Mitsubishi Electric Mr. Slim MXZ-2A20NA User manual

Models
SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES· ·································· 2
2. PART NAMES AND FUNCTIONS····················· 6
3. INDOOR UNITS COMBINATION ······················ 7
4. SPECIFICATION·············································· 43
5. NOISE CRITERIA CURVES···························· 46
6. OUTLINES AND DIMENSIONS ······················ 47
7. WIRING DIAGRAM·········································· 52
8. REFRIGERANT SYSTEM DIAGRAM············· 58
9. DATA································································ 64
10. ACTUATOR CONTROL··································· 80
11. SERVICE FUNCTIONS···································· 80
12. TROUBLESHOOTING····································· 82
13. DISASSEMBLY INSTRUCTIONS·················· 100
14. PARTS LIST····················································112
15. RoHS PARTS LIST········································ 120
16. OPTIONAL PARTS········································ 136
No. OB444
REVISED EDITION-G
The Slim Line.
From Mitsubishi Electric. TM
OUTDOOR UNIT
MXZ-2A20NA
MXZ-2A20NA - 1
MXZ-2A20NA - 2
MXZ-3A30NA
MXZ-3A30NA - 1
MXZ-4A36NA
NOTE:
• This service manual describes technical
data of the outdoor units.
• RoHS compliant products have <G> mark
on the spec name plate.
For servicing of RoHS compliant products,
refer to the RoHS Parts List.
MXZ-2A20NA
MXZ-2A20NA - 1
Indoor unit service manual
MSZ-A·NA Series (OB450)
SEZ-KD·NA.TH Series
Revision G:
• SPECIFICATION, NOISE CRITERIA CURVES
and OPTIONAL PARTS have been modified.
Please void OB444 REVISED EDITION-F.
SPLIT-TYPE AIR CONDITIONERS
HFC
utilized
R410A
33223
9700058

TECHNICAL CHANGES
2
1
MXZ-2A20NA
New model
MXZ-30TN2 MXZ-3A30NA
1. Combinations of connectable indoor units have been increased.
2. capacity (BTU/h) class of connectable indoor units have been made larger.
3. Compressor has been changed. (THV247FBA TNB220FMCH)
4. Outdoor fan motor has been changed. (RA6N60-AA RC0J60-AB)
5. Refrigerant has been changed. (R22 R410A)
6. Refrigerant system diagram has been changed.
• 1 of 2 high pressure switch has been removed.
• Accumulator has been removed.
• Receiver has been added.
7. Communication system has been changed.
8. Power supply way has been changed (change to supply to outdoor unit).
9. Evaporation temperature thermistor has been added.
10. Ambient temperature thermistor has been added.
MXZ-2A20NA MXZ-2A20NA - 1
1. Compressor has been changed. (SNB130FPDH1 SNB130FQBH1)
2. Gas pipe temperature thermistor has been removed.
3. Pre-heat control has been added.
4. Electronic control P.C. board has been changed.
5. Power board has been changed.
MXZ-3A30NA MXZ-3A30NA - 1
1. Ball valve has been changed to stop valve.
2. Gas pipe temperature thermistor has been removed.
3. Pre-heat control has been added.
4. Auto line correcting function has been added.
5. Noise filter P.C. board has been changed.
6. Electronic control P.C. board has been changed.
7. Weight has been changed. (158lb. 148lb.)
Revision A:
• RoHS PARTS LIST has been added.
Revision B:
• MXZ-2A20NA - 1and MXZ-3A30NA - 1have been added.
Revision C:
• MXZ-4A36NA has been added.
Revision D:
• MXZ-2A20NA - 2has been added.
Revision E:
• Wiring diagrams of MXZ-2A20NA - 2MXZ-4A36NA have been corrected.
Revision F:
• Indoor units combinations for SEZ series have been added.
Revision G:
• SPECIFICATION, NOISE CRITERIA CURVES and OPTIONAL PARTS have been modified.

3
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
conditioners.
As R410A has working pressure approximately 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
installation, 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
piping.)
Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrigerant to prevent
composition change.
Refrigeration
oil
Refrigerant
New refrigerant
R410A
HFC-32: HFC-125 (50%:50%)
Pseudo-azeotropic refrigerant
Not included
A1/A1
72.6
-60.5
225.82
3.995
Non combustible
0
1730
From liquid phase in cylinder
Possible
Incompatible oil
None
None
Previous refrigerant
R22
R22 (100%)
Single refrigerant
Included
A1
86.5
-41.4
136.34
2.772
Non combustible
0.055
1700
Gas phase
Possible
Compatible oil
Light yellow
None
Refrigerant
Composition (Ratio)
Refrigerant handling
Chlorine
Safety group (ASHRAE)
Molecular weight
Boiling point (-˚F)
Steam pressure [77-˚F](PSIG)
Saturated steam density [77˚F](lb/ft3)
Combustibility
ODP 1
GWP 2
Refrigerant charge method
Additional charge on leakage
Kind
Color
Smell
1: Ozone Depletion Potential : based on CFC-11
2: Global Warming Potential : based on CO2
MXZ-4A36NA
New model
MXZ-2A20NA - 1MXZ-2A20NA - 2
1. Electronic control P.C. board has been changed.
2. Noise filter P.C. board has been changed.
3. Ball valve has been changed to stop valve.
4. Sub panel has been added.

4
R410A tools Can R22 tools be used?
Gas leak detector
R410A has high pressures beyond the measurement range of existing
gauges.
Hose material has been changed to improve the pressure resistance.
Dedicated for HFC refrigerant.
1/4in. and 3/8in.
Description
Clamp bar hole has been enlarged to reinforce the spring strength in the tool.
Provided for flaring work (to be used with R22 flare tool).
Provided to prevent the back flow of oil. This adapter enables you to use
vacuum pumps.
It is difficult to measure R410A with a charging cylinder because the
refrigerant bubbles due to high pressure and high-speed vaporization.
No
No
No
Yes
Yes
New
New
New
Gauge manifold
Charge hose
Torque wrench
Flare tool
Flare gauge
Vacuum pump
adapter
Electronic scale for
refrigerant charging
No : Not Substitutable for R410A Yes : Substitutable for R410A
No 1/2in. and 5/8in.
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.
New Specification Current Specification
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,
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
Compressor
-22 -4 14 32 50 68 86 104 122 140
-73
0
73
145
218
290
363
435
508
580
(PSIG)
R410A
R22
C
onversion chart of refrigerant temperature and pressure
Saturated liquid pressure
(°F)

5
R410A
Pipe diameter
(inch)
1/4
3/8
1/2
5/8
17 [11/16]
22 [7/8]
26 [1-1/32]
29 [1-5/32]
Dimension of flare nut
R22
(mm) [inch]
17 [11/16]
22 [7/8]
24 [15/16]
27 [1-1/16]
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”.
3. Refrigeration 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
circuit.
• 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, ability 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.
2. Refrigerant piping
Specifications
Use the copper or copper-alloy seamless pipes for refrigerant that meet the following specifications.
Wall thickness
(inch)
Outside diameter
(inch)
1/4
3/8
1/2
5/8
0.0315
0.0315
0.0315
0.0394
Heat resisting foam plastic
Specific gravity 0.045 Thickness 0.315 inch
Insulation material
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)

6
PART NAMES AND FUNCTIONS
2
MXZ-2A20NA MXZ-2A20NA - 1
MXZ-3A30NA
Air inlet
Drain outlet
(Back and side)
Air outlet
Air inlet
Drain outlet
(Back and side)
Air outlet
MXZ-3A30NA - 1MXZ-4A36NA
Air outlet
Drain outlet
Air inlet
(Back and side)
MXZ-2A20NA - 2
Air outlet
Drain outlet
Air inlet
(Back and side)

7
INDOOR UNITS COMBINATION
3
MXZ-2A20NA MXZ-2A20NA - 1MXZ-2A20NA- 2Cooling
Indoor units
combination Indoor type Cooling capacity (BTU/h) Power consumption (W) Current(A) Power
factor
(%)
A B Unit A Unit B Total 208V 230V
09
Wall — 9000 — 9000 730 3.69 3.34 95
( 5400 - 9000 ) ( 490 - 730 )
Duct — 9000 — 9000 750 3.80 3.43 95
( 5400 - 9000 ) ( 510 - 750 )
12
Wall — 12000 — 12000 990 5.01 4.53 95
( 5400 - 12000 ) ( 490 - 990 )
Duct — 12000 — 12000 1010 5.11 4.62 95
( 5400 - 12000 ) ( 510 - 1010 )
15
Wall — 15000 — 15000 1540 7.79 7.05 95
( 5400 - 15000 ) ( 490 - 1540 )
Duct — 15000 — 15000 1560 7.89 7.14 95
( 5400 - 15000 ) ( 510 - 1560 )
09+09
Wall Wall 9000 9000 18000 1740 8.62 7.80 97
( 7800 - 18000 ) ( 630 - 1740 )
Wall Duct 9000 9000 18000 1760 8.72 7.89 97
( 7800 - 18000 ) ( 650 - 1760 )
Duct Duct 9000 9000 18000 1780 8.82 7.98 97
( 7800 - 18000 ) ( 670 - 1780 )
09+12
Wall Wall 8500 11500 20000 2150 10.66 9.64 97
( 7800 - 20000 ) ( 630 - 2150 )
Wall Duct 8500 11500 20000 2170 10.76 9.73 97
( 7800 - 20000 ) ( 650 - 2170 )
Duct Wall 8500 11500 20000 2170 10.76 9.73 97
( 7800 - 20000 ) ( 650 - 2170 )
Duct Duct 8500 11500 20000 2190 10.85 9.82 97
( 7800 - 20000 ) ( 670 - 2190 )
09+15
Wall Wall 7500 12500 20000 2150 10.66 9.64 97
( 7800 - 20000 ) ( 630 - 2150 )
Wall Duct 7500 12500 20000 2170 10.76 9.73 97
( 7800 - 20000 ) ( 650 - 2170 )
Duct Wall 7500 12500 20000 2170 10.76 9.73 97
( 7800 - 20000 ) ( 650 - 2170 )
Duct Duct 7500 12500 20000 2190 10.85 9.82 97
( 7800 - 20000 ) ( 670 - 2190 )
12+12
Wall Wall 10000 10000 20000 2150 10.66 9.64 97
( 7800 - 20000 ) ( 630 - 2150 )
Wall Duct 10000 10000 20000 2170 10.76 9.73 97
( 7800 - 20000 ) ( 650 - 2170 )
Duct Duct 10000 10000 20000 2190 10.85 9.82 97
( 7800 - 20000 ) ( 670 - 2190 )

8
Indoor units
combination Indoor type Heating capacity (BTU/h) Power consumption (W) Current(A) Power
factor
(%)
A B Unit A Unit B Total 208V 230V
09
Wall — 10900 — 10900 940 4.76 4.30 95
( 5200 - 15400 ) ( 480 - 1430 )
Duct — 10900 — 10900 940 4.76 4.30 95
( 5200 - 15400 ) ( 480 - 1430 )
12
Wall — 13600 — 13600 1180 5.97 5.40 95
( 5200 - 16400 ) ( 480 - 1460 )
Duct — 13600 — 13600 1180 5.97 5.40 95
( 5200 - 16400 ) ( 480 - 1460 )
15
Wall — 18000 — 18000 1720 8.70 7.87 95
( 5200 - 21100 ) ( 480 - 2100 )
Duct — 18000 — 18000 1720 8.70 7.87 95
( 5200 - 21100 ) ( 480 - 2100 )
09+09
Wall Wall 10900 10900 21800 1820 9.02 8.16 97
( 8500 - 21800 ) ( 520 - 1820 )
Wall Duct 10900 10900 21800 1820 9.02 8.16 97
( 8500 - 21800 ) ( 520 - 1820 )
Duct Duct 10900 10900 21800 1820 9.02 8.16 97
( 8500 - 21800 ) ( 520 - 1820 )
09+12
Wall Wall 9500 12500 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Wall Duct 9500 12500 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Duct Wall 9500 12500 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Duct Duct 9500 12500 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
09+15
Wall Wall 8250 13750 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Wall Duct 8250 13750 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Duct Wall 8250 13750 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Duct Duct 8250 13750 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
12+12
Wall Wall 11000 11000 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Wall Duct 11000 11000 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
Duct Duct 11000 11000 22000 1780 8.82 7.98 97
( 8500 - 22000 ) ( 520 - 1780 )
MXZ-2A20NA MXZ-2A20NA - 1MXZ-2A20NA- 2Heating

9
MXZ-3A30NA MXZ-3A30NA - 1Cooling
Indoor units
combination Indoor type Cooling capacity (BTU/h) Power consumption (W) Current(A) Power
factor
(%)
A B C UnitA Unit B Unit C Total 208V 230V
09
Wall — — 9000 — — 9000 800 4.05 3.66 95
( 7200 - 9000 ) ( 650 - 800 )
Duct — — 9000 — — 9000 820 4.15 3.75 95
( 7200 - 9000 ) ( 670 - 820 )
12
Wall — — 12000 — — 12000 1000 5.06 4.58 95
( 7200 - 12000 ) ( 650 - 1000 )
Duct — — 12000 — — 12000 1020 5.16 4.67 95
( 7200 - 12000 ) ( 670 - 1020 )
15
Wall — — 15000 — — 15000 1320 6.68 6.04 95
( 7200 - 15000 ) ( 650 - 1320 )
Duct — — 15000 — — 15000 1340 6.78 6.13 95
( 7200 - 15000 ) ( 670 - 1340 )
17 Wall — — 16200 — — 16200 1480 7.49 6.77 95
( 7200 - 16200 ) ( 650 - 1480 )
18 Duct — — 17200 — — 17200 1590 8.05 7.28 95
( 7200 - 17200 ) ( 670 - 1590 )
24 Wall — — 22000 — — 22000 2200 11.13 10.07 95
( 7200 - 22000 ) ( 650 - 2200 )
09+09
Wall Wall — 9000 9000 — 18000 1800 8.92 8.07 97
( 12000 - 18000 ) ( 920 - 1800 )
Wall Duct — 9000 9000 — 18000 1820 9.02 8.16 97
( 12000 - 18000 ) ( 940 - 1820 )
Duct Duct — 9000 9000 — 18000 1840 9.12 8.25 97
( 12000 - 18000 ) ( 960 - 1840 )
09+12
Wall Wall — 9000 12000 — 21000 2000 9.91 8.96 97
( 12000 - 21000 ) ( 920 - 2000 )
Wall Duct — 9000 12000 — 21000 2020 10.01 9.05 97
( 12000 - 21000 ) ( 940 - 2020 )
Duct Wall — 9000 12000 — 21000 2020 10.01 9.05 97
( 12000 - 21000 ) ( 940 - 2020 )
Duct Duct — 9000 12000 — 21000 2040 10.11 9.14 97
( 12000 - 21000 ) ( 960 - 2040 )
09+15
Wall Wall — 9000 15000 — 24000 2500 12.39 11.21 97
( 12000 - 24000 ) ( 920 - 2500 )
Wall Duct — 9000 15000 — 24000 2520 12.49 11.30 97
( 12000 - 24000 ) ( 940 - 2520 )
Duct Wall — 9000 15000 — 24000 2520 12.49 11.30 97
( 12000 - 24000 ) ( 940 - 2520 )
Duct Duct — 9000 15000 — 24000 2540 12.59 11.39 97
( 12000 - 24000 ) ( 960 - 2540 )
09+17
Wall Wall — 9000 16200 — 25200 2700 13.38 12.10 97
( 12000 - 25200 ) ( 920 - 2700 )
Duct Wall — 9000 16200 — 25200 2720 13.48 12.19 97
( 12000 - 25200 ) ( 940 - 2720 )
09+18
Wall Duct — 8900 17100 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
Duct Duct — 8900 17100 — 26000 2840 14.08 12.73 97
( 12000 - 26000 ) ( 960 - 2840 )

10
Indoor units
combination Indoor type Cooling capacity (BTU/h) Power consumption (W) Current(A) Power
factor
(%)
A B C UnitA Unit B Unit C Total 208V 230V
09+24
Wall Wall — 7600 20400 — 28000 3200 15.86 14.34 97
( 12000 - 28000 ) ( 920 - 3200 )
Duct Wall — 7600 20400 — 28000 3220 15.96 14.43 97
( 12000 - 28000 ) ( 940 - 3220 )
12+12
Wall Wall — 12000 12000 — 24000 2500 12.39 11.21 97
( 12000 - 24000 ) ( 920 - 2500 )
Wall Duct — 12000 12000 — 24000 2520 12.49 11.30 97
( 12000 - 24000 ) ( 940 - 2520 )
Duct Duct — 12000 12000 — 24000 2540 12.59 11.39 97
( 12000 - 24000 ) ( 960 - 2540 )
12+15
Wall Wall — 11500 14500 — 26000 2800 13.88 12.55 97
( 12000 - 26000 ) ( 920 - 2800 )
Wall Duct — 11500 14500 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
Duct Wall — 11500 14500 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
Duct Duct — 11500 14500 — 26000 2840 14.08 12.73 97
( 12000 - 26000 ) ( 960 - 2840 )
12+17
Wall Wall — 10800 15200 — 26000 2800 13.88 12.55 97
( 12000 - 26000 ) ( 920 - 2800 )
Duct Wall — 10800 15200 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
12+18
Wall Duct — 10400 15600 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
Duct Duct — 10400 15600 — 26000 2840 14.08 12.73 97
( 12000 - 26000 ) ( 960 - 2840 )
15+15
Wall Wall — 13000 13000 — 26000 2800 13.88 12.55 97
( 12000 - 26000 ) ( 920 - 2800 )
Wall Duct — 13000 13000 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
Duct Duct — 13000 13000 — 26000 2840 14.08 12.73 97
( 12000 - 26000 ) ( 960 - 2840 )
15+17
Wall Wall — 12200 13800 — 26000 2800 13.88 12.55 97
( 12000 - 26000 ) ( 920 - 2800 )
Duct Wall — 12200 13800 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
15+18
Wall Duct — 11800 14200 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
Duct Duct — 11800 14200 — 26000 2840 14.08 12.73 97
( 12000 - 26000 ) ( 960 - 2840 )
17+17 Wall Wall — 13000 13000 — 26000 2800 13.88 12.55 97
( 12000 - 26000 ) ( 920 - 2800 )
17+18 Wall Duct — 12600 13400 — 26000 2820 13.98 12.64 97
( 12000 - 26000 ) ( 940 - 2820 )
18+18 Duct Duct — 13000 13000 — 26000 2840 14.08 12.73 97
( 12000 - 26000 ) ( 960 - 2840 )