17
1-13. Example of Tubing Size Selection and Refrigerant Charge Amount
Additional refrigerant charging
Based on the values in Tables 3, 4, 5, 6, 9 and 10, use the liquid tubing size and length, and calculate the amount of additional
refrigerant charge using the formula below.
Required additional
refrigerant charge (kg)
(a) : Liquid tubing Total length of ø25.4 (m) (e) : Liquid tubing Total length of ø12.7 (m)
(b) : Liquid tubing Total length of ø22.22 (m) (
f
) :
Liquid tubing Total length of ø9.52 (m)
(c) : Liquid tubing Total length of ø19.05 (m)
(g) : Liquid tubing Total length of ø6.35 (m)
(d) : Liquid tubing Total length of ø15.88 (m)
● Charging procedure
Be sure to charge with R410A refrigerant in liquid form.
1. After performing a vacuum, charge with refrigerant from the liquid tubing side. At this time, all valves must be in the “fully closed”
position.
2. If not charged as prescribed amount, charge from the refrigerant charge connection port while operating in the cooling mode. (This
is performed at the time of the test run. For this, all valves must be in the “fully open” position. However if only one outdoor unit is
installed, a balance tube is not used. Therefore, leave the valves fully closed.)
Charge with R410A refrigerant in liquid form.
With R410A refrigerant, charge while adjusting the amount being fed a little at a time in order to prevent liquid refrigerant from
backing up.
● After charging is completed, turn all valves to the “fully open” position.
● Replace the tubing covers as they were before.
CAUTION
1. R410A additional charging absolutely must be done through liquid charging.
2. The R410A refrigerant cylinder has a gray base color, and the top part is pink.
3. The R410A refrigerant cylinder includes a siphon tube. Check that the siphon tube is present. (This is
indicated on the label at the top of the cylinder.)
4. Due to differences in the refrigerant, pressure, and refrigerant oil involved in installation, it is not
possible in some cases to use the same tools for R22 and for R410A.
=[490 ×(a) + 366 ×(b) + 259 ×(c) + 185 ×(d) + 128 ×(e) + 56 ×(f) + 26 ×(g)] ×10
–3
+ Necessary
amount of additional refrigerant charge per outdoor unit.
* Use a hexagonal wrench and turn to the left to open.
Gas tube Liquid tube
Hex wrench
width
8 HP 5 mm
4 mm
10 HP
8 mm
12 HP
14 HP
16 HP
18 HP
6 mm
20 HP
Balance tube
Rotate 90 degrees counterclockwise for OPEN
Fully closed (at shipment)
How to turn the tab
Fully open
Refrigerant charge connection port
(width 15 mm)
Tightening torque : 9±1
N · m
Balance tube
Gas tube
Liquid tube
00_340994_2WAY_Eng.indb 17 2022/8/4 14:28:30
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