17
1-13. Example of Tubing Size Selection and Refrigerant Charge Amount
Additional refrigerant charging
Based on the values in Tables 1-9, 10, 11, 12 and 15, use the liquid tubing size and length, and calculate the amount of additional
refrigerant charge using the formula below.
= 3.93
×
(a) + 2.78
×
(b) + 1.99
×
(c) + 1.38
×
(d) + 0.602
×
(e) + 0.279
×
(f)
(a) : Liquid tubing
Total length of ø7/8" (ft.)
(d) : Liquid tubing
Total length of ø1/2" (ft.)
(b) : Liquid tubing
Total length of ø3/4" (ft.)
(e) : Liquid tubing
Total length of ø3/8" (ft.)
(c) : Liquid tubing
Total length of ø5/8" (ft.)
( f ) : Liquid tubing
Total length of ø1/4" (ft.)
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 it was not possible to charge the designated amount, operate the system in Cooling mode while charging with refrigerant
from the gas tubing side. (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.
Required additional
refrigerant charge (oz)
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, pres-
sure, and refrigerant oil involved in installa-
tion, it is not possible in some cases to use
the same tools for R22 and for R410A.
1
2
3
4
LA
LB
LC
A
B
O
u
tdoor
un
it
0905
3
model
0905
3
model
4
8
model
4
8
model
4
8
model
3
6 model
Example:
Example of each tubing length
Main tubing
Distribution joint tubing
LA = 131 ft.
Outdoor side
Indoor side
LB = 16 ft.
A = 7 ft.
1 = 98 ft.
LC = 16 ft.
B = 7 ft.
2 = 16 ft.
3 = 16 ft.
4 = 65 ft.
Bala
n
ce t
u
be
Liq
u
id t
u
be
Ga
s
t
u
be
U
s
e a flathead
s
crewdriver a
n
d
ope
n
by t
u
r
n
i
ng
the part with the
s
crew
g
roove to the ri
g
ht,
from “–” to “|”.
U
s
e a flathead
s
crewdriver a
n
d
ope
n
by t
u
r
n
i
ng
the part with the
s
crew
g
roove to the ri
g
ht,
from “–” to “|”.
U
s
e a hex wre
n
ch (width 5/
3
2 i
n
ch)
a
n
d t
u
r
n
to the left to ope
n
.
07-007 W-2WAY_II_NA 1/23/07 6:09 PM Page 17