5 Piping installation
Installation manual
14
2MXM68+3(A)MXM+3(A)MXF+4MXM+5MXM
R32 Split series
3P600450-1G – 2021.03
2 Install the drain socket.
a Drain hole. Install a drain cap (large).
b Drain hole. Install a drain cap (small).
c Drain hole for drain socket
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:
2MXM68
Liquid piping 2× Ø6.4mm (1/4")
Gas piping 1× Ø9.5mm (3/8")
1× Ø12.7mm (1/2")
3MXM40, 3MXM52, 3MXM68, 3AMXM52, 3MXF52, 3AMXF52,
3MXF68
Liquid piping 3× Ø6.4mm (1/4")
Gas piping 1× Ø9.5mm (3/8")
2× Ø12.7mm (1/2")
4MXM68
Liquid piping 4× Ø6.4mm (1/4")
Gas piping 2× Ø9.5mm (3/8")
2× Ø12.7mm (1/2")
4MXM80
Liquid piping 4× Ø6.4mm (1/4")
Gas piping 1× Ø9.5mm (3/8")
1× Ø12.7mm (1/2")
2× Ø15.9mm (5/8")
5MXM90
Liquid piping 5× Ø6.4mm (1/4")
Gas piping 2× Ø9.5mm (3/8")
1× Ø12.7mm (1/2")
2× Ø15.9mm (5/8")
▪ Piping temper grade and thickness:
Outer diameter
(Ø)
Temper grade Thickness (t)
(a)
6.4mm (1/4")
9.5mm (3/8")
12.7mm (1/2")
Annealed (O) ≥0.8mm
15.9mm (5/8") ≥1mm
(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"[415] for more information.
5.1.2 Refrigerant piping insulation
▪ Use polyethylene foam as insulation material:
▪ with a heat transfer rate between 0.041 and 0.052W/mK (0.035
and 0.045kcal/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)
6.4mm (1/4") 8~10mm ≥10mm
9.5mm (3/8") 10~14mm ≥13mm
12.7mm (1/2") 14~16mm ≥13mm
15.9mm (5/8") 16~20mm ≥13mm
If the temperature is higher than 30°C and the humidity is higher
than RH80%, the thickness of the insulation materials should be at
least 20 mm to prevent condensation on the surface of the
insulation.
Use separate thermal insulation pipes for the gas and liquid
refrigerant piping.
5.1.3 Refrigerant piping length and height
difference
INFORMATION
For the Hybrid for Multi application and the DHW generator
for Multi, see the indoor unit installation manual for the
maximum allowable 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
2MXM68, 3MXM40, 3MXM52,
3AMXM52, 3MXF52, 3AMXF52
4.7m
2
3MXM68, 3MXF68 5.5m
2
4MXM68 6.5m
2
4MXM80 9.8m
2
5MXM90 10.4m
2
Shortest allowable length per room is 3m.