8
7. Installing refrigerant piping
9
9
8
7
G
3456
L
J
H
F
10 to 20
30 to 50
Caution:
Tighten the flare nut with a torque wrench in the specified met d.
Overtightening will cause the flare nut to crack and it will cause refrigerant
leakage over a period of time.
C
Apply refrigeration oil to the entire (Fig. 7-2) surface of the flared seat
D
Basically use flared nuts fitted to the body (commercially available flared nuts
may crack).
Note:
A special fla e nut (optional or attached to the indoor unit) is needed to
some indoor units.
Please refer to the installation manual of outdoor unit and indoor unit for
details.
F
Band
9
G
Pipe covers
3456
H
Tighten
J
Refrigerant piping
L
Thermal insulation for refrigerant piping
► Use the following procedures for indoor connection part which indoor
unit is not connected. (Fig. 7-4)
(1) In order to prevent refrigerant leaks, make sure that the flare nuts are tightened
according to the specified torques* in Table 3
* Refrigerant may also leak if the flare nuts are tightened more than the speci-
fied torques
(
) In order to prevent condensation, install the pipe covers
7
8
against the unit
and fasten them with the supplied bands
9
.
Table 3
Diameters of branch box openings for
connecting indoor units (mm)
Tightening torque
(N•m)
ø6.35
13 ±
ø9.5
30 ±
ø1.7
50 ±
► Refrigerant charge:
Refer to the installation manual of the outdoor unit.
Use only R410A refrigerant (use of other refrigerants may cause troubles).
Caution:
To avoid excessive strain on the branch box, support the piping with one or
more support(s) 1.5 m or less from the branch box.
Refer to Fig. 7-5 as an example.
J
Refrigerant piping
L
Thermal insulation for refrigerant piping
(mm)
Fig. 7-4
Fig. 7-5
1.5 m or less
Support
Pipe cover
Fig. 7-3
C
D
3
6
4
5
Fig. 7-2
