Charging Refrigerant; Precautions; Calculating The Additional Refrigerant Charge - Daikin RXYQ72TTJU Installation Manual

2
3
4
5
1 PC
2 Cable (EKPCCAB*)
3 Outdoor unit main printed circuit board

14 . Charging refrigerant

14 . 1 . Precautions

NOTE
• Refrigerant cannot be charged until field wiring has been com-
pleted.
• Refrigerant may only be charged after performing the leak test and
the vacuum drying.
• When charging a system, care shall be taken that its maximum
permissible charge is never exceeded, in view of the danger of
liquid hammer.
• Charging with an unsuitable substance may cause explosions and
accidents, so always ensure that the appropriate refrigerant R410A
is charged.
• Refrigerant containers shall be opened slowly.
• Always use protective gloves and protect your eyes when charging
refrigerant.
• When the refrigerant system is to be opened, refrigerant must be
treated according to the applicable legislation.
DANGER
See Safety considerations on page i.
• To avoid compressor breakdown. Do not charge the refrigerant
more than the specified amount.
• This outdoor unit is factory charged with refrigerant and depending
on pipe sizes and pipe lengths some systems require additional
charging of refrigerant. See 14.2. Calculating the additional refriger-
ant charge.
• In case recharge is required, refer to the nameplate of the unit.
It states the type of refrigerant and necessary amount.

14 .2 . Calculating the additional refrigerant charge

NOTE
The refrigerant charge of the system must be less than 210 lbs.
(100 kg). This means that in case the calculated total refrigerant
charge is equal to or more than 209 lbs. (95 kg) you must divide your
multiple outdoor system into smaller independent systems, each
containing less than 209 lbs. (95 kg) refrigerant charge. For factory
charge, refer to the unit nameplate.
3P362438-1B English
1 3
2
X27A
A1P
14 .2 . 1 . How to calculate the additional refrigerant to be charged
Additional refrigerant to be charged=R (lbs.). R should be rounded off
in units of 0.1 lbs.
× f7/8) × 0.249+(X × f3/4) × 0.175+(X
R=[(X
1 2
× 0.081+(X × f3/8) × 0.040+(X × f1/4) × 0.015]+[A]+[B]
5 6
X =Total length (ft. (m)) of liquid piping size at Øa
1...6
* In units of 0.1 kg, additional refrigerant to be charged=R (kg).
× f22.2) × 0.37+(X × f19.1) × 0.26+(X
R=[(X
1 2
0.12+(X × f9.5) × 0.059+(X × f6.4) × 0.022]+[A]+[B]
5 6
Parameter [A]
The amount of refrigerant by the module
Outdoor unit capacity type
RXYQ 72-120T type
RXYQ 144T type
RXYQ 168T type
Total indoor
Parameter [B] unit capacity
CR
(a)
Piping length
> 105%
≤ 98 ft. (30 m)
70%<CR≤85% 0.66 lbs. (0.3 kg) 1.10 lbs. (0.5 kg)
Piping length
85%<CR≤105% 1.54 lbs. (0.7 kg) 2.20 lbs. (1.0 kg)
> 98 ft. (30 m)
> 105%
Example for refrigerant branch using REFNET joint and REFNET
header for systems and each pipe length as shown below. (Example
2.2, 7.5.2. System only containing VRV indoor units on page 12)
Outdoor system: RXYQ264TTJU (RXYQ144TTJU + RXYQ120TTJU)
Total capacity of indoor unit: 116%
a: f3/4 × 60 ft. e: f3/8 × 15 ft.
b: f5/8 × 15 ft. f: f3/8 × 15 ft.
c: f3/8 × 15 ft. g: f1/4 × 15 ft.
d: f3/8 × 15 ft. h: f1/4 × 30 ft.
R = ( 60×0.175 + 15×0.121 + 45×0.081 + 100×0.040 + 45×0.015 ) + 8.8 + 3.31+3.31
↑ ↑ ↑
a b i, r, s
= 36.055 ⇒ 36.0 lbs.
Round off in units of 0.1 lbs.
INFORMATION
• When using multi models, add the sum of individual capacity types.
• Piping length is considered the distance from the outdoor unit to the
farthest indoor unit.
When selecting indoor unit, following table with connection ratio limita-
tion has to be respected. More detailed information can be found in
Engineering Data Book.
Used indoor Total capacity
units CR
(a)
VRV 50 – 200%
VRV + Mini-split 80 –130%
Mini-split 80 –130%
× f5/8) × 0.121+(X × f1/2)
3 4
× f15.9) × 0.18+(X × f12.7) ×
3 4
The amount of refrigerant
0.0 lbs. (0.0 kg)
8.8 lbs. (4.0 kg)
9.9 lbs. (4.5 kg)
RXYQ
72T 96 - 168T
1.10 lbs. (0.5 kg)
2.65 lbs. (1.2 kg) 3.31 lbs. (1.5 kg)
i: f1/2 × 20 ft. s: f1/2 × 15 ft.
j: f3/8 × 20 ft.
k: f3/8 × 20 ft.
r: f1/2 × 10 ft.
↑ ↑ ↑ ↑
c, d, e, f, j, k g, h RXYQ144TTJU 116%
Allowable capacity connection ratio
VRV Mini-split
50 – 200% –
0 – 130% 0 – 130%
– 80 – 130%
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