Mitsubishi SUZ-KA35VA4, SUZ-KA71VA4, SUZ-KA50VA4, SUZ-KA60VA4, SUZ-KA25VA4.TH Service Manual

TECHNICAL & SERVICE MANUAL

No.OCH545

SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS

R410A

Outdoor unit
[Model Name]

[Service Ref.]

SUZ-KA25VA4 SUZ-KA25VA4.TH
SUZ-KA35VA4 SUZ-KA35VA4.TH
SUZ-KA50VA4 SUZ-KA50VA4.TH
SUZ-KA60VA4 SUZ-KA60VA4.TH
SUZ-KA71VA4 SUZ-KA71VA4.TH

CONTENTS

1.

COMBINATION OF INDOOR AND OUTDOOR UNITS

.....

2

2. TECHNICAL CHANGES

...................................

3

3. PARTS NAMES AND FUNCTIONS

..................

7

4. SPECIFICATION

................................................

8

5. NOISE CRITERIA CURVES

............................

10

6. OUTLINES AND DIMENSIONS

.......................

11

7. WIRING DIAGRAM

..........................................

13

8. REFRIGERANT SYSTEM DIAGRAM

.............

16

9. ACTUA TOR CONTROL

...................................

19

10. SERVICE FUNCTIONS

....................................

20

11. TROUBLESHOOTING

.....................................

20

12. DISASSEMBLY INSTRUCTIONS

....................

36

Indication of
model name

Note:

• This service manual
describes technical data of
the outdoor units.

HFC

utilized

R410A

SUZ-KA25VA4.TH
SUZ-KA35VA4.TH

August 2013

PARTS CATALOG (OCB545)

2

1

COMBINATION OF INDOOR AND OUTDOOR UNITS

Heat pump type

Outdoor unit

SUZ-

SLZ-KA25VAL2.TH
SLZ-KA35VALR3.TH
SLZ-KA50VALR3.TH
SLZ-KA25VAQ2.TH
SLZ-KA35VAQR2.TH
SLZ-KA50VAQR2.TH
SEZ-KD25VA(L)R2.TH
SEZ-KD35VA(L)R2.TH
SEZ-KD50VA(L)R2.TH
SEZ-KD60VA(L)R2.TH
SEZ-KD71VA(L)R2.TH
SEZ-KD25VAQR2.TH
SEZ-KD35VAQR2.TH
SEZ-KD50VAQR2.TH
SEZ-KD60VAQR2.TH
SEZ-KD71VAQR2.TH

—
—

—
—

—
—
—
—

—
—
—
—

—

—
—

—
—

—
—
—
—

—
—
—

—
—

—
—

—
—

—
—
—
—

—
—

—
—
—
—
—
—
—
—
—

—
—
—
—

—

—
—
—
—
—
—
—
—
—
—

—
—
—
—

OC320

OCH493

Indoor unit

Service

Manual No.

Service Ref.

Heat pump without electric heater

KA25V A4.TH

KA60VA4.TH KA71A4.THKA50VA4.TH

HWE0711

BWE102050

BWE102040

HWE1008

KA35V A4.TH

Note: Please refer to the service manual of indoor unit or the technical data book for the combination data.

INDOOR UNIT SERVICE MANUAL

OCH545

3

2

TECHNICAL CHANGES

Refrigerant

oil

Refrigerant

New refrigerant

R410A

HFC-32: HFC-125 (50%:50%)

Pseudo-azeotropic refrigerant

Not included

A1/A1

72.6

-51.4

1.557
64

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

-40.8

0.94

44.4

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 (°C)
Steam pressure [25°C](Mpa)
Saturated steam density [25°C](Kg/*)
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 CO

2

INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT

• This room air conditioner adopts an 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 conditioners.

As R410A has working pressure approximate 1.6 times as high as that of R22, some special tools and piping parts/materi-

als are required. Refer to the table below.

Take sufficient care not to allow water and other contaminations to enter the R410A refrigerant during storage and installa-

tion, since it is more susceptible to contaminations than R22.

For refrigerant piping, use clean, pressure-proof parts/materials specifically designed for R410A. (Refer to 2. Refrigerant

piping.)

Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrigerant to prevent

composition change.

NOTE : The unit of pressure has been changed to MPa on the international system of units (SI unit system).

The conversion factor is: 1 (MPa [Gauge]) =10.2 (kgf/cm

2

[Gauge])

New Specification Current Specification

The incompatible refrigerant 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
refrigerant oil of the upper layer to flow back to the
compressor.

Since refrigerant and refrigerant oil are compatible with
each other, refrigerant oil backs to the compressor through
the lower position oil back hole.

Compressor

Suction muffler

Oil back hole

Refrigerant oil

Refrigerant

Compressor

Suction muffler

Oil back hole

Refrigerant oil /Refrigerant

Compressor

OCH545

4

R410A tools Can R22 tools be used?

Gas leak detector

R410A has high pressures beyond the measurement range of existing
gauges. Port diameters have been changed to prevent any other refrigerant
from being charged into the unit.

Hose material and cap size have been changed to improve the pressure
resistance.

Dedicated for HFC refrigerant.

6.35 mm and 9.52 mm

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 12.7 mm and 15.88 mm

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.
The diameter of the service port on the stop valve in outdoor unit has been changed to prevent any other refrigerant being
charged into the unit. Cap size has been changed from 7/16 UNF with 20 threads to 1/2 UNF with 20 threads.

-30 -20 -10 0 10 20

30

40 50 60

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

(MPa [Gauge])

R410A

R22

Conversion chart of refrigerant temperature and pressure

Saturated liquid pressure

()

NOTE: The unit of pressure has been changed to MPa on the

international system of units (SI unit system).

The conversion factor is: 1 (MPa [Gauge]) =10.2 (kgf/cm2 [Gauge])

OCH545

5

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)

R410A

Pipe diameter (mm)

6.35

9.52

12.7

15.88

17
22
26
29

Dimension of flare nut (mm)

R22

17
22
24
27

• Use a copper pipe or a copper-alloy seamless pipe with a thickness of 0.8 mm. Never use any pipe with a thickness less
than 0.8mm, as the pressure resistance is insufficient.

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. Refrigerant oil

Apply the special refrigerant 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 refrigerating 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 refrigerant pipes that meet the following specifications.

Wall thicknessOutside diameter

Pipe

mm mm

For liquid

For gas

6.35

9.52

9.52

12.7

15.88

0.8

0.8

0.8

0.8

1.0

Heat resisting foam plastic
Specific gravity 0.045
Thickness 8 mm

Insulation material

OCH545

6

6. Pumping Down

When relocating or disposing of the air conditioner, pump down the system by following the procedure below so that no
refrigerant is released into the atmosphere.

1 Turn off the power supply (circuit breaker).
2 Connect the gauge manifold valve to the service port of the stop valve on the gas pipe side of the outdoor unit.
3 Fully close the stop valve on the liquid pipe side of the outdoor unit.
4 Supply power (circuit breaker).
5 Perform the refrigerant collecting operation (cooling test run).

• For the PAR-31MAA, select “Service”  “TestRun” from the main menu to start the test run, and then select the cooling
mode.

• For details or for other information about starting the test run when using remote controllers, refer to the installation manual
for the indoor unit or the remote controller.
6 Fully close the stop valve on the gas pipe side of the outdoor unit when the pressure gauge shows 0.05 to 0 MPa [Gauge]
(approx. 0.5 to 0 kgf/cm²) and quickly stop the air conditioner.

• Push the “ON/OFF” button on the remote controller to stop the air conditioner.
Note:
When the extension piping is very long with a large refrigerant amount, it may not be possible to perform a pump down
operation. In this case, use refrigerant recovery equipment to collect all of the refrigerant in the system.
7 Turn off the power supply (circuit breaker), remove the gauge manifold valve, and then disconnect the refrigerant pipes.

.Warning: When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes.

• If the refrigerant pipes are disconnected while the compressor is operating and the stop valve (ball valve) is open,
the pressure in the refrigeration cycle could become extremely high if air is drawn in, causing the pipes to burst,
personal injury, etc.

OCH545

77

3

PARTS NAMES AND FUNCTIONS

SUZ-KA25VA4.TH
SUZ-KA35VA4.TH

SUZ-KA50VA4.TH
SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

Air outlet

Drain outlet

Piping

Drain hose

Air inlet

(back and side)

Model SUZ-KA·VA4.TH

Drain socket 1

Piping

Air outlet

Drain outlet

Air inlet

(back and side)

Drain hose

OCH545

8

SPECIFICATION

4

NOTE: Test conditions are based on ISO 5151
Cooling : Indoor D.B. 27°C W.B. 19°C
Outdoor D.B. 35°C
Heating : Indoor D.B. 20°C
Outdoor D.B. 7°C W.B. 6°C
Refrigerant piping length (one way): 5 m
*Measured under rated operating frequency.

Outdoor model

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH SUZ-KA60VA4.TH SUZ-KA71VA4.TH

Power supply Single phase 230V, 50Hz

Compressor

Model KNB073FKFMC KNB092FFAMC SNB130FGBMT SNB172FEKMT

Output W 550 650 900 1,200

Current*

Cooling

A

2.76 4.06 5.58 6.62 8.02

Heating 3.24 4.09 5.75 6.37 8.13

Refrigeration oil
(Model)

L 0.31 (FV50S) 0.27 (FV50S) 0.35 (FV50S) 0.4 (FV50S)

Fan motor

Model RC0J50-FA RC0J60-BD RC0J60-BC

Current*

Cooling

A

0.24 0.29 0.84 0.84 0.83

Heating 0.27 0.28 0.93 0.93 0.82

Dimensions W × H × D mm 800 × 550 × 285 840 × 880 × 330

Weight kg 30 35 54 50 53

Special remarks

Air
fl ow*

Cooling

High

m³/h

1,806 2,868 3,492 3,426

Med. 1,806 2,868 3,066 3,006

Low 1,170 1,038 1,602 1,692 1,512

Heating

High 2,106 2,778 2,952 2,892

Med. 1,806 1,770 2,778 2,952 2,892

Low 1,452 1,326 2,124 2,226 2,280

Sound level*

Cooling

dB(A)

47 49 52 55

Heating 48 50 52 55

Fan
speed

Cooling

High

rpm

740 810 840 950

Med. 740 810 840

Low 740 490 480 450

Heating

High 860 900 810

Med. 740 770 810

Low 600 610 620 650

Fan speed regulator 3

Refrigerant fi lling capacity
(R410A)

kg 0.80 1.15 1.60 1.80 1.80

OCH545

99

SUZ-KA25VA4.TH SUZ-KA35VA4.TH
SUZ-KA50VA4.TH SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

Specifications and rating conditions of main electric parts

Model

Item

SUZ-KA25VA4.TH SUZKA35VA4.TH SUZ-KA50VA4.TH SUZ-KA60VA4.TH SUZ-KA71VA4.TH

Smoothing
capacitor

(C61) — — 620F 420V — —

(C62, C63) 620F 420V 620F 420V 620F420V — —

(CB1, 2, 3) — — — 560F 450V 560F 350V

Diode module (DB61) 15A 600V 15A 600V 25A 600V — —

Fuse

(F61) T20A L250V T20A L250V T20A L250V — —

(F62) — — — T20A L250V T20A L250V

(F701, F801, F901)

T3.15A L250V T3.15A L250V T3.15A L250V — —

(IC700) 15A 600V 15A 600V 20A 600V — —

Inteligent power
module

(IPM) — — — 20A 600V

(IC932) 8A 600V 8A 600V 8A 600V 5A 600V 5A 600V

Power factor
controller

(PFC) — — — 20A 600V 20A 600V

(IC820) 20A 600V 20A 600V 20A 600V — —

Expansion valve
coil

(LEV) DC12V

Reactor

(L61) 18mH 23mH 23mH — —

(L) — — — 340H 20A 340H 20A

Current-Limiting
PTC thermistoe

(PTC64, PTC65) 33

Terminal block

(TB1, TB2) — — — 3P 3P

(TB) 5P 5P 5P — —

Relay

(X63) 3A 250V 3A 250V 3A 250V — —

(X64) 20A 250V

(X601) — — — 3A 250V 3A 250V

(X602) — — — 3A 250V 3A 250V

R.V. coil (21S4) AC220-240V

OCH545

10

NOISE CRITERIA CURVES

5

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

COOLING

FUNCTION

SPL(dB(A))

LINE

High
Med.

FAN SPEED

HEATING

47

48

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

BAND CENTER FREQUENCIES, Hz

NC-10

SUZ-KA25VA4.TH

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

COOLING

FUNCTION

SPL(dB(A))

LINE

FAN SPEED

HEATING

49

50

High

Med.

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

BAND CENTER FREQUENCIES, Hz

NC-10

SUZ-KA35VA4.TH

COOLING

FUNCTION

SPL(dB(A)) LINE

High

FAN SPEED

HEATING

52

52

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

BAND CENTER FREQUENCIES, Hz

NC-10

SUZ-KA50VA4.TH

Test conditions
Cooling: Dry-bulb temperature 35°C
Heating: Dry-bulb temperature 7°C
Wet-bulb temperature 6°C

OUTDOOR UNIT

MICROPHONE

1 m

SUZ-KA60VA4.TH SUZ-KA71VA4.TH

OCTAVE BAND SOUND PRESSURE LEVEL, 0dB re 0.0002 MICRO BAR

COOLING

FUNCTION

SPL(dB(A)) LINE

High

FAN SPEED

HEATING

55

55

90

80

70

60

50

40

30

20

10

63 125 250 500 1000 2000 4000 8000

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

BAND CENTER FREQUENCIES, Hz

NC-10

OCH545

11

6

OUTLINES AND DIMENSIONS

10

69

800

302.5

500 Bolt pitch for installation

150

22.3

Handle

550

280

164.5

99.5

170.5

23

Service panel

Service port

285

344.5

44

400

Air in

Air out

Air in

17.5

Bolt pitch for

installation

304~325

40

Liquid refrigerant pipe joint
Refrigerant pipe (flared) :6.35

Gas refrigerant pipe joint
Refrigerant pipe (flared) :9.52

43

35

2-Oval holes 10×21

REQUIRED SPACE

Basically open 100mm or more
without any obstruction in front
and on both sides of the unit.

350mm or more

200mm or more

100mm or more

100mm or more

Open two sides of left,
right, or rear side.

Drain hole :42

Unit: mm

SUZ-KA25VA4.TH
SUZ-KA35VA4.TH

OCH545

12

417.5

40

42

Drain hole

175

500

330

50

Air in

Air out

2-Oval holes 10 21

840

109

81

880

452

Service panel

99.5

164.5
195

35

44

Liquid refrigerant
pipe joint
Refrigerant pipe
(flared)

Ø 6.35...(SUZ-KA50/60VA4)
Ø 9.52...(SUZ-KA71VA4)

Gas refrigerant
pipe joint
Refrigerant pipe
(flared)

Ø 12.7...(SUZ-KA50VA4)
Ø 15.88...(SUZ-KA60/71VA4)

350 mm or more

100 mm or more

REQUIRED SPACE

Open as a rule
500mm or more if
the front and both
sides are open

100mm or more
200mm or more if
there are obstacles
to both sides

Open as a rule
500mm or more if the back,
both sides and top are open

Air in

Bolt pitch for

installation

360

SUZ-KA50VA4.TH
SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

Unit: mm

OCH545

1313

7

WIRING DIAGRAM

SUZ-KA25VA4.TH
SUZ-KA35VA4.TH

OCH545

14

SUZ-KA50VA4.TH

OCH545

15

SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

OCH545

16

REFRIGERANT SYSTEM DIAGRAM

8

Unit: mm

SUZ-KA25VA4.TH

Unit: mm

SUZ-KA35VA4.TH

Flared connection

Defrost
thermistor
RT61

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve
(with strainer)

Stop valve
(with service port)

Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

Refrigerant pipe ø9.52
(with heat insulator)

Refrigerant pipe ø6.35
(with heat insulator)

R.V. coil
heating ON
cooling OFF

Strainer
#100

Ambient
temperature
thermistor
RT65

Muffler

Capillary tube
ø3.0×ø2.0×240

Outdoor heat
exchanger
temperature
thermistor
RT68

Muffler

Outdoor
heat
exchanger

LEV

Outdoor
heat
exchanger

Flared connection

Defrost
thermistor
RT61

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve
(with strainer)

Stop valve
(with service port)

Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

Refrigerant pipe ø9.52
(with heat insulator)

Refrigerant pipe ø6.35
(with heat insulator)

R.V. coil
heating ON
cooling OFF

Strainer
#100

Capillary tube
ø3.0×ø1.8×600(×2)

LEV

Ambient
temperature
thermistor

Muffler

Capillary tube
ø3.0×ø2.0×240

Outdoor heat
exchanger
temperature
thermistor

Muffler

RT65

RT68

OCH545

1717

Unit: mm

SUZ-KA50VA4.TH

Outdoor
heat
exchanger

Flared connection

Defrost
thermistor
RT61

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve

Stop valve
(with service port)

Capillary tube

ø

4.0

×

ø

2.4×100
Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

Refrigerant pipe

ø

12.7

(with heat insulator)

Refrigerant pipe ø6.35
(with heat insulator)

LEV

R.V. coil
heating ON
cooling OFF

Muffler

#100

Strainer

#100

Outdoor heat
exchanger
temperature
thermistor
RT68

Ambient
temperature
thermistor
RT65

Strainer

#100

Muffler

Unit: mm

SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

Outdoor
heat
exchanger

Flared connection

Defrost
thermistor
RT61

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve

Stop valve
(with service port)

Capillary tube

ø

4.0

×

ø

2.4×100
Refrigerant flow in cooling

Compressor

4-way valve

Refrigerant flow in heating

Refrigerant pipe
(with heat insulator)

ø

15.88

Refrigerant pipe
(with heat insulator)

ø

6.35...(SUZ-KA60VA4)

ø

9.52...(SUZ-KA71VA4)

LEV

R.V. coil
heating ON
cooling OFF

Muffler

#100

Strainer

#100

Outdoor heat
exchanger
temperature
thermistor
RT68

Ambient
temperature
thermistor
RT65

Strainer

#100

OCH545

18

ADDITIONAL REFRIGERANT CHARGE (R410A: g)

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH
SUZ-KA60VA4.TH SUZ-KA71VA4.TH

MAX. REFRIGERANT PIPING LENGTH

Max. Length
A

* Height difference limitations are binding regardless of which unit, indoor or outdoor, is position high.

* Max. Height
difference
B

Indoor
unit

Outdoor unit

MAX. HEIGHT DIFFERENCE

Calculation : Xg=20g/m × (Refrigerant piping length(m)–7)

Calculation : Xg=55g/m × (Refrigerant piping length(m)-7)

Model

Outdoor unit

precharged

Refrigerant piping length (one way)

7m 8m 9m 10m 11m 12m 13m 14m 15m 20m

SUZ-KA25VA4.TH 800 0 30 60 90 120 150 180 210 240 390
SUZ-KA35VA4.TH 1,150 0 30 60 90 120 150 180 210 240 390

Calculation: Xg=30g/m×(Refrigerant piping length(m)-7)

Model

Refrigerant piping: m Piping size O.D: mm

Max. Length A

Max. Height difference B

Gas Liquid

SUZ-KA25VA4.TH

20 12 9.52

6.35

SUZ-KA35VA4.TH
SUZ-KA50VA4.TH

30 30

12.7

SUZ-KA60VA4.TH

15.88

SUZ-KA71VA4.TH 9.52

Model

Outdoor unit

precharged

Refrigerant piping length (one way)

7m 10m 15m 20m 25m 30m

SUZ-KA50VA4.TH 1,600 0 60 160 260 360 460
SUZ-KA60VA4.TH 1,800 0 60 160 260 360 460

Model

Outdoor unit

precharged

Refrigerant piping length (one way)

7m 10m 15m 20m 25m 30m

SUZ-KA71VA4.TH 1,800 0 165 440 715 990 1,265

OCH545

1919

ACTUATOR CONTROL

9

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH
SUZ-KA60VA4.TH

SUZ-KA71VA4.TH

9-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR

9-2. R.V. COIL CONTROL

Heating

. . . . . . . . . . . . . . . . .

ON

Cooling . . . . . . . . . . . . . . . . . OFF

Dry

. . . . . . . . . . . . . . . . . . . .

OFF

ON

OFF

ON

OFF

Outdoor fan

Compressor

5 seconds 15 seconds

ON

OFF

Compressor

Outdoor fan

motor

R.V.coil

ON

OFF

ON

OFF

<COOL>

5 seconds

<HEAT>

5 seconds

9-1. OUTDOOR FAN MOTOR CONTROL

The fan motor turns ON/OFF, interlocking with the compressor.
[ON] The fan motor turns ON 5 seconds before the compressor starts up.
[OFF] The fan motor turns OFF 15 seconds after the compressor has stopped running.

NOTE: The 4-way valve reverses for 5 seconds

right before start-up of the compressor.

Sensor Purpose

Actuator

Compressor

LEV

Outdoor fan

motor

R.V.coil

Indoor fan

motor

Discharge temperature
thermistor

Protection



Indoor coil temperature
thermistor

Cooling: Coil frost prevention



Heating: High pressure protection



Defrost thermistor Heating: Defrosting



Fin temperature thermistor Protection



Ambient temperature
thermistor

Cooling: Low ambient temperature operation



Outdoor heat exchanger
temperature thermistor

Cooling: Low ambient temperature operation



Cooling: High pressure protection



OCH545

20

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH
SUZ-KA60VA4.TH SUZ-KA71VA4.TH

CHANGE IN DEFROST SETTING

Changing defrost finish temperature

<JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board. (Refer to 11-6-1.)

11

TROUBLESHOOTING

3. Troubleshooting procedure

1) Check if the OPERATION INDICATOR lamp on the outdoor P.C. board is blinking on and off to indicate an abnormal­ity. To make sure, check how many times the abnormality indication is blinking on and off before starting service work.

2) Before servicing check that the connector and terminal are connected properly.

3) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.

4) When troubleshooting, refer to 11-2. and 11-3.

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH
SUZ-KA60VA4.TH SUZ-KA71VA4.TH

11-1. CAUTIONS ON TROUBLESHOOTING

1. Before troubleshooting, check the following:

1) Check the power supply voltage.

2) Check the indoor/outdoor connecting wire for miswiring.

2. Take care the following during servicing.

1)

Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and turn off the breaker.

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.

Housing point

Lead wire

10

SERVICE FUNCTIONS

Jumper wire

Defrost fi nish temperature (°C)

SUZ-KA25VA4.TH
SUZ-KA35VA4.TH

SUZ-KA50VA4.TH

SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

JS

Soldered (Initial setting) 5 9 10

None (cut) 10 18 18

OCH545

2121

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH SUZ-KA60VA4.TH SUZ-KA71VA4.TH

temperature thermistor, outdoor heat exchanger temperature

No. Symptoms

Abnormal point/

Condition

RemedyCondition

1

Outdoor unit
does not op­erate.

1-time flash
every

2.5 seconds

Outdoor power sys-

tem

Overcurrent protection cut-out operates 3 consecutive times
within 1 minute after the compressor gets started.

Reconnect connector of compres­sor.
Refer to 11-5. "How to check in­verter/compressor".
Check stop valve.







2

Outdoor thermistors Discharge temperature thermistor shorts, or opens during
compressor running.

defrost thermistor, P.C. board

thermistor or ambient temperature thermistor shorts, or opens
during compressor running.

Refer to 11-5.F"Check of outdoor
thermistors".



3

Outdoor control sys­tem

Nonvolatile memory data cannot be read properly.

Replace inverter P.C. board. 

4

6-time flash

2.5 seconds
OFF

Serial signal The communication fails between the indoor and outdoor unit

for 3 minutes.

5

11-time flash

2.5 seconds
OFF

Stop valve/
Closed valve

Closed valve is detected by compressor current. Check stop valve.



6



7

'Outdoor unit
stops and
restarts 3
minutes later'
is repeated.

2-time flash

2.5 seconds OFF

Overcurrent protec­tion

Large current flows into intelligent power module.

Reconnect connector of compressor.

Refer to 11-5. "How to check in­verter/compressor".
Check stop valve.






8

3-time flash

2.5 seconds OFF

Discharge tempera­ture overheat pro­tection

Temperature of discharge temperature thermistor exceeds
116°C, compressor stops. Compressor can restart if discharge
temperature thermistor reads 100°C or less 3 minutes later.

Check refrigerant circuit and refrig­erant amount.
Refer to 11-5.  "Check of LEV".





9

4-time flash

2.5 seconds OFF

Fin temperature
/P.C. board tem­perature thermistor
overheat protection

Temperature of fin temperature thermistor on the heat sink
exceeds 72 ~ 86°C or temperature of P.C. board temperature
thermistor on the inverter P.C.board exceeds 72 ~ 85°C.

Check around outdoor unit.
Check outdoor unit air passage.

Refer to 11-5. "Check of outdoor

fan motor".





10

5-time flash

2.5 seconds OFF

High pressure pro­tection

Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost
thermistor exceeds 70°C in COOL mode.

Check refrigerant circuit and refrig­erant amount.
Check stop valve.





11

8-time flash

2.5 seconds OFF

Compressor syn­chronous abnormal­ity

The waveform of compressor current is distorted.

Reconnect connector of compressor.
Refer to 11-5. "How to check in­verter/compressor".




12

10-time flash

2.5 seconds OFF

Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds

after outdoor fan start-up.

Refer to 11-5. "Check of outdoor
fan motor.
Refer to 11-5. "Check of inverter
P.C. board.





13

12-time flash

2.5 seconds OFF

Each phase current
of compressor

Each phase current of compressor cannot be detected nor­mally.

Refer to 11-5. "How to check in­verter/compressor".



14

13-time flash

2.5 seconds OFF

DC voltage DC voltage of inverter cannot be detected normally. Refer to 11-5. "How to check in-

verter/compressor".



15

Outdoor unit
operates.

1-time flash

2.5 seconds OFF

Frequency drop by
current protection

When the input current exceeds approximately 7A(KA25)/
8A(KA35)/12A(KA50)14A(KA60)/16A(KA71), compressor

The unit is normal, but check the
following.

Check if indoor filters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air
circulation is short cycled.





16

3-time flash

2.5 seconds OFF

Frequency drop by
high pressure pro­tection

Temperature of indoor coil thermistor exceeds 55°C in HEAT
mode, compressor frequency lowers.

Frequency drop by
defrosting in COOL
mode

Indoor coil thermistor reads 8°C or less in COOL mode, com­pressor frequency lowers.

17

4-time flash

2.5 seconds OFF

Frequency drop by
discharge tempera­ture protection

Temperature of discharge temperature thermistor exceeds
111°C, compressor frequency lowers.

Check refrigerant circuit and refrig­erant amount.
Refer to 11-5. "Check of LEV".
Refer to 11-5. "Check of outdoor
thermistors".






18

19

7-time flash

2.5 seconds OFF

Low discharge tem­perature protection

Temperature of discharge temperature thermistor has been
50°C or less for 20 minutes.

Refer to 11-5. "Check of LEV".
Check refrigerant circuit and refrig-

erant amount.




8-time flash

2.5 seconds OFF

PAM protection
PAM: Pulse Ampli­tude Modulation

The overcurrent flows into PFC (Power factor correction :
IC820) or the bus-bar voltage reaches 394 V or more, PAM
stops and restarts.

This is not malfunction. PAM pro­tection will be activated in the fol­lowing cases:

1. Instantaneous power voltage
drop. (Short time power failure)

2. When the power supply voltage
is high.

9-time flash

2.5 seconds OFF

Inverter check mode The connector of compressor is disconnected, inverter check

mode starts.

Check if the connector of the com­pressor is correctly connected.
Refer to 11-5. "How to check
inverter/compressor".



NOTE: 1. The location of LED is illustrated at the right figure. Refer to 11-6-1.

2. LED is lighted during normal operation.
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
OFF

2.5-second OFF

2.5-second OFF

0.5-second ON

0.5-second ON

LED

Flashing ĺ

Inverter P.C. board



I

H

H

J

I
F

I



Check of indoor/outdoor connecting
wire.

Replace indoor or outdoor P.C.
board if abnormality is displayed
again.

(KA25/35/50)

(KA60/71)
Zero cross detecting
circuit

Zero cross signal for PAM control cannot be detected.

LED

indication

check

code

UP

U3

U4

FC

E8
E9

UE

Fin temperature thermistor,

/

frequency lowers.

11-2. TROUBLE SHOOTING CHECK TABLE

OCH545

22

F1 F2 F3 F4

unem ecivreS

rosruC

:unem niaM

Test run
Input maintenance info.
Function setting
Check
Self check

kcehc fleS

:tceleS

Ref. address

sserddA

kcehc fleS

Ref. address

Return:

teseR

Error Unt # CI.prG

Self check

Contact

Return:

Reset

M-NET address

Error Grp.

---- ---

When there is no error history

Self check

Delete error history?

Ref. address

Cancel OK

Self check

Return:

Ref. address

Error history deleted

2

With theF1or

F2

button, enter the refrigerant address, and press the button.

Select "Self check" with the F1 or F2 button, and press the button.

1

Select "Service" from the Main menu, and press the button.

3

Error code, unit number, attribute will appear.

"-" will appear if no error history is available.

4

Resetting the error history.

Press the

F4

button (Reset) on the screen that shows the error history.

A confi rmation screen will appear asking if you want to delete the error history.

Press the

F4

button (OK) to delete the error history.

If deletion fails, "Request rejected" will appear.
"Unit not exist" will appear if no indoor units that are correspond to the entered
address are found.

Navigating through the screens

• To go back to the Main menu ..........

button

• To return to the previous screen .......

button

11-3. HOW TO PROCEED "SELF-DIAGNOSIS"

11-3-1. Self-diagnosis <PAR-30MAA> <PAR-31MAA>

As this air conditioner has a function to memorize all the failures that had occured, the latest failure detail can be recalled by
following the procedure below.
Use this function when the check code is not displayed with wired remote controller or the remote controller at use is wireless
type.

OCH545

23

If operations cannot be completed with the remote controller, diagnose the remote controller with this function.

F1 F2 F3 F4

unem ecivreS

rosruC

:unem niaM

Maintenance password
Remote controller check

F1 F2 F3 F4

Remote controller check

:nigeB

Start checking?

Remote controller check

:nigeB

Start checking?

1

Select "Service" from the Main menu, and press the button.

Select "Remote controller check" with the F1

or F2 button, and press

the

button.

2

Select "Remote controller check" from the Service menu, and press the but-

ton to start the remote controller check and see the check results.

To cancel the remote controller check and exit the Remote controller check
menu screen, press the

or the button.

The remote controller will not reboot itself.

Check the remote controller display and see if anything is displayed
(including lines). Nothing will appear on the remote controller display
if the correct voltage (8.5 – 12 VDC) is not supplied to the remote con­troller. If this is the case, check the remote controller wiring and indoor
units.

OK: No problems are found with the remote controller. Check other

parts for problems.

E3, 6832: There is noise on the transmission line, or the indoor unit or another

remote controller is faulty. Check the transmission line and the
other remote controllers.

NG (ALL0, ALL1):

Send-receive circuit fault. Remote controller needs replacing.

ERC:

The number of data errors is the discrepancy between the number of
bits in the data transmitted from the remote controller and that of the
data that was actually transmitted over the transmission line. If data
errors are found, check the transmission line for external noise inter­ference.

Remote controller check results screen

If the button is pressed after the remote controller check results are dis­played, remote controller check will end, and the remote controller will automati-

cally reboot itself.

11-3-2. Remote controller check <PAR-30MAA> <PAR-31MAA>

3

OCH545

24

When a problem occurs to the air conditioner, the indoor and outdoor units will stop,
and the problem is shown in the remote controller display.

[CHECK] and the refrigerant address are displayed on the temperature
display, and the error code and unit number are displayed alternately as
shown below.

1 (If the outdoor unit is malfunctioning, the unit number will be "00".)
2 In the case of group control, for which one remote controller controls

multiple refrigerant systems, the refrigerant address and error code of the
unit that first experienced trouble (i.e., the unit that transmitted the error
code) will be displayed.

3 To clear the error code, press the

ON/OFF

button.

When using remote-/local-controller combined operation, cancel the error code after turning off remote operation.
During central control by a MELANS controller, cancel the error code by pressing the

ON/OFF

button.

Since each unit has a function that stores error codes, the latest check code can be recalled even if it is cancelled by the remote
controller or power is turned off.

Check the error code history for each unit using the remote controller.

1

Switch to self-diagnosis mode.
Press the

CHECK

button (

H in the picture above)

twice within 3 seconds.

The display content will change as shown below.

2

Set the unit number or refrigerant address you want to diagnose.

Press the [TEMP] buttons (

and ) (

F in the picture above)

to select the desired number or address. The number (address) changes between
[01] and [50] or [00] and [15].

3

Display self-diagnosis results.
<When there is error code history>
(For the definition of each error code, refer to the indoor unit's installation manual or service handbook.)

4

Reset the error history.
Display the error history in the diagnosis result display screen (see step

3

).

F

E

G

C

D

H

B

A

I

Error code (2 or 4 digits)

(Alternating Display)

Address (3 digits) or unit number (2 digits)

The refrigerant address will begin to blink
approximately 3 seconds after being
selected and the self-diagnosis process will begin.

Unit number or refrigerant address
to be diagnosed

Error code (2 or 4 digits)

(Alternating Display)

Address (3 digits) or unit number (2 digits)

<When there is no error code history> <When there is no corresponding unit>

11-3-3. Self-diagnosis <PAR-21MAA>

11-3-4. Self-Diagnosis During Maintenance or Service <PAR-21MAA>

OCH545

25

Transmission data from remote controller

Transmission data on transmission path

When the number of data errors is "02":

Press the

ON/OFF

button ( in the picture in the previous page) twice

within 3 seconds. The self-diagnosis address or refrigerant address will blink.

When the error history is reset, the display will look like the one shown below.
However, if you fail to reset the error history, the error content will be displayed again.

 Cancel self-diagnosis.

Self-diagnosis can be cancelled by the following 2 methods.

Press the

CHECK

button ( in the picture in the previous page) → Self-diagnosis will be cancelled and the screen will return to the previous state in effect

before the start of self-diagnosis.

Press the

ON/OFF

button ( in the picture in the previous page). → Self-diagnosis will be cancelled and the indoor unit will stop.

10-3-3. Remote Controller Diagnosis

If the air conditioner cannot be operated from the remote controller, diagnose the remote controller as explained below.

 First, check that the power-on indicator is lit.

If the correct voltage (DC12 V) is not supplied to the remote controller, the
indicator will not light.
If this occurs, check the remote controller's wiring and the indoor unit.

 Switch to the remote controller self-diagnosis mode.

Press the

CHECK

button ( in the picture in the previous page)

for 5 seconds or more. The display content will change as shown below.

Press the

FILTER

button ( in the picture in the previous page)

 Remote controller self-diagnosis result

[When the remote controller is functioning correctly]

Check for other possible causes, as there is no problem with the remote
controller.

[When the remote controller malfunctions]
(Error display 1) "NG" blinks. → The remote controller's transmitting-receiv-

ing circuit is defective.

The remote controller must be replaced with a new one.

[Where the remote controller is not defective, but cannot be operated.]
(Error display 2) [E3], [6833] or [6832] blinks.

→ Transmission is not possible.

There might be noise or interference on the transmission path, or the indoor unit
or other remote controllers are defective. Check the transmission path and other
controllers.

(Error display 3)

"ERC" and the number of data errors are displayed.
→ Data error has occurred.

The number of data errors is the difference between the number of bits sent from
the remote controller and the number actually transmitted through the transmis­sion path. If such a problem is occurring, the transmitted data is affected by noise,
etc. Check the transmission path.

 To cancel remote controller diagnosis

Press the

CHECK

button ( in the picture in the previous page) for 5 seconds or more. Remote controller diagnosis will be cancelled,

"PLEASE WAIT" and operation lamp will blink. Afterapproximately 30 seconds, the state in effect before the diagnosis will be restored.

Power on indicator

twice within 3 seconds.

to start self-diagnosis.

11-3-5. Remote controller check <PAR-21MAA>

OCH545

26

• "CHECK" lights, and refrigerant address
"00" flashes.

• Check that the remote controller's
display has stopped before continuing.

• Select the refrigerant address of the
indoor unit for the self-diagnosis.

Note: Set refrigerant address using the

outdoor unit’s DIP switch (SW1).
(For more information, see the
outdoor unit installation manual.)

• If an air conditioner error occurs, the
indoor unit's sensor emits an intermittent
buzzer sound, the operation light
flashes, and the error code is output.
(It takes 3 seconds at most for error
code to appear.)

• The check mode is cancelled.

[Procedure]

1. Press the CHECK button twice.

2. Press the temperature
buttons.

3. Point the remote controller at the
sensor on the indoor unit and
press the HOUR button.

4. Point the remote controller at the
sensor on the indoor unit and
press the ON/OFF button.

<Malfunction-diagnosis method at maintenance service>

11-3-6. Self-diagnosis <Wireless remote controller>

<In case of trouble during operation>

When a malfunction occurs to air conditioner, both indoor unit and outdoor unit will stop and operation lamp blinks to inform
unusual stop.

ON/OFF

TEMP

FAN

VAN E

MODE

CHECK

LOUVER

TEST RUN

AUTO STOP

AUTO START

h

min

RESET

SET

CLOCK

CHECK

CHECK
display

Temperature
button

CHECK
button

Refrigerant
address
display

HOUR
button

ON/OFF
button

OCH545

27

[Output pattern A] Errors detected by indoor unit

[Output pattern B]

E9

1. If the beeper does not sound again after the initial

2 beeps to confirm the self-check start signal was received and

the OPERATION INDICATOR lamp does not come on,

there are no error records.

2. If the beeper sounds 3 times continuously “beep, beep, beep (0.4 + 0.4 + 0.4 sec.)” after the initial 2 beeps to confirm
the self-check start signal was received, the specified refrigerant address is incorrect.

OPERATION
INDICATOR
lamp flash
pattern

Beep Beep Beep Beep Beep

Beep Beep

Off

Approx. 2.5 sec.OnApprox. 3 sec.On0.5 sec.On0.5 sec.On0.5 sec.On0.5 sec.

Off

Approx. 2.5 sec.OnApprox. 3 sec.On0.5 sec.On0.5 sec.

· · · Repeated

Number of blinks/beeps in pattern indicates the check
code in the following table (i.e., n=5 for “U2”)

Number of blinks/beeps in pattern indicates
the check code in the following table

n

th

1st2nd3

rd

1st2

nd

Self-check
starts
(Start signal
received)

Beeper sounds

[Output pattern B]

OPERATION
INDICATOR
lamp flash
pattern

Beep

Beep Beep Beep Beep Beep Beep

Off

Approx. 2.5 sec.On0.5 sec.On0.5 sec.On0.5 sec.

On

0.5 sec.

Off

Approx. 2.5 sec.On0.5 sec.On0.5 sec.

· · · Repeated

Number of blinks/beeps in pattern indicates the check
code in the following table (i.e., n=5 for “P5”)

Number of blinks/beeps in pattern indicates
the check code in the following table

n

th

1st2nd3

rd

1st2

nd

Self-check
starts
(Start signal
received)

Beeper sounds

 Refer to the following tables for details on the check codes.
[Output pattern A]

Notes:

*The check code in the parenthesis indicates PAR-30MAA model.

Beeper sounds/OPERATION

INDICATOR lamp flashes Check code

Symptom Remark

(Number of times)

Wireless remote controller

Wired remote controller

Beeper sounds/OPERATION

INDICATOR lamp flashes Check code

(Number of times)

Wireless remote controller

Wired remote controller

1P1

Intake sensor error

P9 Pipe (TH5) sensor error

2

P2 Pipe (TH2) sensor error

3E6,E7

Indoor/outdoor unit communication error

4 P4 Drain sensor error/Float switch connector (CN4F) open
5

P5 Drain pump error

PA Forced compressor stop (due to water leakage abnormality)
6 P6 Freezing/Overheating protection operation
7 EE Communication error between indoor and outdoor units

9 E4, E5 Remote controller signal receiving error

Errors detected by unit other than indoor unit (outdoor unit, etc.)

Symptom

1

Indoor/outdoor unit communication error

2

(Transmitting error) (Outdoor unit)

3

Open/short of outdoor unit thermistors

UP
U3,U4
Others

14

Other errors (Refer to the technical manual for the outdoor unit.)

12
14

Fb (FB)*

PL

Indoor unit control system error (memory error, etc.)

–

E0, E3
– E1, E2 Remote controller control board error

Remote controller transmission error

Abnormality of refrigerant circuit

Compressor overcurrent interruption

As for indoor
unit, refer to
indoor unit's
service manual.

OCH545

28

11-4. TROUBLE CRITERION OF MAIN PARTS

Parts name

Figure

Check method and criterion

Outdoor fan motor

R.V. coil (21S4)

Expansion valve coil
(LEV)

Measure the resistance between terminals with a tester.
(Temperature: -10°C ~ 40°C)

WHT - BLK

BLK - RED

RED - WHT

Normal

Measure the resistance between terminals with a tester.
(Temperature : -10°C ~ 40°C)

Normal

WHT - RED

RED - ORN
YLW - BRN
BRN - BLU

Normal

37  ~ 54 

Measure the resistance with a tester.
(Temperature : -10°C ~ 40°C)

Measure the resistance with a tester.
Refer to 11-6. “Test point diagram and voltage”, 11-6-1. (KA25/35/50) or

11-6-2. (KA60/71) “Inverter P.C. board”, for the chart of thermistor.

Color of the lead wire

Color of the lead wire

Discharge temperature
thermistor (RT62)

Measure the resistance with a tester.
Before measurement, hold the thermistor with your hands to warm it up.
Refer to 11-6. “Test point diagram and voltage”, 11-6-1. (KA25/35/50) or
11-6-2. (KA60/71) “Inverter P.C. board”, for the chart of thermistor.

Defrost thermistor (RT61)
Fin temperature

thermistor (RT64)

29  ~ 42 

Measure the resistance between terminals with a tester.
(Temperature: -10°C ~ 40°C)

Compressor

U-V
U-W
V-W

Normal

W

U

V

WHT

RED BLK

W

U

V

WHT

RED BLK

Ambient temperature
thermistor (RT65)

Outdoor heat exchanger
temperature thermistor(RT68)

SUZ-KA25VA4.TH

1.36  ~ 1.93 

SUZ-KA35VA4.TH

1.52  ~ 2.17 

1.19 k ~ 1.78 k

SUZ-KA50/60VA4.TH

0.78  ~ 1.11 

SUZ-KA71VA4.TH

0.92  ~ 1.12 

SUZ-KA25/35VA4.TH SUZ-KA50/60/71VA4.TH

12  ~ 17 

SUZ-KA25/35VA4.TH

LEV

WHT

RED

YLW

ORN

BLU

Measure the resistance with a tester.
(Temperature : -10°C ~ 40°C)

RED - ORN

RED - WHT

RED - BLU

RED - YLW

Normal

37  ~ 54 

Color of the lead wire

SUZ-KA50/60/71VA4.TH

LEV

WHT

RED
ORN

YLW

BRN

BLU

SUZ-KA25VA4.TH SUZ-KA35VA4.THSUZ-KA50VA4.TH SUZ-KA60VA4.TH SUZ-KA71VA4.TH

OCH545

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A How to check inverter/compressor

Are the voltages balanced?

Disconnect the connector between the
compressor and the intelligent power module
(KA25/35/50: IC700, KA60/71: IPM)
.

Replace the inverter P.C. board.

Check the voltage between terminals.

Check the compressor.

See 11-5. “Check of compressor”.

No

Yes

See 11-5. “Check of open phase”.

With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if

the inverter is normal by measuring the voltage balance between the terminals.

Output voltage is 50 - 130V. (The voltage may differ according to the tester.)

<< Operation method (Test run operation)>>

• For the PAR-31MAA, select “Service”  “Test Run” from the main menu to start the test run, and then select the cooling

mode.

• For details or for other information about starting the test run when using remote controllers, refer to the installation manual
for the indoor unit or the remote controller.

<<Measurement point>>
At 3 points
BLK (U) - WHT (V)
BLK (U) - RED (W)
WHT (V) - RED (W)

NOTE: 1. Output voltage varies according to power supply voltage.

2. Measure the voltage by analog type tester.

3. During this check, LED of the inverter P.C. board fl ashes 9 times. (KA25/35/50: Refer to 11-6-1, KA60/71: 11-6-2)

Refer to 11-5. “Check of compressor
operation time”.
Does the compressor operate continuously?

OK

No

Yes

Refer to 11-5. “Check of compressor
winding”.
Is the compressor normal?

Replace the compressor.

No

Yes

C Check of compressor

B Check of open phase

11-5. TROUBLESHOOTING FLOW

* Measure AC voltage between the lead wires at 3 points.

Is the compressor

operation time more than

10 seconds?

Replace the compressor.

No

Yes

Check the refrigerant circuit

OCH545

30

D Check of compressor winding

Disconnect the connector between the compressor and intelligent power module, and measure the resistance between the

compressor terminals.
<<Measurement point>>
at 3 points
BLK-WHT
BLK-RED
WHT-RED
<<Judgement>>
Refer to 11-4.
0 [] ················Abnormal [short]
Infinite [] ·······Abnormal [open]
NOTE: Be sure to zero the ohmmeter before measurement.

* Measure the resistance between the lead wires at 3 points.

E Check of compressor operation time

Compressor starts

Abnormal
(IPM failure)
(Compressor winding short)

Abnormal
(Compressor lock out)
(Starting defect)

Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)

Abnormal
(Refrigerant circuit defect)
(Closed valve)

Normal

0 second

1 second

2 seconds

10 seconds

10 minutes

<<Judgement>>

Connect the compressor and activate the inverter. Then measure the

time until the inverter stops due to over current.
<<Operation method>>
Start heating or cooling test run.
(TEST RUN OPERATION : Refer to 11-5

.)
<<Measurement>>
Measure the time from the start of compressor to the stop of

compressor due to overcurrent.

Is the resistance of thermistor normal?

(KA25/35/50: Refer to 11-6-1, KA60/71: 11-6-2.)

Disconnect the connector of thermistor in the outdoor P.C. board (see
below table), and measure the resistance of thermistor.

Replace the thermistor except RT64.
When RT64 is abnormal, replace the inverter
P.C. board.

Reconnect the connector of thermistor.
Turn ON the power supply and press EMERGENCY OPERATION switch.

No

Yes

F Check of outdoor thermistors

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

Yes

OK.
(Cause is poor contact.)

No

Replace the inverter P.C. board.

Thermistor Symbol

Connector, Pin No.

Board

SUZ-KA25/35/50VA4.TH SUZ-KA60/71VA4.TH

Defrost RT61 Between CN641 pin1 and pin2 Between CN671 pin1 and pin2

Inverter

P.C. board

Discharge temperature RT62 Between CN641 pin3 and pin4 Between CN671 pin3 and pin4
Fin temperature RT64 Between CN642 pin1 and pin2 Between CN673 pin1 and pin2
Ambient temperature RT65 Between CN643 pin1 and pin2 Between CN672 pin1 and pin2
Outdoor heat exchanger temperature RT68 Between CN644 pin1 and pin3 Between CN671 pin5 and pin6

OCH545

31

G Check of R.V. coil

First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 11-4.
In case CN721(KA25/35/50)/CN602(KA60/71) is not connected or R.V. coil is open, voltage is generated between the
terminal pins of the connector although any signal is not being transmitted to R.V. coil.
Check if CN721(KA25/35/50)/CN602(KA60/71) is connected.

Is there 230 VAC between CN721
(KA25/35/50)/CN602(KA60/71)

and
on the inverter P.C. board 3 minutes after
the power supply is turned ON?

No

Yes

Replace the inverter
P.C. board.

Replace the 4-way valve.

Unit operates COOL mode even if it is set to HEAT mode.

Is there 230 VAC between CN721
(KA25/35/50)/CN602(KA60/71)

and
on the inverter P.C. board 3 minutes after
the power supply is turned ON?

Yes

No

Replace the inverter
P.C. board.

Replace the 4-way valve.

Unit operates HEAT mode even if it is set to COOL mode.

Disconnect connector between
the compressor and the intelligent
power module.
Turn ON the power supply and start
heating test run.
(TEST RUN OPERATION: Refer to
11-5

)

Disconnect connector between
the compressor and the intelligent
power module.
Turn ON the power supply and start
cooling test run.
(TEST RUN OPERATION: Refer to
11-5

)

H Check of outdoor fan motor

Is the resistance between each ter­minal of outdoor fan motor normal?
(Refer to 11-4.)

Disconnect the connectors CN931
and CN932 from the inverter P.C.
board. Check the connection between
the connector CN931 and CN932.

Disconnect CN932 from the inverter

P.C. board, and turn on the power sup-

ply.

Rotate the outdoor fan motor manually and measure the voltage of CN931.
Between 1(+) and 5(-)
Between 2(+) and 5(-)
Between 3(+) and 5(-)

Does the voltage between each terminal become 5 and 0
VDC repeatedly?

Does the outdoor fan motor rotate smoothly?

Replace the outdoor fan motor.

Replace the inverter P.C. board.

Yes

Yes

No

(Fixed to either 5 or 0 VDC)

No

No

Yes

OCH545

32

I Check of LEV

Turn on power supply to the outdoor unit after checking
LEV coil is fi xed to the LEV body securely.

Yes

Disconnect the connector CN724 is there nor­mal resistance to LEV coil?

No

Replace the inverter P.C. board.

Replace the LEV coil.

No

Normal

Start

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

Yes

Check the outdoor fan motor.
(Refer to .)

Is the fuse (F901) blown on the in­verter P.C. board?

Check the connection of the connectors
(CN931, CN932) of the outdoor fan mo­tor.
If the connection is poor, make it correct.

Operate the outdoor unit by starting
EMERGENCY OPERATION.

Check the LED indication on the in­verter P.C. board.
Does the LED fl ash 10 times?

Replace the inverter P.C. board.

Check the corresponding parts
following LED indication.
(Refer to 11-3.)

Yes

No

Yes
(10-time fl ash)

No

J Check of inverter P.C. board

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33

Electromagnetic noise enters into TV sets or radios

Yes

Is the unit earthed?

No

Earth the unit.

Yes

Is the distance between the antennas
and the indoor unit within 3 m, or is the
distance between the antennas and the
outdoor unit within 3 m?

No

Extend the distance between the antennas and
the indoor unit, and/or the antennas and the
outdoor unit.

Is the distance between the TV sets or
radios and the indoor unit within 1 m, or
is the distance between the TV sets or
radios and the outdoor unit within 3 m?

Yes

Extend the distance between the TV sets and/or
radios and the indoor unit, or the TV sets or
radios and the outdoor unit.

Are the antennas damaged?
Is the coaxial cable damaged?
Is there any poor contact in the anten­na wiring?

Yes

No

No

Replace or repair the antenna.
Replace or repair the coaxial cable.

Is the indoor/outdoor connecting wire
of the air conditioner and the wiring of
the antennas close?

Yes

Extend the distance between the indoor/outdoor
connecting wire of the air conditioner and the wir­ing of the antennas.

No

Even if all of the above conditions are fulfi lled, the electromagnetic noise may enter, depending on the electric fi eld strength
or the installation condition (combination of specifi c conditions such as antennas or wiring).
Check the following before asking for service.

1. Devices affected by the electromagnetic noise
TV sets, radios (FM/AM broadcast, shortwave)

2. Channel, frequency, broadcast station affected by the electromagnetic noise

3. Channel, frequency, broadcast station unaffected by the electromagnetic noise

4. Layout of ;
indoor/outdoor unit of the air conditioner, indoor/outdoor wiring, earth wire, antennas, wiring from antennas, receiver

5. Electric fi eld intensity of the broadcast station affected by the electromagnetic noise

6. Presence or absence of amplifi er such as booster

7. Operation condition of air conditioner when the electromagnetic noise enters in

1) Turn OFF the power supply once, and then turn ON the power supply. In this situation, check for the electromagnetic
noise.

2) Within 3 minutes after turning ON the power supply, press OPERATE/STOP (ON/OFF) button on the remote controller
for power ON, and check for the electromagnetic noise.

3) After a short time (3 minutes later after turning ON), the outdoor unit starts running. During operation, check for the
electromagnetic noise.

4) Press OPERATE/STOP (ON/OFF) button on the remote controller for power OFF, when the outdoor unit stops but the
indoor/outdoor communication still runs on. In this situation, check for the electromagnetic noise.

K

OCH545

34

11-6. TEST POINT DIAGRAM AND VOLTAGE

11-6-1. Inverter P.C. board

SUZ-KA25VA4.TH SUZ-KA35VA4.TH SUZ-KA50VA4.TH

-20 -10 0 10 20 30 40

0

10

20

30

40

50

60

70

80

90

100

Temperature( )

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

Temperature( )

Discharge temperature thermistor(RT62)

0 102030405060708090100110120

0

100

200

300

400

500

600

700

0 1020304050607080

0

20

40

60

80

100

120

140

160

180

200

Temperature( )

Fin temperature thermistor(RT64)

Resistance(k )

Resistance(k )

Resistance(k )

Fin temperature

thermistor/RT64

(CN642)

Ambient temperature

thermistor/RT65

(CN643)

Discharge temperature

thermistor/RT62

(CN641)

Defrost thermistor

/RT61(CN641)

DB61
260 - 370 VDC

Front side of unit

230 VAC

Smoothing
capacitor
(C62)

Output to
drive
compressor
(LDU,
LDV,
LDW)

(+)

(-)

Fuse (F701)
T3.15AL250V

Smoothing
capacitor
(C61)

Smoothing
capacitor (C63)

Fuse (F901)
T3.15AL250V

R.V.coil
(CN721)
230 VAC

Jumper wire for
changing defrost
setting (JS)

Signal of outdoor

fan motor (CN931)

230 VAC

Outdoor heat exchanger

temperature thermistor

/RT68 (CN644)

Jumper wire
for pre-heat
control setting
(JK)

Heater connector
(CN722)

Fuse (F801)
T3.15AL250V

Back side of unit

LEV connector

(CN724)

Output to
drive outdoor
fan motor
(CN932)

LED

OCH545

35

11-6-2. Inverter P.C. board
SUZ-KA60VA4.TH SUZ-KA71VA4.TH

-20 -10 0 10 20 30 40

0

10

20

30

40

50

60

70

80

90

100

Temperature( )

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

Temperature( )

Discharge temperature thermistor(RT62)

0 102030405060708090100110120

0

100

200

300

400

500

600

700

0 1020304050607080

0

20

40

60

80

100

120

140

160

180

200

Temperature( )

Fin temperature thermistor(RT64)

Resistance(k )

Resistance(k )

Resistance(k )

Fin temperature
thermistor/RT64
(CN673)

Ambient temperature
thermistor/RT65

(CN672)

Discharge temperature
thermistor/RT62
(CN671)

Defrost thermistor
/RT61 (CN671)

Output to
drive outdoor
fan motor
(CN932)

Outdoor heat exchanger
temperature thermistor
/RT68 (CN671)

Fuse (F901)
T3.15AL250V

Fuse (F880)
T3.15AL250V

LEV connector (CN724)

Jumper wire for
changing defrost
setting (JS)

Jumper wire for
pre-heat control
setting (JK)

Fuse (F62)
T2.0AL250V

Fuse (F601)
T3.15AL250V

Signal of out­door fan motor
(CN931)

R.V. coil (CN602)
230VAC

325 - 370 VDC

JP715 (+)

JP30 (-)

LED

OCH545

36

12

DISASSEMBLY INSTRUCTIONS

(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

NOTE: Turn OFF power supply before disassembling.

SOTOPERUDECORP GNITAREPO

1. Removing the cabinet

(1) Remove the screw fixing the service panel.
(2) Pull down the service panel and remove it.
(3) Disconnect the power supply and indoor/outdoor con-

necting wire.
(4) Remove the screws fixing the top panel.
(5) Remove the top panel.
(6) Remove the screws fixing the cabinet.
(7) Remove the cabinet.
(8) Remove the screws fixing the back panel.
(9) Remove the back panel.

Photo 1

Photo 2

Back
panel

Screws
of the back
panel

Service

panel

Screws of the
top panel

Screws of
the cabinet

Screws of
the top panel

Screw of the

service panel

Direction to
remove

Screws of
the cabinet

Hooks

Screw of the
cabinet

H

SUZ-KA25VA4.TH SUZ-KA35VA4.TH
OUTDOOR UNIT

OCH545

3737

OPERATING PROCEDURE

PHOTOS

2. Removing the inverter assembly, inverter P.C. board

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the lead wire to the reactor and the following con-

nectors:

<Inverter P.C. board>

CN721 (R.V. coil)
CN932 (Fan motor)
CN641 (Defrost thermistor and discharge temperature ther-

mistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)
CN724 (LEV)

(3) Remove the compressor connector (CN61).
(4) Remove the screws fixing the relay panel. (Photo 3)
(5) Remove the inverter assembly. (Photo 4)
(6) Remove the screw of the earth wire and screw of the

T.B.support. (Photo 4)

(7) Remove the relay panel from the inverter assembly.
(8) Remove the inverter P.C. board from the relay panel.

Photo 3

Photo 4 (Inverter assembly)

Photo 5

3. Removing R.V. coil

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the following connectors:
<Inverter P.C. board>

CN721 (R.V. coil)

(3) Remove the R.V. coil. (Photo 5)

4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger tempera­ture thermistor and ambient temperature thermistor

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the lead wire to the reactor and the following con-

nectors:
<Inverter P.C. board>
CN641 (Defrost thermistor and discharge temperature ther-

mistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)

(3) Pull out the discharge temperature thermistor from its holder.

(Photo 5)
(4) Pull out the defrost thermistor from its holder. (Photo 6)
(5) Pull out the outdoor heat exchanger temperature thermistor

from its holder. (Photo 6)
(6) Pull out the ambient temperature thermistor from its holder.

Discharge temperature thermistor

R.V. coil

Screws of the
relay panel

Heat sink

Inverter
P.C. board

Screw of the
earth wire

T.B.support

Screw of the
T.B.support

Relay panel

OCH545

38

OPERATING PROCEDURE

PHOTOS

5. Removing outdoor fan motor

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the following connectors:
<Inverter P.C. board>

CN932 (Fan motor)
(3) Remove the propeller nut. (Photo 7)
(4) Remove the propeller. (Photo 7)
(5) Remove the screws fixing the fan motor. (Photo 7)
(6) Remove the fan motor.

Photo 6

Photo 7

Photo 8

6. Removing the compressor and 4-way valve

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Remove the inverter assembly. (Refer to procedure 2.)
(3) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure gauge

shows 0 kg/cm² (0 MPa).

(4) Detach the welded part of the suction and the discharge pipe

connected with compressor.
(5) Remove the nuts of compressor legs.
(6) Remove the compressor.
(7) Detach the welded part of pipes connected with 4-way valve.

(Photo 8)

Defrost thermistor

Outdoor heat
exchanger tempera­ture thermistor

Propeller nut

Screws of the outdoor fan motor

Propeller

Welded parts of 4-way valve

OCH545

39

SUZ-KA50VA4.TH

NOTE: Turn OFF power supply before disassembly.

OPERATING PROCEDURE

PHOTOS

1. Removing the cabinet

(1) Remove the screws of the service panel.
(2) Remove the screws of the top panel.
(3) Remove the screw of the valve cover.
(4) Remove the service panel.
(5) Remove the top panel.
(6) Remove the valve cover.
(7) Disconnect the power supply and indoor/outdoor connect-

ing wire.
(8) Remove the screws of the cabinet.
(9) Remove the cabinet.
(10)

Remove the screws of the back panel.

(11)

Remove the back panel.

Photo 1

Photo 2

Screws of the
cabinet

Screws of the top panel

Screws of the top panel

Screw of the back panel

Screws of the
cabinet

Screws of the
cabinet

Screws of the
service panel

Screw of
the valve
cover

Screws
of the
cabinet

Screws of the
back panel

Screws
of the
cabinet

OCH545

40

OPERATING PROCEDURE

PHOTOS

2. Removing the inverter assembly, inverter P.C. board

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the lead wire to the reactor and the following con-

nectors:
<Inverter P.C. board>
CN721 (R.V. coil)
CN931, CN932 (Fan motor)
CN641 (Defrost thermistor and discharge temperature ther-

mistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)
CN724 (LEV)

(3) Remove the compressor connector.
(4) Remove the screws fixing the heat sink support and the sep-

arator.

(5) Remove the fixing screws of the terminal block support and

the back panel.

(6) Remove the inverter assembly.
(7) Remove the screw of the earth wire, screw of the P.C. board

cover and screws of the terminal block support.

(8) Remove the heat sink support from the P.C. board support.
(9) Remove the screw of the inverter P.C. board and the inverter

P.C. board from the P.C. board support.

Photo 3

Photo 4

Photo 5

3. Removing R.V. coil

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the following connector:
<Inverter P.C. board>

CN721 (R.V. coil)

(3) Remove the R.V. coil.

Screw of the heat sink
support and the separator

Brazed
parts of
4-way
valve

Screw of the
R.V. coil

Heat sink

Screw of
the inverter
P.C. board

Screw of the
earth wire

Screws of the
terminal block
support

Screw of the
P.C. board
cover

Screw of the terminal
block support and the
back panel

P.C. board
support

Heat sink
support

OCH545

41

OPERATING PROCEDURE PHOTOS

4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger tempera­ture thermistor and ambient temperature thermistor

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the lead wire to the reactor and the following

connectors:
<Inverter P.C. board>
CN641 (Defrost thermistor and discharge temperature ther-

mistor)
CN643 (Ambient temperature thermistor)
CN644 (Outdoor heat exchanger temperature thermistor)

(3)

Pull out the discharge temperature thermistor from its holder.
(4) Pull out the defrost thermistor from its holder.
(5) Pull out the outdoor heat exchanger temperature thermistor

from its holder.

(6) Pull out the ambient temperature thermistor from its holder.

Photo 6

Photo 7

Photo 8

5. Removing outdoor fan motor

(1)

Remove the top panel, cabinet and service panel. (Refer to

procedure

1.)

(2) Disconnect the following connectors:

<Inverter P.C. board>

CN931 and CN932 (Fan motor)
(3) Remove the propeller nut.
(4) Remove the propeller.
(5) Remove the screws fixing the fan motor.
(6) Remove the fan motor.

6. Removing the compressor and 4-way valve

(1)

Remove the top panel, cabinet and service panel. (Refer to

procedure

1.)
(2) Remove the back panel. (Refer to procedure 1.)
(3) Remove the inverter assembly. (Refer to procedure 2.)
(4) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure gauge

shows 0 kg/cm² (0 MPa).

(5) Detach the brazed part of the suction and the discharge

pipe connected with compressor.
(6) Remove the rieCONNECTOR:
Yellow nuts.
(7) Remove the compressor.
(8) Detach the brazed part of 4-way valve and pipe. (Photo 5)

Screws of the
outdoor fan motor

Brazed part of the
discharge pipe

Brazed part of the
suction pipe

Discharge temperature
thermistor

Outdoor heat
exchanger tempera­ture thermistor

Ambient tem-

perature

thermistor

Defrost thermistor

Propeller nut

OCH545

42

NOTE: Turn OFF power supply before disassembling.

OPERATING PROCEDURE

PHOTOS

1. Removing the cabinet

(1) Remove the screws of the service panel.
(2) Remove the screws of the top panel.
(3) Remove the screw of the valve cover.
(4) Remove the service panel.
(5) Remove the top panel.
(6) Remove the valve cover.
(7) Disconnect the power supply and indoor/outdoor connect-

ing wire.
(8) Remove the screws of the cabinet.
(9) Remove the cabinet.
(10)

Remove the screws of the back panel.

(11)

Remove the back panel.

Photo 1

Photo 2

Screws of the
cabinet

Screws of the top panel

Screws of the top panel

Screw of the back panel

Screws of the
cabinet

Screws of the
cabinet

Screws of the
service panel

Screw of
the valve
cover

Screws
of the
cabinet

Screws of the
back panel

SUZ-KA60VA4.TH
SUZ-KA71VA4.TH

OCH545

43

OPERATING PROCEDURE

PHOTOS

2. Removing the inverter assembly, inverter P.C. board

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the lead wire to the reactor and the following con-

nectors:
<Inverter P.C. board>
CN602 (R.V. coil)
CN931, CN932 (Fan motor)
CN671 (Defrost thermistor, discharge temperature thermistor

and outdoor heat exchanger temperature thermistor)
CN672 (Ambient temperature thermistor)
CN724 (LEV)

(3) Remove the compressor connector.
(4) Remove the screws fixing the relay panel.
(5) Remove the relay panel.
(6) Remove the earth wires and the lead wires of the inverter P.C.

board.

(7) Remove the screw of the PB support.
(8) Remove the inverter P.C. board from the relay panel.

Photo 3

Photo 4

3. Removing R.V. coil

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the following connector:
<Inverter P.C. board>

CN602 (R.V. coil)

(3) Remove the R.V. coil.

Screws of the
PB support

Screws of
the relay
panel

Inverter P.C
board

Earth wires

Screw of the

relay panel

Screws
of the PB
support

Welded parts of
4-way valve

Screw of the
R.V. coil

OCH545

44

OPERATING PROCEDURE PHOTOS

4. Removing the discharge temperature thermistor,
defrost thermistor, outdoor heat exchanger tempera­ture thermistor and ambient temperature thermistor

(1) Remove the cabinet and panels. (Refer to procedure 1.)
(2) Disconnect the lead wire to the reactor and the following

connectors:
<Inverter P.C. board>
CN671 (Defrost thermistor, discharge temperature thermis-

tor and outdoor heart exchanger temperature ther­mistor)

CN672 (Ambient temperature thermistor)

(3) Pull out the discharge temperature thermistor from its hold-

er. (Photo 7)
(4) Pull out the defrost thermistor from its holder.
(5) Pull out the outdoor heat exchanger temperature thermistor

from its holder.
(6) Pull out the ambient temperature thermistor from its holder.

Photo 5

Photo 6

Photo 7

5. Removing outdoor fan motor

(1)

Remove the top panel, cabinet and service panel. (Refer to 1.)

(2) Disconnect the following connectors:

<Inverter P.C. board>

CN931 and CN932 (Fan motor)

(3) Remove the propeller.
(4) Remove the screws fixing the fan motor.
(5) Remove the fan motor.

6. Removing the compressor and 4-way valve

(1)

Remove the top panel, cabinet and service panel. (Refer to

procedure

1.)
(2) Remove the back panel. (Refer to procedure 1.)
(3) Remove the inverter assembly. (Refer to procedure 2.)
(4) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure gauge

shows 0 kg/cm² (0 MPa).

(5) Detach the welded part of the suction and the discharge

pipe connected with compressor.
(6) Remove the compressor nuts.
(7) Remove the compressor.
(8) Detach the welded part of 4-way valve and pipe. (Photo 4)

Screws of the
outdoor fan motor

Welded part of the
discharge pipe

Welded part of the
suction pipe

Discharge temperature
thermistor

Outdoor heat
exchanger tempera­ture thermistor

Ambient tem­perature
thermistor

Defrost thermistor

OCH545

45

OCH545

HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO100-8310, JAPAN

Copyright 2013 MITSUBISHI ELECTRIC CORPORATION

Distributed in Aug. 2013 No.OCH545
Made in Japan

New publication, effective Aug. 2013
Specifications are subject to change without notice.

TM