Mitsubishi Electric PAC-MK50BC Installation Manual page 8

7. Installing refrigerant piping
C
5
6
Fig. 7-2
Caution:
Tighten the flare nut with a torque wrench in the specified met
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).
7
F
G 8
3456
H
L
J
Fig. 7-3
1.5 m or less
Fig. 7-5
8
D
4
3
d.
9
9 10 to 20
30 to 50
Fig. 7-4
Support
Pipe cover
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
and fasten them with the supplied bands
Table 3
Diameters of branch box openings for
connecting indoor units (mm)
ø6.35
ø9.5
ø1.7
► Refrigerant charge:
Refer to the installation manual of the outdoor unit.
Use only R410A refrigerant (use of other refrigerants may cause troubles).
(mm)
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
against the unit
7 8
.
9
Tightening torque
(N•m)
13 ± 
30 ± 
50 ±