Mounting The Branch Box; Installing Refrigerant Piping - Mitsubishi Electric M Series Installation Manual

6. Mounting the Branch Box

B
C
D ( E )
A
F
G
Fig. 6-1
Fig. 6-2

7. Installing refrigerant piping

A
45°± 2°
A
Flare cutting dimensions
B
Flare nut tightening torque
Fig. 7-1
A
Flare cutting dimensions
Table 1
Flare dimensions
Copper pipe O.D.
øA dimensions
(mm)
ø6.35
ø9.52
ø12.7
ø15.88
B
Flare nut tightening torque
Table 2
Copper pipe O.D. Flare nut O.D.
(mm) (mm)
ø6.35
ø6.35
ø9.52
ø9.52
ø12.7
ø12.7
ø15.88
ø15.88
H
* Purchase an appropriate
bracket locally if the unit
is to be mounted on a
wall.
B
(mm)
8.7-9.1
12.8-13.2
16.2-16.6
19.3-19.7
Tightening torque
(N•m)
17 14-18
22 34-42
22 34-42
26 49-61
26 49-61
29 68-82
29 68-82
36 100-120
*1 N•m ≈ 10 kgf•cm
(mm) (1) Install the suspension bolts (procure locally) at the specifi ed pitch (Fig. 4-2, 4-3).
(2) Fit the washers and nuts (1, 2, procure locally) to the suspension bolts.
(Fig. 6-1)
(3) Hang the unit on the suspension bolts.
(4) Fully tighten the nuts (check ceiling height).
B
(5) Use a level to adjust the branch box to the horizontal.
A
When unit is hung and nuts tightened
B
Suspension bolt
C
Nut
D
Washer (with cushion) 1
E
Ensure that cushion faces downwards
F
Washer (without cushion) 2
G
Nut (procure locally)
H
Ceiling board
(mm)
► Connect the liquid and gas pipes of each indoor unit to the same end
connection numbers as indicated on the indoor unit flare connection
section of each Branch Box. If connected to wrong end connection
numbers, it doesn't work normally.
► When connecting indoor units, make sure to connect refrigerant pipes
and connection wires to the appropriate connection ports marked with
matching alphabets. (Ex. A, B, C, D, E)
Note:
Be sure to mark all the local refrigerant piping (liquid pipes, gas pipes, etc.)
for each indoor unit designating clearly which room it belongs in. (Ex. A, B,
C, D, E)
► List indoor unit model names in the name plate on the control box of
Branch Box (for identification purposes).
• Conduct suffi cient anti-condensation and insulation work to prevent water drip-
ping from the refrigerant piping. (liquid pipe/gas pipe)
• Increase insulation depending on the environment where the refrigerant piping is
installed, or condensation may occur on the surface of the insulation material.
(Insulation material Heat-resistant temperature: 120 °C, Thickness:
15 mm or more)
* When the refrigerant piping is used in locations subject to high temperature
and humidity such as in the attic, further addition of insulation may be re-
quired.
• To insulate the refrigerant piping, apply heat-resistant polyethylene foam be-
tween the indoor unit and insulation material as well as to the net between the
insulation material fi lling all gaps.
(Condensation forming on the piping may result in condensation in the room or
burns when contacting the piping.)
► When using commercially available refrigerant piping, ensure that both
liquid and gas piping are wrapped with commercially available thermal
insulation materials (insulation materials at least 12 mm thick and able
to withstand temperatures in excess of 100 ºC).
► Refer to the installation manual of the outdoor unit when creating a
vacuum and opening or closing valves.
(1) Remove the fl ared nuts and caps from the branch box.
(2) Flare the ends of the liquid and gas piping, and apply refrigeration oil (procure
locally) to the fl ared seat.
Do not apply oil to the threaded portion.
(3) Connect the refrigerant piping immediately. Always tighten the fl ared nuts to
the torque specifi ed in the table 2 using a torque wrench and double spanner.
(4) Press the pipe covers 3 and 5 on the liquid piping against the unit and wrap
to hold in place. (Fig. 7-3)
(5) Press the pipe covers 4 and 6 on the gas piping against the unit and wrap to
hold in place. (Fig. 7-3)
(6) Apply the supplied bands 9 at a position 10 - 20 mm from each end of the
pipe covers (3456).
(7) If the indoor unit is not connected, fi t the supplied pipe covers (with caps, 7
and 8) to the branch box refrigerant piping connections against the unit to
prevent condensation dripping from the pipes. (Fig. 7-4)
(8) Clamp the pipe covers (78) in place with the supplied bands 9.
7