Service manual

SiUS28-902 Precautions for New Refrigerant (R-410A)
Precautions for New Refrigerant (R-410A) 172
1.2 Service Tools
R-410A is used under higher working pressure, compared to previous refrigerants (R-22,R-407C).
Furthermore, the refrigerating machine oil has been changed from Suniso oil to Ether oil, and if oil
mixing is occurred, sludge results in the refrigerants and causes other problems. Therefore, gauge
manifolds and charge hoses that are used with a previous refrigerant (R-22,R-407C) can not be
used for products that use new refrigerants.
Be sure to use dedicated tools and devices.
 Tool compatibility
As for the charge mouthpiece and packing, 1/2UNF20 is necessary for mouthpiece size of
charge hose.
 Copper tube material and thickness
* O: Soft (Annealed)
H: Hard (Drawn)
Tool
Compatibility
Reasons for changeHFC HCFC
R-410A R-407C R-22
Gauge manifold
Charge hose

• Do not use the same tools for R-22 and
R-410A.
• Thread specification differs for R-410A
and R-407C.
Gas detector   • The same tool can be used for HFCs.
Vacuum pump
(pump with reverse flow
preventive function)

• To use existing pump for HFCs,
vacuum pump adapter must be
installed.
Weighting instrument 
Flaring tool (Clutch type)  • For R-410A, flare gauge is necessary.
Torque wrench  • Torque-up for 1/2 and 5/8
Pipe cutter 
Pipe expander 
Pipe bender 
Pipe assembling oil 
• Due to refrigerating machine oil
change. (No Suniso oil can be used.)
Refrigerant recovery
device
Check your recovery device.
Refrigerant piping See the chart below.
• Only φ19.1 is changed to 1/2H material
while the previous material is "O".
Pipe size
[mm]
φ6.4
φ9.5
φ12.7
φ15.9
φ19.1
φ22.2
φ25.4
φ28.6
φ31.8
φ38.1
φ44.5
Material
O
O
O
O
O
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
Material
O
O
O
O
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
1/2H
Thickness
[mm]
0.8
0.8
0.8
1.0
1.0
1.0
1.0
1.0
1.2
1.4
1.6
Thickness
[mm]
0.8
0.8
0.8
1.0
1.0
1.0
1.0
1.0
1.1
1.4
1.6
R-407C
R-410A