5 Piping installation
Installation manual
15
2(A)MXM40+50 + 2(A)MXF40+50
R32 Split series
3P600450-3G – 2021.03
d
Hose (field supply)
5
Piping installation
5.1
Preparing refrigerant piping
5.1.1
Refrigerant piping requirements
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪
Piping material:
Phosphoric acid deoxidised seamless copper.
▪
Piping diameter:
Class 40
Liquid piping
2× Ø6.4 mm (1/4")
Gas piping
2× Ø9.5 mm (3/8")
Class 50
Liquid piping
2× Ø6.4 mm (1/4")
Gas piping
1× Ø9.5 mm (3/8")
1× Ø12.7 mm (1/2")
▪
Piping temper grade and thickness:
Outer diameter
(Ø)
Temper grade
Thickness (t)
(a)
6.4 mm (1/4")
Annealed (O)
≥0.8 mm
t
Ø
9.5 mm (3/8")
12.7 mm (1/2")
(a)
Depending on the applicable legislation and the maximum
working pressure of the unit (see "PS High" on the unit name
plate), larger piping thickness might be required.
Usage of reducers might be required based on the indoor unit. See
"5.2.1 Connections between outdoor and indoor unit using
reducers"
5.1.2
Refrigerant piping insulation
▪ Use polyethylene foam as insulation material:
▪ with a heat transfer rate between 0.041 and 0.052 W/mK (0.035
and 0.045 kcal/mh°C)
▪ with a heat resistance of at least 120°C
▪ Insulation thickness
Pipe outer diameter
(Ø
p
)
Insulation inner
diameter (Ø
i
)
Insulation thickness
(t)
6.4 mm (1/4")
8~10 mm
≥10 mm
9.5 mm (3/8")
12~15 mm
≥13 mm
12.7 mm (1/2")
14~16 mm
≥13 mm
Ø
i
Ø
i
t
Ø
p
Ø
p
If the temperature is higher than 30°C and the humidity is higher
than RH 80%, the thickness of the insulation materials should be at
least 20 mm to prevent condensation on the surface of the
insulation.
5.1.3
Refrigerant piping length and height
difference
The shorter the refrigerant piping, the better the performance of the
system.
The piping length and height differences must comply with the
following requirements.
Model
Minimum required space
Class 40
1.2 m
2
Class 50
1.8 m
2
Shortest allowable length per room is 3 m.
Refrigerant piping length to each indoor unit
≤20 m
Refrigerant piping total length
≤30 m
Height difference
outdoor-indoor
Height difference
indoor-indoor
Outdoor unit installed
higher than indoor
unit
≤15 m
≤7.5 m
Outdoor unit installed
lower than at least 1
indoor unit
≤7.5 m
≤15 m
5.2
Connecting the refrigerant piping
DANGER: RISK OF BURNING/SCALDING
CAUTION
▪ No brazing or welding on site for units with R32
refrigerant charge during shipment.
▪ During installation of the refrigeration system, joining of
parts with at least one part charged shall be performed
taking into account the following requirements: inside
occupied spaces non permanent joints are not allowed
for R32 refrigerant except for site made joints directly
connecting the indoor unit to piping. Site made joints
directly connecting piping to indoor units shall be of non
permanent type.
CAUTION
Do NOT connect the embedded branch piping and the
outdoor unit when only carrying out piping work without
connecting the indoor unit in order to add another indoor
unit later.
5.2.1
Connections between outdoor and indoor
unit using reducers
Total indoor unit capacity class that can be connected to this
outdoor unit:
Outdoor unit
Total indoor unit capacity
class
2MXM40, 2AMXM40, 2AMXF40,
2MXF40
≤6.0 kW
2MXM50, 2AMXM50, 2AMXF50,
2MXF50
≤8.5 kW
Port
Class
Reducer
2MXM40, 2AMXM40
A
15, 20, 25, 35
—
B
15, 20, 25, 35
—
2AMXF40
A
25, 35
—