– 74 –
Side panel
Tightening connection
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers.
Then tighten the nut with a spanner and torque
wrench as shown in the figure.
CAUTION
• Do not apply excess torque. Otherwise, the
nut may crack depending on the conditions.
(Unit : N·m)
Fig. 9-3-7
4. Connect 2 or more indoor units for heat pump.
5. If the outdoor units is to be mounted on a wall,
make sure that the platform supporting it is
sufficiently strong. The platform should be
designed and manufactured to maintain its
strength over a long period of time, and sufficient
consideration should be given to ensuring that the
outdoor unit will not fall.
6. When the outdoor unit is to be mounted high on a
wall, take particular care to ensure that parts do
not fall installer is protected.
7. When doing installation work on level ground, it is
usual to wiring and piping connections to the
indoor units. And/then make to the outdoor unit.
However if outdoor work is difficult it is possible
instead to make changes to the procedure.
For example by making adjustments to the wiring
and piping length on the inside (rather than the
outside).
How to remove the side panel
1. Remove 3 screws
of the side panel.
2. Pull the side
panel downward.
1. Piping connections to the outdoor unit should be
arranged in the sequence A, B, C, D starting from
the bottom.
(For each piping connection, the gas pipe is on
the bottom and the liquid pipe is on the top.)
2. When multiple indoor units are to be connected
to the outdoor unit, make the ends of the pipes
and wires from each indoor unit to ensure that
they will be connected to the outdoor unit cor-
rectly.
(Problems caused by indoor units being con-
nected to the outdoor unit incorrectly are very
common in multiple-unit installations.)
3. The length and height difference of the connect-
ing pipes between the indoor and outdoor units
must be within the ranges indicated below.
• Total piping length :
4 units (A + B + C + D) Multi,
Non. Additional refrigerant .......... 70 m
3 units (A + B + C) Multi,
Non. Additional refrigerant .......... 50 m
• Minimum piping length :
A or B or C or D = 2 m or more
• Maximum indoor piping length :
A or B or C or D = 25 m or less
• Maximum piping height difference :
A or B or C or D = 15 m or less
• Maximum piping/height
difference between 2 units
= 15 m or less
Fig. 9-3-8
Half union
Flare nut
Externally
threaded side
Internally
threaded side
Use a wrench to secure.
Use a torque wrench to tighten.
Outdoor
unit
Indoor unit
D
D UNIT
4M27 only
Ø6.35
Ø9.52
A
A UNIT
Ø6.35
Ø12.7
C
C UNIT
Ø6.35
Ø9.52
B
B UNIT
Ø6.35
Ø9.52
Fig. 9-3-9
Fig. 9-3-10
Fig. 9-3-11
3M26
4M27
Connectable capacity class
A B C D Total
10, 13 16 16
—
(with reducer) (with expander) (with expander)
45
16 10, 13 10, 13 —
10, 13 16 16 16
(with reducer) (with expander) (with expander) (with expander)
52
16 10, 13 10, 13 10, 13
• Tightening torque of flare pipe connections
Pressure of R410A becomes higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque
wrench, tighten firmly the flare
pipe connecting sections
which connect the indoor
and outdoor units up to the
specified tightening torque.
Incorrect connections may
cause not only a gas
leakage, but also a trouble
of the refrigeration cycle.
Outdoor
unit
15 m or less
A
B
C
D
Flare at
indoor
unit side
Flare at
outdoor
unit side
Outer dia. of copper pipe
Ø6.35 mm
Ø9.52 mm
Ø12.7 mm
Tightening torque
14 to 18 (1.4 to 1.8 kgf•m)
33 to 42 (3.3 to 4.2 kgf•m)
50 to 62 (5.0 to 6.2 kgf•m)
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