Mitsubishi Electric PUZ-ZM35VKA2 User manual

SERVICE MANUAL R32
PARTS CATALOG (OCB751)
Note:
• This manual describes ser-
vice data of the outdoor
units only.
September 2021
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
Outdoor unit
[Model Name] [Service Ref.]
No. OCH751
CONTENTS
1. REFERENCE MANUAL ······················2
2. SAFETY PRECAUTION ······················2
3. FEATURES····································· 12
4. SPECIFICATIONS···························· 13
5. DATA ············································· 14
6. OUTLINES AND DIMENSIONS ·········· 16
7. WIRING DIAGRAM ·························· 17
8. WIRING SPECIFICATIONS················ 18
9. REFRIGERANT SYSTEM DIAGRAM··· 23
10. TROUBLESHOOTING ······················ 25
11. FUNCTION SETTING ······················· 72
12. MONITORING THE OPERATION DATA
BY THE REMOTE CONTROLLER ······ 73
13. EASY MAINTENANCE FUNCTION ····· 81
14. DISASSEMBLY PROCEDURE ··········· 82
15. REMOTE CONTROLLER ·················· 87
PUZ-ZM35VKA2
PUZ-ZM50VKA2
PUZ-ZM35VKA2-ET
PUZ-ZM50VKA2-ET
PUZ-ZM35VKA2-ER
PUZ-ZM50VKA2-ER
PUZ-ZM35VKA2
PUZ-ZM50VKA2
PUZ-ZM35VKA2-ET
PUZ-ZM50VKA2-ET
PUZ-ZM35VKA2-ER
PUZ-ZM50VKA2-ER

2
OCH751
INDOOR UNIT SERVICE MANUAL
2SAFETY PRECAUTION
1REFERENCE MANUAL
Model Name Service Ref. Service manual No.
Parts catalog No.
PLA-ZM35/50EA2
PLA-ZM35/50EA2-ET
PLA-ZM35/50EA2-ER
PLA-ZM35/50EA2.UK
PLA-ZM35/50EA2-ET.UK
PLA-ZM35/50EA2-ER.UK
–
–
PLA-M35/50EA2
PLA-M35/50EA2-ET
PLA-M35/50EA2-ER
PLA-M35/50EA2.UK
PLA-M35/50EA2-ET.UK
PLA-M35/50EA2-ER.UK
–
–
PKA-M35/50LA2
PKA-M35/50LA2-ET
PKA-M35/50LA2-ER
PKA-M35/50LAL2
PKA-M35/50LAL2-ET
PKA-M35/50LAL2-ER
PKA-M35/50LA2.UK
PKA-M35/50LA2-ET.UK
PKA-M35/50LA2-ER.UK
PKA-M35/50LAL2.UK
PKA-M35/50LAL2-ET.UK
PKA-M35/50LAL2-ER.UK
–
–
PCA-M35/50KA2
PCA-M35/50KA2-ET
PCA-M35/50KA2-ER
PCA-M35/50KA2.UK
PCA-M35/50KA2-ET.UK
PCA-M35/50KA2-ER.UK
OCH752
OCB752
SLZ-M35/50FA2
SLZ-M35/50FA2-ET
SLZ-M35/50FA2-ER
SLZ-M35/50FA2.UK
SLZ-M35/50FA2-ET.UK
SLZ-M35/50FA2-ER.UK
–
–
SEZ-M35/50/DA2
SEZ-M35/50/DA2-ET
SEZ-M35/50/DA2-ER
SEZ-M35/50/DAL2
SEZ-M35/50/DA2.TH
SEZ-M35/50/DA2-ET.TH
SEZ-M35/50/DA2-ER.TH
SEZ-M35/50DAL2.TH
–
–
PEAD-M35/50JA2
PEAD-M35/50JA2-ET
PEAD-M35/50JA2-ER
PEAD-M35/50JAL2
PEAD-M35/50JA2.UK
PEAD-M35/50JA2-ET.UK
PEAD-M35/50JA2-ER.UK
PEAD-M35/50JAL2.UK
–
–
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
OCH751
2-1. ALWAYS OBSERVE FOR SAFETY
Before obtaining access to terminal, all supply circuits must be disconnected.
2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Cautions for units utilizing refrigerant R32
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 deterio-
ration 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.
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 o󰀨 the power, exercise great
caution not to touch the live parts.
• When opening or closing the valve below freezing
temperatures, refrigerant may spurt out from the gap
between the valve stem and the valve body, resulting in
injuries.
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 the 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
o󰀨 the power-supply breaker.
• Discharge the condenser before the work involving the
electric parts.

4
OCH751
[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 the 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.
[2] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
[3] Additional refrigerant charge
When charging directly from cylinder
R32 is a single refrigerant and its composition does not change. Therefore, both liquid charging and gas charging are
possible. Liquid charging of refrigerant all at once from the low pressure side may cause the compressor malfunction.
Accordingly, make sure that charging is gradual.
< Cylinder without a siphon tube >< Cylinder with a siphon tube >
Charging liquid refrigerant
Cylinder
Cylinder
Liquid
Valve
Liquid
Valve

5
OCH751
[4] 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 con-
ditions 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, includ-
ing 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 proce-
dures. 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 ade-
quate 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 prevent-
ing the ingress of flammable atmospheres.
Replacement parts shall be in accordance with the manufacturer’s specifications.

6
OCH751
(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 atmos-
phere. 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 equip-
ment 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 pro-
cess.
(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 considera-
tion. 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 refrig-
erants, 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 leak-
tested 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
OCH751
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 stat-
ing 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 refrig-
erant 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 refriger-
ants. In addition, a set of calibrated weighing scales shall be available and in good working order. Hoses shall be com-
plete 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 pro-
cess. When oil is drained from a system, it shall be carried out safely.

Perform the airtight test, vacuum air purging,
additional refrigerant charging (if necessary),
and gas leak check.
Measure the existing pipe thickness and
check for damage.
The existing pipe thickness meets specica-
tions and the pipes are not damaged.
Check if the existing air conditioner can operate.
After operating the cooling system for about 30
minutes, do a pump down work.
Disconnect the existing air conditioner from the
pipes.
Attach the new air conditioner
Test run
The existing pipes cannot be reused.
Use new pipes.
Note:
If the existing air conditioner cannot operate, use a
refrigerant recovery device to collect the refrigerant.
Note:
Use new pipes.
The existing pipe thickness does not meet
specications or the pipes are damaged.
8
OCH751
2-3. PRECAUTIONS WHEN REUSING EXISTING R22/R410a REFRIGERANT PIPES
(1) Flowchart
[5] Service tools
Use the below service tools as exclusive tools for R32 refrigerant.
No. Tool name Specifications
1Gauge manifold · Only for R32
· Use the existing fitting specifications. (UNF1/2)
· Use high-tension side pressure of 5.3MPa·G or over.
2Charge hose · Only for R32
· Use pressure performance of 5.09MPa·G or over.
3Electronic weighing scale —
4Gas leak detector · Use the detector for R134a, R407C, R410a or R32.
5Adaptor for reverse flow check · Attach on vacuum pump.
6Refrigerant charge base —
7Refrigerant cylinder · Only for R32
· Cylinder with syphon
8Refrigerant recovery equipment —
• Refer to the owchart below to determine if the existing pipes can be used and if it is necessary to use a lter dryer.
• If the diameter of the existing pipes is di󰀨erent from the specied diameter, refer to technical data materials to conrm if the
pipes can be used.

9
OCH751
(2) Cautions for refrigerant piping work
New refrigerant R32 is adopted for replacement inverter series. Although the refrigerant piping work for R32 is same as for
R22, exclusive tools are necessary so as not to mix with different kind of refrigerant. Furthermore as the working pressure
of R32 is 1.6 times higher than that of R22, their sizes of flared sections and flare nuts are different.
1Thickness of pipes
Because the working pressure of R32 is higher compared to R22, be sure to use refrigerant piping with thickness shown
below. (Never use pipes of 0.7 mm or below.)
2Dimensions of flare cutting and flare nut
The component molecules in HFC refrigerant are smaller compared to conventional refrigerants. In addition to that, R32
is a refrigerant, which has higher risk of leakage because its working pressure is higher than that of other refrigerants.
Therefore, to enhance airtightness and strength, flare cutting dimension of copper pipe for R32 has been specified sepa-
rately from the dimensions for other refrigerants as shown below. The dimension B of flare nut for R32 also has partly
been changed to increase strength as shown below. Set copper pipe correctly referring to copper pipe flaring dimensions
for R32 below. For 1/2 and 5/8 inch pipes, the dimension B changes.
Use torque wrench corresponding to each dimension.
3 Tools for R32 (The following table shows whether conventional tools can be used or not.)
1/4
3/8
1/2
5/8
3/4
6.35
9.52
12.70
15.88
19.05
0.8
0.8
0.8
1.0
—
0.8
0.8
0.8
1.0
1.0
Nominal
dimensions(inch)
Diagram below: Piping diameter and thickness
Outside
diameter (mm)
Thickness (mm)
R32/R410a R22
Dimension A
Dimension B
Tools and materials Use R32 tools Can R22 tools be used? Can R407C tools be used? Can R410a tools be used?
Gauge manifold Air purge, refrigerant
charge and operation
check
Tool exclusive for R32
Charge hose Tool exclusive for R32
Gas leak detector Gas leak check Tool for HFC refrigerant
Refrigerant recovery
equipment Refrigerant recovery Tool exclusive for R32
Refrigerant cylinder Refrigerant charge Tool exclusive for R32
Safety charger Prevent compressor malfunction
when charging refrigerant by
spraying liquid refrigerant
Tool exclusive for R32
Charge valve Prevent gas from blowing out
when detaching charge hose
Tool exclusive for R32
Vacuum pump
Vacuum drying and air
purge
Tools for other refrigerants
can be used if equipped
with adapter for reverse
ow check
(Usable if equipped with
adapter for reverse
ow)
(Usable if equipped with
adapter for reverse
ow)
(Usable if equipped with
adapter for reverse
ow)
Flare tool
Flaring work of piping
Tools for other refrigerants
can be used by adjusting
aring dimension
(Usable by adjusting
aring dimension)
(Usable by adjusting
aring dimension)
(Usable by adjusting
aring dimension)
Bender Bend the pipes Tools for other refrigerants
can be used
Pipe cutter Cut the pipes Tools for other refrigerants
can be used
Welder and nitrogen
gas cylinder Weld the pipes Tools for other refrigerants can be used
Refrigerant charging
scale Refrigerant charge Tools for other refrigerants can be used
Vacuum gauge or
thermistor vacuum
gauge and vacuum
valve
Check the degree of vacuum.
(Vacuum valve prevents back
ow of oil and refrigerant to
thermistor vacuum gauge)
Tools for other refrigerants
can be used
Charging cylinder Refrigerant charge Tool exclusive for R32 –
: Prepare a new tool. (Use the new tool as the tool exclusive for R32.)
: Tools for other refrigerants can be used under certain conditions.
: Tools for other refrigerants can be used.
Flare cutting dimensions
Nominal
dimensions (inch)
Outside
diameter (mm)
Dimension A ( )(mm)
R32/R410A R22
1/4 6.35 9.1 9.0
3/8 9.52 13.2 13.0
1/2 12.70 16.6 16.2
5/8 15.88 19.7 19.4
3/4 19.05 — 23.3
0
-0.4
Flare nut dimensions
Nominal
dimensions (inch)
Outside
diameter (mm)
Dimension B (mm)
R32/R410A R22
1/4 6.35 17.0 17.0
3/8 9.52 22.0 22.0
1/2 12.70 26.0 24.0
5/8 15.88 29.0 27.0
3/4 19.05 — 36.0

10
OCH751
2-4. 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 with-
out depressions.
2-5. 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].
Correct Correct
Correct Incorrect
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
8.0 89
8.5 95
9.0 100
9.5 106