Mitsubishi Electric Mr. Slim MXZ-2B20NA User manual

Models
SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES· ·································· 2
2. PART NAMES AND FUNCTIONS····················· 2
3. SPECIFICATION················································ 3
4. NOISE CRITERIA CURVES······························ 4
5. OUTLINES AND DIMENSIONS ························ 5
6. WIRING DIAGRAM············································ 6
7. REFRIGERANT SYSTEM DIAGRAM··············· 7
8. DATA·································································· 9
9. ACTUATOR CONTROL··································· 17
10. SERVICE FUNCTIONS···································· 17
11. TROUBLESHOOTING····································· 18
12. DISASSEMBLY INSTRUCTIONS···················· 34
INDOOR UNITS COMBINATION SHEETS
No. OBH560
REVISED EDITION-A
The Slim Line.
From Mitsubishi Electric. TM
OUTDOOR UNIT
MXZ-2B20NA
MXZ-2B20NA - 1
MXZ-2B20NA
Indoor unit service manual
MSZ-A·NA Series (OB450)
MSZ-FD·NA Series (OBH497)
MSZ-FE·NA Series (OBH542)
MSZ-GE·NA Series (OBH548)
SEZ-KD·NA.TH Series
SPLIT-TYPE AIR CONDITIONERS
HFC
utilized
R410A
33223
9700058
Revision A:
• MXZ-2B20NA- 1has been added.

TECHNICAL CHANGES
2
1
PART NAMES AND FUNCTIONS
2
MXZ-2B20NA MXZ-2B20NA - 1
Air outlet
Drain outlet
Air inlet
(Back and side)
Revision A:
• MXZ-2B20NA- 1has been added.
MXZ-2B20NA
New model.
MXZ-2B20NA MXZ-2B20NA - 1
1. Outdoor fan motor has been changed.
2. Outdoor electronic control P.C. board has been changed.
3. LEV coil has been changed.

3
SPECIFICATION
3
Item
Outdoor model
Indoor type Wall (09+09) Duct (09+12)
Capacity
Power
consumption
EER
SEER
HSPF IV (V)
COP
External finish
Power supply
Max. fuse size (time delay)
Min. circuit ampacity
Fan motor
Compressor
Refrigerant control
Sound level
Defrost method
Dimensions
Weight
Remote controller
Control voltage (by built-in transformer)
Refrigerant piping
Valve size
Connection method
Refrigerant charge (R410A)
Refrigeration oil (Model)
Model
Winding resistance (at 68°F) Ω
W
D
H
Liquid
Gas
Indoor
Outdoor
Btu/h
Btu/h
Btu/h
W
W
W
V, phase, Hz
A
A
F.L.A
R.L.A
L.R.A
dB(A)
in.
in.
in.
lb.
in.
in.
lb.
oz.
Cooling
Heating 47
Heating 17
Cooling
Heating 47
Heating 17
Cooling
Cooling
Heating
Heating
MXZ-2B20NA MXZ-2B20NA -
Munsell 3.0Y 7.8/1.1
208/230, 1, 60
20
15
0.96
SNB130FQBH1
U-V 0.98 V-W 0.98 W-U 0.98
10.1
15
LEV
49/51
Reverse cycle
33-1/16
13
27-15/16
130
Wireless type
12-24 V DC
Not supplied (optional parts)
1/4
A,B: 3/8
Flared
Flared
5 lb. 15 oz.
23.7 (NEO22)
18,000
22,000
12,500
1,440
1,650
1,350
12.5
18.0
8.9 (7.0)
3.91
20,000
22,000
12,500
2,190
1,780
1,430
9.1
15.5
8.5 (6.9)
3.62
1
Cooling
Heating
Mode
1: "A" Cooling steady state at rated compressor speed
"B-2" Cooling steady state at rated compressor speed
"B-1" Cooling steady state at minimum compressor speed
Low ambient cooling steady state at minimum compressor speed
Intermediate cooling steady state at intermediate compressor speed
1: Standard rating-heating at rated compressor speed
2: Low temperature heating at maximum compressor speed
Maximum temperature heating at minimum compressor speed
High temperature heating at minimum compressor speed
Frost accumulation at rated compressor speed
Frost accumulation at intermediate compressor speed
Test Indoor air condition Outdoor air condition
Dry bulb Wet bulb Dry bulb Wet bulb
80
80
80
80
80
70
70
70
70
70
70
67
67
67
67
67
60
60
60
60
60
60
95
82
82
67
87
47
17
62
47
35
35
(75)
(65)
(65)
(53.5)
(69)
43
15
56.5
43
33
33
Unit: °F
NOTE : Test conditions are based on ARI 210/240.

4
90
80
70
60
50
40
30
20
10
63 125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, 0dB = 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
CoolingHigh
FUNCTION
FAN SPEED
HeatingHigh
49
SPL(dB(A))
51
LINE
NOISE CRITERIA CURVE
4
MXZ-2B20NA
MXZ-2B20NA - 1

5
OUTLINES AND DIMENSIONS
5
MXZ-2B20NA MXZ-2B20NA - 1Unit: inch
LIQ 1/4"FLARE
GAS 3/8"FLARE
Unit B
Unit A
LIQ
GAS
GAS
LIQ
1-3/16" 1/2"13"
2-5/8"
7-7/8"
9-7/16"
14-3/16"
11-3/4"
27-15/16"
1-3/16"33-1/16"
(Bolt Pitch)
3- (1-5/16") Drain Hole
4-(13/32"×13/16") Oval Hole
(Foundation Bolt M10)
Air
Discharge
Side Air Intake
Rear Air
Intake
1-7/32"
6-21/32"19-11/16"6-9/16"
17/32" 13/16"
9-3/16" 11-11/32"
21/32"
14-3/16"
2-1/2"
15-19/32"
11/16"11/16"
3- 7/8" Punched holes
(Connecting wire hole)
2-3/8"
1-3/16"
14-1/4"
5-5/16"
3-5/16"
1-25/32"
29/32"
1-5/32"
More than 3-15/16"
More than 19-11/16"
More than 7-7/8"
More than13-25/32"
More than 3-15/16"
More than 19-11/16"
More than 13-25/32"
More than 13-25/32"
More than 3-15/16"
SERVICE SPACE
More than 3-15/16"
More than 19-11/16"
Note : Leave front and both sides
clearance fully.
Note : Leave front and overhead
clearance fully.
Note : Leave rear, overhead and
both sides clearance fully.
1.Installation space
2.Service space
Lock nut Connector
Grounding terminal
Conduit
cover

6
WIRING DIAGRAM
6
MXZ-2B20NA
MXZ-2B20NA - 1

7
Stop valve with
service port
Stop valve
Strainer
#100
Power
receiver
LEV A
LEV B
Oil separator
Compressor
Defrost
thermistor
RT61
Distributor
Muffler
4-way valve
LEV E
Indoor unit
B
Indoor unit
A
Indoor unit
A
Indoor unit
B
Capillary tube
O.D.0.14 x I.D.0.09 x 19.68
Capillary tube
O.D.0.10 x I.D.0.02 x 39.37
Capillary tube
O.D.0.16 x I.D.0.11 x 3.93
Capillary tube
O.D.0.16 x I.D.0.11 x 3.93
Discharge
temperature
thermistor RT62
Strainer
#100
Strainer
#100
R.V. coil
OFF
ON
Refrigerant flow in cooling
Refrigerant flow in heating
Ambient
temperature
thermistor
RT65
Outdoor heat
exchanger
temperature
thermistor
RT68
FAN-OUT
HEX-OUT
Service
port
Service
port
Strainer
#100
REFRIGERANT SYSTEM DIAGRAM
7
Unit: mm
MXZ-2B20NA MXZ-2B20NA - 1

8
Refrigerant pipe diameter is different according to indoor unit to be connected. When using extension pipes, refer to the
tables below.
When diameter of refrigerant pipe is different from that of outdoor unit union, use optional Different-diameter pipe.
For further information on Different-diameter pipe. Unit: inch
It does not matter which unit is higher.
MAX. REFRIGERANT PIPING LENGTH & PIPE SIZE SELECTION
MXZ-2B20NA MXZ-2B20NA - 1
Operating Range MXZ-2B20NA MXZ-2B20NA - 1
Cooling
Heating
Maximum
Minimum
Maximum
Minimum
Indoor intake air temperature
95°FDB, 71°FWB
67°FDB, 57°FWB
80°FDB, 67°FWB
70°FDB, 60°FWB
Outdoor intake air temperature
115°FDB
14°FDB
75°FDB, 65°FWB
6°FDB, 5°FWB
a
b
Outdoor
unit
Indoor
units
49 ft.
33 ft.
49 ft.
Max. height difference
Indoor unit class Extension pipe diameter
09 or less Liquid 1/4
Gas 3/8
12 Liquid 1/4
Gas 3/8
15 Liquid 1/4
Gas 1/2
Outdoor unit union diameter
For
Indoor unit A Liquid 1/4
Gas 3/8
Indoor unit B Liquid 1/4
Gas 3/8
Piping length each indoor unit (a, b) 82 ft. MAX.
Total piping length (a+b) 164 ft. MAX.
Bending point for each unit 25 MAX.
Total bending point 60 MAX.

9
DATA
8
Model MXZ-2B20NA MXZ-2B20NA - 1
Indoor type Wall (09+09) Duct (09+12)
Item Unit Cooling Heating Cooling Heating
Total Capacity But/h 18,000 22,000 20,000 22,000
SHF – – – – –
Input kW 1.44 1.65 2.19 1.78
Electrical
circuit Power supply (V,phase,Hz) 208/230, 1, 60
Input kW 1.396 1.604 2.06 1.69
Comp. current (208/230V) A 6.08/5.87 7.25/6.80 9.81/8.87 7.98/7.22
Fan motor current A 0.43/0.39 0.43/0.39 0.43/0.39 0.43/0.39
Refrigerant
circuit Condensing pressure PSIG 411 319 417 350
Suction pressure PSIG 141 102 130 101
Discharge temperature ºF 169 154 174 172
Condensing temperature ºF 114 100 120 104
Suction temperature ºF 71 46 65 46
Comp. shell bottom temp. ºF 163 149 185 167
Ref. pipe length
[Total pipe length for multi-system] ft 82 [164]
Refrigerant charge (R410A) – 5 lb. 15 oz.
Outdoor
unit Intake air temperature DB ºF 95 47 95 47
WB ºF – 43 – 43
Fan speed rpm 650 700 650 700
Airflow CFM 1485 1640 1485 1640
8-1. OPERATING RANGE
(1) POWER SUPPLY
Outdoor unit
Rating
208/230 V 60 Hz 1
Guaranteed Voltage
Model
Min. 198 V Max. 253 V
208 V 230 V
MXZ-2B20NA
MXZ-2B20NA-
1

10
(2) OPERATION
Function
Cooling
Heating
"A" Cooling steady state
at rated compressor speed
"B-2" Cooling steady state
at rated compressor speed
"B-1" Cooling steady state
at minimum compressor speed
Low ambient cooling steady state
at minimum compressor speed
Intermediate cooling steady state
at intermediate compressor speed
Standard rating-heating
at rated compressor speed
Low temperature heating
at rated compressor speed
Max. temperature heating
at minimum compressor speed
High temperature heating
at minimum compressor speed
Frost accumulation
at rated compressor speed
Frost accumulation
at intermediate compressor speed
DB (°F)
80
80
80
80
80
70
70
70
70
70
70
WB (°F)
67
67
67
67
67
60
60
60
60
60
60
Indoor
DB (°F)
95
82
82
67
87
47
17
62
47
35
35
WB (°F)
(75)
(65)
(65)
(53.5)
(69)
43
15
56.5
43
33
33
Outdoor
Condition
Intake air
temperature