OUTDOOR UNIT SERVICE MANUAL HFC

Models

SERVICE MANUAL

CONTENTS

1. TECHNICAL CHANGES ··································· 22. PART NAMES AND FUNCTIONS ····················· 23. SPECIFICATION ················································ 34. NOISE CRITERIA CURVES ······························ 75. OUTLINES AND DIMENSIONS ························ 86. WIRING DIAGRAM ···········································117. REFRIGERANT SYSTEM DIAGRAM ············· 138. DATA ································································ 19

9. ACTUATOR CONTROL ··································· 3710. SERVICE FUNCTIONS ···································· 3711. TROUBLESHOOTING ····································· 3912. DISASSEMBLY INSTRUCTIONS ···················· 57

INDOOR UNITS COMBINATION SHEETS

No. OBH560REVISED EDITION-C

The Slim Line.From Mitsubishi Electric.

TM

OUTDOOR UNIT

MXZ-2B20NA, - 1

MXZ-3B24NAMXZ-3B30NAMXZ-4B36NA

MXZ-2B20NA

Indoor unit service manualMSZ-A·NA Series (OB450)MSZ-FD·NA Series (OBH497)MSZ-FE·NA Series (OBH542)MSZ-GE·NA Series (OBH548)MFZ-KA·NA Series(OBH568)SEZ-KD·NA.TH Series

SPLIT-TYPE AIR CONDITIONERS

HFCutilized

R410A

332239700058

Revision C:• MXZ-3B30NA has been added.

Please void OBH560 REVISED EDITION-B.

PARTS CATALOG (OBB560)

TECHNICAL CHANGES

2

1

PART NAMES AND FUNCTIONS2

MXZ-2B20NA

Air outlet

Drain outlet

Air inlet(Back and side)

Revision B:• MXZ-3B24NA and MXZ-4B36NA have been added.

MXZ-2B20NANew 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.

MXZ-3B24NA New model

MXZ-3B30NA New model

MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

Air outlet

Drain outlet

Air inlet(Back and side)

Revision A:• MXZ-2B20NA- 1 has been added.

Revision C:• MXZ-3B30NA has been added.

3

SPECIFICATION3

ItemOutdoor model

Indoor type Non-Duct (09+09) Duct (09+12)

Capacity

Powerconsumption

EERSEERHSPF IV (V)COPExternal finishPower supplyMax. fuse size (time delay)Min. circuit ampacityFan motor

Compressor

Refrigerant controlSound level Defrost method

Dimensions

WeightRemote controllerControl voltage (by built-in transformer)Refrigerant piping

Valve size

Connection method

Refrigerant charge (R410A)Refrigeration oil (Model)

ModelWinding resistance (at 68°F) Ω

WDH

LiquidGasIndoorOutdoor

Btu/hBtu/hBtu/h

WWW

V, phase, HzAA

F.L.A

R.L.AL.R.A

dB(A)

in.in.in.lb.

in.in.

lb.oz.

CoolingHeating 47Heating 17CoolingHeating 47Heating 17CoolingCoolingHeatingHeating

MXZ-2B20NA

Munsell 3.0Y 7.8/1.1208/230, 1, 60

2015

0.96SNB130FQBH1

U-V 0.98 V-W 0.98 W-U 0.9810.115

LEV49/51

Reverse cycle33-1/16

1327-15/16

130Wireless type12-24 V DC

Not supplied (optional parts)1/4

A,B: 3/8FlaredFlared

5 lb. 15 oz.23.7 (NEO22)

18,00022,00014,5001,4401,6501,50012.5018.0

8.9 (7.0)3.91

20,00022,00012,5002,1901,7801,4309.1015.5

8.5 (6.9)3.62

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 speedIntermediate 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 speedHigh temperature heating at minimum compressor speedFrost accumulation at rated compressor speedFrost accumulation at intermediate compressor speed

TestIndoor air condition Outdoor air conditionDry bulb Wet bulb Dry bulb Wet bulb

8080808080707070707070

6767676767606060606060

9582826787471762473535

(75)(65)(65)

(53.5)(69)4315

56.5433333

Unit: °F

NOTE : Test conditions are based on ARI 210/240.

4

Item

Outdoor modelIndoor type Non-Duct (06+06+09) Duct (09+09+09)

Capacity

Powerconsumption


Compressor


Dimensions


Valve size

Connection method



WDH


Btu/hBtu/hBtu/h

WWW

V, phase, Hz AA

F.L.A

R.L.AL.R.A

dB(A)

in.in.in.lb.

in.in.

lb.oz.

22,00025,00018,8001,7601,7502,12012.5017.5

9.3 (7.0)4.20

23,60024,60017,0002,4601,9002,2309.6015.0

8.5 (6.9)3.80

Munsell 3.0Y 7.8/1.1208/230, 1, 60

2015

0.93TNB220FMCH

U-V 0.61 V-W 0.61 W-U 0.611115

LEV54/49


12-19/3235-7/16



A: 1/2 B,C: 3/8FlaredFlared

7 lb. 11 oz.29.4 (NEO22)


MXZ-3B24NA

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 speedIntermediate 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 speedHigh temperature heating at minimum compressor speedFrost accumulation at rated compressor speedFrost accumulation at intermediate compressor speed


8080808080707070707070

6767676767606060606060

9582826787471762473535

(75)(65)(65)

(53.5)(69)4315

56.5433333

Unit: °F


5

Item

Outdoor modelIndoor type Non-Duct (06+06+09) Duct (09+09+09)

Capacity

Powerconsumption


Compressor


Dimensions


Valve size

Connection method



WDH


Btu/hBtu/hBtu/h

WWW

V, phase, Hz AA

F.L.A

R.L.AL.R.A

dB(A)

in.in.in.lb.

in.in.

lb.oz.

28,40028,60018,8003,1202,1502,1209.1017.5

10.5 (7.2)3.90

27,40027,60018,0003,3302,2202,1408.2314.5

9.5 (7.0)3.64

Munsell 3.0Y 7.8/1.1208/230, 1, 60

2015

0.93TNB220FMCH

U-V 0.61 V-W 0.61 W-U 0.611115

LEV49/49


12-19/3235-7/16



A: 1/2 B,C: 3/8FlaredFlared

7 lb. 11 oz.29.4 (NEO22)


MXZ-3B30NA

Cooling

Heating

Mode



8080808080707070707070

6767676767606060606060

9582826787471762473535

(75)(65)(65)

(53.5)(69)4315

56.5433333

Unit: °F

6

Item

Outdoor modelIndoor type Non-Duct (09+09+09+09) Duct (09+09+09+09)

Capacity

Powerconsumption


Compressor


Dimensions


Valve size

Connection method



WDH


Btu/h

Btu/h

Btu/hW

W

W

V, phase, Hz AA

F.L.A

R.L.AL.R.A

dB(A)

in.in.in.lb.

in.in.

lb.oz.

35,40036,00036,000

24,6003,7603,0203,0203,3409.4018.0

9.3 (7.2)3.50

34,40034,40034,400

25,4003,9403,1003,1003,4508.7015.0

9.0(7.0)3.25

Munsell 3.0Y 7.8/1.1208/230, 1, 60

2019

0.93TNB220FMCH

U-V 0.61 V-W 0.61 W-U 0.6114.415

LEV54/57

Reverse cycle35-7/1612-19/3235-7/16



A: 1/2 B,C,D: 3/8FlaredFlared

8 lb. 13 oz.29.4 (NEO22)

Cooling

Heating 47

Heating 17Cooling

Heating 47

Heating 17CoolingCoolingHeatingHeating

MXZ-4B36NA

208 V230 V

208 V230 V

208 V230 V

208 V230 V

Cooling

Heating

Mode



8080808080707070707070

6767676767606060606060

9582826787471762473535

(75)(65)(65)

(53.5)(69)4315

56.5433333

Unit: °F


7

90

80

70

60

50

40

30

20

1063 125 250 500 1000 2000 4000 8000

APPROXIMATETHRESHOLD OFHEARING FORCONTINUOUSNOISE

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

OC

TAVE

BA

ND

SO

UN

D P

RES

SUR

E LE

VEL,

0dB

= 0

.000

2 M

ICR

O B

AR

BAND CENTER FREQUENCIES, Hz

CoolingHigh

FUNCTIONFAN SPEED

HeatingHigh

49

SPL(dB(A))

51

LINE

NOISE CRITERIA CURVES4

MXZ-2B20NA

90

80

70

60

50

40

30

20

1063 125 250 500 1000 2000 4000 8000


NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

OC

TAVE

BA

ND

SO

UN

D P

RES

SUR

E LE

VEL,

0dB

= 0

.000

2 M

ICR

O B

AR


CoolingHigh

FUNCTIONFAN SPEED

HeatingHigh

54

SPL(dB(A))

57

LINE

90

80

70

60

50

40

30

20

1063 125 250 500 1000 2000 4000 8000


NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

OC

TAVE

BA

ND

SO

UN

D P

RES

SUR

E LE

VEL,

0dB

= 0

.000

2 M

ICR

O B

AR


CoolingHigh

FUNCTIONFAN SPEED

HeatingHigh

54

SPL(dB(A))

49

LINE

MXZ-4B36NA

MXZ-3B24NA

MXZ-3B30NA

90

80

70

60

50

40

30

20

1063 125 250 500 1000 2000 4000 8000


NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

OC

TAVE

BA

ND

SO

UN

D P

RES

SUR

E LE

VEL,

0dB

= 0

.000

2 M

ICR

O B

AR


CoolingHigh

FUNCTIONFAN SPEED

HeatingHigh

49

SPL(dB(A))

49

LINE

8

OUTLINES AND DIMENSIONS5

MXZ-2B20NA Unit: inch

LIQ 1/4"FLAREGAS 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"

27-1

5/16

"

1-3/16"33-1/16"

(Bol

t Pitc

h)

3- (1-5/16") Drain Hole

4-(13/32"×13/16") Oval Hole(Foundation Bolt M10)

AirDischarge

Side Air Intake

Rear AirIntake

1-7/

32"

6-21/32"19-11/16"6-9/16"

17/3

2"13

/16"

9-3/16" 11-11/32"

21/3

2"

14-3

/16"

2-1/2"

15-1

9/32

"

11/1

6"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"

Mor

e th

an 1

9-11

/16"

Mor

e th

an 7

-7/8

"

More than13-25/32"

Mor

e th

an 3

-15/

16"

Mor

e th

an 1

9-11

/16"

More than 13-25/32"More than 13-25/32"

More than 3-15/16"SERVICE SPACE

More than 3-15/16"

Mor

e th

an 1

9-11

/16"

Note : Leave front and both sides free of obstruction.

Note : Leave front and overhead free of obstruction.

Note : Leave rear, overhead and both sides free of obstruction.

1.Installation space

2.Service space

Lock nut Connector

Grounding terminalConduitcover

9

MXZ-3B24NAMXZ-3B30NA

Unit: inch

A

B

C

15/1

6"7/

16"

5/8"

5/8"1-1/

16"

1-9/

16"

14"

15-1

/4"

10-5/8"9-27/32"

1-3/8"

19-11/16" 7-7/8"7-7/8"2-

29/3

2"

1-3/

8"

(Bol

t pitc

h)

Air in

Air out

Air in

2-(15/32" x 1-13/32") Oval hole

2-U Shaped notched hole (Base bolt M10)

3- 7/8"Punched hole(Connect wiring hole)

35-7/16"

(Connect wiring hole)2- 7/8"Knockout

Handle

Handle8-

27/3

2"

1-25

/32"

19-1

/8"

12-1/2"

18-1

/8"

29/32"

13/32"12-19/32"1-3/16"

3-15/32"

Gas pipe 3/8 (B,C unit) 1/2 (A unit)

More than 3-15/16"

Mor

e th

an 1

9-11

/16"

Mor

e th

an 7

-7/8

"

More than13-25/32"

Mor

e th

an 3

-15/

16"

Mor

e th

an 1

9-11

/16"



More than 3-15/16"

Mor

e th

an 1

9-11

/16"

5-3/

16"

Liquid pipe 1/4 flared

35-7

/16"

1-3/

16"

4-3/

4"

(Base bolt M10)

Drain hole 3- 1-5/16"

Note : Leave front and both sidesfree of obstruction.

Note : Leave front and overheadfree of obstruction.

Note : Leave rear, overhead and both sidesfree of obstruction.


2.Service space

C unit connectionB unit connectionA unit connection

Conduit coverLock nut Connector

10

MXZ-4B36NA

A

B

C

D

15/1

6"7/

16"

5/8"

5/8"

1-1/

16"

1-9/

16"

14"

15-1

/4"

10-5/8"9-27/32"

1-3/8"

19-11/16" 7-7/8"7-7/8"

2-29

/32"

1-3/

8"

(Bol

t pitc

h)

Air in

Air out

Air in

2-(15/32" x 1-13/32") Oval hole

2-U Shaped notched hole (Base bolt M10)

3- 7/8"Punched hole(Connect wiring hole)

35-7/16"

(Connect wiring hole)2- 7/8"Knockout

Handle

Handle

12-1

3/32

"

1-25

/32"

19-1

/8"

12-1/2"

18-1

/8"

29/32"

13/32"12-19/32"1-3/16"

3-15/32"

Gas pipe 3/8 (B,C,D unit) 1/2 (A unit)

More than 3-15/16"

Mor

e th

an 1

9-11

/16"

Mor

e th

an 7

-7/8

"

More than13-25/32"

Mor

e th

an 3

-15/

16"

Mor

e th

an 1

9-11

/16"



More than 3-15/16"

Mor

e th

an 1

9-11

/16"

5-3/

16"

Liquid pipe 1/4 flared

35-7

/16"

1-3/

16"

4-3/

4"

(Base bolt M10)

Drain hole 3- 1-5/16"

Note : Leave front and both sidesfree of obstruction.

Note : Leave front and overheadfree of obstruction.

Note : Leave rear, overhead and both sidesfree of obstruction.


2.Service space

C unit connectionD unit connection

B unit connectionA unit connection

Conduit coverLock nut Connector

Unit: inch

11

WIRING DIAGRAM6

MXZ-2B20NA

MXZ-2B20NA - 1

12

MXZ-3B24NAMXZ-3B30NA

MXZ-4B36NA

13

Stop valve withservice port

Stop valveStrainer#100

Powerreceiver

LEV A

LEV B

Oil separator

Compressor

DefrostthermistorRT61

Distributor

Muffler

4-way valve

LEV E

Indoor unitB

Indoor unitA

Indoor unitA

Indoor unitB

Capillary tube O.D.0.14 x I.D.0.09 x 19.68


Capillary tubeO.D.0.16 x I.D.0.11 x 3.93


Dischargetemperaturethermistor RT62

Strainer#100

Strainer#100

R.V. coilOFFON

Refrigerant flow in coolingRefrigerant flow in heating

AmbienttemperaturethermistorRT65

Outdoor heatexchangertemperaturethermistorRT68

FAN-OUT

HE

X-O

UT

Serviceport

Serviceport

Strainer#100

REFRIGERANT SYSTEM DIAGRAM7

Unit: inchMXZ-2B20NA

14

Refrigerant pipe diameter is different according to indoor unit to be connected. When using extension pipes, refer to the tables below.

When the diameter of refrigerant pipe is different from that of outdoor unit union, use optional Different-diameter pipe. For further information on Different-diameter pipe, see the appropriate parts catalog, Optional parts "DIFFERENT DIAMETER PIPE"(2-1.).

Unit: inch

It is irrelevant which unit is higher.

MAX. REFRIGERANT PIPING LENGTH & PIPE SIZE SELECTIONMXZ-2B20NA

Operating Range MXZ-2B20NA

Cooling

Heating

MaximumMinimumMaximumMinimum

Indoor intake air temperature95°FDB, 71°FWB67°FDB, 57°FWB80°FDB, 67°FWB70°FDB, 60°FWB

Outdoor intake air temperature115°FDB14°FDB

75°FDB, 65°FWB6°FDB, 5°FWB

a

b

Outdoorunit

Indoorunits

49 ft.

33 ft.

49 ft.

Max. height difference

Indoor unit class Extension pipe diameter

09 or less Liquid 1/4Gas 3/8

12 Liquid 1/4Gas 3/8

15 Liquid 1/4Gas 1/2

Outdoor unit union diameterFor

Indoor unit A Liquid 1/4Gas 3/8

Indoor unit B Liquid 1/4Gas 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 50 MAX.

15

Stop valve (with service port)

Stop valve

Powerreceiver

LEV A

LEV B

LEV C

Oil separator

Compressor

Muffler

4-way valve

LEV F

Indoor unitC

Indoor unitB

Indoor unitA

Indoor unitA

Indoor unitB

Indoor unitC




Service port

Serviceport

Strainer#100

Strainer#100

Strainer#100

Strainer#100

R.V. coil OFF ON


Strainer#100 Distributor

Outdoorheatexchanger



Outdoor heat exchangertemperaturethermistorRT68


High-pressureswitch

Unit: inchMXZ-3B24NAMXZ-3B30NA

16



Unit : inch

Piping length each indoor unit (a, b, c) 82 ft. MAX. Total piping length (a+b+c) 230 ft. MAX. Bending point for each unit 25 MAX. Total bending point 70 MAX.


MAX. REFRIGERANT PIPING LENGTH & PIPE SIZE SELECTIONMXZ-3B24NA MXZ-3B30NA

Operating Range MXZ-3B24NA MXZ-3B30NA

Cooling

Heating





a

c

Outdoorunit

Indoorunits


49 ft.

33 ft.

b 49 ft.


09 or lessLiquid 1/4Gas 3/8

12Liquid 1/4Gas 3/8

15Liquid 1/4Gas 1/2

17Liquid 1/4Gas 1/2

18Liquid 1/4Gas 1/2

24 (MXZ-3B30NA only)Liquid 1/4Gas 5/8


Indoor unit ALiquid 1/4Gas 1/2

Indoor unit BLiquid 1/4Gas 3/8

Indoor unit CLiquid 1/4Gas 3/8

17

Stop valve (with service port)

Stop valve

Powerreceiver

LEV A

LEV B

LEV C

Oil separator

Compressor

Muffler

4-way valve

LEV F

Indoor unitC

Indoor unitB

Indoor unitA

Indoor unitA

Indoor unitB

Indoor unitC




Service port

Serviceport

Strainer#100

Strainer#100

Strainer#100

Strainer#100

R.V. coil OFF ON


Strainer#100 Distributor

Outdoorheatexchanger



Outdoor heat exchangertemperaturethermistorRT68


High-pressureswitch

Indoor unitD

LEV DIndoor unit

D Strainer#100

MXZ-4B36NA Unit: inch

18



Unit : inch

Piping length each indoor unit (a, b, c, d) 82 ft. MAX. Total piping length (a+b+c+d) 230 ft. MAX. Bending point for each unit 25 MAX. Total bending point 70 MAX.


MAX. REFRIGERANT PIPING LENGTH & PIPE SIZE SELECTIONMXZ-4B36NA

Operating Range MXZ-4B36NA

a

b

c

d

Outdoorunit

Indoorunits

49 ft.

33 ft.

49 ft.


Cooling

Heating






09 or lessLiquid 1/4Gas 3/8

12Liquid 1/4Gas 3/8

15Liquid 1/4Gas 1/2

17Liquid 1/4Gas 1/2

18Liquid 1/4Gas 1/2

24Liquid 1/4Gas 5/8


Indoor unit ALiquid 1/4Gas 1/2

Indoor unit BLiquid 1/4Gas 3/8

Indoor unit CLiquid 1/4Gas 3/8

Indoor unit DLiquid 1/4Gas 3/8

19

DATA8

Model MXZ-2B20NAIndoor type Non-Duct (09+09) Duct (09+12)Item Unit Cooling Heating Cooling HeatingTotal Capacity But/h 18,000 22,000 20,000 22,000

SHF – – – – –Input kW 1.44 1.65 2.19 1.78

Electricalcircuit

Power supply (V,phase,Hz) 208/230, 1, 60Input kW 1.396 1.604 2.06 1.69Comp. current (208/230V) A 6.08/5.87 7.25/6.80 9.81/8.87 7.98/7.22Fan motor current A 0.43/0.39 0.43/0.39 0.43/0.39 0.43/0.39

Refrigerantcircuit

Condensing pressure PSIG 411 319 417 350Suction pressure PSIG 141 102 130 101Discharge temperature ºF 169 154 174 172Condensing temperature ºF 114 100 120 104Suction temperature ºF 71 46 65 46Comp. shell bottom temp. ºF 163 149 185 167Ref. pipe length[Total pipe length for multi-system] ft 25 [50]

Refrigerant charge (R410A) – 5 lb. 15 oz.Outdoorunit

Intake air temperature DB ºF 95 47 95 47WB ºF – 43 – 43

Fan speed rpm 650 700 650 700Airfl ow CFM 1485 1640 1485 1640

Model MXZ-3B24NAIndoor type Non-Duct (06+06+09) Duct (09+09+09)Item Unit Cooling Heating Cooling HeatingTotal Capacity But/h 22,000 25,000 23,600 24,600

SHF – – – – –Input kW 1.76 1.75 2.46 1.9

Electricalcircuit

Outdoor unit MXZ-3B24NAPower supply (V,phase,Hz) 208/230,1,60Input kW 1.694 1.681 2.28 1.78Comp. current (208/230V) A 8.00/7.23 7.94/7.18 10.90/9.86 8.43/7.62Fan motor current A 0.43/0.39 0.43/0.39 0.43/0.39 0.43/0.39

Refrigerantcircuit

Condensing pressure PSIG 394 296 408 324Suction pressure PSIG 158 98 139 100Discharge temperature ºF 173 153 167 164Condensing temperature ºF 115 93 117 99Suction temperature ºF 79 47 58 49Comp. shell bottom temp. ºF 159 134 153 144Ref. pipe length[Total pipe length for multi-system] ft 25[75]

Refrigerant charge (R410A) – 7 lb.11 oz.Outdoorunit


Fan speed rpm 750 600 750 600Airfl ow CFM 2,068 1,605 2,068 1,605

20

Model MXZ-4B36NAIndoor type Non-Duct (09+09+09+09) Duct (09+09+09+09)Item Unit Cooling Heating Cooling HeatingTotal Capacity But/h 35,400 36,000 34,400 34,400

SHF – – – – –Input kW 3.76 3.02 3.94 3.1

Electricalcircuit


Refrigerantcircuit





Model MXZ-3B30NAIndoor type Non-Duct (09+09+12) Duct (09+09+09)Item Unit Cooling Heating Cooling HeatingTotal Capacity But/h 28,400 28,600 27,400 27,600

SHF – – – – –Input kW 3.12 2.15 3.33 2.22

Electricalcircuit


Refrigerantcircuit





21

(2) OPERATION

Function

Cooling

Heating

"A" Cooling steady stateat rated compressor speed "B-2" Cooling steady state at rated compressor speed"B-1" Cooling steady state at minimum compressor speedLow ambient cooling steady state at minimum compressor speedIntermediate cooling steady state at intermediate compressor speedStandard rating-heating at rated compressor speedLow temperature heatingat rated compressor speedMax. temperature heatingat minimum compressor speedHigh temperature heating at minimum compressor speedFrost accumulationat rated compressor speedFrost accumulationat 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

8-1. OPERATING RANGE(1) POWER SUPPLY

Outdoor unit

Rating

208/230 V 60 Hz 1

Guaranteed VoltageModel

Min. 198 V Max. 253 V208 V 230 VMXZ-2B20NAMXZ-3B24NAMXZ-3B30NAMXZ-4B36NA

22

MXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NAThe standard specifications apply only to the operation of the air conditioner under normal conditions.Since operating conditions vary according to the areas where these units are installed, the following information has been pro-vided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.(1) GUARANTEED VOLTAGE 198 ~ 253 V 60 Hz(2) AIR FLOW Air flow should be set at MAX.(3) MAIN READINGS (1) Indoor intake air wet-bulb temperature : °FWB (2) Indoor outlet air wet-bulb temperature : °FWB (3) Outdoor intake air dry-bulb temperature : °FDB (4) Total input: W (5) Indoor intake air dry-bulb temperature : °FDB (6) Outdoor intake air wet-bulb temperature : °FWB (7) Total input : W

Indoor air wet/dry-bulb temperature difference on the left side of the following chart shows the difference between the indoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for your reference at service.

}}

Cooling

Heating

How to measure the indoor air wet-bulb/dry-bulb temperature difference1. Attach at least 2 sets of wet and dry-bulb thermometers to the indoor air intake as shown in the figure, and at least 2 sets

of wet and dry-bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where air speed is high.

2. Attach at least 2 sets of wet and dry-bulb thermometers to the outdoor air intake. Cover the thermometers to prevent direct rays of the sun.3. Check that the air filter is cleaned.4. Open windows and doors of room.5. Press the EMERGENCY OPERATION switch once (twice) to start the EMERGENCY COOL (HEAT) MODE.6. Compressor starts running at 33 Hz (COOL) or 45 Hz (HEAT). The frequency at each operation mode is fixed.7. When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.8. 10 minutes later, measure temperature again and check that the temperature does not change.

INDOOR UNIT OUTDOOR UNIT

Wet-and dry-bulbthermometers

Wet-and dry-bulbthermometers

23

09 c

lass

(47H

z)

12 c

lass

(59H

z)

15 c

lass

(78H

z)

Indo

or u

nit c

lass

(Inve

rter

out

put

freq

uenc

y)In

door

air

DB

tem

pera

ture

diffe

renc

e (d

egre

e)

22.120.518.717.115.313.711.910.3

8.56.8

32.830.227.725.222.720.217.615.112.610.1

40.937.634.631.328.325.022.018.915.712.6

06 c

lass

(31H

z)

47.543.740.136.532.829.225.622.018.214.6

Outdoor intake air Wet-bulb temperature (°F) 5 14 23 32 41 50 59

0.40.50.60.70.80.91.01.11.21.3

Heating capacity (at Rated frequency)

Cap

acity

cor

rect

ion

fact

or

596879


0.40.50.60.70.80.91.01.11.21.3

Total input (Heating : at Rated frequency)

Inpu

t cor

rect

ion

fact

or

596879

Indoor intake air D

ry-bulb temperature (°F)

Indoor intake air Dry-bulb temperature (°F)

NOTE: The above broken lines are for the heating operation without any frost and defrost operation.

0.8

0.9

1.0

1.1

1.2

1.3

14 23 32 41 50 59 68 77 86 95 104 113

Outdoor intake air Dry-bulb temperature (°F)

Inpu

t cor

rect

ion

fact

ors

79 75 726864

Indoor intake air Wet-bulbtemperature( F)

Total input (Cooling : at Rated frequency)

09 c

lass

(35H

z)

15 c

lass

(69H

z)

12 c

lass

(50H

z)

Indo

or u

nit c

lass

(Inve

rter

out

put

freq

uenc

y)In

door

air

WB

tem

pera

ture

diffe

renc

e (d

egre

e)

7.2

6.7

6.1

5.6

5.0

4.7

4.1

11.2

10.3

9.5

8.6

7.9

7.0

6.3

13.5

12.4

11.5

10.4

9.5

8.6

7.6

06 c

lass

(25H

z)

14.4

13.1

12.1

11.2

10.1

9.0

8.1

Cooling capacity (at Rated frequency)

0.9

1.0

1.1

1.2

1.3

1.4

1.5

14 23 32 41 50 59 68 77 86 95 104 113

Outdoor intake air Dry-bulb temperature(°F)

Cap

acity

cor

rect

ion

fact

ors

79

75

6864

72

Indoor intake air Wet-bulbtemperature(°F)

8-2. CAPACITY AND THE INPUT CURVES MXZ-2B20NA

24

06 c

lass

(15H

z)

*24

clas

s(5

6Hz)

18 c

lass

(49H

z)

15 c

lass

(33H

z)

12 c

lass

(29H

z)

Indo

or u

nit c

lass

(Inve

rter

out

put

freq

uenc

y)In

door

air

WB

tem

pera

ture

diffe

renc

e (d

egre

e)

09 c

lass

(20H

z)

11.2

10.3

9.5

8.6

7.9

7.0

6.3

7.7

7.2

6.7

6.1

5.6

5.0

4.5

13.5

12.4

11.5

10.4

9.5

8.6

7.6

13.1

12.2

11.2

10.3

9.4

8.5

7.6

19.3

17.8

16.2

14.8

13.3

12.1

10.6

16.7

15.5

14.2

13.0

11.7

10.6

9.4

Cooling capacity (at Rated frequency)

0.9

1.0

1.1

1.2

1.3

1.4

1.5

14 23 32 41 50 59 68 77 86 95 104 113

Outdoor intake air Dry-bulb temperature(°F)

Cap

acity

cor

rect

ion

fact

ors

79

75

6864

72

Indoor intake air Wet-bulbtemperature(°F)


0.8

0.9

1.0

1.1

1.2

1.3

14 23 32 41 50 59 68 77 86 95 104 113

Outdoor intake air Dry-bulb temperature (°F)

79 75 726864

Inpu

t cor

rect

ion

fact

ors

Indoor intake air Wet-bulbtemperature( F)

Total input (Cooling : at Rated frequency)

09 c

lass

(26H

z)

12 c

lass

(32H

z)

15 c

lass

(44H

z)

*24

clas

s(7

2Hz)

18 c

lass

(50H

z)

Indo

or u

nit c

lass

(Inve

rter

out

put

freq

uenc

y)In

door

air

DB

tem

pera

ture

diffe

renc

e (d

egre

e)

47.343.740.136.432.829.225.621.818.214.6

51.547.543.639.635.631.727.723.819.815.8

32.830.227.725.222.720.217.615.112.610.1

23.421.619.818.016.214.412.610.8

9.07.2

43.240.036.533.329.926.623.220.016.613.3

47.543.740.136.532.829.225.622.018.214.6

06 c

lass

(18H

z) Outdoor intake air Wet-bulb temperature (°F) 5 14 23 32 41 50 59

0.40.50.60.70.80.91.01.11.21.3

Heating capacity (at Rated frequency)

Cap

acity

cor

rect

ion

fact

or

5968

779


0.40.50.60.70.80.91.01.11.21.3

Total input (Heating : at Rated frequency)

Inpu

t cor

rect

ion

fact

or

596879

Indoor intake air D

ry-bulb temperature (°F)

Indoor intake air Dry-bulb temperature (°F)

* MXZ-3B30/4B36NA only

NOTE: The above broken lines are for the heating operation without any frost and defrost operation.

25

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz

<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz

<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz

2. 09-class unit in single operation



0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100 0 50 100

1.0

1.5

2.0

2.5<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz


0.5

1.0

1.5

2.0

2.5

0.5

8-3. CAPACITY AND INPUT CORRECTION BY MEANS OF INVERTER OUTPUT FREQUENCY (OUTDOOR UNIT: MXZ-2B20NA)

26

(OUTDOOR UNIT: MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA)

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

0.5

1.0

1.5

2.0

0 50 100

1.0

1.5

2.0

2.5

Frequency

<HEAT>Total input

Hz

0.5

<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz

<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz

<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz


<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz




5. 18-class unit in single operation<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input <HEAT>Capacity

Frequency Frequency

<HEAT>Total input

6. 24-class unit in single operation (MXZ-3B30/4B36NA only)<COOL>Capacity

FrequencyHz

Frequency

<COOL>Total input

Hz

<HEAT>Capacity

FrequencyHz

Frequency

<HEAT>Total input

Hz

0 50 100

0.5

1.0

1.5

2.0

Hz0 50 100

0.5

1.0

1.5

2.0

Hz0 50 100

0.5

1.0

1.5

2.0

Hz0 50 100

0.5

1.0

1.5

2.0

27

8-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT1. 06-class unit in single operation (OUTDOOR UNIT: MXZ-2B20NA)(1) COOL operation

Data is based on the condition of indoor humidity 50%

Air flow speed: High Inverter output frequency: 40 Hz

65 70 75 80 85 90 95 100 105 110 115 120

130

140

150

160

170

Ambient temperature (°F)

(°F)

86

80

75

70

Indoor DB temperature (°F)

65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(°F)

(°F)15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

48 Hz

(PSIG)

40 Hz

40 Hz

65

7570

86807570Indoor DB temperature (°F)


<How to work fixed-frequency operation> 1. Set emergency switch to COOL or HEAT. The switch is located

on indoor unit.2. Press emergency run ON/OFF button.3. Compressor starts running at 40 Hz (COOL) or 48 Hz (HEAT).4. Indoor fan runs at High speed and continues for 30 minutes.5. To cancel this operation, press emergency run ON/OFF button

or any button on remote controller.

(2) HEAT operation Data is based on the condition of indoor humidity 75%

Set air flow to High speed. Inverter output frequency is 48 Hz.

28

2. 09-class unit in single operation (OUTDOOR UNIT: MXZ-2B20NA)(1) COOL operation



(2) HEAT operation

65 70 75 80 85 90 95 100 105 110 115 120

130

140

150

160

170


(°F)

86

80

75

70


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(°F)

(°F)15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

48 Hz

(PSIG)

40 Hz

40 Hz

65

7570

86807570Indoor DB temperature (°F)







29


65 70 75 80 85 90 95 100 105 110 115120

140

150

160

170

130

Ambient temperature (˚F)

(˚F)

86

80

75

70

86807570

15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)

(PSIG)

Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

48 Hz

40 Hz

40 Hz

657075

Indoor DB temperature (˚F)










30


65 70 75 80 85 90 95 100 105 110 115120

130

140

150

160

170


(˚F)

86

80

75

70

86807570

15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)

(PSIG)

Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

48 Hz

40 Hz

40 Hz

657075











31

5. 06-class unit in single operation (OUTDOOR UNIT : MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA)(1) COOL operation


Air flow speed : HighInverter output frequency : 24 Hz

(2) HEAT operation




65 70 75 80 85 90 95 100 105 110 115110

120

130

140

150

160


(˚F)

86

80

75

70


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

32 Hz

(PSIG)

24 Hz

24 Hz

65

7570

86807570Indoor DB temperature (˚F)


Data is based on the condition of outdoor humidity 75%.


32




65 70 75 80 85 90 95 100 105 110 115110

120

130

140

150

160


(˚F)

86

80

75

70


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

32 Hz

(PSIG)

24 Hz

24 Hz

65

7570

86807570Indoor DB temperature (˚F)


(2) HEAT operationData is based on the condition of outdoor

humidity 75%.Set air flow to High speed. Inverter output frequency is 32 Hz.




33


65 70 75 80 85 90 95 100 105 110 115110

120

130

140

150

160


(˚F)

86

80

75

70

86807570

15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)

(PSIG)

Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

32 Hz

24 Hz

24 Hz

657075





(2) HEAT operation







34


65 70 75 80 85 90 95 100 105 110 115120

130

140

150

160

170


(˚F)

86

80

75

70

86807570

15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)

(PSIG)

Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

32 Hz

24 Hz

24 Hz

657075





humidity 75%Set air flow to High speed. Inverter output frequency is 32 Hz.


Data is based on the condition of indoor humidity 50% <How to work fixed-frequency operation>

1. Set emergency switch to COOL or HEAT. The switch is located on indoor unit.

2. Press emergency run ON/OFF button.3. Compressor starts running at 24 Hz (COOL) or 32 Hz (HEAT).4. Indoor fan runs at High speed and continues for 30 minutes.5. To cancel this operation, press emergency run ON/OFF button


35


(2) HEAT operation

65 70 75 80 85 90 95 100 105 110 115120

130

140

150

160

170


(˚F)

86

80

75

70

86807570

15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


65 70 75 80 85 90 95 100 105 110 1150.0

1.0

2.0

3.0

4.0

5.0

6.0


(˚F)

(˚F)

(PSIG)

Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

32 Hz

24 Hz

24 Hz

657075











36

10. 24-class unit in single operation (OUTDOOR UNIT : MXZ-4B36NA)(1) COOL operation

65 70 75 80 85 90 95 100 105 110 115130

140

150

160

170

180


(˚F)

15 20 25 30 35 40 45 50 55 60 65 70 752.0

3.0

4.0

5.0

6.0

7.0


65 70 75 80 85 90 95 100 105 110 1151.0

2.0

3.0

4.0

5.0

6.0

7.0


(˚F)

(˚F)

(PSIG)

Out

door

low

pre

ssur

e

Out

door

uni

t cur

rent

(A)

Out

door

uni

t cur

rent

(A)

32 Hz

24 Hz

24 Hz

86807570

757065




86

80

75

70


humidity 75%Set air flow to High speed. Inverter output frequency is 32 Hz.


Data is based on the condition of indoor humidity 50% <How to work fixed-frequency operation>

1. Set emergency switch to COOL or HEAT. The switch is located on indoor unit.

2. Press emergency run ON/OFF button.3. Compressor starts running at 24 Hz (COOL) or 32 Hz (HEAT).4. Indoor fan runs at High speed and continues for 30 minutes.5. To cancel this operation, press emergency run ON/OFF button


37

SERVICE FUNCTIONS10

ACTUATOR CONTROL9

Relation between main sensor and actuatorMXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

Discharge temperature thermistor

Indoor coil thermistor

Defrost thermistorFin temperature thermistor

Ambient temperature thermistor

Outdoor heat exchanger temperature

Capacity code

Purpose

Protection

Defrosting Protection

DefrostingProtection

Control

Protection

Control

Compressor LEV Outdoorfan motor

4-wayvalve

SensorActuator

10-1. PRE-HEAT CONTROLIf moisture gets into the refrigerant cycle, or when refrigerant is liquefied and collected in the compressor, it may interfere the start-up of the compressor.To improve start-up condition, the compressor is energized even while it is not operating. This is to generate heat at the winding.The compressor uses about 50 W when pre-heat control is turned ON.Pre-heat control is ON at initial setting.

[How to deactivate pre-heat control]

Turn OFF the power supply for the air conditioner before making the setting. Set the 4th Dip Switch of SW1 on the outdoor electronic control P.C. board to ON to deactivate pre-heat control func-tion.

Set the 4th Dip Switch of SW2 on the outdoor electronic control P.C. board to ON to deactivate pre-heat control func-tion (MXZ-3B24NA, MXZ-3B30NA, MXZ-4B36NA).

ONSW1

1 2 3 4

ON

1 2 3 4

SW1 MXZ-2B20NA

Turn ON the power supply for the air conditioner.

NOTE: Pre-heat control will be turned OFF when the breaker is turned OFF.

ONSW2

1 2 3 4 5 6

ONSW2

1 2 3 4 5 6

MXZ-3B24NAMXZ-3B30NA MXZ-4B36NA

SW2SW1

SW871

38

10-2. AUTO LINE CORRECTING <MXZ-3B24NA, MXZ-3B30NA, MXZ-4B36NA>Outdoor unit has an auto line correcting function which automaticallydetects and corrects improper wiring or piping.

Improper wiring or piping can be automatically detected by pressing the piping/wiring correction switch (SW871). When improper wiring or piping is detected, wiring lines are corrected.This will be completed in about 10 to 15 minutes.

[How to activate this function]

1. Check that outside temperature is above 32˚F. (This function does not work when outside temperature is not above 32˚F.) 2. Check that the stop valves of the liquid pipe and gas pipe are open. 3. Check that the wiring between indoor and outdoor unit is correct. (If the wiring is not correct, this function does not work.) 4. Turn ON the power supply and wait at least 1 minute. 5. Press the piping/wiring correction switch (SW871) on the electronic control P.C. board. Do not touch energized parts.

6. Press the switch to cancel.

NOTE : Indoor unit cannot be operated while this function is activated. When this function is activated while indoor unit is operating, the operation will be stopped. Operate indoor unit after the auto line correcting is finished. Pressing the switch during detection cancels this function.

SW871

Make sure that the valves are open and the pipes are not collapsed or clogged.

LED indication after cancel :

LED1 (Red)Lighting

LED indication during detection:

LED indication after detection:

LED2 (Yellow)Lighting

LED3 (Green)Blinking

LED1 (Red)Lighting

LED2 (Yellow)Lighting

LED3 (Green)Goes out

LED1 (Red)LightingBlinking

LED2 (Yellow)Goes outBlinking

Other indications

LED3 (Green)LightingBlinking

Completed (Detected successfully)Cannot be correctedRefer to "SAFETY PRECAUTIONS WHEN LED FLASHES"located behind the service panel.

Indication

SW871

Press the switch for more than 5 seconds.LED will show the record of auto correcting for about 30 seconds as shown in the table below:

NOTE : Activate this function to confirm the correct wiring after replacing the electronic control P.C. board. (Previous records are deleted when the electronic control P.C. board is replaced.) The record cannot be shown if auto line correcting is not canceled (Refer to "How to activate this function").

LED1 (Red)Once

3 times

LED2 (Yellow)Once

3 times

LED3 (Green)LightingLighting

Not correctedCorrected

Number of blinks Wiring line

The record of auto line correcting can be confirmed in the following way:

39

11

3. Troubleshooting procedure1) 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) If the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the com-

ponents for bursting and discoloration.3) When troubleshooting, refer to 11-2, 11-3 and 11-4.

Lead wiring Housing point

11-1. CAUTIONS ON TROUBLESHOOTING1. Before troubleshooting, check the following:

1) Check the power supply voltage.2) Check the indoor/outdoor connecting wire for mis-wiring.

2. Take care of the following during servicing.1) Before servicing the air conditioner, be sure to turn off the unit first with the remote controller, and then after confirm-

ing 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.

MXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

11-2. FAILURE MODE RECALL FUNCTIONThis air conditioner can memorize the abnormal condition which has occurred once.Even though LED indication listed on the troubleshooting check table (11-4.) disappears, the memorized failure detailscan be recalled.This mode is very useful when the unit needs to be repaired for the abnormality which does not recur.

1. Type of failure mode recall functionThere are 2 types in failure mode recall function as shown below.

Indoor and outdoor unit failure mode recall function With this function, failure mode of indoor unit and a part of failure mode of outdoor unit can be recalled.

The details of outdoor unit failure mode recall function With this function, more detailed failure mode of outdoor unit can be recalled.

Refer to the service manual of indoor unit for how to recall the failure mode and the details of indoor unit failure mode.The outdoor unit failure mode is indicated by the operation indicator lamp on the indoor unit and the LED of outdoor unit.See "11-2.2. Outdoor unit failure mode table".

TROUBLESHOOTING

40

The left lamp of OPERATION INDICATOR

lamp (Indoor unit)

OFF2-time flash

3-time flash

4-time flash

5-time flash

6-time flash

7-time flash

8-time flash

Lighting LightingLighting Lighting

Lighting Once

Lighting OnceLighting TwiceLighting 3 timesLighting 4 times

Lighting 9 times

Once Goes out

Lighting Lighting

Lighting Lighting

3 times Goesout

4 times Goesout

Lighting Lighting

Lighting Lighting

Lighting 5 times9-time flash

10-time flash

• Replace the outdoor electronic control P.C. board.


•Check refrigerant circuit and refrigerant amount.• Refer to 11-6. "Check of LEV".

• Reconnect compressor connector.• Refer to 11-6. "How to check inverter/ compressor".• Check the stop valve.

•Check refrigerant circuit and refrigerant amount.• Check the stop valve.

• Refer to 11-6. "Check of outdoor fan motor".

•Check refrigerant circuit and refrigerant amount.• Refer to 11-6. "Check of LEV".

• Check around outdoor unit.• Check outdoor unit air passage.• Refer to 11-6. "Check of outdoor fan motor".

• Check the connection of the compressor connecting wire.• Refer to 11-6. "How to check inverter/compressor".• Check the stop valve.

• Refer to 11-6. "Check of outdoor thermistors".


When overcurrent protection stop is continuously performed three times within 1 minute after the compressor gets started, or when converterprotection stop or bus-bar voltageprotection stop is continuouslyperformed three times within 3minutes after start-up.

When thermistor shorts or opens during compressor running.

When 28A current flows into intelligentpower module.

When discharge temperature exceeds 240.8°F during operation. Compressor can restart if dischargetemperature thermistor reads 212°F or less 3 minutes later.

When the outdoor heat exchangertemperature exceeds 158°Fduring cooling or the indoor gaspipe temperature exceeds 158°Fduring heating.

When the fin temperature exceeds188.6°F during operation.

When the P.C. board temperatureexceeds 158°F during operation.

When failure occurs continuouslythree times within 30 seconds afterthe fan gets started.

When nonvolatile memory datacannot be read properly.

When the frequency of thecompressor is kept 80Hz ormore and the dischargetemperature is kept under 102.2°Ffor more than 20 minutes.

Outdoor power system

Discharge temperaturethermistor

Defrost thermistorAmbient temperature thermistorFin temperature thermistorP.C. board temperaturethermistor

Outdoor heat exchanger temperature thermistor

Overcurrent

Discharge temperature

High pressure

Fin temperature

P.C. board temperature

Outdoor fan motor

Nonvolatile memory data

Discharge temperature

None (Normal)

Abnormal point(Failure mode/protection)

Condition RemedyIndoor/outdoor

unit failure moderecall function

LED indication(Outdoor P.C. board)LED 1 LED 2

2. Outdoor unit failure mode table

NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (11-4.).

41

Operation start

Check the outdoor unit LED indicator.

Refer to 11-6. "Check of power supply".

• Indoor unit serial signal errorRefer to 11-6. "How to checkmis-wiring andserial signalerror".

• COOL or HEAToperation onlyRefer to 11-6. "Check of R.V. coil".

• When cooling, room is not cool.Refer to 11-6."How to checkinverter/compressor".

• When cooling, heat exchanger of non-operating indoor unit frosts.•When heating, non- operating indoor unit gets warm.Refer to 11-6. "Check of LEV".

• When heating,room does not get warm.Refer to 11-6."How to checkinverter/compressor".Check mis-piping, shortage of capacity.

• When coolingdew drops in thenon-operatingindoor unit.Check ofmiss-piping.

Refer to 11-4. "Troubleshooting check table".

Both LED1 andLED2 are OFF.

Both LED 1 and LED 2 are lighting.

LED 1 or LED 2has blinked.

11-3. INSTRUCTION OF TROUBLESHOOTING• Check the indoor unit with referring to the indoor unit service manual, and confirm that there is any problem in the indoor unit. Then, check the outdoor unit with referring to this page.

11-time flash

15-time flash

• Check the connecting wire between outdoor electronic control P.C. board and power board.

• Replace the power board.

• Check the connecting wire among electronic control P.C. board, noise filter P.C. board and power board.

• Check the voltage of power supply.• Replace the power board.

• Check the voltage of power supply.• Replace the outdoor electronic control P.C. board.

• Refer to 11-6. "Check of LEV". • Check the drain pump of the indoor unit.

When the communication betweenboards protection stop iscontinuously performed twice.

Communication error occursbetween the electronic control P.C.board and power board for morethan 10 seconds.

Current sensor protection stop iscontinuously performed twice.

When a short or open circuit isdetected in the current sensorduring compressor operating.

The protection stop of the zerocross detecting circuit iscontinuously performed 10 times.

When zero cross signal cannot bedetected while the compressor isoperating.

When a failure is detected in theoperation of the converter duringoperation.When the bus-bar voltage exceeds400V or falls to 200V or belowduring compressor operating.When the bus-bar voltage exceeds400V or falls to 50V or below duringcompressor operating.

Communication errorbetween P.C. boards

Current sensor

Zero cross detecting circuit

Converter

Bus-bar voltage(1)

Bus-bar voltage(2) Even if this protection stop isperformed continuously threetimes, it does not mean theabnormality in outdoor powersystem.

LEV for drain

Lighting 6 times

Lighting 7 times

5 times Goesout

5 times Goesout

5 times

6 times

Goesout

Goesout

When the indoor unit detects anyabnormal in the LEV for drain.

Lighting Lighting

Abnormal point(Failure mode/protection)

Condition RemedyIndoor/outdoor

unit failure moderecall function

LED indication(Outdoor P.C. board)LED 1 LED 2

The left lamp of OPERATION INDICATOR

lamp(Indoor unit)

NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (11-4.).

42

11-4. TROUBLESHOOTING CHECK TABLE

LED2 LED1

Outdoor electronic control P.C. board (Parts side)

Lighting

LED1 LED2

Lighting

LED1(Red) LED2(Yellow)

Lighting Twice Outdoor power system

• Check the connection of the compressor connecting wire.• Refer to 11-6. "How to check inverter/compressor". • Check the stop valve.

Lighting 3 times Discharge temperaturethermistor


Outdoor heat exchangertemperature thermistor

Defrost thermistor

Lighting 7 times Nonvolatile memory data • Replace the outdoor electronic control P.C. board.

Lighting 8 times Current sensor • Replace the power board.

Lighting 11 times Communication errorbetween P.C. boards


Lighting 12 times Zero cross detectingcircuit

• Check the connecting wire among outdoor electronic control P.C. board, noise filter P.C. board and power board.

Abnormal point / Condition Correspondence

When a short circuit is detected in the thermistor during operation, orwhen an open circuit is detected in the thermistor after 5 minutes (incooling) and 10 minutes (in heating) of compressor start-up.

When a short circuit is detected in the thermistor during operation, orwhen an open circuit is detected in the thermistor after 5 minutes ofcompressor start-up.




Indication

When over current protection stop is continuously performed three times within 1 minute after the compressor gets started, or when converter protection stop or bus-bar voltage protection stop is continuously performed three times within 3 minutes after start-up.

When a short circuit is detected in the thermistor during operation, orwhen an open circuit is detected in the thermistor after 10 minutes of compressor start-up.

Condition

When the nonvolatile memory data cannot be read properly.

Fin temperaturethermistorP.C board temperaturethermistor

Lighting 4 times

Ambient temperaturethermistor

Current sensor protection stop is continuously performed twice.

When the communication protection stop between boards is continuously performed twice.

The protection stop of the zero cross detecting circuit is continuouslyperformed 10 times.

When a short or open circuit is detected in the thermistor duringoperation.

When a short or open circuit is detected in the thermistor duringoperation.

5 timesLighting

IPM protection

Lock protection

3 times Goes out Discharge temperatureprotection

Fin temperatureprotectionP.C. board temperatureprotection

High-pressureprotection

8 times Goes out Converter protection • Replace the power board.

Bus-bar voltageprotection (1)

• Check the voltage of power supply.• Replace the power board or the outdoor electronic control P.C. board.• Refer to 11-6. "Check of bus-bar voltage".

Bus-bar voltageprotection (2)

13 times Goes out Outdoor fan motor • Refer to 11-6. "Check of outdoor fan motor".

Lighting 8 timesCurrent sensorprotection • Replace the power board.

Lighting 11 times Communication between P.C.boards protection


Lighting 12 times Zero cross detecting circuitprotection

• Check the connecting wire among outdoor electronic control P.C. board, noise filter P.C. board and power board.

• Check around of gas and the refrigerant circuit.• Check of stop valve.

• Check the amount of gas and refrigerant circuit.• Refer to 11-6. "Check of LEV".

•Check refrigerant circuit and refrigerant amount.•Refer to 11-6. "Check of outdoor fan motor".

• Reconnect compressor connector.• Refer to 11-6. "How to check inverter/compressor". • Check the stop valve.• Check the power module (PAM module).

Twice Goes out

4 times Goes out

5 times Goes out

9 times Goes out

When overcurrent is detected after 30 minutes of compressor start-up.

When overcurrent is detected within 30 minutes of compressor start-up

When the bus-bar voltage exceeds 400V or falls to 200V or below during compressor operating.When the bus-bar voltage exceeds 400V or falls to 50V or below during compressor operating.

When discharge temperature exceeds 240.8°F during operation. Compressor can restart if discharge temperature thermistor reads 212°For less 3 minutes later.

When the fin temperature exceeds 188.6°F during operation.

When the P.C. board temperature exceeds 158°F during operation.

When failure occurs continuously three times within 30 seconds after the fan gets started.When a short or open circuit is detected in the current sensor duringcompressor operating.Communication error occurs between the outdoor electronic control P.C. board and power board for more than 10 seconds.When zero cross signal cannot be detected while the compressor isoperating.

When high-pressure is detected with the high-pressure switch (HPS)during operation. (MXZ-3B24NA, MXZ-3B30NA, MXZ-4B36NA)When the outdoor heat exchanger temperature exceeds 158°Fduring cooling or when indoor gas pipe temperature exceeds 158°Fduring heating.When a failure is detected in the operation of the converter duringoperation.

Outdoor unit does not operate.

Lighting Once LEV for drain • Refer to 11-6. "Check of LEV".• Check the drain pump of the indoor unit.When the indoor unit detects any abnormality in the LEV for drain.

No.

1

2

3

4

5

6

7

9

8

10

11

12

13

14

15

16

17

18

19

Symptom

'Outdoor unit stops and restarts 3 minuteslater' is repeated.

MXZ-2B20NA

MXZ-3B24NA, MXZ-3B30NAMXZ-4B36NA

The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.(Example) When the flashing frequency is “2”.

ON

OFF2.5-second OFF 2.5-second OFF

0.5-second ON 0.5-second ON

NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.1. 2. LED is lighted during normal operation.

43

Primary current protection

Secondary current protection

High-pressure protection

Defrosting in cooling

3 times Lighting Discharge temperatureprotection

• Check refrigerant circuit and refrigerant amount.• Refer t1 11-6. "Check of LEV".• Refer to 11-6. "Check of outdoor thermistors".

4 times LightingLow dischargetemperature protection

• Refer to 11-6. "Check of LEV".• Check refrigerant circuit and refrigerant amount.

5 times LightingCooling high-pressureprotection

This symptom does not mean any abnormality of theproduct, but check the following points.• Check if indoor filters are clogged. • Check if refrigerant is short.• Check if indoor/outdoor unit air circulation is short cycled.

-

-

These symptoms do not mean any abnormality of theproduct, but check the following points.• Check if indoor filters are clogged.• Check if refrigerant is short.• Check if indoor/outdoor unit air circulation is short cycled.Twice Lighting

Once Lighting

When the frequency of the compressor is kept 80Hz or more and the discharge temperature is kept under 122°F(COOL mode)/104°F(HEAT mode) for more than 40 minutes.

When the frequency of the compressor is kept 80Hz or more and the discharge temperature is kept under 102.2°F for more than 20minutes.

When the outdoor heat exchanger temperature exceeds 136.4°Fduring operation.

9 times Lighting Inverter check mode

Lighting Lighting Normal

When the unit is operated with emergency operation switch.

-

When the input current exceeds 15A.

When the current of the compressor exceeds 15A.

When the indoor gas pipe temperature exceeds 113°F during heating.

When the indoor gas pipe temperature falls 37.4°F or below during cooling.

Outdoor electronic control P.C. board(Parts side)

LED2 LED1

Lighting

MXZ-2B20NA

LED1 LED2

Lighting

MXZ-3B24NA, MXZ-3B30NAMXZ-4B36NA

LED1(Red) LED2(Yellow)Abnormal point / Condition RemedyIndication Condition

Outdoor unit operates.

Outdoor unitoperatesnormally.

No. Symptom

21

22

23

24

25

26

27

The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.(Example) When the flashing frequency is “2”.

ON

OFF2.5-second OFF 2.5-second OFF

0.5-second ON 0.5-second ON

NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.1. 2. LED is lighted during normal operation.

44

11-5. TROUBLE CRITERION OF MAIN PARTS MXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

Normal

Discharge temperaturethermistor (RT62)

Fin temperaturethermistor (RT64)

Measure the resistance using a tester. (Part temperature: 14°F ~ 104°F)

Part name Check method and criterion

1.2 k Ω ~1.56 kΩ

Measure the resistance between terminals using a tester.(Winding temperature: 14°F ~ 104°F)

Compressor

Measure the resistance between lead wires using a tester.(Part temperature: 14°F ~ 104°F)

Outdoor fan motor

R.V. coil

Measure the resistance using a tester. (Part temperature: 14°F ~ 104°F)

13.4 Ω ~ 16.4 Ω

Normal (Each phase)

13 Ω ~ 16 ΩMXZ-2B20NA - MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

Defrost thermistor (RT61)

Ambient temperaturethermistor (RT65)Outdoor heat exchangertemperature thermistor(RT68)

Measure the resistance with a tester.

Refer to 11-7. “Test point diagram and voltage”,1. “Outdoor electronic control P.C.board”, or 3. “Outdoor power board” , for the chart of thermistor.

Measure the resistance with a tester.Before measurement, hold the thermistor with your hands to warm it up.Refer to 11-7. “Test point diagram and voltage”,1. “Outdoor electronic control P.C.board”, for the chart of thermistor.

MXZ-2B20NA

0.86 Ω ~ 1.06 Ω 1.29 Ω ~ 1.49 ΩMXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

Normal (Each phase)

MXZ-2B20NA

MXZ-2B20NA -MXZ-3B24NAMXZ-3B30NAMXZ-4B36NA

1

Linear expansion valve

LEV

WHT

RED

YLW BRN

ORN

BLU

The other models

WHT - REDRED - ORN 37.4 Ω ~ 53.9 Ω

Normal

YLW -- BLU

Color of lead wire

MXZ-2B20NA

WHT - REDRED - ORNYLW - REDRED - BLUBRN

BRN

High pressure switch(HPS)MXZ-3B24NAMXZ-3B30NAMXZ-4B36NA

Pressure Normal

HPS537 ± 22 PSIG696 PSIG Open

Close+ 7- 15

1

W

UVWHT

RED

BLK

URED

WHT

BLK

V

W

(W)

(V)

(U)

LEV

WHT

RED

YLW

ORN

BLU

45

Check of power supply

Outdoor unit does not operate.

Turn ON the power supply.

No

Yes

Yes

No

Yes

No

Yes

No Replace the power board.

Check the connecting of parts of main power supply circuit.

Is there voltage of 208/230 V AC in the power supply terminal block?

Is the output voltage from the noisefilter P.C. board 208/230 V AC?

Is the input voltage to the outdoor electronic control P.C. board 294/325 V DC?

Check the power supply cable.

Replace the outdoor electronic control P.C. board.

Replace the noise filter P.C. board.

Is the input voltage to the power board208/230 V AC? Replace the reactor.

11-6. TROUBLESHOOTING FLOWMXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

46

Is there rated voltage in the power supply ?

Is there any mis-wiring, poor contact, or wire disconnection of the indoor/outdoor connecting wire ?

1 Mis-wiring may damage indoor electronic control P.C. board during the operation. Be sure to confirm the wiring is correct before the operation starts.

(Lighted or not lighted)

No

Yes

No

Yes

Yes

No

Yes

No

Be sure to release the failure-moderecall function after checking.

No

No

Yes

No

Yes

Yes

Yes

No

Yes

Refer to indoor unit service manual.

Turn OFF the power supply.


Is there rated voltage betweenoutdoor terminal block S1 andS2 ?

Does the left lamp of OPERATIONINDICATOR lamp light up ? <Confirmation of the power to the indoor unit>

Press EMERGENCY OPERATION switch once.

Check the powersupply.

A

Turn OFF the power supply.Check once more if the indoor/outdoorconnecting wire is not mis-wiring.Short-circuit outdoor terminal block S2 andS3.

1

B


Check the wiring.

Correct them.

Turn OFF the power supply.Remove the short-circuit betweenoutdoor terminal block S2 and S3.Turn ON the power supply.Is there amplitude of 10 to 20 V DCbetween outdoor terminal block S2and S3 ? <Confirmation of serialsignal>

Is there rated voltage between indoor terminal block S1 and S2 ?<Confirmation of power voltage>

Replace the indoor electronic control P.C. board.

2 Be careful of the residual voltage of smoothing capacitor.

Replace the outdoor electronic control P.C. board. 2

Is there any error of theindoor/outdoor connecting wire,such as the damage of the wire,intermediate connection, poorcontact to the terminal block ?

Replace theindoor/outdoorconnecting wire.

Is serial signalerror indicated 6 minutes later ?

Yes

No

· Turn OFF inverter-controlled lighting equipment.

· Turn OFF the power supply and then turn ON again.

· Press EMERGENCY OPERATION switch.

B

· Reinstall either the unit or the light away from each other.

· Attach a filter on remote controlreceivingsection of the indoor unit.

A

Is serial signal error indicated 6 minutes later ?

No

Does the LED on the outdoor electronic control P.C. board repeat "3.6-second-OFF and 0.8-second-ON quick blinking" ?

MXZ-2B20NA

LED indication for communication statusCommunication status is indicated by the LED.

Blinking: normal communicationLighting: abnormal communication or not connectedPattern 1 and 2 is repeatedly displayed alternately. Each pattern is displayed for 15 seconds.

NOTE: "Lighting" in the table below does not indicate abnormal communication.

Outdoor electronic control P.C. board

Blinking

LED 3

Lighting

Goes out

LED 1LED 2

(Parts side)

LED3 LED2 LED1

Unit status

Pattern

1

2

Unit Bstatus

Lighting

Unit AstatusUnit Cstatus

MXZ-3B24NAMXZ-3B30NAMXZ-4B36NAOutdoor electronic control P.C. board

Blinking

(Parts side)

LED1 LED2 LED3

LED 1 LED 3LED 2Pattern

1

2

Unit Bstatus

Unit AstatusUnit Dstatus

Unit Cstatus

Goes outLighting

How to check mis-wiring and serial signal error

• When unit cannot operate neither by the remote controller nor by EMERGENCY OPERATION switch. Indoor unit does not operate.• When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second. Outdoor unit does not operate.

47

Check of R.V. coil

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

1. Disconnect the lead wire leading to the compressor.2. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION in HEAT mode.

Is there voltage of 208/230 V AC between pin1 and pin 2 at connector CN912 ?

Turn OFF the power supply of indoor and outdoor unit.

1. Turn OFF the power supply of indoor and outdoor unit, and disconnect the connector CN781.2. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION in HEAT mode.

Replace the 4-way valve. Replace the noise filter P.C. board.

Replace the R.V. coil.Is there voltage of 12 V DC between the connector CN781 pin 5 (+) and pin 3 (-) ?


Disconnect the connector CN912. Is there normal resistance to R.V. coil ?(Refer to 11-5.)

1. Disconnect the lead wire leading to the compressor.2. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION in COOL mode.

Is there voltage of 208/230 V AC between pin1 and pin 2 at connector CN912 ?

1. Turn OFF the power supply of the indoor and the outdoor unit, and disconnect the connector CN781.2. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION in COOL mode.

Replace the 4-way valve.

Replace the noise filter P.C. board.Is there voltage of 12 V DC between the connector CN781 pin 5 (+) and pin 3 (-) ?


If the connector CN912 is not connected or R.V. coil is open, voltage occurs between terminals even when the control is OFF.

• When heating operation does not work.

• When cooling operation does not work.

The cooling operation or heating operation does not operate.

CN912CN781

Noise filter P.C. boardOutdoor electronic controlP.C. board

48

Check of LEV

No

Yes

No

Yes

Turn ON the power supply to the outdoor unit after checking LEV coil is mounted to the LEV body securely.

Is "click - click" sound heard ?Or, do you feel vibration of LEV coil with your hand ?

Disconnect the connectors.MXZ-2BCN791: LEV A, CN792: LEV B, CN795: LEV E MXZ-3B/4BCN791: LEV A, CN792: LEV B, CN793: LEV C, CN794: LEV D(MXZ-4B only), CN796: LEV F Is there normal resistance to LEV coil ?(Refer to 11-5.)

Normal


Replace LEV coil.

• When cooling, heat exchanger of non-operating indoor unit frosts.• When heating, non-operating indoor unit get warm.

49

How to check inverter/compressor

• When heating, room does not get warm.• When cooling, room does not get cool.

No

No

Yes

Yes

Yes

No

Yes

No

Disconnect the terminal of the compressor. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION.

Is output balanced ?

Clarify the causes by counting time until the inverter stops.0 to 10 seconds: compressor layer short 10 to 60 seconds: compressor lock60 seconds to 5minutes: refrigerant circuit defective5 minutes or more: normal

Turn OFF the power supply of indoor and outdoor unit, and measure the compressor winding resistance between the compressor terminals.Is the resistance between each terminal normal ?(Refer to 11-5.)

Is the input voltage to the outdoor electronic control P.C. board 370 V or more ?

Reconnect the lead wire of compressor, and turn ON the power supply to indoor and outdoor unit. 3 minutes later, start EMERGENCY OPERATION.

Replace the compressor.

Replace the power board.

1 • After the outdoor fan starts running, wait for 1 minute or more before measuring the voltage. • The output voltage values have the tolerance of ± 20%. 2 • The output differs depending on the capacity or the number of indoor units to be operated.

Measure the voltage between each lead wire leading to the compressor.U (BLK) - V (WHT) V (WHT) - W (RED) W (RED) - U (BLK) Output voltage: 50V-250VIs proper output voltage detected? 1, 2

50

Check of outdoor thermistors

• When thermistor is abnormal.

ThermistorDefrostDischarge temperatureOutdoor heat exchanger temperature Ambient temperatureFin temperature

SymbolRT61RT62RT68RT65RT64

Connector, Pin No.Between CN661 pin1 and pin2Between CN661 pin3 and pin4Between CN661 pin7 and pin8 Between CN663 pin1 and pin2Between CN3 pin1 and pin2

Outdoor electronic control P.C. board

Outdoor power board

Board

Check of outdoor fan motor

• Fan motor does not operate or stops operating shortly after starting the operation.

Yes

Yes

YesNo

(Fixed to either 5 V or 0 V DC)

No

No

Turn ON the power supply.Rotate the outdoor fan motor manually and measure the voltage of CN931.Between (+) and (-)Between (+) and (-)Between (+) and (-)

Does the outdoor fan motor rotate smoothly ?

Does the voltage between each terminal become 5 V DC and 0 V DCrepeatedly ?

Replace the outdoor fan motor. Replace the outdoor electronic control P.C. board.

Disconnect CN932 from the outdoor electronic control P.C. board, and measure the resistance of the outdoor fan motor.

Is the resistance of outdoor fan motor normal? (Refer to 11-5.)

Normal

Yes

No

AbnormalDisconnect the connector in the following table and measure the resistance of the thermistor to check whether the thermistor is normal or not. (Refer to 11-7.)

Does the unit operate 10 minutes or more without showing thermistor abnormality ?

Replace the thermistor except RT64. In case that RT64 is abnormal, replace the outdoor power board since RT64 is combined with the outdoor power board.

Normal

Replace the outdoor electronic controlP.C. board or the outdoor power board.

Reconnect the connector in the following table and disconnect the lead wire leading to the compressor. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION.

51

The other cases

Indoor unit does not operate. (different operating models in multi system)• When you try to run two indoor units simultaneously, one for cooling and the other for heating, the unit which transmits signal to the outdoor units first decides the operation mode. • When the above situation occurs, set all the indoor units to the same mode, turn OFF the indoor units, and then turn them back ON.• Though the top of the indoor unit sometimes gets warm, this does not mean malfunction. The reason is that the refrigerant gas continuously flows into the indoor unit even while it is not operating.

• When the operation frequency does not go up from the lowest frequency.

Check of bus-bar voltage•Check the voltage of power supply. •Confi rm outdoor unit failure mode recall function. (Refer to 11-2.2.)

Blink 5 times

Confi rm LED1 indication lamp on the outdoor electronic control P.C. board.


Blink 9 times

Replace the outdoor elec-tronic control P.C. board.

Turn OFF power supply before removing P.C. board.

Confi rm LED1 indication lamp on the outdoor electronic con-trol P.C. board.

Turn ON power supply. Start operation.

Blink 6 times


Lighting


Blink 9 times


Confi rm LED1 indication lamp on the outdoor electronic con-trol P.C. board.

Turn ON power supply. Start operation.

NormalLighting Lighting

Check of HPS

Infinity

0 Ω

No

Yes

1. Disconnect the connector CN681 in the electronic control P.C. board.2. Check the resistance of HPS after 1 minute has passed since the outdoor unit power supply was turned OFF.

Check the resistance between each terminal.

Reconnect CN681.Turn ON the power supply to the indoor and outdoor unit.3 minutes later, start EMERGENCY OPERATION.

Is HPS protection displayed immediately after compressor starts ?

Replace HPS.

Replace the electronic control P.C. board.

Normal


52

700

600

500

400

300

200

100

0

Res

ista

nce

(kΩ

)

Temperature (°F)

Discharge temperature thermistor (RT62)

32 50 68 86 104 122 140 158 176 194 212 230 248

-4 14 32 50 68 86 104

100

90

80

70

60

50

40

30

20

10

0

Resis

tanc

e (kΩ

)

Temperature (°F)

Defrost thermistor (RT61)Ambient temperature thermistor (RT65)Outdoor heat exchanger temperaturethermistor (RT68)

11-7. TEST POINT DIAGRAM AND VOLTAGE1. Outdoor electronic control P.C. boardMXZ-2B20NA

LED 1

LED 2

Bus-bar voltageCN801

294 V DC~

370 V DCInput

( (

(LE

V R

oom

A

(12

V D

Cpu

lse

wav

e

(

LEV

Roo

m

B(

12 V

DC

puls

e w

ave

CN

932

20-9

0 V

AC

GN

D5

V5 V

DC

puls

e w

ave

( To fa

nm

otor

Def

rost

ther

mis

tor (

RT6

1)D

isch

arge

tem

pera

ture

ther

mis

tor (

RT6

2)

Out

door

hea

t exc

hang

er

tem

pera

ture

ther

mis

tor (

RT6

8)

( ((+)

(–)(+)Rush

curre

nt re

lay (–

) (–

)R.V

. coi

l

( 12 V

DC

15 V

15 VC

N93

1

(+)(–)

(

CN

661

CN

701

Sig

nal t

rans

mis

sion

(To

pow

er b

oard

)5

V D

C p

ulse

wav

e

(+)

(–)

(G

ND

CN

702

Sig

nal r

ecep

tion

(Fro

m p

ower

boa

rd)

5 V

DC

pul

se w

ave

GND

(pow

er b

oard

)

CN

781

LEV

E ((+)

(–) ((+)

(–) ( CN

791

CN

792

( ( (

F801FUSE

T3.15AL250V

LED 3

( Ambi

ent t

empe

ratu

reth

erm

isto

r (R

T65)

CN

663

Serial signal Room B12~24 V DC

Serial signal Room A12~24 V DC

CN602

CN601

208/230 V ACInput

SW1

CN

795

12 V

DC

puls

e w

ave

DM

06Y7

65

53


LED 1LED 2

F931FUSE

T3.15AL250V

( CN

932

20-9

0 V

AC

GN

D5

V D

C

5 V

DC

puls

e w

ave

( To fa

nm

otor

(+)(–)R

ush

curre

nt re

lay

(–)R

.V. c

oil

CN

781

CN

663

CN

701

CN

702

CN

661

CN681High pressure switch

(

Bus-bar voltageCN801

294~370 V DCInput

LED 3

Serial signal Room A12~24 V DC

CN611Serial signal Room B12~24 V DC

CN621Serial signal Room C12~24 V DC

CN601208/230 V ACInput

SW1SW2

SW871

F801FUSE

T3.15AL250V

CN791LEV Room A

CN792LEV Room B

CN793LEV Room C

((

–

+

{CN796LEV F12 V DCpulse wave

Def

rost

ther

mis

tor (

RT6

1)D

isch

arge

tem

pera

ture

ther

mis

tor (

RT6

2)O

utdo

or h

eat e

xcha

nger

te

mpe

ratu

re th

erm

isto

r (R

T68)

Am

bien

t tem

pera

ture

ther

mis

tor (

RT6

5)S

igna

l tra

nsm

issi

on(T

o po

wer

boa

rd)

5 V

DC

pul

se w

ave

Sig

nal r

ecep

tion

(Fro

m p

ower

boa

rd)

5 V

DC

pul

se w

ave

GN

DG

ND

15 V

DC

-4 14 32 50 68 86 104

100

90

80

70

60

50

40

30

20

10

0

Res

ista

nce

(kΩ

)

Temperature (°F)

Defrost thermistor (RT61)Ambient temperature thermistor (RT65)Outdoor heat exchanger temperature thermistor (RT68)

CN794LEV Room D

CN631Serial signal Room D12~24 V DC

700

600

500

400

300

200

100

0

Res

ista

nce

(kΩ

)

Temperature (°F)

Discharge temperature thermistor (RT62)

32 50 68 86 104 122 140 158 176 194 212 230 248

54

2. Noise filter P.C. board

208/230 V ACOutput

F64 FUSET2AL250V

{

{

CN901To electroniccontrol P.C. board

CN912R.V. coil208/230 V AC

{

CN902To powerboard

CN903To powerboard

F65FUSET6.3AL250V

MXZ-2B20NA

208/230 V ACInput

CN61208/230 V AC Output


208/230 V ACOutput

F64 FUSET2AL250V

{ {

CN901To electroniccontrol P.C. board

CN912R.V. coil208/230 V AC{

CN902To powerboard

CN903To powerboard

208/230 V ACInput

F65FUSET6.3AL250V

CN61208/230 V AC Output

55

MXZ-2B20NA3. Outdoor Power board

(Red)

(White)

Connect to the compressorVoltage among phases: 5 V to 180 V

Connect to the earth

CN5Primary current detection(Connect to the noise filter)

CN2Connect to the controller board(+)1-5(–): Signal transmission (To electronic control P.C. board) 5 V DC pulse wave(+)2-5(–): Zero cross signal 3-4 : Not used(+)6-5(–): 15 V(+)7-5(–): 15 V

(+)

(–)

Signal reception (From electronic control P.C. board) 5 V DC pulse wave

)

CN3Fin temperature thermistor RT64

294-370 V DCOutput

1

3

200

180

160

140

120

100

80

60

40

20

0

Res

ista

nce

(kΩ

)

Temperature (°F)32 50 68 86 104 122 140 158 176

Fin temperature thermistor (RT64)

DM00N019 or DM00N095

56


(Red)

(White)

Connect to the compressorVoltage among phases: 5 V to 180 V

Connect to the earth

CN5Primary current detection(Connect to the noise filter)

CN2Connect to the controller board(+)1-5(–): Signal transmission (To electronic control P.C. board) 5 V DC pulse wave(+)2-5(–): Zero cross signal 3-4 : Not used(+)6-5(–): 15 V(+)7-5(–): 15 V

(+)

(–)

Signal reception (From electronic control P.C. board) 5 V DC pulse wave

)

CN3Fin temperature thermistor RT64

294-370 V DCOutput

1

3

200

180

160

140

120

100

80

60

40

20

0

Res

ista

nce

(kΩ

)

Temperature (°F)32 50 68 86 104 122 140 158 176

Fin temperature thermistor (RT64)

57

DISASSEMBLY INSTRUCTIONS12

(1) Slide the sleeve and check if there is a locking lever or not. (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.

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.

<"Terminal with locking mechanism" Detaching points>

Connector

Sleeve

Locking lever

OPERATING PROCEDURE PHOTOS1. Removing the compressor(1) Remove the screws of the top panel, and remove the top panel.(2) Remove the screws of the service panel, and remove the service panel.(3) Recover gas from the refrigerant circuit.NOTE: Recover gas from the pipes until the pressure gauge shows 0 PSIG.

(4) Remove the screws of the cabinet, and remove the cabinet.(5) Remove the screws of the back panel, and remove the back panel (Photo 3).(6) Disconnect the compressor lead wire from terminal of the compressor (U, V, W).(7) Disconnect the outdoor electronic control P.C. board connectors: CN661, CN663, CN791, CN792, CN795, CN931, CN932 Disconnect the noise filter P.C. board connector: CN912(8) Remove the screws of the electrical parts, and remove the electrical parts (Photo 4).(9) Remove the propeller.(10) Remove the screws of the separator, and remove the separator (Photo 6).(11) Remove the sound proof felt (Photo 6).(12) Detach the welded parts of the compressor suction and discharge pipes (Photo 5).(13) Remove the compressor nuts and remove the compressor.

Photo 2

Photo 1

Screws of the cabinet

Screws of the top panel

Screw of the cabinet

Screws of the cabinetScrews of service panel




Screws of thesub panel

12-1. MXZ-2B20NA

58

OPERATING PROCEDURE PHOTOS

3. Removing the fan motor(1) Remove the top panel, the service panel, and the cabinet (Photo 1, 2).(2) Disconnect the connector CN931 and CN932 on the outdoor electronic control P.C. board.(3) Remove the propeller.(4) Remove the fan motor.

Photo 42. Removing the electronic control P.C. board(1) Remove the screws of the sub panel.(2) Remove the sub panel.(3) Disconnect all connectors and lead wires on the electronic control P.C. board.(4) Remove the electronic control P.C. board.

Photo 3Screw of the rear guard

Screws of the back panel

Screw of theback panel

Screws ofthe back panel

Screws ofthe back panel

Screws ofthe electricalparts

R.V. coil

4 way valve

LEV coil E

Expansion valve E

Suction pipewelded part

Dischargepipe welded part

Photo 5

Compressor nuts

Photo 6

Screws of the outdoor fan motor

PropellerPropeller nutSeparator

Sound proof felt

59


6. Removing the reactor(1) Remove the top panel (Photo 1).(2) Remove the service panel, cabinet, back panel, and the electrical parts (Photo 1, 2, 3, 4).(3) Disconnect the reactor lead wire from the terminal of the reactor.(4) Remove the screws of the reactor, and remove the reactor (Photo 9).

Photo 9

4. Removing the 4-way valve(1) Remove the top panel (Photo 1).(2) Remove the service panel, the cabinet, and the back panel (Photo 1, 2, 3).(3) Recover gas from the refrigerant circuit.NOTE: Recover gas from the pipes until the pressure gauge shows 0 PSIG.

(4) Remove the electrical parts (Photo 4).(5) Detach the welded parts of 4-way valve and pipe (Photo 7).

5. Removing the expansion valve(1) Remove the top panel (Photo 1).(2) Remove the service panel, the cabinet, and the back panel (Photo 1, 2, 3). (Gas recovery is not required if the unit is pumped down.)(3) Remove the electrical parts for removing LEV E (Photo 4, 5).(4) Remove the LEV coils.(5) Detach the welded parts of expansion valves and pipes.

4 way valve

R.V. coil

Photo 7

Photo 8

Welded parts

Expansion valves LEV coils

Screws of the reactor

60

1. Removing the compressor(1) Remove the screws of the top panel, and remove the top

panel.(2) Remove the screws of the service panel, and remove the

service panel.(3) Recover gas from the refrigerant circuit. NOTE : Recover gas from the pipes until the pressure gauge shows 0 PSIG.(4) Remove the screws of the front panel, and remove the front

panel.(5) Remove the screws of the rear panel, and remove the rear

panel.(6) Disconnect the compressor lead wire from terminal of compressor (U, V, W).(7) Disconnect the outdoor electronic control P.C. board connectors: CN661, CN663, CN681, CN791, CN792, CN793, CN794 (MXZ-4B36NA), CN796, CN931, CN932 Disconnect the noise filter P.C. board connector: CN912(8) Remove the screws of the electrical parts, and remove the electrical parts.(9) Remove the propeller.(10) Remove the screws of the separator, and remove the separator.(11) Remove the sound proof felt (Photo 5).(12) Detach the welded parts of the compressor suction and discharge pipes (Photo 4).(13) Remove the compressor nuts and remove the compressor.

OPERATING PROCEDURE PHOTOSPhoto 1

Photo 2

12-2. MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA

Photo 3



Screws of the side panel

Screws of the front panel

Screws of service panel

Screws of the service panel

Screws of the rear panel

Screws of the electrical parts

Photo 4

Discharge pipe welded part

Suction pipe welded part

Photo : MXZ-3B24NA

61


3. Removing the 4-way valve(1) Remove the top panel (Photo 1, 2).(2) Remove the service panel, rear panel, and pipe cover (Photo

1,2). (3) Recover gas from the refrigerant circuit. NOTE : Recover gas from the pipes until the pressure gauge shows 0 PSIG.(4) Remove the electrical parts (Photo 3).(5) Detach the welded parts of 4-way valve and pipe.

4. Removing the expansion valve(1) Remove the top panel (Photo 1, 2).(2) Remove the service panel (Photo 1, 2). (Gas recovery is not required if the unit is pumped down.) (3) Remove the front panel for removing LEV F (Photo 1).(4) Remove the electrical parts for removing LEV F (Photo 3).(5) Remove the LEV coils.(6) Detach the welded parts of expansion valves and pipes.

LEV coils

Expansion valves

Photo 7

2. Removing the fan motor(1) Remove the top panel, the service panel, and the front panel (Photo 1, 2).(2) Disconnect the connectors CN931 and CN932 on the outdoor

electronic control P.C. board.(3) Remove the propeller.(4) Remove the fan motor.

Photo 5

Separator

Sound proof felt

Propeller

Screws of the outdoor fan motor

4 way valve

R.V. coil

Welded parts

Photo 6

LEV coil F Expansion valve F

Propeller nut

Photo : MXZ-3B24NA

62

OPERATING PROCEDURE PHOTOS5. Removing the reactor(1) Remove the top panel (Photo 1, 2).(2) Disconnect the reactor lead wire.(3) Remove the screws of the reactor, and remove the reactor.

Photo 8

Photo : MXZ-3B24NA

Screws of the reactor

HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN

© Copyright 2009 MITSUBISHI ELECTRIC CO., LTDDistributed in Mar. 2010. No. OBH560 REVISED EDITION-C 6Distributed in Feb. 2010. No. OBH560 REVISED EDITION-B 6Distributed in Dec. 2009. No. OBH560 REVISED EDITION-A 5Distributed in Sep. 2009. No. OBH560 5Made in Japan

New publication, effective Mar. 2010Specifications subject to change without notice.

MXZ-2B20NA MXZ-2B20NA-1 COOLING

MXZ-2B20NA MXZ-2B20NA-1 HEATING

MXZ-3B24NA COOLING

MXZ-3B24NA HEATING

MXZ-3B30NA COOLING

MXZ-3B30NA HEATING

MXZ-4B36NA COOLING

MXZ-4B36NA HEATING

OUTDOOR UNIT SERVICE MANUAL HFC

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Transcript of OUTDOOR UNIT SERVICE MANUAL HFC