Mitsubishi Electric SUZ-M25VA, SUZ-M25VA-ET, SUZ-M50VA-ET, SUZ-M60VA, SUZ-M60VA-ET Service Manual

TECHNICAL & SERVICE MANUAL

R32

[Model Name]

SUZ-M25VA

SUZ-M25VA-ET

SUZ-M35VA

SUZ-M35VA-ET

SUZ-M50VA

SUZ-M50VA-ET

SUZ-M60VA

SUZ-M60VA-ET

SUZ-M71VA

SUZ-M71VA-ET

CONTENTS

1.

COMBINATION OF INDOOR AND OUTDOOR UNITS

.....

2

2. SAFETY PRECAUTION

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

2

3. PARTS NAMES AND FUNCTIONS

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

10

4. SPECIFICATION

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

11

5. NOISE CRITERIA CURVES

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

13

6. OUTLINES AND DIMENSIONS

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

14

7. WIRING DIAGRAM

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

16

8. REFRIGERANT SYSTEM DIAGRAM

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

20

9. ACTUATOR CONTROL

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

23

10. SERVICE FUNCTIONS

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

24

11. TROUBLESHOOTING

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

24

12. DISASSEMBLY PROCEDURE

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

41

Note:

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

HFC

utilized

R32

SUZ-M25VA.TH
SUZ-M35VA.TH

PARTS CATALOG (OCB684)

No. OCH684

December 2018

SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS

[Service Ref.]

SUZ-M25VA.TH
SUZ-M25VA-ET.TH

SUZ-M35VA.TH
SUZ-M35VA-ET.TH

SUZ-M50VA.TH
SUZ-M50VA-ET.TH

SUZ-M60VA.TH
SUZ-M60VA-ET.TH

SUZ-M71VA.TH
SUZ-M71VA-ET.TH

2

OCH684

1

COMBINATION OF INDOOR AND OUTDOOR UNITS

INDOOR UNIT SERVICE MANUAL

Indoor unit

Outdoor unit

Heat pump type

SUZ-

Service Ref.

Service

manual No.

M25VA.TH

M25VA-ET.TH

M35VA.TH

M35VA-ET.TH

M50VA.TH

M50VA-ET.TH

M60VA.TH

M60VA-ET.TH

M71VA.TH

M71VA-ET.TH

Heat pump without electric heater

SLZ-M25FA.TH

OCH522A
OCB522A

─ ─ ─ ─

SLZ-M35FA.TH ─ ─ ─ ─
SLZ-M50FA.TH ─ ─ ─ ─
SLZ-M60FA.TH ─ ─ ─ ─
SEZ-M25VA.TH

─

─ ─ ─ ─

SEZ-M35VA.TH ─ ─ ─ ─
SEZ-M50VA.TH ─ ─ ─ ─
SEZ-M60VA.TH ─ ─ ─ ─
SEZ-M71VA.TH ─ ─ ─ ─
MLZ-KP25VF-E1

OBH801
OBB801

─ ─ ─ ─

MLZ-KP35VF-E1 ─ ─ ─ ─
MLZ-KP50VF-E1 ─ ─ ─ ─
PLA-M35EA.UK

OCH697
OCB697

─ ─ ─ ─

PLA-M50EA.UK ─ ─ ─ ─
PLA-M60EA.UK ─ ─ ─ ─
PLA-M71EA.UK ─ ─ ─ ─
PCA-M35KA

OCH659
OCB659

─ ─ ─ ─

PCA-M50KA ─ ─ ─ ─
PCA-M60KA ─ ─ ─ ─
PCA-M71KA ─ ─ ─ ─
PEAD-M35JA(L).UK

BWE017010

─ ─ ─ ─

PEAD-M50JA(L).UK ─ ─ ─ ─
PEAD-M60JA(L).UK ─ ─ ─ ─
PEAD-M71JA(L).UK ─ ─ ─ ─

2-1. ALWAYS OBSERVE FOR SAFETY

Before obtaining access to terminal, all supply circuits must be disconnected.

2

SAFETY PRECAUTION

MEANINGS OF SYMBOLS DISPLAYED ON THE UNIT

WARNING

This mark is for R32 refrigerant only. Refrigerant type is written on nameplate of outdoor unit.

Read the OPERATION MANUAL carefully before operation.

Service personnel are required to carefully read the OPERATION MANUAL and INSTALLATION MANUAL before operation.

Further information is available in the OPERATION MANUAL, INSTALLATION MANUAL, and the like.

3

OCH684

3

2-2. CAUTIONS RELATED TO NEW REFRIGERANT

Cautions for units utilizing refrigerant R32

Precautions during the repair service

• Do not perform the work involving the electric parts
with wet hands.

• Do not pour water into the electric parts.

• Do not touch the refrigerant.

•

Do not touch the hot or cold areas in the refrigerating cycle.

• When the repair or the inspection of the circuit needs
to be done without turning off the power, exercise great
caution not to touch the live parts.

Use a vacuum pump with a reverse ow check

valve.

Vacuum pump oil may ow back into refrigerant cycle

and that can cause deterioration of refrigerant oil, etc.

Use new refrigerant pipes.

In case of using the existing pipes for R22, be careful
with the following.

· Be sure to clean the pipes and make sure that the
insides of the pipes are clean.

· Change are nut to the one provided with this product.
Use a newly ared pipe.

· Avoid using thin pipes.

Preparation before the repair service

• Prepare the proper tools.

• Prepare the proper protectors.

• Provide adequate ventilation.

• After stopping the operation of the air conditioner, turn
off the power-supply breaker.

• Discharge the condenser before the work involving the
electric parts.

Handle tools with care.

If dirt, dust or moisture enters into refrigerant cycle, that
can cause deterioration of refrigerant oil or malfunction of
compressor.

Use the specied refrigerant only.

Never use any refrigerant other than that specied.

Doing so may cause a burst, an explosion, or re when

the unit is being used, serviced, or disposed of.

Correct refrigerant is specied in the manuals and on the

spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.

Ventilate the room if refrigerant leaks during

operation. If refrigerant comes into contact with

a ame, poisonous gases will be released.

Use the following tools specically designed for

use with R32 refrigerant.

The following tools are necessary to use R32 refrigerant.

Tools for R32
Gauge manifold Flare tool
Charge hose Size adjustment gauge
Gas leak detector Vacuum pump adaptor
Torque wrench Electronic refrigerant

charging scale

Make sure that the inside and outside of

refrigerant piping is clean and it has no
contaminants such as sulfur, oxides, dirt,
shaving particles, etc, which are hazard to
refrigerant cycle.

In addition, use pipes with specied thickness.

Contamination inside refrigerant piping can cause deterio­ration of refrigerant oil, etc.

Store the piping indoors, and keep both ends of

the piping sealed until just before brazing.

(Leave elbow joints, etc. in their packaging.)

If dirt, dust or moisture enters into refrigerant cycle, that
can cause deterioration of refrigerant oil or malfunction of
compressor.

The refrigerant oil applied to are and ange

connections must be ester oil, ether oil or

alkylbenzene oil in a small amount.

If large amount of mineral oil enters, that can cause
deterioration of refrigerant oil, etc.

Do not use refrigerant other than R32.

If other refrigerant (R22, etc.) is used, chlorine in
refrigerant can cause deterioration of refrigerant oil, etc.

4

OCH684

[1] Warning for service

(1) Do not alter the unit.

(2) For installation and relocation work, follow the instructions in the Installation Manual and use tools and pipe

components specifically made for use with refrigerant specified in the outdoor unit installation manual.

(3) Ask a dealer or an authorized technician to install, relocate and repair the unit.

For appliances not accessible to the general public.
(4) Refrigerant pipes connection shall be accessible for maintenance purposes.
(5)

If the air conditioner is installed in a small room or closed room, measures must be taken to prevent the refrigerant
concentration in the room from exceeding the safety limit in the event of refrigerant leakage. Should the refrigerant
leak and cause the concentration limit to be exceeded, hazards due to lack of oxygen in the room may result.

(6) Keep gas-burning appliances, electric heaters, and other fire sources (ignition sources) away from the location

where installation, repair, and other air conditioner work will be performed.

If refrigerant comes into contact with a flame, poisonous gases will be released.
(7) When installing or relocating, or servicing the air conditioner, use only the specified refrigerant (R32) to charge

the refrigerant lines.
Do not mix it with any other refrigerant and do not allow air to remain in the lines.
If air is mixed with the refrigerant, then it can be the cause of abnormal high pressure in the refrigerant line, and

may result in an explosion and other hazards.

(8) After installation has been completed, check for refrigerant leaks. If refrigerant leaks into the room and comes

into contact with the flame of a heater or portable cooking range, poisonous gases will be released.

(9) Do not use low temperature solder alloy in case of brazing the refrigerant pipes.
(10)

When performing brazing work, be sure to ventilate the room sufficiently. Make sure that there are no hazardous

or flammable materials nearby.

When performing the work in a closed room, small room, or similar location, make sure that there are no refriger-

ant leaks before performing the work.
If refrigerant leaks and accumulates, it may ignite or poisonous gases may be released.

(11) Do not install the unit in places where refrigerant may build-up or places with poor ventilation such as a semi-base-

ment or a sunken place in outdoor: Refrigerant is heavier than air, and inclined to fall away from the leak source.

(12)

Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manu-

facturer.
(13)

The appliance shall be stored in a room without continuously operating ignition sources (for example: open

flames, an operating gas appliance or an operating electric heater).
(14)

Do not pierce or burn.

(15)

Be aware that refrigerants may not contain an odour.

(16)

Pipe-work shall be protected from physical damage.

(17)

The installation of pipe-work shall be kept to a minimum.

(18)

Compliance with national gas regulations shall be observed.

(19)

Keep any required ventilation openings clear of obstruction.

(20)

Servicing shall be performed only as recommended by the manufacturer.

(21)

The appliance shall be stored in a well-ventilated area where the room size corresponds to the room area as

specified for operation.
(22) Maintenance, service and repair operations shall be performed by authorized technician with required qualification.
(23)

Be sure to have appropriate ventilation in order to prevent ignition. Furthermore, be sure to carry out fire preven-

tion measures that there are no dangerous or flammable objects in the surrounding area.

5

OCH684

[2] Cautions for unit using R32 refrigerant

Basic work procedures are the same as those for conventional units using refrigerant R410A. However, pay careful

attention to the following points.

(1) Information on servicing
(1-1) Checks on the Area

Prior to beginning work on systems containing flammable refrigerants, safety checks are necessary to ensure that the
risk of ignition is minimized.
For repair to the refrigerating systems, (1-3) to (1-7) shall be completed prior to conducting work on the systems.

(1-2) Work Procedure

Work shall be undertaken under a controlled procedure so as to minimize the risk of a flammable gas or vapor being
present while the work is being performed.

(1-3) General Work Area

All maintenance staff and others working in the local area shall be instructed on the nature of work being carried out.
Work in confined spaces shall be avoided. The area around the workspace shall be sectioned off. Ensure that the con­ditions within the area have been made safe by control of flammable material.

(1-4) Checking for Presence of Refrigerant

The area shall be checked with an appropriate refrigerant detector prior to and during work, to ensure the technician is
aware of potentially toxic or flammable atmospheres. Ensure that the leak detection equipment being used is suitable
for use with all applicable refrigerants, i.e. non-sparking, adequately sealed or intrinsically safe.

(1-5) Presence of Fire Extinguisher

If any hot work is to be conducted on the refrigeration equipment or any associated parts, appropriate fire extinguishing
equipment shall be available to hand.
Have a dry powder or CO2 fire extinguisher adjacent to the charging area.

(1-6) No Ignition Sources

No person carrying out work in relation to a refrigeration system which involves exposing any pipe work shall use any
sources of ignition in such a manner that it may lead to the risk of fire or explosion. All possible ignition sources, includ­ing cigarette smoking, should be kept sufficiently far away from the site of installation, repairing, removing and disposal,
during which refrigerant can possibly be released to the surrounding space. Prior to work taking place, the area around
the equipment is to be surveyed to make sure that there are no flammable hazards or ignition risks. “No Smoking” signs
shall be displayed.

(1-7) Ventilated Area

Ensure that the area is in the open or that it is adequately ventilated before breaking into the system or conducting any
hot work. A degree of ventilation shall continue during the period that the work is carried out. The ventilation should
safely disperse any released refrigerant and preferably expel it externally into the atmosphere.

(1-8) Checks on the Refrigeration Equipment

Where electrical components are being changed, they shall be fit for the purpose and to the correct specification. At all
times the manufacturer’s maintenance and service guidelines shall be followed. If in doubt, consult the manufacturer’s
technical department for assistance.
The following checks shall be applied to installations using flammable refrigerants:

•

The charge size is in accordance with the room size within which the refrigerant containing parts are installed.

•

The ventilation machinery and outlets are operating adequately and are not obstructed.

•

Marking to the equipment continues to be visible and legible. Markings and signs that are illegible shall be corrected.

•

Refrigeration pipe or components are installed in a position where they are unlikely to be exposed to any substance
which may corrode refrigerant containing components, unless the components are constructed of materials which are
inherently resistant to being corroded or are suitably protected against being corroded.

(1-9) Checks on Electrical Devices

Repair and maintenance to electrical components shall include initial safety checks and component inspection proce­dures. If a fault exists that could compromise safety, then no electrical supply shall be connected to the circuit until it is
satisfactorily dealt with. If the fault cannot be corrected immediately but it is necessary to continue operation, an ade­quate temporary solution shall be used. This shall be reported to the owner of the equipment so all parties are advised.
Initial safety checks shall include that:

•

capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking;

•

no live electrical components and wiring are exposed while charging, recovering or purging the system;

•

there is continuity of earth bonding

(2) Repairs to Sealed Components
(2-1) During repairs to sealed components, all electrical supplies shall be disconnected from the equipment being worked

upon prior to any removal of sealed covers, etc. If it is absolutely necessary to have an electrical supply to equipment
during servicing, then a permanently operating form of leak detection shall be located at the most critical point to warn
of a potentially hazardous situation.

(2-2) Particular attention shall be paid to the following to ensure that by working on electrical components, the casing is not

altered in such a way that the level of protection is affected. This shall include damage to cables, excessive number of
connections, terminals not made to original specification, damage to seals, incorrect fitting of glands, etc.
Ensure that the apparatus is mounted securely.
Ensure that seals or sealing materials have not degraded to the point that they no longer serve the purpose of prevent­ing the ingress of flammable atmospheres.
Replacement parts shall be in accordance with the manufacturer’s specifications.

6

OCH684

(3) Repair to intrinsically Safe Components

Do not apply any permanent inductive or capacitance loads to the circuit without ensuring that this will not exceed the
permissible voltage and current permitted for the equipment in use.
Intrinsically safe components are the only types that can be worked on while live in the presence of a flammable atmos­phere. The test apparatus shall be at the correct rating.
Replace components only with parts specified by the manufacturer. Other parts may result in the ignition of refrigerant in
the atmosphere from a leak.

(4) Cabling

Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any other adverse
environmental effects. The check shall also take into account the effects of aging or continual vibration from sources such
as compressors or fans.

(5) Detection of Flammable Refrigerants

Under no circumstances shall potential sources of ignition be used in the searching for or detection of refrigerant leaks.
A halide torch (or any other detector using a naked flame) shall not be used.

(6) Leak Detection Methods

Electronic leak detectors may be used to detect refrigerant leaks but, in the case of flammable refrigerants, the sensitivity
may not be adequate, or may need re-calibration. (Detection equipment shall be calibrated in a refrigerant-free area.)
Ensure that the detector is not a potential source of ignition and is suitable for the refrigerant used. Leak detection equip­ment shall be set at a percentage of the LFL of the refrigerant and shall be calibrated to the refrigerant employed, and the
appropriate percentage of gas (25% maximum) is confirmed.
Leak detection fluids are suitable for use with most refrigerants but the use of detergents containing chlorine shall be
avoided as the chlorine may react with the refrigerant and corrode the copper pipe-work.
If a leak is suspected, all naked flames shall be removed/extinguished.
If a leakage of refrigerant is found which requires brazing, all of the refrigerant shall be recovered from the system, or
isolated (by means of shut off valves) in a part of the system remote from the leak. For appliances containing flammable
refrigerants, oxygen free nitrogen (OFN) shall then be purged through the system both before and during the brazing pro­cess.

(7) Removal and Evacuation

When breaking into the refrigerant circuit to make repairs – or for any other purpose conventional procedures shall be
used. However, for flammable refrigerants it is important that best practice is followed since flammability is a considera­tion. The following procedure shall be adhered to:

• remove refrigerant

• purge the circuit with inert gas

• evacuate

• purge again with inert gas

• open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders. For appliances containing flammable refrig­erants, the system shall be “flushed” with OFN to render the unit safe. This process may need to be repeated several
times.
Compressed air or oxygen shall not be used for purging refrigerant systems.
For appliances containing flammable refrigerants, flushing shall be achieved by breaking the vacuum in the system with
OFN and continuing to fill until the working pressure is achieved, then venting to atmosphere, and finally pulling down to
a vacuum. This process shall be repeated until no refrigerant is within the system. When the final OFN charge is used,
the system shall be vented down to atmospheric pressure to enable work to take place. This operation is absolutely vital
if brazing operations on the pipe-work are to take place.
Ensure that the outlet for the vacuum pump is not close to any ignition sources and that ventilation is available.

(8) Charging Procedures

In addition to conventional charging procedures, the following requirements shall be followed:

•

Ensure that contamination of different refrigerants does not occur when using charging equipment. Hoses or lines
shall be as short as possible to minimize the amount of refrigerant contained in them.

•

Cylinders shall be kept upright.

•

Ensure that the refrigeration system is earthed prior to charging the system with refrigerant.

•

Label the system when charging is complete (if not already).

•

Extreme care shall be taken not to overfill the refrigeration system.
Prior to recharging the system, it shall be pressure-tested with the appropriate purging gas. The system shall be leak­tested on completion of charging but prior to commissioning. A follow up leak test shall be carried out prior to leaving the
site.

(9) Decommissioning

Before carrying out this procedure, it is essential that the technician is completely familiar with the equipment and all its
detail. It is recommended good practice that all refrigerants are recovered safely. Prior to the task being carried out, an
oil and refrigerant sample shall be taken in case analysis is required prior to re-use of reclaimed refrigerant. It is essential
that electrical power is available before the task is commenced.

a) Become familiar with the equipment and its operation.

7

OCH684

b) Isolate system electrically.
c) Before attempting the procedure, ensure that:

• mechanical handling equipment is available, if required, for handling refrigerant cylinders;

• all personal protective equipment is available and being used correctly;

• the recovery process is supervised at all times by a competent person;

• recovery equipment and cylinders conform to the appropriate standards.
d) Pump down refrigerant system, if possible.
e) If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of the system.
f) Make sure that cylinder is situated on the scales before recovery takes place.
g) Start the recovery machine and operate in accordance with manufacturer’s instructions.
h) Do not overfill cylinders. (No more than 80 % volume liquid charge).

i) Do not exceed the maximum working pressure of the cylinder, even temporarily.

j) When the cylinders have been filled correctly and the process completed, make sure that the cylinders and the equip-

ment are removed from site promptly and all isolation valves on the equipment are closed off.

k) Recovered refrigerant shall not be charged into another refrigeration system unless it has been cleaned and checked.

(10) Labelling

Equipment shall be labelled stating that it has been de-commissioned and emptied of refrigerant. The label shall be
dated and signed. For appliances containing flammable refrigerants, ensure that there are labels on the equipment stat­ing the equipment contains flammable refrigerant.

(11) Recovery

When removing refrigerant from a system, either for servicing or decommissioning, it is recommended good practice
that all refrigerants are removed safely. When transferring refrigerant into cylinders, ensure that only appropriate refrig­erant recovery cylinders are employed. Ensure that the correct number of cylinders for holding the total system charge
are available. All cylinders to be used are designated for the recovered refrigerant and labelled for that refrigerant (i.e.
special cylinders for the recovery of refrigerant). Cylinders shall be complete with pressure-relief valve and associated
shut-off valves in good working order. Empty recovery cylinders are evacuated and, if possible, cooled before recovery
occurs.
The recovery equipment shall be in good working order with a set of instructions concerning the equipment that is at
hand and shall be suitable for the recovery of all appropriate refrigerants including, when applicable, flammable refriger­ants. In addition, a set of calibrated weighing scales shall be available and in good working order. Hoses shall be com­plete with leak-free disconnect couplings and in good condition. Before using the recovery machine, check that it is in
satisfactory working order, has been properly maintained and that any associated electrical components are sealed to
prevent ignition in the event of a refrigerant release. Consult manufacturer if in doubt.
The recovered refrigerant shall be returned to the refrigerant supplier in the correct recovery cylinder, and the relevant
waste transfer note arranged. Do not mix refrigerants in recovery units and especially not in cylinders. If compressors or
compressor oils are to be removed, ensure that they have been evacuated to an acceptable level to make certain that
flammable refrigerant does not remain within the lubricant. The evacuation process shall be carried out prior to returning
the compressor to the suppliers. Only electric heating to the compressor body shall be employed to accelerate this pro­cess. When oil is drained from a system, it shall be carried out safely.

8

OCH684

2-3. Choosing the outdoor unit installation location

R32 is heavier than air—as well as other refrigerants—
so tends to accumulate at the base (in the vicinity of the
floor). If R32 accumulates around base, it may reach a
flammable concentration in case room is small. To avoid
ignition, maintaining a safe work environment is required
by ensuring appropriate ventilation. If a refrigerant leak is
confirmed in a room or an area where there is insufficient
ventilation, refrain from using of flames until the work
environment can be improved by ensuring appropriate
ventilation.
Install outdoor units in a place where at least one of the
four sides is open, and in a sufficiently large space with­out depressions.

2-4. Minimum installation area

If you unavoidably install a unit in a space where all four sides are blocked or there are depressions, confirm that one of
these situations (A, B or C) is satisfied.

Note: These countermeasures are for keeping safety not for specification guarantee.

A) Secure sufficient installation space (minimum installation area Amin).

Install in a space with an installation area of Amin or more, corresponding to refrigerant quantity M (factory-charged
refrigerant + locally added refrigerant).

B) Install in a space with a depression height of [ 0.125 [m]

OK OK

OK NG

Amin

Height from the bottom of

0.125 [m] or less

Height from the bottom of

0.125 [m] or less

M [kg] Amin [m²]

1.0 12

1.5 17

2.0 23

2.5 28

3.0 34

3.5 39

4.0 45

4.5 50

5.0 56

5.5 62

6.0 67

6.5 73

7.0 78

7.5 84

9

OCH684

C) Create an appropriate ventilation open area.

Make sure that the width of the open area is 0.9 [m] or more and the height of the open area is 0.15 [m] or more.
However, the height from the bottom of the installation space to the bottom edge of the open area should be 0.125 [m]
or less.
Open area should be 75% or more opening.

■ Indoor units

Install in a room with a floor area of Amin or more, corresponding to refrigerant quantity M (factory-charged refrig­erant + locally added refrigerant).
* For the factory-charged refrigerant amount, refer to the spec nameplate or installation manual.
For the amount to be added locally, refer to the installation manual.
Install the indoor unit so that the height from the floor to the bottom of the indoor unit is h0;
for wall mounted: 1.8 m or more;
for ceiling suspended, cassette and ceiling concealed: 2.2 m or more.
* There are restrictions in installation height for each model, so read the installation manual for the particular unit.

75% or more opening

Width W 0.9 [m] or more

Height from the bottom

0.125 [m] or less

Height H 0.15 [m] or more

M [kg] Amin [m²]

1.0 4

1.5 6

2.0 8

2.5 10

3.0 12

3.5 14

4.0 16

4.5 20

5.0 24

5.5 29

6.0 35

6.5 41

7.0 47

7.5 54
Wall mounted

h0 ] 1.8 [m]

Ceiling concealedCassetteCeiling suspended

h0 ] 2.2 [m]h0 ] 2.2 [m]h0 ] 2.2 [m]

10

OCH684

3

PARTS NAMES AND FUNCTIONS

SUZ-M25VA.TH
SUZ-M25VA-ET.TH
SUZ-M35VA.TH
SUZ-M35VA-ET.TH

SUZ-M50VA.TH
SUZ-M50VA-ET.TH

Model SUZ-M·VA

Drain socket 1

Air outlet

Drain outlet

Piping

Drain hose

Air inlet

(back and side)

SUZ-M60VA.TH
SUZ-M60VA-ET.TH
SUZ-M71VA.TH
SUZ-M71VA-ET.TH

Air outlet

Drain outlet

Piping

Drain hose

Air inlet

(back and side)

Piping

Air outlet

Drain outlet

Air inlet

(back and side)

Drain hose

11

OCH684

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-M25VA

(-ET)

SUZ-M35VA

(-ET)

SUZ-M50VA

(-ET)

SUZ-M60VA

(-ET)

SUZ-M71VA

(-ET)

Power supply Single phase 230 V, 50 Hz

Compressor

Model KVB073FYXMC SV092FBAMT SVB130FBBMT SVB172FCKMT

Output W 470 660 900 1,200

Current*

Cooling

A

2.78 3.90 6.81 7.56 8.26

Heating 3.50 4.77 7.71 8.46 8.66

Refrigeration oil
(Model)

L 0.27 (FW68S) 0.35 (FW68S) 0.35 (FW68S) 0.40 (FW68S)

Fan motor

Model RC0J50-NC RC0J50-RA RC0J60-BC

Current*

Cooling

A

0.22 0.20 0.29 0.84

Heating 0.20 0.23 0.29 0.84

Dimensions W × H × D mm 800 × 550 × 285 800 × 714 × 285 840 × 880 × 330

Weight kg 30 35 41 54

Special remarks

Air

ow*

Cooling

High

m³/h

2,178 2,058 2,748 3,006

Low 1,038 906 1,320 1,716

Heating

High 2,076 1,962 2,622 3,006

Med. 1,788 1,686 2,238 2,892

Low 1,452 1,260 1,704 2,280

Sound pressure level*

Cooling

dB(A)

45 48 49

Heating 46 48 49 51

Sound power level

59 64 65 66

Fan
speed

Cooling

High

rpm

940 840

Low 470 460 490 450

Heating

High 900 840

Med. 780 810

Low 640 600 610 650

Fan speed regulator 3

Refrigerant lling capacity

(R32)

kg 0.65 0.90 1.20 1.25 1.45

12

OCH684

Specifications and rating conditions of main electric parts

Model

Item

SUZ-M25VA

(-ET)

SUZ-M35VA

(-ET)

SUZ-M50VA

(-ET)

SUZ-M60VA

(-ET)

SUZ-M71VA

(-ET)

Smoothing
capacitor

(C61) — 620 μF 420 V 620 μF 420 V — —

(C62, C63) 620 μF 420 V 620 μF 420 V 620 μF420 V — —

(CB1, 2, 3) — — — 560 μF 450 V

Diode module

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

(DB65) 25 A 600 V — —

Fuse

(F61) 25 A 250 V — —

(F62) 15 A 250 V — —

(F701, F801, F901)

T3.15 A L250 V — —

(F601, F880, F901)

— — — T3.15 A L250 V

Power module

(IC700) 15 A 600 V 20 A 600 V

(IC932) 5 A 600 V

Switch power
transistor

(Q821) 30 A 600 V — —

Expansion valve
coil

(LEV) 12 V DC

Reactor

(L61) 18 mH 23 mH — —

(L) — — — 282 μH

Diode (D3A, D3B) — — — 20 A 600 V

Diode module (DB41A, DB41B) — — — 20 A 600 V

Current-Limiting
PTC thermistor

(PTC64, PTC65) 33Ω

Terminal block (TB1) 5P 3P

Relay

(X63) 3 A 250 V — —

(X64) 20 A 250 V

(X601) — — — 3 A 250 V

(X602) — — — 3 A 250 V

R.V. coil (21S4) 220–240 V AC

13

OCH684

13

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

45

46

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-M25VA.TH
SUZ-M25VA-ET.TH

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

COOLING

FUNCTION

SPL(dB(A))

LINE

FAN SPEED

HEATING

48

48

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-M35VA.TH
SUZ-M35VA-ET.TH

COOLING

FUNCTION

SPL(dB(A)) LINE

High

FAN SPEED

HEATING

48

49

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-M50VA.TH
SUZ-M50VA-ET.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-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

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

COOLING

FUNCTION

SPL(dB(A)) LINE

High

FAN SPEED

HEATING4951

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

14

OCH684

mm (inch)

mm (inch)

6

OUTLINES AND DIMENSIONS

Unit: mm

SUZ-M25VA.TH SUZ-M35VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH

Unit: mm

SUZ-M50VA.TH
SUZ-M50VA-ET.TH

15

OCH684

15

SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

417.5

40

42

Drain hole

175

500

330

50

Air in

Air out

2-holes 10 21

360

840

109

81

880

452

Service panel

99.5

164.5

195

35

44

Liquid refrigerant pipe joint
Refrigerant pipe (flared)
Ø 6.35

Gas refrigerant pipe joint
Refrigerant pipe (flared)
Ø 12.7

Air in

350 mm or more

100 mm or more

REQUIRED SPACE

100 mm or more

500 mm

or more *2

*1 500 mm or more when front
and sides of the unit are clear

*2 When any 2 sides of left, right
and rear of the unit are clear

Clear *1

Unit: mm

16

OCH684

7

WIRING DIAGRAM

SUZ-M25VA.TH
SUZ-M25VA-ET.TH

17

OCH684

17

SUZ-M35VA.TH
SUZ-M35VA-ET.TH

18

OCH684

SUZ-M50VA.TH
SUZ-M50VA-ET.TH

19

OCH684

SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

20

OCH684

REFRIGERANT SYSTEM DIAGRAM

8

Unit: mm

SUZ-M25VA.TH SUZ-M35VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.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(M35)

Outdoor heat
exchanger
temperature
thermistor
RT68

Muffler

Outdoor
heat
exchanger

LEV

Strainer
#50

ø4.0×ø2.4×240(M25)

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×ø2.0×210(×2)

LEV

Ambient
temperature
thermistor

Muffler

Capillary tube
ø4.0×ø2.4×240

Outdoor heat
exchanger
temperature
thermistor

Muffler

RT65

RT68

Strainer
#50

Unit: mm

SUZ-M50VA.TH
SUZ-M50VA-ET.TH

21

OCH684

21

Unit: mm

SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.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

15.88

(with heat insulator)

Refrigerant pipe ø6.35
(with heat insulator)

LEV

R.V. coil
heating ON
cooling OFF

Muffler

Strainer

#100

Outdoor heat
exchanger
temperature
thermistor
RT68

Ambient
temperature
thermistor
RT65

Strainer

#100

Strainer

#50

Strainer

#100

Muffler

Capillary tube

ø3.0×ø2.0×200(×6)

Distributer

22

OCH684

ADDITIONAL REFRIGERANT CHARGE (R32: g)

MAX. REFRIGERANT PIPING LENGTH

Max. Length
A

* Height difference limitations are binding regardless of the height position at which either indoor or outdoor is placed higher.

* 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)

7 m 10 m 15 m 20 m

SUZ-M25VA(-ET) 650 0 60 160 260
SUZ-M35VA(-ET) 900 0 60 160 260

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-M25VA(-ET)

20 12 9.52

6.35

SUZ-M35VA(-ET)
SUZ-M50VA(-ET)

30 30

12.7

SUZ-M60VA(-ET)

15.88

SUZ-M71VA(-ET) 9.52

Model

Outdoor unit

precharged

Refrigerant piping length (one way)

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

SUZ-M50VA(-ET) 1,200 0 60 160 260 360 460
SUZ-M60VA(-ET) 1,250 0 60 160 260 360 460

Model

Outdoor unit

precharged

Refrigerant piping length (one way)

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

SUZ-M71VA(-ET) 1,450 0 120 320 520 720 920

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-3xMAA ("x" represents 0 or later), 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.
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.

23

OCH684

23

ACTUATOR CONTROL

9

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

○ ○ ○

SUZ-M25VA.TH SUZ-M35VA.TH SUZ-M50VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH SUZ-M50VA-ET.TH
SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

24

OCH684

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.
Inverter P.C. board".)

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. TROUBLESHOOTING CHECK TABLE" and "11-3. HOW TO PROCEED "SELF­DIAGNOSIS"".

11-1. CAUTIONS ON TROUBLESHOOTING

1. Before troubleshooting, check the following items:

1) Check the power supply voltage.

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

2. Take care of 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 nish temperature (°C)

SUZ-M25 SUZ-M35 SUZ-M50

SUZ-M60
SUZ-M71

JS

Soldered (Initial setting) 5 9 9 10

None (cut) 8 13 18 18

SUZ-M25VA.TH SUZ-M35VA.TH SUZ-M50VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH SUZ-M50VA-ET.TH
SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

SUZ-M25VA.TH SUZ-M35VA.TH SUZ-M50VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH SUZ-M50VA-ET.TH
SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

25

OCH684

25

temperature thermistor, outdoor heat exchanger temperature

No. Symptoms

Abnormal point/

Condition

RemedyCondition

1

Outdoor unit
does not op­erate.

1-time blink
every

2.5 seconds

Outdoor power sys­tem

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 blink

2.5 seconds
OFF

Serial signal The communication fails between the indoor and outdoor unit

for 3 minutes.

5

11-time blink

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 blink

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 blink

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 blink

2.5 seconds OFF

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

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

Check around outdoor unit.
Check outdoor unit air passage.
Refer to 11-5. "Check of outdoor
fan motor".

•

•

•

10

5-time blink

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 blink

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 blink

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 blink

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 blink

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 blink

2.5 seconds OFF

Frequency drop by
current protection

When the input current exceeds approximately 7A(M25 )/
8A(M35)/12A(M50)14A(M60)/16A(M71), 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 blink

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 blink

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 blink

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 blink

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 blink

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".

•

Notes: 1. The location of LED is illustrated at the right figure. Refer to “11-6. Test point diagram and voltage”.

2. LED is lighted during normal operation.

The blinking frequency shows the number of times the LED blinks after every 2.5-second OFF.

(Example) When the blinking frequency is “2”.

ON

OFF

2.5-second OFF

2.5-second OFF

0.5-second ON

0.5-second ON
LED

Blinking →

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.

(M25/35/50)

(M60/71)
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.

16-time blink

2.5 seconds
OFF

PL

Outdoor refrigerant
system abnormality

A closed valve and air trapped in the refrigerant circuit are detected
based on the temperature sensed by the indoor and outdoor thermistors
and the current of the compressor.

•

Check for a gas leak in a connecting

piping, etc.

Check stop valve.

•
Refer to 11-5

.

L

refrigerant circuit”.

•

"Check of outdoor

20

11-2. TROUBLESHOOTING CHECK TABLE

26

OCH684

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

Return:

Reset

Ref. address

Error

--

Unt #

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 theF1orF2button, 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

Check 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 con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 Service menu ..........

button

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

button

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

11-3-1. Self-diagnosis <PAR-3xMAA ("x" represents 0 or later)>

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.

27

OCH684

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 but­ton 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 (8.5–2 V DC) 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 inter

-

ference.

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-3xMAA ("x" represents 0 or later)>

3

28

OCH684

11-3-3. Self-diagnosis <PAC-YT52CRA>

Retrieve the error history of each unit using the Simple MA controller.

1 Switch to the self-diagnosis mode.

When the A button and the button are pressed for 5 seconds or longer, the

figure shown below is

2

Set the address or refrigerant address No. you want to self-diagnosis.
When the

B

and

C

are pressed, the address decreases and increases between 01 and 50 or 00 and 15.

Set it to the address No. or refrigerant address No. you want to self-diagnosis.

ON

OFF

.

. .

C

Self-diagnosis address
or self-diagnosis
refrigerant address

Approximately 3 seconds
after the change operation, the
self-diagnosis refrigerant
address changes from blinking
to a steady light and self­diagnosis begins.

3

Self-diagnosis result display <error history>

the contents of the check code, refer to the indoor unit installation

Check code 4 digits or
check code 2 digits

Error detection attribute

Address 3 digits or
unit address No. 2 digits

<When there is no error history> <When opposite side does not exist>

(Alternate
display)

4

Error history reset
The error history is displayed in 3 self-diagnosis results display.
When the

D button is pressed 2 times successively within 3 seconds, the self-diagnosis object address

When the error history was reset, the display shown below appears.
When error history reset is failed, the error contents are displayed again.

5

Self-diagnosis reset

There are the following 2 ways of resetting self-diagnosis.
Press the

A button and the C button simultaneously for 5 seconds or longer.

→

Resets self-diagnosis and returns to the state before self-diagnosis.

Press the

A

button. → Self-diagnosis resets and indoor units stop.

prohibited, this operation is ineffective.)

ON

OFF

.

ON

OFF

displayed.

manual or service handbook.)

and refrigerant address blink.

(For

(When operation is

29

OCH684

11-3-4. Remote Controller Check <PAC-YT52CRA>

When the air conditioner cannot be controlled from the Simple MA controller, use this function

to check the remote controller.

1

First, check the power mark.

When normal voltage (12 V DC) is not applied to the remote controller, the power mark goes off.
When the power mark is off, check the remote controller wiring and the indoor unit.

2

Switch to the remote controller check mode.
When the B

button and

D

button are pressed simultaneously for 5 seconds or

longer, the figure

When the

A

button is pressed, remote controller check begins.

.

ON

OFF

Remote controller check result

<When remote controller is normal>

3

Since there is no problem at the remote controller, check for other causes.

<When remote controller is faulty>

(Error display 1) “NG” blinks →

Remote controller sends/receives circuit abnormal

Remote controller switching is necessary.

When the problem is other than the checked remote controller

(Error display 2) “E3” “6833” “6832” blink

→

Cannot send

(Error display 3) “ERC” and data error count are displayed

→

Data error generation

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.

“Data error count” is the difference between the number of bits of remote controller send
data and the number of bits actually sent to the transmission line. In this case, the

send

data was disturbed by the noise, etc. Check the transmission line.

When data error count is 02

Remote controller send data
Send data on transmission line

4

Remote controller check reset

When the

B

button and

D

button are pressed simultaneously for 5 seconds or

longer, remote controller

and run lamp blink for a certain period of time, and then the remote controller returns to its

.

diagnosis is

reset, the [HO]

shown below is displayed.

Power mark

state before diagnosis.

30

OCH684

[Procedure]

1. Press the CHECK button twice.

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

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

2. Press the TEMP buttons.

• 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.)

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

• If an air conditioner error occurs, the indoor unit's sensor emits an

intermittent buzzer sound, the operation light blinks, and the check
code is output.

(It takes 3 seconds at most for check code to appear.)

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

• The check mode is cancelled.

<Malfunction-diagnosis method at maintenance service>

11-3-5. Self-diagnosis <Wireless remote controller> *

For SLZ model, refer to the indoor unit's service manual.

<In case of trouble during operation, except for SLZ model*>

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

VANE

MODE

CHECK

LOUVER

TEST RUN

AUTO STOP

AUTO START

h

min

RESET

SET

CLOCK

CHECK

CHECK
display

TEMP
button

CHECK
button

Refrigerant
address
display

HOUR
button

ON/OFF
button

31

OCH684

OPERATION
INDICATOR
lamp blink
pattern

Beep Beep Beep Beep Beep

Beep Beep

Off

Approx. 2.5 sOnApprox. 3 sOn0.5 sOn0.5 sOn0.5 s

On

0.5 s

Off

Approx. 2.5 sOnApprox. 3 sOn0.5 sOn0.5 s

··· 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 blink
pattern

Beep

Beep Beep Beep Beep Beep Beep

Off

Approx. 2.5 s

On

0.5 sOn0.5 sOn0.5 s

On

0.5 s

Off

Approx. 2.5 sOn0.5 sOn0.5 s

··· 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]

[Output pattern A] Errors detected by indoor unit

Wireless remote controller

Wired remote controller

Symptom Remark

Beeper sounds/OPERATION

INDICATOR lamp blinks

(Number of times)

Check code

1 P1 Intake sensor error

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

2

P2 Pipe (TH2) sensor error

P9 Pipe (TH5) sensor error
3 E6,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

12 Fb (FB)* Indoor unit control system error (memory error, etc.)
14 PL Abnormality of refrigerant circuit

- E0,E3 Remote controller transmission error

- E1,E2 Remote controller control board error

[Output pattern B] Errors detected by unit other than indoor unit (outdoor unit, etc.)

Wireless remote controller

Wired remote controller

Symptom

Beeper sounds/OPERATION

INDICATOR lamp blinks

(Number of times)

Check code

1 E9

Indoor/outdoor unit communication error

(Transmitting error) (Outdoor unit)
2 UP Compressor overcurrent interruption
3 U3,U4 Open/short of outdoor unit thermistors

14 PL or Others

Abnormality of refrigerant circuit or other errors

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

Notes: 1. If the beeper does not sound again after the initial 2 beeps to conrm 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

conrm the self-check start signal was received, the specied refrigerant address is incorrect.

*The check code in the parenthesis indicates PAR-3xMAA model.("x" represents 0 or later).

32

OCH684

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 to 40°C)

WH - BK

BK - RD

RD - WH

Normal

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

Normal

Measure the resistance with a tester.

Refer to “11-6. Test point diagram and voltage”, 11-6-1. (M25/35/50) or
11-6-2. (M60/71) “Inverter P.C. board”, for the chart of thermistor.

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. (M25/35/50) or
11-6-2. (M60/71) “Inverter P.C. board”, for the chart of thermistor.

Defrost thermistor (RT61)

Fin temperature
thermistor (RT64)

32 to 43 Ω

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

Compressor

U-V

U-W

V-W

Normal

W

U

V

WH

RD BK

W

U

V

WH

RD BK

Ambient temperature
thermistor (RT65)

Outdoor heat exchanger
temperature thermistor(RT68)

SUZ-M25

1.59 to 2.16Ω

SUZ-M35

1.60 to 2.17 Ω

1.41 to 2.00 kΩ

SUZ-M50/60

0.82 to 1.11 Ω

SUZ-M71

0.87 to 1.18 Ω

SUZ-M25/35 SUZ-M50

15 to 20 Ω

LEV

WH

RD

YE

OG

BU

Measure the resistance with a tester.
(Temperature : −10 to 40°C)

RD - OG

RD - WH

RD - BU

RD - YE

Normal

37 to 54 Ω

Color of the lead wire

SUZ-M60/71

25 to 34 Ω

1.17 to 1.66 kΩ

SUZ-M25/35/50 SUZ-M60/71

SUZ-M25VA.TH SUZ-M35VA.TH SUZ-M50VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH SUZ-M50VA-ET.TH
SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

33

OCH684

A How to check inverter/compressor

Are the voltages balanced?

Disconnect the connector between the
compressor and the intelligent power module
(IC700)
.

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 50–130 V. (The voltage may differ according to the tester.)

< Operation method (Test run operation)>

• For the

PAR-3xMAA model.("x" represents 0 or later), 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
BK (U) - WH (V)
BK (U) - RD (W)
WH (V) - RD (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 blinks 9 times. (M25/35/50: Refer to 11-6-1, M60/71: 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.

34

OCH684

D Check of compressor winding

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

compressor terminals.
<Measurement point>
Measure the resistance between the lead wires at 3 points.
BK-WH
BK-RD
WH-RD
<Judgement>
Refer to "11-4. TROUBLE CRITERION OF MAIN PARTS".

0 [Ω] ················Abnormal [short]
Infinite [Ω] ·······Abnormal [open]

NOTE: Be sure to zero the ohmmeter before measurement.

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 overcurrent.
<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?

(M25/35/50: Refer to 11-6-1,M60/71: 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-M25/35/50 SUZ-M60/71

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

35

OCH684

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. TROUBLE CRITERION OF
MAIN PARTS".
In case CN721(M25/35/50)/CN602(M60/71) 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(M25/35/50)/CN602(M60/71) is connected.

Is there 230 VAC between CN721
(M25/35/50)/CN602(M60/71)

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
(M25/35/50)/CN602(M60/71)

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. TROUBLE CRITERION
OF MAIN PARTS". )

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 V
DC 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 V DC)

No

No

Yes

36

OCH684

I Check of LEV

Turn on power supply to the outdoor unit after checking

LEV coil is 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, correct it.

Operate the outdoor unit by starting
EMERGENCY OPERATION.

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

Replace the inverter P.C. board.

Check the corresponding parts
following LED indication.
(Refer to "11-3. HOW TO PRO­CEED "SELF-DIAGNOSIS"".)

Yes

No

Yes
(10-time blink)

No

J Check of inverter P.C. board

37

OCH684

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 fullled, the electromagnetic noise may enter, depending on the electric eld strength
or the installation condition (combination of speci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 eld intensity of the broadcast station affected by the electromagnetic noise

6. Presence or absence of ampli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

38

OCH684

Check of outdoor refrigerant circuit

L

The unit occasionally stops when the
stop valve is opened or closed during
operation. Open the stop valve and
start the cooling operation again.

No

Has the operation stopped
during pump down?

Yes

Was the operation started with
the stop valve closed, and was
it opened during operation?

Yes

The refrigerant gas amount may
be 60% or less than the normal
amount. Identify where the gas is

leaking from, and x the leak.

No

CAUTION:
Do not start the operation again to
prevent hazards.

The operation has stopped to
prevent the diesel explosion caused
by air trapped in the refrigerant
circuit. Close the stop valve, and
disconnect the power plug or turn
the breaker OFF.

Note: If the abnormality can not be reset with remote controllers, it is

detected in the connected indoor unit. Please refer to the indoor
unit's service manual.

39

OCH684

11-6. TEST POINT DIAGRAM AND VOLTAGE

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

SUZ-M25VA.TH SUZ-M35VA.TH SUZ-M50VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH SUZ-M50VA-ET.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)

0 10 20 30 40 50 60 70 80

0

20

40

60

80

100

120

140

160

180

200

Temperature( )

Fin temperature thermistor(RT64)

Resistance(k )

Resistance(k )

Temperature (°C)

Discharge temperature thermistor (RT62)

Resistance (kΩ)

0

100

200

300

400

500

600

700

800

0 10 20 30 40 50 60 70 8 0 90 10 01 10 120

Fin temperature
thermistor/RT64
(CN642)

Ambient temperature
thermistor/RT65

(CN643)

Discharge temperature
thermistor/RT62
(CN641)

Defrost thermistor
/RT61(CN641)

DB61
260 - 370 V DC

Front side of unit

230 V AC

Output to
drive
compressor
(LDU,
LDV,
LDW)

(+)

(-)

Fuse (F701)
T3.15AL250V

R.V.coil
(CN721)
230 V AC

Jumper wire for
changing defrost
setting (JS)

Signal of outdoor
fan motor (CN931)

230 V AC

Outdoor heat exchanger
temperature thermistor
/RT68 (CN644)

Jumper wire
for pre-heat
control setting
(JK)

Fuse (F801)
T3.15AL250V

Back side of unit

LEV (CN724)

Output to
drive outdoor
fan motor
(CN932)

LED

Defrost heater
(CN722)

Fuse (F62)
15 A 250 V

Fuse (F901)
T3.15AL250V

Smoothing
capacitor
(C63)

Smoothing
capacitor
(C62)

Smoothing
capacitor (C61)

(SUZ-M35/50)

Fuse (F61)
25 A 250V

40

OCH684

11-6-2. Inverter P.C. board
SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.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 10 20 30 40 50 60 70 80 90 100 11 0 120

0

100

200

300

400

500

600

700

0 10 20 30 40 50 60 70 80

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 (CN724)

Jumper wire for
changing defrost
setting (JS)

Jumper wire for
pre-heat control
setting (JK)

Fuse (F601)
T3.15AL250V

Signal of out­door fan motor
(CN931)

R.V. coil (CN602)
230 V AC

230 V AC

260 - 370 V DC

IC700 (N)

IC700 (P)

LED

41

OCH684

41

12

DISASSEMBLY PROCEDURE

(1) Slide the sleeve and check if there is a locking lever or not. (2) The terminal with this connector has the

locking mechanism.

1Slide the sleeve.
2Pull the terminal while

pushing the locking
lever.

1Hold the sleeve, and
pull out the terminal
slowly.

The terminal which has the locking mechanism can be detached as shown below.
There are 2 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

SUZ-M25VA.TH SUZ-M35VA.TH
SUZ-M25VA-ET.TH SUZ-M35VA-ET.TH

: Indicates the visible parts in the photos/gures.
: Indicates the invisible parts in the photos/gures.

NOTE: Turn OFF the power supply before disassembly.

OPERATING PROCEDURE PHOTOS/FIGURES

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 cord and indoor/outdoor

connecting 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 3

Photo 1

Photo 2

Back panel

Service panel

Screws of the top panel

Screws of the terminal block support and the back panel

Screws of the cabinet

Screws of
the back panel

Screws of
the top panel

Direction to
remove

Screws of the cabinet

Hooks of
the service
panel

Screw of the cabinet

Screw of
the service
panel

42

OCH684

OPERATING PROCEDURE

PHOTOS/FIGURES

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

(1) Remove the cabinet and panels. (Refer to section 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 (CN61).
(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 and screw of the termi-

nal 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 remove the

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

Photo 4

Photo 5 (Inverter assembly)

Photo 6

3. Removing R.V. coil

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

CN721 (R.V. coil)

(3) Remove the R.V. coil.

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

from its holder. (Photo 7)

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

Discharge temperature thermistor

Screw of the
R.V. coil

Screws of the heat sink
support and the separator

Screws of the terminal block
support and the back panel

Heat sink

Screw of the
earth wire

Screw of the
Terminal block
support

Screw of the
inverter P.C. board

Heat sink support

P.C. board

support

Terminal
block
support

43

OCH684

OPERATING PROCEDURE

PHOTOS/FIGURES

5. Removing outdoor fan motor

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

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

Photo 7

NOTE: SUZ-M25/35VA are different in the installation

position of thermistors.

Photo 8

6. Removing the compressor and 4-way valve

(1) Remove the cabinet and panels. (Refer to section 1.)
(2) Remove the inverter assembly. (Refer to section 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 brazed 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 brazed part of pipes connected with 4-way valve.

7. Removing the LEV assembly

(1) Detaching the brazed part of pipes connected with LEV

valve.

Photo 10

Photo 9

Defrost thermistor

Outdoor heat
exchanger tempera­ture thermistor

Brazed parts of 4-way valve

Ambient temperature
thermistor

Brazed parts of LEV valve

Propeller fan nut

Screws of the outdoor fan motor

Propeller fan

44

OCH684

SUZ-M50VA.TH
SUZ-M50VA-ET.TH

NOTE: Turn OFF the power supply before disassembly.

OPERATING PROCEDURE

PHOTOS/FIGURES

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 2

Photo 1

Screws of
the cabinet

Screws of the top panel

Screws of
the cabinet

Screws of the top panel

Screw of the back panel

Screws of
the service panel

Screw of
the valve cover

Screws of
the cabinet

Screws of
the back panel

45

OCH684

OPERATING PROCEDURE PHOTOS/FIGURES

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

(1) Remove the cabinet and panels. (Refer to section 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 (CN61).
(4) Remove the screws fixing the heat sink support and the sep-

arator.

(5)

Remove the fixing screw of the P.B. support and the separator.

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

the back panel.
(7) Remove the inverter assembly.
(8) Remove the heat sink support from the P.C. board support.
(9) Remove the screw of the inverter P.C. board and remove the

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

*

Connection procedure when attaching the inverter P.C.

board (Photo 4)

1. Connect the lead wires of the heat exchanger temperature
thermistor, the defrost thermistor and discharge tempera­ture thermistor to the connector on the inverter P.C. board.
Pull the lead wires toward you and put them on the right
hook on the P.C. board support.

2. Connect the lead wires of the LEV to the connector on the
inverter P.C. board. Pull the lead wires toward you and put
them on the right hook on the P.C. board support.

3. Connect the lead wires of the ambient temperature ther­mistor to the connector on the inverter P.C. board. Pull
the lead wires toward you and put them on the left hook
on the P.C. board support so that the fan motor lead wires
are bundled up as shown in Photo 4.

Photo 3

Photo 4

Photo 5 (Inverter assembly)

Screw of the heat sink
support and the separator

Screws of
the terminal block
support and
the back panel

Screw of the P.B. support
and the separator

Heat sink

Screws of
the earth wire

Screw of the inverter P.C. board

Heat sink support

P.C. board support

Inverter P.C. board

Lead wires of
the heat exchanger
temperature and
discharge temperature
thermistor

Inverter P.C. board support

Lead wires of
the ambient
temperature
thermistor

46

OCH684

OPERATING PROCEDURE

PHOTOS/FIGURES

3. Removing R. V. coil

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

CN721 (R.V. coil)

(3) Remove the R.V. coil.

Photo 6

Photo 7

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 section 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.
(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.

5. Removing outdoor fan motor

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

CN931, CN932 (Fan motor)

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

Photo 8

Discharge temperature thermistor

Screw of the R.V. coil

Defrost thermistor

Outdoor heat
exchanger tempera­ture thermistor

Ambient temperature
thermistor

Screws of the outdoor fan motor

Propeller fan

Propeller fan nut

47

OCH684

OPERATING PROCEDURE

PHOTOS/FIGURES

6. Removing the compressor and 4-way valve

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

NOTE: Recover gas from the pipes until the pressure gauge

shows 0 kg/cm

2

(0 MPa).

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

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

Photo 9

Brazed parts of 4-way valve

Suction pipe
brazed part

Discharge pipe
brazed part

48

OCH684

SUZ-M60VA.TH SUZ-M71VA.TH
SUZ-M60VA-ET.TH SUZ-M71VA-ET.TH

NOTE: Turn OFF the power supply before disassembly.

OPERATING PROCEDURE

PHOTOS/FIGURES

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 2

Photo 1

Screws of
the cabinet

Screws of the top panel

Screws of
the cabinet

Screws of the top panel

Screw of the back panel

Screws of
the cabinet

Screws of
the service panel

Screw of
the valve cover

Screws of
the cabinet

Screws of
the back panel

49

OCH684

OPERATING PROCEDURE

PHOTOS/FIGURES

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

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

connectors:
<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 earth wires and the lead wires of the inverter P.C.

board.
(5) Remove the screws of the P.B. support.
(6) Remove the P.B. support from the relay panel.
(7) Remove the screws of the inverter P.C. board.
(8) Remove the inverter P.C. board from P.B. support.

*

Notes about attaching the inverter P.C. board

1.

When attaching the inverter P.C. board, clip the lead wires of

the reactor to the wire saddles on the bottom of relay panel.

2. After attaching the inverter P.C. board, make sure that the
lead wires are connected and placed as shown in Photo 3.

Photo 3

Photo 4

Screws of the relay panel

Inverter P.C board

Earth wires

Screws of
the P.B.
support

Screws of
the inverter
P.C. board

Screw of
the relay
panel

Screw of the P.B. support

50

OCH684

OPERATING PROCEDURE PHOTOS/FIGURES

3. Removing R.V. coil

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

CN602 (R.V. coil)

(3) Remove the R.V. coil.

Photo 5

Photo 6

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 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 heat exchanger temperature ther­mistor)

CN672 (Ambient temperature thermistor)

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

er. (Photo 8)
(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.

Outdoor heat
exchanger
temperature thermistor

Ambient
temperature
thermistor

Defrost thermistor

Brazed parts of
4-way valve

Screw of
the R.V. coil

51

OCH684

OPERATING PROCEDURE PHOTOS/FIGURES

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, CN932 (Fan motor)

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

Photo 7

Photo 8

6. Removing the compressor and 4-way valve

(1)

Remove the top panel, cabinet and service panel. (Refer to 1.)
(2) Remove the back panel. (Refer to 1.)
(3) Remove the screws fixing the relay panel.
(4) Remove the relay panel.
(5) Remove the inverter assembly. (Refer to 2.)
(6) Recover gas from the refrigerant circuit.

NOTE: Recover gas from the pipes until the pressure

gauge shows 0 kg/cm

2

(0 MPa).

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

pipe connected with compressor.
(8) Remove the compressor nuts.
(9) Remove the compressor.
(

10

) Detach the brazed parts of 4-way valve and pipe. (Photo 5)

Brazed part of
the discharge pipe

Brazed part of
the suction pipe

Discharge temperature
thermistor

Screws of the outdoor fan motor

Propeller fan

Propeller fan
nut

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

Copyright 2018 MITSUBISHI ELECTRIC CORPORATION
Published: Dec. 2018 No. OCH684
Made in Japan

Specifications are subject to change without notice.