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Piping installation
Installer and user reference guide
95
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452191-1B – 2020.10
INFORMATION
After opening the stop valve, it is possible that the pressure in the refrigerant piping
does NOT increase. This might be caused by e.g. the closed state of the expansion
valve in the outdoor unit circuit, but does NOT present any problem for correct
operation of the unit.
18.4.6 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.
▪
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.
3×
a
b
a
Insulation material
b
Caulking etc.
18.5 Charging refrigerant
18.5.1 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.
