Daikin VRV IV RXMLQ8T7Y1B Series - Charging Refrigerant; Precautions When Charging Refrigerant; About Charging Refrigerant; To Determine the Additional Refrigerant Amount

5 Installation
Installation and operation manual
15
RXMLQ8 + RXYLQ10~14T7Y1B*
VRV IV system air conditioner
4P543426-1 – 2018.07
▪ 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
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
below figure.
a
b
a Insulation material
b Caulking etc.
5.6 Charging refrigerant
5.6.1 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.
NOTICE
Be sure to turn on the power 6 hours before operation in
order to have power running to the crankcase heater and
to protect the compressor.
NOTICE
If operation is performed within 12 minutes after the indoor
and outdoor units are turned on, the compressor will not
operate before the communication is established in a
correct way between outdoor unit(s) and indoor units.
NOTICE
Before starting charging procedures, check if the
7‑segment display indication of the outdoor unit A1P PCB
is as normal (see "6.1.4 To access mode 1 or 2" on
page 21). If a malfunction code is present, see
"9.1Solving problems based on error codes"on page25.
NOTICE
Close the front panel before any refrigerant charge
operation is executed. Without the front panel attached the
unit cannot judge correctly whether it is operating properly
or not.
NOTICE
In case of maintenance and the system (outdoor unit+field
piping+indoor units) does not contain any refrigerant any
more (e.g., after refrigerant reclaim operation), the unit has
to be charged with its original amount of refrigerant (refer
to the nameplate on the unit) by pre-charging before the
automatic charging function can be started.
5.6.2 About charging refrigerant
Once vacuum drying is finished, additional refrigerant charging can
start.
To speed up the refrigerant charging process, it is in case of larger
systems recommended to first pre-charge a portion of refrigerant
through the liquid line before proceeding with the manual charging.
This step is included in below procedure (see "5.6.5 To charge
refrigerant" on page 17). It can be skipped, but charging will take
longer then.
A flow chart is available which gives an overview of the possibilities
and actions to be taken (see "5.6.4 To charge refrigerant: Flow
chart"on page16).
5.6.3 To determine the additional refrigerant
amount
INFORMATION
For final charge adjustment in the test laboratory, please
contact your local dealer.
NOTICE
The refrigerant charge of the system must be less than
100 kg. This means that in case the calculated total
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.
Formula:
R=[(X
1
×Ø22.2)×0.37+(X
2
×Ø19.1)×0.26+(X
3
×Ø15.9)×0.18+
(X
4
×Ø12.7)×0.12+(X
5
×Ø9.5)×0.059+(X
6
×Ø6.4)×0.022]+A+B
R Additional refrigerant to be charged [in kg and rounded off
to 1 decimal place]
X
1...6
Total length [m] of liquid piping size at Øa
A, B Parameters A and B (see tables below)
In case of a multi-outdoor-unit system, add the sum of the individual
outdoor unit charge factors.
Parameter A
Piping length
(a)
CR A
8 HP 10~14 HP
≤30m 105%<CR≤130% 0.5kg
>30m 105%<CR≤130% 1.2kg 1.5kg
(a) Piping length is considered the distance from the outdoor
unit to the farthest indoor unit
CR Total indoor unit capacity connection ratio
Parameter B
8~10 HP 12~14 HP
B=3.5kg B=3.8kg