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

16 | Piping installation
Installer and user reference guide
83
RKXYQ5T8+8T7Y1B + RDXYQ5T8+8T7V1B
VRV IV heat pump for indoor installation
4P499898-1B – 2021.12
16.4.2 Precautions when charging refrigerant
INFORMATION
Also read the precautions and requirements in the following chapters:
▪ General safety precautions
▪ Preparation
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
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 compressor unit, heat
exchanger unit and indoor units are turned on, the compressor will not operate
before the communication is established in a correct way between the compressor
unit, heat exchanger unit and indoor units.
NOTICE
Before starting charging procedures:
▪ In case of 5 HP: Check if the 7‑LEDs display is as normal (see "18.2.4 To access
mode 1 or 2"[4102]), and there is no malfunction code on the user interface of
the indoor unit. If a malfunction code is present, see "22.3 Solving problems
based on error codes"[4124].
▪ In case of 8HP: Check if the 7‑segment display indication of the compressor unit
A1P PCB is as normal (see "18.2.4 To access mode 1 or 2" [4 102]). If a
malfunction code is present, see "22.3 Solving problems based on error
codes"[4124].
NOTICE
Make sure all connected units (heat exchanger unit + indoor units) are recognised
(setting [1‑5]).
16.4.3 To determine the additional refrigerant amount
Formula:
R=[(X
1
×Ø12.7)×0.12+(X
2
×Ø9.5)×0.059+(X
3
×Ø6.4)×0.022]×A+B
R Additional refrigerant to be charged [in kg and rounded off to 1 decimal place]
X
1...3
Total length [m] of liquid piping size at Øa
A, B Parameters A and B