Refrigerant Piping Installation; Caution - Mitsubishi Electric PUHY-P72ZKMU-A(-BS) Manuel D'installation

[Fig. 8.1.2]
Outlet
Inlet
In abnormally harsh environments such as cold and/or windy areas,
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].

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.
units, gas pipes and liquid pipes for outdoor units, brazed connection. Note that
the branched sections are brazed.
Warning:
Do not use refrigerant other than the type indicated in the manuals
provided with the unit and on the nameplate.
during use, during repair, or at the time of disposal of the unit.
- It may also be in violation of applicable laws.
- MITSUBISHI ELECTRIC CORPORATION cannot be held responsible
for malfunctions or accidents resulting from the use of the wrong type of
refrigerant.
Always use extreme care to prevent the refrigerant gas from leaking while
from any source, such as a gas stove, it breaks down and generates
a poisonous 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
deoxidized 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 decline 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
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.
Inlet
Inlet
CAP
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.
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
continuously 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.
personal injury.
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.
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
bending radius as big as possible.
8 For indoor and outdoor branching, be sure to use the following twinning pipe
sets in the table 1 (sold separately).
9 Use a charging hose with a diameter that accommodates the check joint
(Diameter: 1/2) on the outdoor unit.
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
brazing 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
decline in heating/cooling performance, water drops from condensation
forming and other such problems. (Refer to item 10.4 for thermal insulation
of refrigerant 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
refrigerant piping for the outdoor and indoor units has been connected, a
refrigerant leakage test has been performed, and the evacuation process
has been completed.
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 servicing, 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 information on refrigerant piping system.)
Copper pipe size and radial thickness for R410A CITY MULTI.
Radial thickness
Size (mm) Size (inch)
(mm)
ø6.35 ø1/4" 0.8
ø9.52 ø3/8" 0.8
ø12.7 ø1/2" 0.8
ø15.88 ø5/8" 1.0
*ø19.05 ø3/4" 1.2
*ø19.05 ø3/4" 1.0
ø22.2 ø7/8" 1.0
ø25.4 ø1" 1.0
ø28.58 ø1-1/8" 1.0
ø31.75 ø1-1/4" 1.1
ø34.93 ø1-3/8" 1.2
ø41.28 ø1-5/8" 1.4
* Both pipe types can be used for pipe size ø19.05 (3/4 inch) for R410A air
conditioner.
Radial thickness
Pipe type
(mil)
32 Type-O
32 Type-O
32 Type-O
40 Type-O
48 Type-O
40 Type-1/2H or H
40 Type-1/2H or H
40 Type-1/2H or H
40 Type-1/2H or H
44 Type-1/2H or H
48 Type-1/2H or H
56 Type-1/2H or H
9