17
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Piping installation
Installer and user reference guide
82
RXYTQ
VRV IV+ heat pump for high ambient temperatures
4P561157-1B – 2021.11
17.3.6 To insulate the refrigerant piping
After finishing the leak test and vacuum drying, the piping must be insulated. Take
into account the following points:
▪
Make sure to insulate the connection piping and refrigerant branch kits entirely.
▪
Be sure to insulate the liquid and gas piping (for all units).
▪
Use heat resistant polyethylene foam which can withstand a temperature of 70°C
for liquid piping and polyethylene foam which can withstand a temperature of
120°C for gas piping.
▪
Reinforce the insulation on the refrigerant piping according to the installation
environment.
Ambient temperature
Humidity
Minimum thickness
≤30°C
75% to 80% RH
15 mm
>30°C
≥80% RH
20 mm
▪
If there is a possibility that condensation on the stop valve might drip down into
the indoor unit through gaps in the insulation and piping because the outdoor
unit is located higher than the indoor unit, this must be prevented by sealing up
the connections. See below figure.
a
b
a
Insulation material
b
Caulking etc.
17.4 Charging refrigerant
17.4.1 Precautions when charging refrigerant
WARNING
▪
ONLY use R410A as refrigerant. Other substances may cause explosions and
accidents.
▪
R410A contains fluorinated greenhouse gases. Its global warming potential (GWP)
value is 2087.5. Do NOT vent these gases into the atmosphere.
▪
When charging refrigerant, ALWAYS use protective gloves and safety glasses.
NOTICE
If the power of some units is turned off, the charging procedure cannot be finished
properly.
NOTICE
In case of a multiple outdoor system, turn on the power of all outdoor units.
