Mitsubishi Electric QAHV-N560YA-HPB How to use

i
HWE1517A GB
Safety Precautions
• Thoroughly read the following safety precautions prior to use.
• Observe these precautions carefully to ensure safety.
WARNING
CAUTION
WARNING
Indicates a risk of death or serious injury
CAUTION
Indicates a risk of injury or structural damage
IMPORTANT
Indicates a risk of damage to the unit or other components in the system
General
All electric work must be performed by personnel certified by Mitsubishi Electric.
Do not use refrigerant other than the type indicated in
the manuals provided with the unit and on the
nameplate.
• Doing so may cause the unit or pipes to burst, or result in
explosion or fire during use, during repair, or at the time of
disposal of the unit.
• It may also be in violation of applicable laws.
• MITSUBISHI ELECTRIC CORPORATION cannot be held
responsible for malfunctions or accidents resulting from the
use of the wrong type of refrigerant.
Do not install the unit in a place where large amounts of
oil, steam, organic solvents, or corrosive gases, such as
sulfuric gas, are present or where acidic/alkaline
solutions or sprays containing sulfur are used
frequently.
These substances can compromise the performance of the
unit or cause certain components of the unit to corrode, which
can result in refrigerant leakage, water leakage, injury,
electric shock, malfunctions, smoke, or fire.
Do not try to defeat the safety features of the unit or
make unauthorized setting changes.
Forcing the unit to operate the unit by defeating the safety
features of the devices such as the pressure switch or the
temperature switch, making unauthorized changes to the
switch settings, or using accessories other than the ones
recommended by Mitsubishi Electric may result in smoke,
fire, or explosion.
To reduce the risk of fire or explosion, do not use volatile or
flammable substances as a heat carrier.
To reduce the risk of burns or electric shock, do not touch
exposed pipes and wires.
To reduce the risk of shorting, current leakage, electric shock,
malfunctions, smoke, or fire, do not splash water on electric
parts.
To reduce the risk of electric shock, malfunctions, smoke or
fire, do not operate the switches/buttons or touch other
electrical parts with wet hands.
To reduce the risk of electric shock and injury from the fan or
other rotating parts, stop the operation and turn off the main
power before cleaning, maintaining, or inspecting the unit.
To reduce the risk of burns or frost bites, do not touch the
refrigerant pipes or refrigerant circuit components with bare
hands during and immediately after operation.
Before cleaning the unit, switch off the power.
(Unplug the unit, if it is plugged in.)
To reduce the risk of injury, keep children away while
installing, inspecting, or repairing the unit.
Children should be supervised to ensure that they do not play
with the appliance.
This appliance is not intended for use by persons (including
children) with reduced physical, sensory or mental
capabilities, or lack of experience and knowledge, unless
they have been given supervision or instruction concerning
use of the appliance by a person responsible for their safety.
Keep the space well ventilated. Refrigerant can displace
air and cause oxygen starvation.
If leaked refrigerant comes in contact with a heat source,
toxic gas may be generated.
Always replace a fuse with one with the correct current
rating.
The use of improperly rated fuses or a substitution of fuses
with steel or copper wire may result in fire or explosion.
If any abnormality (e.g., burning smell) is noticed, stop
the operation, turn off the power switch, and consult
your dealer.
Continuing the operation may result in electric shock,
malfunctions, or fire.
Properly install all required covers and panels on the
terminal box and control box to keep moisture and dust
out.
Dust accumulation and water may result in electric shock,
smoke, or fire.
Consult an authorized agency for the proper disposal of
the unit
Refrigerant oil and refrigerant that may be left in the unit pose
a risk of fire, explosion, or environmental pollution.
To reduce the risk of fire or explosion, do not place flammable
materials or use flammable sprays around the unit.
Do not operate the unit without panels and safety guards
properly installed.
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ii
HWE1517A GB
WARNING
CAUTION
WARNING
To reduce the risk of injury, do not sit, stand, or place objects
on the unit.
Do not connect the makeup water pipe directly to the
potable water pipe. Use a cistern tank between them.
Connecting these pipes directly may cause the water in the
unit to migrate into the potable water and cause health
problems.
To reduce the risk of adverse effects on plants and animals,
do not place them where they are directly exposed to
discharge air from the unit.
Do not install the unit on or over things that are
vulnerable to water damage.
Condensation may drip from the unit.
The model of heat pump unit described in this manual is not
intended for use to preserve food, animals, plants, precision
instruments, or art work.
To reduce the risk of injury, do not touch the heat exchanger
fins or sharp edges of components with bare hands.
Do not place a container filled with water on the unit.
If water spills on the unit, it may result in shorting, current
leakage, electric shock, malfunction, smoke, or fire.
Always wear protective gears when touching electrical
components on the unit.
Several minutes after the power is switched off, residual
voltage may still cause electric shock.
To reduce the risk of injury, do not insert fingers or foreign
objects into air inlet/outlet grills.
To reduce the risk of injury, wear protective gear when
working on the unit.
Do not release refrigerant into the atmosphere. Collect
and reuse the refrigerant, or have it properly disposed of
by an authorized agency.
Refrigerant poses environmental hazards if released into the
air.
To prevent environmental pollution, dispose of brine in
the unit and cleaning solutions according to the local
regulations.
It is punishable by law not to dispose of them according to the
applicable laws.
The water heated by the heat pump is not suitable for
use as drinking water or for cooking.
It may cause health problems or degrade food.
In areas where temperature drops to freezing during the
periods of non-use, blow the water out of the pipes or fill
the pipes with anti-freeze solution.
Not doing so may cause the water to freeze, resulting in burst
pipes and damage to the unit or the furnishings.
In areas where temperature drops to freezing, use an anti-
freeze circuit and leave the main power turned on to prevent
the water in the water circuit from freezing and damaging the
unit or causing water leakage and resultant damage to the
furnishings.
Use clean tap water.
The use of acidic or alkaline water or water high in chlorine
may corrode the unit or the pipes, causing water leakage and
resultant damage to the furnishings.
In areas where temperature can drop low enough to
cause the water in the pipes to freeze, operate the unit
often enough to prevent the water from freezing.
Frozen water in the water circuit may cause the water to
freeze, resulting in burst pipes and damage to the unit or the
furnishings.
Periodically inspect and clean the water circuit.
Dirty water circuit may compromise the unit’s performance or
corrodes the unit or cause water leakage and resultant
damage to the furnishings.
Transportation
Lift the unit by placing the slings at designated
locations. Support the outdoor unit securely at four
points to keep it from slipping and sliding.
If the unit is not properly supported, it may fall and cause
personal injury.
To reduce the risk of injury, do not carry the product by the PP
bands that are used on some packages.
To reduce the risk of injury, products weighing 20 kg or more
should be carried by two or more people.
Installation
Do not install the unit where there is a risk of leaking
flammable gas.
If flammable gas accumulates around the unit, it may ignite
and cause a fire or explosion.
Properly dispose of the packing materials.
Plastic bags pose suffocation hazard to children.
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iii
HWE1517A GB
CAUTION
WARNING
CAUTION
The unit should be installed only by personnel certified
by Mitsubishi Electric according to the instructions
detailed in the Installation/Operation Manual.
Improper installation may result in refrigerant leakage, water
leakage, injury, electric shock, or fire.
Periodically check the installation base for damage.
If the unit is left on a damaged base, it may fall and cause
injury.
Remove packing materials from the unit before operating
the unit. Note that some accessories may be taped to the
unit. Properly install all accessories that are required.
Failing to remove the packing materials or failing to install
required accessories may result in refrigerant leakage,
oxygen starvation, smoke, or fire.
Consult your dealer and take appropriate measures to
safeguard against refrigerant leakage and resultant oxygen
starvation. An installation of a refrigerant gas detector is
recommended.
Any additional parts must be installed by qualified personnel.
Only use the parts specified by Mitsubishi Electric.
Take appropriate safety measures against wind gusts and
earthquakes to prevent the unit from toppling over and
causing injury.
Be sure to install the unit horizontally, using a level.
If the unit is installed at an angle, it may fall and cause injury
or cause water leakage.
The unit should be installed on a surface that is strong
enough to support its weight.
As an anti-freeze, use ethylene glycol or propylene
glycol diluted to the specified concentration.
The use of other types of anti-freeze solution may cause
corrosion and resultant water leakage. The use of flammable
anti-freeze may cause fire or explosion.
Do not install the unit on or over things that are
vulnerable to water damage.
When the indoor humidity exceeds 80% or if the drain water
outlet becomes clogged, condensation may drip from the
indoor unit onto the ceiling or floor.
All drainage work should be performed by the dealer or
qualified personnel according to the instructions
detailed in the Installation Manual.
Improper drainage work may cause rain water or drain water
to enter the buildings and damage the furnishings.
Pipe installation
To prevent explosion, do not heat the unit with refrigerant gas
in the refrigerant circuit. Check for refrigerant leakage at the completion of
installation.
If leaked refrigerant comes in contact with a heat source,
toxic gas may be generated.
Check that no substance other than the specified
refrigerant (R744) is present in the refrigerant circuit.
Infiltration of other substances may cause the pressure to
rise abnormally high and cause the pipes to explode.
To keep the ceiling and floor from getting wet due to
condensation, properly insulate the pipes.
Piping work should be performed by the dealer or
qualified personnel according to the instructions
detailed in the Installation Manual.
Improper piping work may cause water leakage and damage
the furnishings.
Electrical wiring
To reduce the risk of wire breakage, overheating, smoke, and
fire, keep undue force from being applied to the wires.
Properly secure the cables in place and provide
adequate slack in the cables so as not to stress the
terminals.
Improperly connected cables may break, overheat, and
cause smoke or fire.
To reduce the risk of injury or electric shock, switch off the
main power before performing electrical work.
All electric work must be performed by a qualified
electrician according to the local regulations, standards,
and the instructions detailed in the Installation Manual.
Capacity shortage to the power supply circuit or improper
installation may result in malfunction, electric shock, smoke,
or fire.
To reduce the risk of electric shock, smoke, or fire, install an
inverter circuit breaker on the power supply to each unit.
Use properly rated breakers and fuses (inverter breaker,
Local Switch <Switch + Type-B fuse>, or no-fuse
breaker).
The use of improperly rated breakers may result in
malfunctions or fire.
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HWE1517A GB
CAUTION
WARNING
CAUTION
To reduce the risk of current leakage, overheating, smoke, or
fire, use properly rated cables with adequate current carrying
capacity.
Keep the unsheathed part of cables inside the terminal
block.
If unsheathed part of the cables come in contact with each
other, electric shock, smoke, or fire may result.
Proper grounding must be provided by a licensed
electrician. Do not connect the grounding wire to a gas
pipe, water pipe, lightning rod, or telephone wire.
Improper grounding may result in electric shock, smoke, fire,
or malfunction due to electrical noise interference.
To reduce the risk of current leakage, wire breakage, smoke,
or fire, keep the wiring out of contact with the refrigerant
pipes and other parts, especially sharp edges.
To reduce the risk of electric shock, shorting, or malfunctions,
keep wire pieces and sheath shavings out of the terminal
block.
Transportation and repairs
The unit should be moved, disassembled, or repaired
only by qualified personnel. Do not alter or modify the
unit.
Improper repair or unauthorized modifications may result in
refrigerant leakage, water leakage, injury, electric shock, or
fire.
After disassembling the unit or making repairs, replace
all components as they were.
Failing to replace all components may result in injury, electric
shock, or fire.
If the supply cord is damaged, it must be replaced by the
manufacturer, its service agent or similarly qualified persons
in order to avoid a hazard.
To reduce the risk of shorting, electric shock, fire, or
malfunction, do not touch the circuit board with tools or with
your hands, and do not allow dust to accumulate on the
circuit board.
IMPORTANT
To avoid damage to the unit, use appropriate tools to install,
inspect, or repair the unit.
To reduce the risk or malfunction, turn on the power at least
12 hours before starting operation, and leave the power
turned on throughout the operating season.
Recover all refrigerant from the unit.
It is punishable by law to release refrigerant into the
atmosphere.
Do not unnecessarily change the switch settings or
touch other parts in the refrigerant circuit.
Doing so may change the operation mode or damage the
unit.
To reduce the risk of malfunctions, use the unit within its
operating range.
Do not switch on or off the main power in a cycle of
shorter than 10 minutes.
Short-cycling the compressor may damage the compressor.
To maintain optimum performance and reduce the risk of
malfunction, keep the air pathway clear.
To ensure proper operation of the unit, periodically
check for proper concentration of anti-freeze.
Inadequate concentration of anti-freeze may compromise the
performance of the unit or cause the unit to abnormally stop.
Take appropriate measures against electrical noise
interference when installing the air conditioners in
hospitals or facilities with radio communication
capabilities.
Inverter, high-frequency medical, or wireless communication
equipment as well as power generators may cause the air
conditioning system to malfunction. Air conditioning system
may also adversely affect the operation of these types of
equipment by creating electrical noise.
Check the water system, using a relevant manual as a
reference.
Using the system that does not meet the standards (including
water quality and water flow rate) may cause the water pipes
to corrode.
To reduce the risk of power capacity shortage, always use a
dedicated power supply circuit.
This appliance is intended to be used by expert or trained
users in shops, in light industry and on farms, or for
commercial use by lay persons.
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CONTENTS
HWE1517A GB
I Read Before Servicing
[1] Read Before Servicing.............................................................................................................. 3
[2] Necessary Tools and Materials ................................................................................................ 4
[3] Brazing...................................................................................................................................... 5
[4] Procedure ................................................................................................................................. 6
[5] CO2 refrigerant manifold structure ......................................................................................... 11
[6] Characteristics of the Conventional and the New Refrigerants .............................................. 12
[7] Notes on Refrigerating Machine Oil........................................................................................ 13
II Restrictions
[1] System Configuration ............................................................................................................. 17
[2] Types and Maximum allowable Length of Cables .................................................................. 18
[3] Main Power Supply Wiring and Switch Capacity .................................................................... 19
[4] Sample Installation ................................................................................................................. 23
[5] Switch Types and the Factory Settings .................................................................................. 24
[6] Configuring the Settings ......................................................................................................... 25
[7] Water Pipe Installation............................................................................................................ 33
[8] Using the Unit in Sub-freezing or Snowy Conditions .............................................................. 37
[9] Secondary side control system...............................................................................................38
III Unit Components
[1] Unit Components and Refrigerant Circuit ............................................................................... 47
[2] Control Box of the Unit............................................................................................................ 50
[3] Unit Circuit Board.................................................................................................................... 52
IV Remote Controller
[1] Using the Remote Controller .................................................................................................. 59
V Electrical Wiring Diagram
[1] Electrical Wiring Diagram ....................................................................................................... 73
VI Refrigerant Circuit
[1] Refrigerant Circuit Diagram .................................................................................................... 79
[2] Principal Parts and Functions ................................................................................................. 80
VII Control
[1] Functions and Factory Settings of the Dip switches ............................................................... 85
[2] Operating characteristics and Control Capabilities............................................................... 105
VIII Test Run Mode
[1] Items to be checked before a Test Run................................................................................ 115
[2] Operating the Unit................................................................................................................. 117
[3] Refrigerant ............................................................................................................................ 118
[4] Standard operating characteristics (Reference data) ........................................................... 118
IX Troubleshooting
[1] Maintenance items................................................................................................................ 121
[2] Troubleshooting .................................................................................................................... 126
[3] Troubleshooting Principal Parts............................................................................................ 136
[4] Refrigerant Leak ................................................................................................................... 152
[5] Parts Replacement Procedures............................................................................................ 153
[6] Removing scale from the gas cooler .................................................................................... 159
X Attachments
[1] R744 refrigerant saturation temperature table ..................................................................... 167
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CONTENTS
HWE1517A GB
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- 1 -
HWE1517A GB
I Read Before Servicing
[1] Read Before Servicing .......................................................................................................3
[2] Necessary Tools and Materials.......................................................................................... 4
[3] Brazing............................................................................................................................... 5
[4] Procedure .......................................................................................................................... 6
[5] CO2 refrigerant manifold structure................................................................................... 11
[6] Characteristics of the Conventional and the New Refrigerants ....................................... 12
[7] Notes on Refrigerating Machine Oil ................................................................................. 13
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HWE1517A GB
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[ I Read Before Servicing ]
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HWE1517A GB
I Read Before Servicing
[1] Read Before Servicing
1. Check the type of refrigerant used in the system to be serviced.
Refrigerant Type
Hot water Heat pump QAHV-N560YA-HPB:R744
2. Check the symptoms exhibited by the unit to be serviced.
Refer to this service handbook for symptoms relating to the refrigerant cycle.
3. Thoroughly read the safety precautions at the beginning of this manual.
4. Preparing necessary tools: Prepare a set of tools to be used exclusively with each type of refrigerant.
Refer to "Necessary Tools and Materials" for information on the use of tools.(page 4)
5. If there is a leak of gaseous refrigerant and the remaining refrigerant is exposed to an open flame, a poisonous gas
may form. Keep workplace well ventilated.
CAUTION
Install new pipes immediately after removing old ones to keep moisture out of the refrigerant circuit.
The use of refrigerant that contains chloride, such as R22, will cause the refrigerating machine oil to deteriorate.
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[ I Read Before Servicing ]
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HWE1517A GB
[2] Necessary Tools and Materials
Prepare the following tools and materials necessary for servicing the unit.
Replacement procedures for refrigerant circuit components
Preparation
1. Tools required
(1) Special tools for use with CO2refrigerant
1) Manifold: Withstand pressure of 21 MPa (Maximum unit pressure: 14 MPa)
2) Refrigerant charging hose (Withstand pressure: maximum unit pressure of 14 MPa); Unit connection: Swagelok (7/16-20UNF)
3) Pipe cutter: One capable of thick-wall pipe
4) CO2refrigerant (Two 7 Kg cylinders)
5) Mouthpiece for CO2refrigerant
(2) Other tools
1) Welder (Welder nozzle #250 or greater)
2) Packless valve: for checking the degree of vacuum
3) VaVacuum pump (with a check valve or an adapter) cuuming hose (for R404A/R407C); Unit connection: Swagelok (7/16-
20UNF)
4) Vacuum pump (with a check valve or an adapter)
5) Nitrogen (pressure reductin valve): for gas leak check, for non-oxidizing welding →Pressure reduction valve that can be ad-
justed to the pressure of 8.5 MPa
6) Scale: for controlling refrigerant charge
7) General tools for replacing parts (screwdriver, etc.)
8) Gas leak test liquid (foam test)
2. Replacement workflow
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[ I Read Before Servicing ]
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HWE1517A GB
[3] Brazing
No changes have been made in the brazing procedures. Perform brazing with special care to keep foreign objects (such as oxide
scale, water, and dust) out of the refrigerant system.
Example: Inside the brazed connection
1. Items to be strictly observed
Do not conduct refrigerant piping work outdoors if raining.
Use non-oxidized solder.
Use a brazing material (BCuP-3) that requires no flux when brazing between copper pipes or between a copper pipe and
copper coupling.
If installed refrigerant pipes are not immediately connected to the equipment, then braze and seal both ends.
2. Reasons
The new refrigerating machine oil is 10 times as hygroscopic as the conventional oil and is more likely to cause unit failure if
water infiltrates into the system.
Flux generally contains chloride. Residual flux in the refrigerant circuit will cause sludge to form.
3. Notes
Do not use commercially available antioxidants because they may cause the pipes to corrode or refrigerating machine oil to
deteriorate.
Use of oxidized solder for brazing Use of non-oxidized solder for brazing
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[ I Read Before Servicing ]
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HWE1517A GB
[4] Procedure
(1) Refrigerant purging
No.
1
2
3
㻌
Cautionary notesProcedure
CO
2
release ports
High-pressure service valve
Low-pressure service valve
Refrigerant service port
Make sure the high- and low-pressure service valves
are closed all the way.
If the valves are open, there is a risk of refrigerant
gushing out when the sealing caps are removed.
Remove the sealing caps from the high- and
low-pressure service joints.
Use caution because a small amount of refrigerant
may gush out.
Slowly open the high- and low-pressure service valves.
Open the valves to the point where water drips form on
the pipes (without freezing).
Be sure to open the valves slowly. Opening the
valves too quickly may cause dry ice to form at the
release port, which may trap the refrigerant in the
unit or cause a large amount of refrigerant oil to
come out. If no refrigerant oil is coming out, heating
the release port can reduce the CO
2
release time.
Make sure the released CO
2
will not accumulate
around the work area and cause oxygen starvation.
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[ I Read Before Servicing ]
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HWE1517A GB
(2) Parts replacement
No.
1
2
3
High-pressure service valve
Low-pressure service valve
Gas charging/
release side
CO
2
valve
CO
2
manifold
Vacuuming valve
To unit
Refrigerant service port
Nitrogen cylinder
Pressure
reduction
valve
Using a pipe cutter, cut a slit in the pipe on the side of
the unit where parts are replaced to ensure an absence
of pressure in the pipe.
Residual pressure in the pipe can pose safety
hazards.
Connect a nitrogen cylinder to purge the refrigerant
circuit at a pressure of 0.05 MPa.
Be sure to thoroughly purge the refrigerant circuit to
keep oxidized scale from forming.
Replace the parts by heating the welded areas. Be careful that the heat from welding can expand the
residual CO
2
inside the pipe and cause it to gush
out.
Cautionary notesProcedure
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[ I Read Before Servicing ]
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HWE1517A GB
(3) Gas leak test
No.
1
2
3
4
5
–
High-pressure service valve
Low-pressure service valve
Gas charging/
release side
CO2valve
CO2manifold
Vacuuming valve
To unit
Refrigerant service port
Nitrogen cylinder
Pressure
reduction
valve
Connect a pressure reduction valve to the nitrogen
cylinder, and then connect the cylinder to the gas
charging/release hose that connects to the manifold.
Connect the manifold to the high-pressure service
valve. Fully close the low-pressure service valve.
CO2manifold has a structure different than that of
HFC manifold. Refer to the “[5] CO2refrigerant
manifold structure” in the Attachment.
Charge the unit with nitrogen, adjusting the pressure
with the reduction valve to 8.5 MPa. Once the charging
pressure reaches 8.5MPa, shut off the nitrogen cylinder
valve.
Use caution because the charging pressure is high.
Charge nitrogen from the high-pressure side.
Test the brazed areas for gas leak, using foaming
solution.
Make sure there is no leak.
When the leak test is done, slowly open the
low-pressure service valve to release the nitrogen.
Be careful that nitrogen may suddenly gush out.
Purge the nitrogen only from the low-pressure side
or from both the low- and high-pressure sides
simultaneously, but not only from the high-pressure
side.
Cautionary notesProcedure
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[ I Read Before Servicing ]
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HWE1517A GB
(4) Vacuuming the refrigerant circuit
No.
1
2
3
4
5
6
High-pressure service valve
Low-pressure service valve
CO2valve
CO2manifold
Vacuum valve
Refrigerant service port
CO2cylinder
–
Vacuum pump
(with a check valve)
Packless valve
Vacuuming hose
Vacuuming hose
–
Scale
Connect the CO2cylinder to the gas charging/release
hose that connects to the manifold.
Fully close the low-pressure service valve on the unit.
Connect a packless valve to the vacuum port on the
manifold via a hose, and connect a vacuum pump to
the packless valve (see the figure below).
Make sure the high-pressure service valve, the CO2
valve on the manifold, and the packless valve are
OPEN.
Make sure the vacuum valve on the manifold, the
low-pressure service valve, and CO2cylinder valve are
securely CLOSED.
This is done to evacuate the hose between the unit
and the CO2cylinder.
Packless valve is necessary for checking the degree
of vacuum inside the unit. Ordinary hose can be
connected to this valve.
Because residual refrigerant may be present in dry
ice condition, perform vacuuming three times as
shown below.
Vacuum for 30 minutes. →Leave the refrigerant
circuit open to air for 5 minutes. →Vacuum for 30
minutes. →Leave the refrigerant circuit open to air
for 5 minutes. →Vacuum for 60 minutes. →Check
the degree of vacuum five minutes later. →Proceed
to the next step if the degree of vacuum is
satisfactory.
Operate the vacuum pump, and slowly open the
vacuum valve on the manifold to start vacuuming.
The target degree of vacuum is 266 Pa or below.
Cautionary notesProcedure
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[ I Read Before Servicing ]
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HWE1517A GB
(5) Refrgerant charging 1: Charging the unit with refrigerant while the unit is stopped
No.
1
2
3
4
5
6
7
High-pressure service valve
Low-pressure service valve
CO2valve
CO2manifold
Vacuum valve
Refrigerant service port
CO2cylinder
–
Vacuum pump
(with a check valve)
Packless valve
Vacuuming hose
Vacuuming hose
–
–
Scale
First, check the degree of vacuum.
When the vacuum completion time is reached, close
the packless valve.
Make sure the vacuum is properly held (the vacuum
gauge on the manifold does not rise).
Securely close the vacuum valve on the manifold.
Place the CO2cylinder on a scale to allow for the
measurement of the weight of the cylinder.
Open the high-pressure service valve on the unit, and
charge the unit with the specified amount of CO2.
Securely close the high-pressure service valve on the
unit, open the valve on the CO2cylinder, and fill the
section of the hose between the unit and the CO2
cylinder with CO2.
If measurement of vacuum degree with a vacuum
gauge is possible, make sure the gauge reading is
266 Pa or below.
Failing to close the valve will cause refrigerant to
flow into the vacuumed circuit in the later step of
refrigerant charging, which will pose serious safety
hazards and will damage the vacuum gauge.
Charge CO2from the high-pressure side.
Check the refrigerant charge at this point.
When the amount of CO2charge reaches the specified
amount (6.5kg), stop the charge by closing the high-
pressure service valve on the unit.
Cautionary notesProcedure
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[ I Read Before Servicing ]
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HWE1517A GB
[5] CO2refrigerant manifold structure
1. Structural comparison between CO2manifold and HFC/HCFC manifold
(1) CO2manifold
(2) H(C)FC manifold
2. Differences of CO2manifold from the HFC/HCFC manifold
1) CO2manifold only has one connection to the unit.
2) CO2manifold has a designated vacuum circuit that ordinary manifolds do not have.
3) Pressure gauge on the CO2manifold is only open to the refrigerant cylinder when valve is closed.
(H(C)FC manifold is also open to the unit connection circuit when valve is closed.)
<Circuit structure>
A: Vacuum gauge B: Pressure gauge
Vacuum valve Pressure valve
Connection to
air-conditioning unit
Connection to
refrigerant cylinder
Connection to
vacuum pump
Purge valve
V
VConnection to
air-conditioning unit
V
Connection
to vacuum
pump
B: Pressure gauge
2: Pressure gauge valve
1: Purge valve
3: Vacuum valve
A: Vacuum gauge
Connection
to refrigerant
cylinder
<Circuit structure>
Low-pressure gauge High-pressure gauge
High-pressure valve
Low-pressure valve
V
High-pressure gauge
V
Low-pressure gauge
Connection
to refrigerant
cylinder
Connection to
low-pressure-side
unit
Connection to
high-pressure-
side unit
Connection
to refrigerant
cylinder
High-
pressure
valve
Connection to
high-pressure-
side unit
Connection to
low-pressure-
side unit
Low-
pressure
valve
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[ I Read Before Servicing ]
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HWE1517A GB
[6] Characteristics of the Conventional and the New Refrigerants
1. Chemical property
As with R22, the new refrigerant (R744) is low in toxicity and chemically stable nonflammable refrigerant.
However, because the specific gravity of vapor refrigerant is greater than that of air, leaked refrigerant in a closed room will
accumulate at the bottom of the room and may cause hypoxia.
If exposed to an open flame, refrigerant will generate poisonous gases. Do not perform installation or service work in a con-
fined area.
*1 When CFC11 is used as a reference
*2 When CO2is used as a reference
2. Pressure characteristics
The pressure in the system using R744 is 7 to 14 times as great as that in the system using R22.
R744
(CO2)
HFC type HCFC type
R410A R407C R22
R32/R125 R32/R125/R134a R22
Composition (wt%) (100) (50/50) (23/25/52) (100)
Type of Refrigerant Single Refrigerant Pseudo-azeotropic
Refrigerant
Non-azeotropic
Refrigerant
Single Refrigerant
Chloride Not included Not included Not included Included
Safety Class A1 A1/A1 A1/A1 A1
Molecular Weight 44.0 72.6 86.2 86.5
Boiling Point (°C/°F) -78.4/-109.1 -51.4/-60.5 -43.6/-46.4 -40.8/-41.4
Steam Pressure
(25°C,MPa/77°F,psi) (gauge)
6.30/914 1.557/226 0.9177/133 0.94/136
Saturated Steam Density
(25°C,kg/m3/77°F,psi)
242 64.0 42.5 44.4
Flammability Nonflammable Nonflammable Nonflammable Nonflammable
Ozone Depletion Coefficient
(ODP)*1 0 0 0 0.055
Global Warming Coefficient
(GWP)*2 1 2090 1774 1810
Refrigerant Charging Method Refrigerant charging
in the liquid state
Refrigerant charging
in the liquid state
Refrigerant charging
in the liquid state
Refrigerant charging
in the gaseous state
Replenishment of Refrigerant
after a Refrigerant Leak
Available Available Available Available
Temperature (°C/°F)
Saturation Pressure (gauge)
R744 R410A R407C R22
MPa/psi MPa/psi MPa/psi MPa/psi
-20/-4 1.87/271 0.30/44 0.18/26 0.14/20
0/32 3.39/492 0.70/102 0.47/68 0.40/58
20/68 5.63/817 1.34/194 0.94/136 0.81/117
40/104 - 2.31/335 1.44/209 1.44/209
60/140 - 3.73/541 2.43/354 2.33/338
65/149 - 4.17/605 2.74/399 2.60/377
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HWE1517A GB
[7] Notes on Refrigerating Machine Oil
1. Refrigerating machine oil in the HFC refrigerant system
R744 refrigerants use a refrigerating machine oil different from that used in the R22 or HFC system.
2. Effects of contaminants*1
Refrigerating machine oil used in the R744 system must be handled with special care to keep contaminants out.
The table below shows the effect of contaminants in the refrigerating machine oil on the refrigeration cycle.
3. The effects of contaminants in the refrigerating machine oil on the refrigeration cycle.
Refrigerant Refrigerating machine oil
R744 PAG (Polyalkylene glycol)
R22 Mineral oil
R407C Ester oil
R410A Ester oil
*1. Contaminants is defined as moisture, air, processing oil, dust/dirt, wrong types of refrigerant, and refrigerating machine oil.
Cause Symptoms Effects on the refrigerant cycle
Water infiltration Frozen expansion valve
and capillary tubes
Clogged expansion valve and capillary tubes
Poor cooling performance
Compressor overheat
Motor insulation failure
Burnt motor
Coppering of the orbiting scroll
Lock
Burn-in on the orbiting scroll
Hydrolysis
Sludge formation and ad-
hesion
Acid generation
Oxidization
Oil degradation
Air infiltration Oxidization
Infiltration of
contaminants
Dust, dirt
Adhesion to expansion valve and capillary
tubes
Clogged expansion valve, capillary tubes, and
drier
Poor cooling performance
Compressor overheat
Infiltration of contaminants into the com-
pressor
Burn-in on the orbiting scroll
Mineral oil
etc.
Sludge formation and adhesion Clogged expansion valve and capillary tubes
Poor cooling performance
Compressor overheat
Oil degradation Burn-in on the orbiting scroll
0000001906.book 13 ページ ２０１８年７月１９日 木曜日 午前７時２２分