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