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55

Port size

Conventional manifold

Manifold for R410A

7/16 UNF

20 threads per inch

1/2 UNF

20 threads per inch

b) Charge Hose

As R410A is characterized by high pressure, the pressure resistance of the charge hose has been
increased. The material has also been changed to an HFC resistant type, and, as is the case of each
port of the manifold, the hose cap size has been changed. Furthermore, for prevention of gas pressure
reaction, a charge hose with a valve placed near the cap is also available.

Pressure
resistance

Conventional charge hose

Charge hose for R410A

3.4 MPa (34 kgf/cm

2

)

17.2 MPa (172 kgf/cm

2

)

NBR rubber

7/16 UNF

20 threads per inch

5.1 MPa (51 kgf/cm

2

)

27.4 MPa (274 kgf/cm

2

)

HNBR rubber

internally coated with nylon

1/2 UNF

20 threads per inch

Engineering material

Normal pressure

Breaking pressure

Cap size

c) Electronic Balance for Refrigerant Charging

As R410A belonging to the HFCs features high pressure and high evaporating speed, when R410A is
charged by using a charging cylinder, R410A in the cylinder cannot be kept in a liquefied state and
gasified  refrigerant bubbles in the charging cylinder, it becomes difficult to read values. Therefore, it is
advisable to adequately use an electronic balance for refrigerant charging.
An electronic balance for refrigerant charging has higher strength due to its structure
with four points of support for refrigerant cylinder weight detection. As the charge hose connecting part
has two ports-one for R22 (7/16 UNF 20 threads per inch) and the other for R410A (1/2 UNF 20 threads
per inch)-it can also be used for charging the conventional refrigerant.
Two types of electronic balance for refrigerant charging are available-one for 10 kg cylinder and the other
for 20 kg cylinder.
Electronic balance for 10 kg cylinder ...... precision 

±

 2g

Electronic balance for 20 kg cylinder ...... precision 

±

 5g

Refrigerant is charged maunally by opening/closing the valve.

d) Torque Wrench (for nominal diameters 1/2 and 5/8)

Along with changes is flare nut sizes for enhanced pressure resisting strength, torque wrenches for
R410A differ in opposite side size.

For 1/2 
(opposite x torque)

For 5/8 
(opposite x torque)

Conventional torque wrench

Torque wrench for R410A

24 mm x 55 N m

(550 kgf cm)

27 mm x 65 N m

(650 kgf cm)

26 mm x 55 N m

(550 kgf cm)

29 mm x 65 N m

(650 kgf cm)

e) Flare Tool (clutch trpe)

A flare tool for R410A is provided with a large clamp bar receiving hole so that the projection of the copper
pipe from the clamp bar can be se at 0 ~ 0.5 mm in flare processing, and also features higher spring
strength for increased expansion pipe torque. This flare tool can also be used for R22 copper pipe.

f)

Gauge for Projection Adjustment (used when flare processing is made by using conventional flare
tool [clutch type] )

A gauge 1.0 mm in thickness which helps in easily setting the projection of the copper pipe from the
clamp bar at 1.0 ~1.5 mm.

g) Vacuum Pump Adapter

It is necessary to use an adapter for preventing vacuum pump oil from flowing back to the charge hose.
The charge hose connecting part has two ports-one for conventional refrigerant (7/16 UNF 20 threads
per inch) and the other for R410A. If the vacuum pump oil (mineral) mixes with R410A, a sludge may
occur and damage the equipment.

56

h) Refrigerant Cylinder

A refrigerant cylinder exclusive for R410A comes identified with refrigerant name and is coated with pink
paint as designated by the ARI, U. S. A

i)

Charge Port and Packing for Refrigerant Cylinder

According to the charge hose's cap size, a charge port with 1/2 UNF 20 threads per inch and
corresponding packing are required.

j)

Gas Leakage Detector

A high sensitivity gas leakage detector exclusive for HFC refrigerant is used. In the case of R410A, the
detection sensitivity is about 23 g per year.

(2) General Tools

a)   Vacuum pump
b)   Torque wrench

for 1/4 : opposite side 17 mm x
for 1/4 : opposite side 17 mm x
for 3/8 : opposite side 22 mm x

c)   Pipe cutter
d)   Reamer
e)   Screwdriver (+,   )
f )   Hacksaw

g)   Hole core drill (Ø65 or 70)
h)   Hexagonal wrench (opposite side 4 or 5 mm)
i )   Spanner, or monkey wrench
j )   Tape measure
k)   Thermometer
l )   Clamping ampere meter

m)  Insulation resistance tester (mege tester)

n)  Electro circuit tester
o)  Pipe bender

(16 N  m)
(160 kgf  cm)

(18 N  m)
180 kgf  cm)
(42 N  m)
(420 kgf  cm)

(3) Applicability or R410A Tools to R22 Model

Gauge manifold

Tools for R410A

Applicable to R22 model

Charge hose

Electronic balance for refrigerant charging
Torque wrench (norminal diameter 1/2, 5/8)

Flare tool (clutch type)

Gauge for projection adjustment

Vacuum pump adapter
Refrigerant cylinder

Charge port and packing for refrigerant cylinder

Gas leakage detector

Used when conventional flare tool (clutch type) is used.

Note: For inquiry, contact your agent.

a)

b)

c)

d)

e)

f)

g)

h)

i)

j)

(1) Air Purge by Vacuum Pump and Gas Leakage Inspection (See Fig. 6)

a) Connect the charge hose to the outdoor unit. 

1

b) Connect the charge hose to the vacuum pump adapter. 

2

At this time, keep the control valves in the fully closed position. 

3

 

4

c) Place the handle Lo in the fully opened position 

5

, and turn ON the vacuum pumpÅfs power switch.

During this step, perform evacuating (about 10~15 minutes); for the evacuating time, refer to the equipment
manufacturer's manual.

d)  When the compound gauge's pointer has indicated -0.1 MPa (-76 cmHg) 

6

, place the handle Lo in the fully

closed position 

5

, and turn OFF the vacuum pump's power switch.

Keep this state for 1 ~ 2 minutes, and ascertain that the compound gauge's pointer does not retum.

e) Fully open the control valves. 

3

 

4

f)

Detach the charge hoses. 

1

 

2

g) Tightly secure the cap on the service port. 

7

57

h) After securing the caps on the control valves, check the capsÅf periphery if there is any gas leakage. 

3

 

4

 

7

(2)  Additional Refrigerant Charging Required for Refrigerant Piping Length Longer Than Standard Length (The

following steps should be taken following the step e) in (1) above. See Fig. 7)

a) Set the refrigerant cylinder to the electronic balance, and connect the connecting hoses on the cylinder and

electronic balanceÅfs connecting port.

Be sure to make setting so that liquid con be charged. When using a cylinder equipped with a siphon, liquid
can be charged without turning it upside down.

b) Connect the gauge manifoldÅfs charge hose to the electronic balanceÅfs connecting port. 

3

 

2

c) Open the refrigerant cylindesÅfs valve, and, after opening the charging valve a little, close it. 

1

 

2

d) After making zero (0) adjustment, open the charging valve and, by opening the gauge maniflod's valve Lo,

charge the liquid refrigerant. 

2

 

5

e) When the designated amount of refrigrant could not be charged, make additional charging bit by bit by cooling

operation (for the amount of each addition, follow the instruction manual prepared by the equipment
manufacturer) . If the first additional charging was not enough, make the second additional charging after about
one miunte in the same manner as the first additional charging.

Be sure never to charge a large amount of liquid refrigerant at once to the unit in cooling mode, since liquid

is charged from the gas siede.

f)

After charging liquid refrigerant into the air conditioner by closing the charging valve, stop operation by fully

closing the gauge manifold's valve Lo. 

2

 

5

g) Quickly remove the charge hose from the service port. 

6

When stopped halfway, refrigerant being cycled will be released.

Compound pressure
gauge

Control valve (2-way)

Control valve 
(3-way)

Service port

Charge hose

Handle Lo

Handle Hi (always closed)

Charge hose

Gauge manifold

Vacuum pump adapter

Vacuum pump

76cmHg

Caution:
      Be sure to use the vacuum pump,
      adapter and gauge manifold to refer to
      tion manuals beforehand.
      Ascertion that the vacuum pump is fille
      the level designated on the oil gauge.

6

5

1

3

4

7

8

2

58

h) After securintg the caps on the service port and control valve, check the capsÅfperiphery to see if there is

any gas leakage. 

6

 

7

Refrigerant cylinder

(with syphon)

1

4

5

3

6

7

7

2

(Indoor unit)

(Liquid side)

Control valve
(2-way)

Control valve
(3-way)

Opened

Opened

Service port

Service port

Charging

valve

Electronic balance for

refrigerant charging

(Gas side)

(Outdoor unit)

(1) Removing the Unit

a) Recovery of Refrigerant from the Outdoow Unit by Pump Down

At the time of pump down, use a gauge manifold exclusive for R410A.
Operating the unit in forced cooling mode, recover refrigerant from the outdoor unit.
(For details of reclaiming steps and precautions, see the instruction manual prepared by the equipment
maunfacturer)

Caution:
In the case of an outdoor unit which is inacapable pump down, use a refrigerant recovery unit.

b) Removing the Indoor/Outdoor Units

Remove the piping and wiring between the indoor an outdoor units.
Tighten the outdoor unitÅfs control valves and service port with the specified torque.
Tighten the capped flare nuts at the indoor/outdoor units connecting part with the specified torque.
Remove the indoor/outdoor units.

When storing the indoor unit piping in its original position, be careful not to break the piping.

(2) Installing the Unit

a) Proceed with the installation following the steps described in "3.2 New Installation Work" .

Use a brand-new refrigerant piping (1) when replacing the air conditioner using the conventional refrigerant (R22)
with an air conditioner using the alternative refrigerant (R410A) or (2) even when replacing the air conditioner using
the alternative refrigerant (R410A) with another air conditioner using R410A, as a problem may occur due to
differences in pressure characteristics of refrigerant or differences in type of lubricating oil (air conditioners using
R410A do not always use the same type of the lubricating oils) .

Do not operate the air conditioner which has used the conventional refrigerant (R22) by charging the altemative
refrigerant (R410A) . Otherwise, the equipment may cease to function normally and go wrong, or even cause
serious problems such as rupture of the refrigeration cycle.