or copper-alloy seamless pipes for refrigerant that meet the following specifications.
Outside diameter (in.) Wall thickness (in.) Insulation material
1/4 0.0315
Heat resisting foam plastic Specific gravity 0.045
Thickness 0.315 in.
3/8 0.0315
1/2 0.0315
5/8 0.0394
Flaring work and flare nut
Flaring work for R410A pipe differs from that for R22 pipe.
For details of flaring work, refer to Installation manual “FLARING WORK”.
Pipe diameter (in.) Dimension of flare nut mm (in.)
R410A R22
1/4 17 (11/16) 17 (11/16)
3/8 22 (7/8) 22 (7/8)
1/2 26 (1-1/32) 24 (15/16)
5/8 29 (1-5/32) 27 (1-1/16)

6
3. Refrigerant oil
Apply the special refrigeration oil (accessories: packed with indoor unit) to the flare and the union seat surfaces.
4. Air purge
• Do not discharge the refrigerant into the atmosphere.
Take care not to discharge refrigerant into the atmosphere during installation, reinstallation, or repairs to the refrigerant cir-
cuit.
• Use the vacuum pump for air purging for the purpose of environmental protection.
5. Additional charge
For additional charging, charge the refrigerant from liquid phase of the gas cylinder.
If the refrigerant is charged from the gas phase, composition change may occur in the refrigerant inside the cylinder and
the outdoor unit. In this case, capacity of the refrigeration cycle decreases or normal operation can be impossible. However,
charging the liquid refrigerant all at once may cause the compressor to be locked. Thus, charge the refrigerant slowly.
Electronic scale for refrigerant charging
Outdoor unit
Refrigerant gas
cylinder
operating valve
Refrigerant gas cylinder
for R410A with siphon
Refrigerant (liquid)
Service port
Gauge manifold
valve (for R410A)
Union
Liquid pipe
Gas pipe
Stop valve
Indoor unit
Charge hose (for R410A)
PART NAMES AND FUNCTIONS
2
Air outlet
Drain outlet
Piping
Drain hose
Air inlet
(back and side)
MUZ-A09NA MUZ-A15NA MUY-A15NA
MUZ-A12NA MUZ-A17NA MUY-A17NA
MUZ-A24NA MUY-A24NA
MUZ-GA24NA MUY-GA24NA
Piping
Air outlet
Drain hose
Drain outlet
Air inlet
(back and side)

7
Item Model MSZ-A09NA MSZ-A12NA
Capacity
Rated (Minimum-Maximum)
Cooling 1 Btu/h 9,000 (5,500-9,000) 12,000 (5,700-12,000)
Heating 47 1 Btu/h 10,900 (5,200-12,600) 13,600 (5,200-13,600)
Capacity Heating 17 2 Btu/h 7,700 8,300
Power consumption
Rated (Minimum-Maximum)
Cooling 1 W 690 (390-690) 1,170 (395-1,170)
Heating 47 1 W 860 (350-1,100) 1,160 (350-1,160)
Power consumption Heating 17 2 W 880 930
EER 1 [SEER] 3 Cooling 13.0 [17.0] 10.3 [17.0]
HSPF IV(V) 4 Heating 8.2 (7.1) 8.2 (7.1)
COP Heating 1 3.71 3.44
Outdoor unit model MUZ-A09NA
MUZ-A09NA - U1
MUZ-A09NA - 1
MUZ-A09NA - U2 MUZ-A12NA
Power supply V , phase , Hz 208/230, 1, 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 12
Fan motor F.L.A 0.52
Compressor
Model KNB092FPAH
Winding resistance (at 68˚F) Ω 0.49
R.L.A 7.8
L.R.A 9.2
Refrigerant control Liner expansion valve
Sound level 1 dB(A) 48
Defrost method Reverse cycle
Dimensions
W in. 31-1/2
D in. 11-1/4
H in. 21-5/8
Weight Ib. 82 75 82
External finish Munsell 3Y 7.8/1.1
Remote controller Wireless type
Control voltage (by built-in transformer) 12 - 24 VDC
Refrigerant piping Not supplied
Refrigerant pipe size
(Min. wall thickness)
Liquid in. 1/4 (0.0315)
Gas in. 3/8 (0.0315)
Connection method Indoor Flared
Outdoor Flared
Between the indoor &
outdoor units
Height difference ft. 40
Piping length ft. 65
Refrigerant charge (R410A) 2 lb. 5 oz. 2 lb. 2 lb. 5 oz.
Refrigeration oil (Model) NEO22
NOTE: Test conditions are based on ARI 210/240.
1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB) Rated frequency
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB Rated frequency
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB Maximum frequency
3SPECIFICATION

8
Item Model MSZ-A15NA MSY-A15NA MSZ-A17NA MSY-A17NA
Capacity
Rated
(Minimum-Maximum)
Cooling 1 Btu/h 15,000
(3,100-15,000)
15,000
(3,100-15,000)
16,200
(3,100-16,200)
16,200
(3,100-16,200)
Heating 47 1 Btu/h 18,000
(3,400-20,900) – 20,100 (3,400-20,900) –
Capacity Rated Heating 17 2 Btu/h 13,000 – 13,000 –
Power consumption
Rated (Minimum-Maximum)
Cooling 1 W 1,690 (210-1,690) 1,690 (210-1,690) 2,070 (210-2,070) 2,070 (210-2,070)
Heating 47 1 W 1,790 (250-2,330) – 2,150 (250-2,330) –
Power consumption Rated Heating 17 2 W 1,740 – 1,740 –
EER 1 [SEER] 3 Cooling 8.9 [16.0] 8.9 [16.0] 7.8 [16.0] 7.8 [16.0]
HSPF IV(V) 4 Heating 8.2 (7.1) – 8.2 (7.1) –
COP Heating 1 2.95 – 2.74 –
Outdoor unit model MUZ-A15NA MUY-A15NA MUZ-A17NA MUY-A17NA
Power supply V , phase , Hz 208/230, 1, 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 14
Fan motor F.L.A 0.52
Compressor
Model SNB130FPDH
Winding resistance (at 68˚F) Ω 0.45
R.L.A 10.1
L.R.A 12
Refrigerant control Liner expansion valve
Sound level 1 dB(A) 50 50 52 52
Defrost method 51 — 53 —
Dimensions
W in. 31-1/2
D in. 11-1/4
H in. 21-5/8
Weight Ib. 88
External finish Munsell 3Y 7.8/1.1
Remote controller Wireless type
Control voltage (by built-in transformer) 12 - 24 VDC
Refrigerant piping Not supplied
Refrigerant pipe size
(Min. wall thickness)
Liquid in. 1/4 (0.0315)
Gas in. 1/2 (0.0315)
Connection method Indoor Flared
Outdoor Flared
Between the indoor &
outdoor units
Height difference ft. 40
Piping length ft. 65
Refrigerant charge (R410A) 2 lb. 7 oz.
Refrigeration oil (Model) NEO22
NOTE: Test conditions are based on ARI 210/240.
1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB) Rated frequency
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB Rated frequency
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB Maximum frequency

9
Item Model MSZ-A24NA MSY-A24NA MSZ-GA24NA MSY-GA24NA
Capacity
Rated Minimum-Maximum)
Cooling 1 Btu/h 22,000
(4,400-22,000)
22,000
(4,400-22,000)
22,000
(4,400-22,000)
22,000
(4,400-22,000)
Heating 47 1 Btu/h 23,200
(3,600-24,400) — 23,200 (3,600-24,400) —
Capacity Rated Heating 17 2 Btu/h 15,200 — 15,200 —
Power consumption
Rated (Minimum-Maximum)
Cooling 1 W 2,880 (290-2,880) 2,880 (290-2,880) 2,500 (270-2,500) 2,500 (270-2,500)
Heating 47 1 W 2,350 (260-2,570) — 2,140 (250-2,520) —
Power consumption Rated Heating 17 2 W 1,960 — 1,870 —
EER 1 [SEER] 3 Cooling 7.6 [16.0] 7.6 [16.0] 8.8 [17.5] 8.8 [17.5]
HSPF IV(V) 4 Heating 8.2 (7.1) — 9.5 (7.1) —
COP Heating 1 2.89 — 3.17 —
Outdoor unit model MUZ-A24NA MUY-A24NA MUZ-GA24NA MUY-GA24NA
Power supply V , phase , Hz 208/230, 1, 60
Max. fuse size (time delay) A 20
Min. circuit ampacity A 17
Fan motor F.L.A 0.93
Compressor
Model SNB130FPDH SNB130FQBH
Winding resistance (at 68˚F) Ω 0.45 0.98
R.L.A 10.1 12.8
L.R.A 16.0 16.0
Refrigerant control Liner expansion valve
Sound level 1 dB(A) 55
Defrost method Reverse cycle
Dimensions
W in. 33-1/16
D in. 13
H in. 33-7/16
Weight Ib. 128 117
External finish Munsell 3Y 7.8 1.1
Remote controller Wireless type
Control voltage (by built-in transformer) 12 - 24 VDC
Refrigerant piping Not supplied
Refrigerant pipe size
(Min. wall thickness)
Liquid in. 1/4 (0.0315)
Gas in. 5/8 (0.0394)
Connection method Indoor Flared
Outdoor Flared
Between the indoor &
outdoor units
Height difference ft. 50
Piping length ft. 100
Refrigerant charge (R410A) 4 lb.
Refrigeration oil (Model) NEO22
NOTE: Test conditions are based on ARI 210/240.
1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB) Rated frequency
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB Rated frequency
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB Maximum frequency

10
Test condition
3, 4
Mode Test
Indoor air condition (˚F) Outdoor air condition (˚F)
Dry bulb Wet bulb Dry bulb Wet bulb
ARI
SEER
(Cooling)
"A" Cooling Steady State at rated compres-
sor Speed 80 67 95 (75)
"B-2" Cooling Steady State at rated com-
pressor Speed 80 67 82 (65)
"B-1" Cooling Steady State at minimum
compressor Speed 80 67 82 (65)
Low ambient Cooling Steady State at mini-
mum compressor Speed 80 67 67 (53.5)
Intermediate Cooling Steady State At Inter-
mediate compressor Speed 5 80 67 87 (69)
HSPF
(Heating)
Standard Rating-Heating at rated compres-
sor Speed 70 60 47 43
Low temperature Heating at rated compres-
sor Speed 70 60 17 15
Max temperature Heating at minimum com-
pressor Speed 70 60 62 56.5
High temperature Heating at minimum com-
pressor Speed 70 60 47 43
Frost Accumulation at rated compressor
Speed 70 60 35 33
Frost Accumulation at Intermediate com-
pressor 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 Guaranteed Voltage (V)
Outdoor unit
208/230 V
1 phase
60 Hz
Min.187 208 230 Max.253
(2) OPERATION
Mode Condition
Intake air temperature (°F)
Indoor Outdoor
DB WB DB WB
Cooling
Standard temperature 80 67 95 —
Maximum temperature 90 73 115 —
Minimum temperature 67 57 14 —
Maximum humidity 78% —
Heating
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 14
5 (MUZ-GA24)
13
4 (MUZ-GA24)
Except - Umodel

11
30°
35°
6-1/28
3-17/32
7-25/32
1-9/16
20-9/32
11-25/32
2-19/32
2
14-3/16
33-7/16
16-15/16
19-11/16
3-3/16
4-25/32
33-1/16
Open as a rule
20 inch or more if
the front and both
sides are open
4 inch or more /
8 inch or more if
there are obstacles
to both sides
Open as a rule
20 inch or more if the back,
both sides and top are open
14 in. or more
4 in. or more
Air in
Air out
13
Service panel
Gas refrigerant
pipe joint
Refrigerant pipe
(flared) ø5/8
Liquid refrigerant
pipe joint
Refrigerant pipe
(flared) ø1/4
Drain hole ø1-5/8
4-3/8 13/16 Oval hole
REQUIRED SPACE
Air in
Liquid pipe :1/4 (flared)
Gas pipe :3/8 (flared) ··· MUZ-A09/12NA
:1/2 (flared) ··· MUZ-A15/17NA, MUY-A15/17NA
6-23/32
2
5-7/8
2-23/32
1-3/4
15-3/4
12 ~ 12-3/4
13-9/16
11/16
1-9/16
7/8
21-5/8
11-1/32
13/32
31-1/2
19-11/16
5-15/16
11-29/32
17/3229/32 11-1/4
Air in
handle
Air in
Air out
2- 3/8 13/16 Oval hole
Drain hole ø1-5/8
{
REQUIRED SPACE Basically open 4 inch or more
without any obstruction in front
and on both sides of the unit.
14 in. or more
8 in. or more
4 in. or more
4 in. or more
Open two sides of left,
right, or rear side.
Unit: inch
MUZ-A09NA MUZ-A12NA MUZ-A15NA MUZ-A17NA MUY-A15NA MUY-A17NA
MUZ-A24NA MUY-A24NA MUZ-GA24NA MUY-GA24NA
4OUTLINES AND DIMENSIONS

12
MUZ-A09NA MUZ-A12NA MUZ-A15NA MUZ-A17NA
5WIRING DIAGRAM

13
MUY-A15NA MUY-A17NA

14
MUZ-A24NA MUZ-A24NA- U1

15
MUZ-A24NA- 1MUZ-A24NA- U2

16
MUY-A24NA

17
MUY-A24NA- 1

18
MUZ-GA24NA

19
MUY-GA24NA

20
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Service
port
Service
port
Flared connection
Stop valve
(with strainer)
Stop valve
(with service port)
Refrigerant flow in cooling
Compressor
4-way valve
Refrigerant flow in heating (MUZ)
Refrigerant pipe ø3/8 (MUZ-A09/12)
ø1/2 (MUZ-A15/17,MUY-A15/17)
(with heat insulator)
Refrigerant pipe ø1/4
(with heat insulator)
R.V. coil
heating ON
cooling OFF
Strainer
#100
Capillary tube
O.D. 0.118 × I.D. 0.071
× 23-5/8
(ø
3.0 × ø1.8 × 600 )
Expansion
valve
Ambient
temperature
thermistor
RT65
Muffler
Muffler
Muffler
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainer)
Stop valve
(with service port)
Refrigerant flow in cooling
Compressor
4-way valve
Refrigerant flow in heating
Refrigerant pipe ø3/8
(with heat insulator)
Refrigerant pipe ø1/4
(with heat insulator)
Capillary tube
O.D. 0.118 × I.D. 0.079
× 9-7/16
(ø3.0 × ø2.0 × 240)
Expansion
valve
R.V. coil
heating ON
cooling OFF
Strainer
#100
Muffler
Muffler
Ambient
temperature
thermistor
RT65
Muffler
Unit: inch
MUZ-A09NA MUZ-A09NA- U1 MUZ-A12NA MUZ-A15NA MUZ-A17NA
MUY-A15NA MUY-A17NA
MUZ-A09NA- 1MUZ-A09NA- U2
6REFRIGERANT SYSTEM DIAGRAM