Toshiba RAS-3M26GAV-E, Service Manual

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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 correctly.
(Problems caused by indoor units being connected
to the outdoor unit incorrectly are very common in
multiple-unit installations.)
3. The length and height difference of the connecting
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
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 break.
(Unit : N·m)
Fig. 10-4-7
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 suffi-
ciently 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.
Fig. 10-4-8
Side panel
Outdoor
unit
15 m or less
A
B
C
D
• Tightening torque of flare pipe
The pressure of R410A is higher than R22. (Approx.
1.6 times) Therefore securely tighten the flare pipes
which connect the outdoor unit and indoor unit with
the specified tightening torque using a torque
wrench.
If any flare pipe is incorrectly
connected, it may cause not
only a gas leakage but also
trouble in the refrigeration cycle.
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
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)
Fig. 10-4-9
Fig. 10-4-10
Fig. 10-4-11
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
Flare at
indoor
unit side
Flare at
outdoor
unit side