Pipe Insulation; Checking Of Unit And Installation Conditions; Charging Refrigerant; Precautions When Adding R410A - Daikin VRV III RXYQ-PY1K Installation Manual

9. P
IPE INSULATION
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 liquid and gas piping (for all units).
Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid side piping and polyethylene foam
which can withstand a temperature of 120°C for gas side piping.
Reinforce the insulation on the refrigerant piping according to
the installation environment.
Ambient temperature
≤30°C
>30°C
Condensation might form on the surface of the insulation.
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
figure 12.
1 Gas line stop valve
2 Liquid line stop valve
3 Service port for adding refrigerant
4 Sealing up treatment
5 Insulation
6 Indoor -outdoor interconnection piping
Be sure to insulate local pipes, as touching them can
cause burns.
10. C
HECKING OF UNIT AND INSTALLATION
CONDITIONS
Be sure to check the following:
The piping work
1 Make sure piping size is correct.
See "6.2. Selection of piping material" on page
2 Make sure insulation work is done.
See "9. Pipe insulation" on page
3 Make sure there is no faulty refrigerant piping.
See "6. Refrigerant piping" on page
The electrical work
1 Make sure there is no faulty power wiring or loose nuts.
See "8. Field wiring" on page
2 Make sure there is no faulty transmission wiring or loose nuts.
See "8. Field wiring" on page
3 Make sure the insulation resistance of the main power circuit is
not deteriorated.
Using a megatester for 500 V, check that the insulation
resistance of 2 MΩ or more is attained by applying a voltage of
500 V DC between the power terminals and earth. Never use
the megatester for the transmission wiring (between outdoor
and indoor unit, outdoor and COOL/HEAT selector, etc.).
RXYQ8~12P7Y1K + RXYQ8~12P7YLK
VRVIII System air conditioner
4PW41760-1
Humidity Minimum thickness
75% to 80% RH 15 mm
≥80 RH
20 mm
5.
16.
4.
10.
10.
11. C
HARGING REFRIGERANT
The outdoor unit is factory charged, but depending on the length of
the piping when installed, the outdoor unit may require additional
charging.
For charging the additional refrigerant follow the procedure as
described in this chapter.
Refrigerant can not be charged until all field wiring and
field piping has been completed.
Refrigerant may only be charged after performing the leak
test and the vacuum drying.
The refrigerant charge of the system must be less than
100 kg. This means that in case the calculated refrigerant
charge is equal to or more than 95 kg you must divide your
multiple outdoor system into smaller independent systems,
each containing less than 95 kg refrigerant charge.
For factory charge, refer to the unit name plate.

11.1. Precautions when adding R410A

Be sure to charge the specified amount of refrigerant in liquid state to
the liquid pipe.
Since this refrigerant is a mixed refrigerant, adding it in gas form may
cause the refrigerant composition to change, preventing normal
operation.
Before charging, check whether the refrigerant cylinder is
equipped with a siphon tube or not.
Charge the liquid
refrigerant with the
cylinder in upright
position.
Be sure to use tools exclusively for R410A to ensure required
pressure resistance and to prevent foreign materials from mixing
into the system.
Charging with an unsuitable substance may cause
explosions and accidents, so always make sure that the
appropriate refrigerant (R410A) is charged.
Refrigerant containers must be opened slowly.
Charge the liquid
refrigerant with the
cylinder in up-side-down
position.
Installation manual
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