iv
Precautions for Installation Using New Refrigerant
1. Care regarding tubing
1-1. Process tubing
l
l
Tubing size: Be sure to use the sizes indicated in the table below.
l
Use a tube cutter when cutting the tubing, and be sure to remove any flash. This also applies to distribution joints
(optional).
l
When bending tubing, use a bending radius that is 4 times the outer diameter of the tubing or larger.
CAUTION
Use sufficient care in handling the tubing. Seal the tubing ends with caps or tape to
prevent dirt, moisture, or other foreign substances from entering.
These substances can result in system malfunction.
Material: O
Material: O
Outer diameter
Wall thickness
Outer diameter
Wall thickness
1/4" (6.35)
0.025 (0.635)
7/8" (22.22)
0.045 (1.143)
3/8" (9.52)
0.030 (0.762)
1-1/8" (28.58)
0.050 (1.27)
1/2" (12.7)
0.035 (0.889)
1-3/8" (34.92)
0.055 (1.397)
5/8" (15.88)
0.040 (1.016)
1-5/8" (41.28)
0.060 (1.524)
3/4" (19.05)
0.042 (1.0668)
Unit: in. (mm)
1-2. Prevent impurities including water, dust and oxide from entering the tubing. Impurities can cause R410A
refrigerant deterioration and compressor defects. Due to the features of the refrigerant and refrigerating machine
oil, the prevention of water and other impurities becomes more important than ever.
2. Be sure to recharge the refrigerant only in liquid form.
2-1. Since R410A is a non-azeotrope, recharging the refrigerant in gas form can lower performance and cause defects
in the unit.
2-2. Since refrigerant composition changes and performance decreases when gas leaks, collect the remaining
refrigerant and recharge the required total amount of new refrigerant after fixing the leak.
3. Different tools required
3-1. Tool specifications have been changed due to the characteristics of R410A.
Some tools for R22- and R407C-type refrigerant systems cannot be used.
Item
New
tools?
R407C
tools
compatible
with
R410A?
Remarks
Manifold gauge
Yes
No
Types of refrigerant, refrigerating machine oil, and
pressure gauge are different.
Charge hose
Yes
No
To resist higher pressure, material must be changed.
Vacuum pump
Yes
Yes
Use a conventional vacuum pump if it is equipped with
a check valve. If it has no check valve, purchase and
attach a vacuum pump adapter.
Leak detector
Yes
No
Leak detectors for CFC and HCFC that react to chlorine
do not function because R410A contains no chlorine.
Leak detector for HFC134a can be used for R410A.
Flaring oil
Yes
No
For systems that use R22, apply mineral oil (Suniso
oil) to the flare nuts on the tubing to prevent refrigerant
leakage. For machines that use R407C or R410A, apply
synthetic oil (ether oil) to the flare nuts.
* Using tools for R22 and R407C and new tools for R410A together can cause defects.
Manifold gauge
Vacuum pump
Outlet
Inlet
Material: Use clean, dry, free of oil, refrigeration grade, seamless, phosphorous deoxidized copper tube rated for
R410A only. Wall thickness shall comply with the applicable legislation. The minimal wall thickness must be in
accordance with the table below.
5
3-2. Use R410A exclusive cylinder only.
Single-outlet valve
(with siphon tube)
Liquid refrigerant should be recharged
with the cylinder standing on end as
shown.
New refrigerant R410A cannot be used for
earlier models
1. Compressor specifications are different.
If recharging a R22 or R407C compressor with
R410A, durability will significantly decrease since
some of the materials used for compressor parts are
different.
2. Existing tubing cannot be used (especially R22).
Completely cleaning out residual refrigerating
machine oil is impossible, even by flushing.
3. Refrigerating machine oil differs (R22).
Since R22 refrigerating machine oil is mineral oil, it
does not dissolve in R410A. Therefore, refrigerating
machine oil discharged from the compressor can
cause compressor damage.
R22 refrigerating machine oil
Mineral oil (Suniso oil)
R407C refrigerating machine oil
Synthetic fluid (ether oil)
R410A refrigerating machine oil
Synthetic fluid (ether oil)
Valve
Liquid
SM830237-07_北米向け2WAY_VRF.indb 5
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