Mitsubishi Electric MUZ-WR09NA User manual

Models
MUZ-WR09NA -U1 , U2
MUZ-WR12NA -U1 , U2
MUZ-WR18NA -U1 , U2
MUZ-WR24NA -U1
HFC
utilized
R410A
MUZ-WR24NA
PARTS CATALOG (OBB819)
SERVICE MANUAL
No. OBH819
REVISED EDITION-B
Indoor unit service manual
MSZ-WR•NA Series (OBH818)
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 ··········· 12
7. DATA······················································ 15
8. ACTUATOR CONTROL ····························· 25
9. SERVICE FUNCTIONS······························ 26
10. TROUBLESHOOTING ······························· 27
11. DISASSEMBLY INSTRUCTIONS················· 52
OUTDOOR UNIT
OBH819 REVISED EDITION-A is void.
Revision B:
• MUZ-WR09/12/18NA- U2 have been added.
• 10-4. The resistant value of the defrost
heater has been corrected.

2
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.
1TECHNICAL CHANGES
MUZ-WR09NA - U1
MUZ-WR12NA - U1
MUZ-WR18NA - U1
MUZ-WR24NA - U1
1. New model
MUZ-WR09NA - U1 MUZ-WR09NA - U2
MUZ-WR12NA - U1 MUZ-WR12NA - U2
1. Fan motor has been changed.
2. Inverter P.C. board has been changed.
3. R.V. coil has been changed.
4. LEV has been changed.
5. Outdoor heat exchanger has been changed.
6. 4-way valve has been changed.
7. Compressor has been changed.
MUZ-WR18NA - U1 MUZ-WR18NA - U2
1. Fan motor has been changed.
2. Inverter P.C. board has been changed.
3. LEV has been changed.
Revision B:
• MUZ-WR09/12/18NA- U2 have been added.
OBH819B

3
MUZ-WR24NA
Piping
Air outlet
Drain outlet
Air inlet
(back and side)
Drain hose
PART NAMES AND FUNCTIONS
2
MUZ-WR09NA MUZ-WR12NA MUZ-WR18NA
Air outlet
Drain outlet
Piping
Drain hose
Air inlet
(back and side)
OBH819B

4
3SPECIFICATION
Outdoor unit model MUZ-WR09NA
-U1
MUZ-WR09NA
-U2
MUZ-WR12NA
-U1
MUZ-WR12NA
- U2
Capacity
Rated (Minimum~Maximum)
Cooling 1 Btu/h 9,000 ( 3,800 - 10,000 ) 12,000 ( 3,800 - 12,200 )
Heating 47 1 Btu/h 10,900 ( 4,500 - 11,800 ) 12,200 ( 4,500 - 14,500 )
Capacity
Rated (Maximum) Heating 17 2 Btu/h 6,700 (7,200) 7,600 (9,000)
Power consumption
Rated (Minimum~Maximum)
Cooling 1 W 820 (240 - 930) 1,330 (240 - 1,400)
Heating 47 1 W 980 (240 - 1,090) 1,090 (240 - 1,340)
Power consumption
Rated (Maximum) Heating 17 2 W 760 (850) 880 (1,090)
EER 1 [SEER] 3Cooling 11.0 [ 16.0 ] 9.0 [ 16.0 ]
HSPF IV 4Heating 8.5
COP Heating 13.25 3.28
Power factor Cooling (208/230) % 87/87 95/95
Heating (208/230) % 90/90 93/93
Power supply V , phase , Hz 208/230 , 1 , 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 9
Fan motor F.L.A A 0.50
Compressor
Model KNB073FRVMC KNB073FRXMC KNB073FRVMC KNB073FRXMC
R.L.A A 6.2
L.R.A A 7.7
Refrigeration oil
 oz. (L) (Model) 9.1 (0.27) (FV50S)
Refrigerant control Linear expansion valve
Sound level 1Cooling dB(A) 48 51
Heating dB(A) 50 51
Airow
High - Med. - Low
Cooling CFM 1,063 - 1,063 - 1,063
Heating CFM 1,282 - 1,105 - 1,105
Fan speed
High - Med. - Low
Cooling rpm 740 - 740 - 740
Heating rpm 890 - 770- 770
Defrost method Reverse cycle
Dimensions
W in. 31-1/2
D in. 11-1/4
H in. 21-5/8
Weight Ib. 73
External nish Munsell 3Y 7.8/1.1
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) 1 lb. 12 oz.
NOTE: Test conditions are based on AHRI 210/240.
1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB)
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB
3: Test condition (Refer to 3-1.)
4: Test condition (Refer to 3-1.)
OBH819B

5
Outdoor unit model MUZ-WR18NA MUZ-WR24NA
Capacity
Rated (Minimum~Maximum)
Cooling 1 Btu/h 17,200 (5,800 - 18,000) 22,500 (5,800 - 22,500)
Heating 47 1 Btu/h 18,000 (5,400 - 20,900) 26,000 (5,400 - 26,000)
Capacity
Rated (Maximum) Heating 17 2 Btu/h 11,500 (15,000) 18,500 (18,500)
Power consumption
Rated (Minimum~Maximum)
Cooling 1 W 1,720 (350 - 2,170) 2,810 (330 - 2,810)
Heating 47 1 W 1,670 (330 - 2,360) 2,680 (320 - 2,680)
Power consumption
Rated (Maximum) Heating 17 2 W 1,360 (2,040) 2,460 (2,460)
EER 1 [SEER] 3Cooling 10.0 [16.0] 8.0 [16.0]
HSPF IV 4Heating 8.5 8.5
COP Heating 13.16 2.84
Power factor Cooling (208/230) % 98/98 99/99
Heating (208/230) % 97/97 99/99
Power supply V , phase , Hz 208/230, 1, 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 10 14
Fan motor F.L.A A 0.50 0.93
Compressor
Model SNB130FQBMT
R.L.A A 7.4 10
L.R.A A 9.3 12.5
Refrigeration oil
 oz. (L) (Model) 11.8 (0.35) (FV50S)
Refrigerant control Linear expansion valve
Sound level 1Cooling dB(A) 53 57
Heating dB(A) 51 55
Airow
High - Med. - Low
Cooling CFM 1,102 - 1,102 - 639 1,742 - 1,742 - 922
Heating CFM 1,186 - 1,045 - 1,045 1,691 - 1,691 - 1,372
Fan speed
High - Med. - Low
Cooling rpm 810 - 810 - 490 840 - 840 - 450
Heating rpm 870 - 770 - 770 810 - 810 - 650
Defrost method Reverse cycle
Dimensions
W in. 31-1/2 33-1/16
D in. 11-1/4 13
H in. 21-5/8 34-5/8
Weight Ib. 81 121
External nish Munsell 3Y 7.8/1.1 Munsell 3Y 7.8/1.1
Refrigerant piping Not supplied Not supplied
Refrigerant pipe size
(Min. wall thickness)
Liquid in. 1/4 (0.0315) 3/8 (0.0315)
Gas in. 1/2 (0.0315) 5/8 (0.0315)
Connection method Indoor Flared
Outdoor Flared
Between the indoor &
outdoor units
Height difference ft. 40 50
Piping length ft. 65 100
Refrigerant charge (R410A) 2 lb. 10 oz. 3 lb. 9 oz.
NOTE: Test conditions are based on AHRI 210/240.
1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB)
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB
2: (Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 17˚FDB, 15˚FWB
3: Test condition (Refer to 3-1.)
4: Test condition (Refer to 3-1.)
OBH819B

6
3-1. TEST CONDITION
ARI Mode Test Indoor air condition (°F) Outdoor air condition (°F)
Dry bulb Wet bulb Dry bulb Wet bulb
SEER
(Cooling)
"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)
"B-1" Cooling steady state
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)
HSPF
(Heating)
"H1-2" Heating steady state
at rated compressor speed 70 60 47 43
"H3-2" Heating
at rated compressor speed 70 60 17 15
"H0-1" Heating steady state
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
= ("Rated compressor speed" - "minimum compressor speed") / 3 + "minimum compressor speed".
3, 4
(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 32 —
Maximum humidity 78 % —
Heating
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 5 4
3-2. 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
OBH819B

7
OUTLINES AND DIMENSIONS
4
Unit: inch
MUZ-WR09NA MUZ-WR12NA MUZ-WR18NA
4 in. (100 mm)
or more
14 in. (350 mm)
or more
8 in. (200 mm)
or more *2
4 in. (100 mm)
or more
Liquid refrigerant pipe joint
Refrigerant pipe (flared) Ø 1/4
Gas refrigerant pipe joint
Refrigerant pipe (flared) Ø 3/8 (WR09/12)
Ø
1/2 (WR18)
REQUIRED SPACE
clear *1
*1 4 in. (100 mm) or more when
front and sides of the unit are clear
*2 When any 2 sides of left, right
and rear of the unit are clear
holes
OBH819B

8
MUZ-WR24NA 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 3/8
Gas refrigerant pipe joint
Refrigerant pipe (flared) Ø 5/8
*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
OBH819B

9
5WIRING DIAGRAM
MUZ-WR09NA-U2 MUZ-WR12NA-U2
MUZ-WR09NA-U1 MUZ-WR12NA-U1
OBH819B

10
MUZ-WR18NA-U1
MUZ-WR18NA-U2
OBH819B