Specifications
EDUS04-906_b Installation Manual
Room Air Conditioners H-Series 31
11
Refrigerant Piping Work
1.
Flaring the pipe end.
1) Cut the pipe end with a pipe cutter.
2) Remove burrs with the cut surface facing downward
so that the chips do not enter the pipe.
3) Put the flare nut on the pipe.
4) Flare the pipe.
5) Check that the flaring is properly made.
WARNING
1) Do not use mineral oil on flared part.
2) Prevent mineral oil from getting into the system as this would reduce the lifetime of the units.
3) Never use piping which has been used for previous installations. Only use parts which are delivered with the unit.
4) Do never install a drier to this R410A unit in order to guarantee its lifetime.
5) The drying material may dissolve and damage the system.
6) Incomplete flaring may cause refrigerant gas leakage.
2.
Refrigerant piping.
CAUTION
1) Use the flare nut fixed to the main unit t o prevent aging and deterioration.
2) To prevent gas leakage, apply refrigeration oil only to the inner surface of the flare. (Use refrigeration oil for R410A.)
3) Use torque wrenches when tightening the flare nuts to prevent damage to the flare nuts and gas leakage.
Align the centers of both flares and tighten the flare nuts 3 or 4 turns by hand. Then tighten them fully with the torque wrenches.
2-1. Caution on piping handling.
1) Protect the open end of the pipe against dust and moisture.
2) All pipe bends should be as gentle as possible. Use a pipe bender for
bending.
2-2. Selection of copper and heat insulation materials.
• When using commercial copper pipes and fittings, observe the following:
1) Insulation material: Polyethylene foam
Heat transfer rate: 0.041 to 0.052W/mK (0.024 to 0.030 Btu/fth°F (0.035 to 0.045 kcal/mh°C))
Choose heat insulation materials that are designed for HVAC use.
2) Be sure to insulate both the gas and liquid piping and to provide insulation dimensions as below.
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
Gas side Liquid side Gas pipe thermal insulation Liquid pipe thermal insulation
O.D. 3/8 inch (9.5mm) O.D. 1/4 inch (6.4mm)
I.D. 0.472-0.590 inch (12-15mm) I.D. 0.315-0.393 inch (8-10mm)
Minimum bend radius
Thickness 0.393 inch (10mm) Min.1-3/16 inch (30mm) or more
Thickness 0.031 inch (0.8mm) (C1220T-O)
Set exactly at the position shown below.
A
Flaring
Die
A
0-0.020 inch (0-0.5mm)
Clutch-type
Flare tool for R410A
0.039-0.059 inch (1.0-1.5mm)
Clutch-type (Rigid-type)
0.059-0.079 inch (1.5-2.0mm)
Wing-nut type (Imperial-type)
Conventional flare tool
(Cut exactly at
right angles.) Remove burrs
Check
Flare’s inner
surface must
be flaw-free.
The pipe end must
be evenly flared in
a perfect circle.
Make sure that the
flare nut is fitted.
24.1-29.4 ft·lbf
(32.7-39.9 N·m)
10.4-12.7 ft·lbf
(14.2-17.2 N·m)
Flare nut tightening torque
Gas side Liquid side
3/8 inch (9.5mm) 1/4 inch (6.4mm)
Do not apply refrigeration
oil to the outer surface.
Flare nut
Apply refrigeration oil to the
inner surface of the flare.
Do not apply refrigeration
oil to the flare nut avoid
tightening with over torque.
[Apply oil]
To rque wrench
Piping union
Flare nut
Spanner
[Tighten]
Wall
If no flare cap is
available, cover
the flare mouth
with tape to keep
dirt or water out.
Be sure to
place a cap.
Rain
Insulation tape
Liquid pipe insulation
Inter-unit wiring
Gas pipe insulation
Gas pipe
Drain hose
Liquid pipe