6 Piping installation
Installation manual
9
CVXM-A, FVXM-A, CVXM-A9, FVXM-A9, FVXTM-A
Split system air conditioners
3P477070-2P – 2022.09
a Drain pan
b Drain socket
c Drain hose (accessory)
d Screw (accessory)
2 Check for water leaks (see "5.3.3 To check for water
leaks"[49]).
3 Insulate the indoor drain socket and drain hose with ≥10 mm
insulation material to prevent condensation.
4 Connect the drain piping to the drain hose. Insert the drain hose
≥50mm, so it will not be pulled out of the drain pipe.
a Drain hose (accessory)
b Vinyl chloride drain pipe (VP-30) (field supply)
c Reducer (field supply)
d Vinyl chloride drain pipe (VP-20) (field supply)
5.3.3 To check for water leaks
1 Remove the air filters.
2 Gradually pour approximately 1l of water in the drain pan, and
check for water leaks.
6 Piping installation
6.1 Preparing refrigerant piping
6.1.1 Refrigerant piping requirements
CAUTION
Piping and joints of a split system shall be made with
permanent joints when inside an occupied space except
joints directly connecting the piping to the indoor units.
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant piping.
INFORMATION
Additional refrigerant charge is NOT allowed in case of
combination of the outdoor unit 3MXM40 or 3MXM52 with
the indoor units CVXM-A and/or FVXM-A. The total piping
length MUST be ≤30m. For CVXM-A9 and FVXM-A9 refer
to "To determine the minimum floor area"[45].
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30mg/10m.
Refrigerant piping diameter
Use the same diameters as the connections on the outdoor units:
Class Pipe outer diameter (mm)
Liquid piping Gas piping
20~35 Ø6.4 Ø9.5
50 Ø6.4 Ø12.7
Refrigerant piping material
▪ Piping material: phosphoric acid deoxidised seamless copper
▪ Flare connections: Only use annealed material.
▪ Piping temper grade and thickness:
Outer diameter
(Ø)
Temper grade Thickness (t)
(a)
6.4mm (1/4") Annealed (O) ≥0.8mm
9.5mm (3/8")
12.7mm (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.
6.1.2 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") 12~15mm ≥13mm
12.7mm (1/2") 14~16mm ≥13mm