7
GB
D
F
E
I
NL
P
GR
RU
TR
CZ
SV
SL
HG
PO
8
For indoor and outdoor branching, be sure to use the following twinning pipe
sets in the table 1 (sold separately).
9
Use an adapter if a specified refrigerant pipe has a different diameter from that
of a branching pipe.
0
Braze only with non-oxide brazing material for piping. Failure to do so
may damage the compressor. Be sure to perform the non-oxidation braz-
ing with a nitrogen purge.
Do not use any commercially available anti-oxidizing agent since it may
cause pipe corrosion and degrading of the refrigerant oil.
Please contact Mitsubishi Electric for more details.
(Refer to item 10.2. for details of the piping connection and valve operation)
A
Always insulate the piping properly. Insufficient insulation will result in a de-
cline in heating/cooling performance, water drops from condensation forming
and other such problems. (Refer to item 10.4 for thermal insulation of refriger-
ant piping.)
B
When connecting the refrigerant piping, make sure the valve of the outdoor
unit is completely closed (the factory setting). Do not operate it until the refrig-
erant piping for the outdoor and indoor units has been connected, a refrigerant
leakage test has been performed, and the evacuation process has been com-
pleted.
C
Never use refrigerant to perform an air purge.
Always evacuate using a
vacuum pump.
D
Be sure to charge the system using liquid refrigerant.
E
Either a lack or an excess of refrigerant causes the unit to make an emergency
stop. Charge the system with an appropriate amount of refrigerant. When serv-
icing, always check the notes concerning pipe length and amount of additional
refrigerant at both locations, the refrigerant volume calculation table on the
back of the service panel and the additional refrigerant section on the labels
for the combined number of indoor units. (Refer to item 9.2. for detailed infor-
mation on refrigerant piping system.)
9. Refrigerant piping installation
The pipe is connected via a terminal-branch type connection in which refrigerant
piping from the outdoor unit is branched at the terminal and is connected to each
of the indoor units.
The method of pipe connection is as follows: flare connection for the indoor units,
gas pipes and liquid pipes for outdoor units, brazed connection. Note that the branched
sections are brazed.
Warning:
Always use extreme care to prevent the refrigerant gas from leaking while
using fire or flame. If the refrigerant gas comes in to contact with a flame
from any source, such as a gas stove, it breaks down and generates a poi-
sonous gas which can cause gas poisoning. Never weld in an unventilated
room. Always conduct an inspection for gas leakage after installation of the
refrigerant piping has been completed.
9.1. Caution
This unit uses refrigerant R410A. Follow the local regulations on materials and
pipe thickness when selecting pipes. (Refer to the table on the right.)
1
Use the following materials for refrigeration piping.
•
Material: Use copper alloy seamless pipes made of phosphorus deoxi-
dized copper. Ensure the inner and outer surfaces of the pipes are clean
and free from hazardous sulfur, oxide, dusts, shaving particles, oils, and
moisture (contamination).
•
Size: Refer to item 9.2. for detailed information on refrigerant piping system.
2
Always observe the restrictions on the refrigerant piping (such as rated length,
height difference, and piping diameter) to prevent equipment failure or a de-
cline in heating/cooling performance.
3
Branching cannot be made after header branching (corresponding parts are
marked with in the diagram below).
To the outdoor unit
To the outdoor unit
CAP
4
Do not install outdoor unit piping when it is raining.
5
Commercially available piping often contains dust and other materials. Always
blow it clean with a dry inert gas.
6
Use care to prevent dust, water or other contaminants from entering the piping
during installation.
7
Reduce the number of bending portions as much as possible, and make bend-
ing radius as big as possible.
Note:
1. Height of frame base for snow damage prevention (H) shall be twice as high as
expected snowfall. Width of frame base shall not exceed that of the unit. The
frame base shall be made of angle steel, etc., and designed so that snow and
wind slip through the structure. (If frame base is too wide, snow will be
accumulated on it.)
2. Install unit so that wind will not directly lash against openings of inlet and outlet ducts.
3. Build frame base at customer referring to this figure.
Material : Galvanized steel plate 1.2T
Painting : Overall painting with polyester powder
Color
: Munsell 5Y8/1 (same as that of unit)
4. When the unit is used in a cold region and the heating operation is continu-
ously performed for a long time when the outside air temperature is below
freezing, install a heater to the unit base or take other appropriate measures to
prevent water from freezing on the base.
Warning:
•
Be sure to install unit in a place strong enough to withstand its weight.
Any lack of strength may cause unit to fall down, resulting in a personal injury.
•
Have installation work in order to protect against strong winds and earthquakes.
Any installation deficiency may cause unit to fall down, resulting in a personal injury.
When building the foundation, give full attention to the floor strength, drain water dis-
posal <during operation, drain water flows out of the unit>, and piping and wiring routes.
Precautions when routing the pipes and wires below the unit
When routing the pipes and wires below the unit, be sure that the foundation and
base work do not block the base through-holes. Also make sure the foundation is
at least 100 mm [3-15/16 in] high so that the piping can pass under the unit.
[Fig. 8.1.2]
Outlet
Inlet
Inlet
Inlet
H
•
In abnormally harsh environments such as cold and/or windy areas, sufficient
countermeasures to guard against excessive wind and snow should be taken
to ensure the unit's correct operation. When the unit is expected to operate in
cooling mode in conditions under 10°C [50°F], in snowy areas, in environments
subject to strong winds or rain, install air inlet and outlet ducting as shown in
[Fig. 8.1.2].
Size (mm)
Size (inch)
Radial thickness
Radial thickness
Pipe type
(mm)
(mil)
ø6.35
ø1/4"
0.8
32
Type-O
ø9.52
ø3/8"
0.8
32
Type-O
ø12.7
ø1/2"
0.8
32
Type-O
ø15.88
ø5/8"
1.0
40
Type-O
*ø19.05
ø3/4"
1.2
48
Type-O
*ø19.05
ø3/4"
1.0
40
Type-1/2H or H
ø22.2
ø7/8"
1.0
40
Type-1/2H or H
ø25.4
ø1"
1.0
40
Type-1/2H or H
ø28.58
ø1-1/8"
1.0
40
Type-1/2H or H
ø31.75
ø1-1/4"
1.1
44
Type-1/2H or H
ø34.93
ø1-3/8"
1.2
48
Type-1/2H or H
ø41.28
ø1-5/8"
1.4
56
Type-1/2H or H
Copper pipe size and radial thickness for R410A CITY MULTI.
* Both pipe types can be used for pipe size ø19.05 (3/4 inch) for R410A air condi-
tioner.
