Panasonic U-36LE1U6, Installation Instructions Manual

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1-7. Additional Refrigerant Charge
Additional refrigerant charge amount is calculated from the liquid tubing total length as follows.
Table 1-7 Amount of Refrigerant Charge Per ft., According to Liquid Tubing Size
Liquid tubing size Amount of refrigerant
(in. (mm)) charge (oz/ft.)
ø1/4" (ø6.35) 0.279
ø3/8" (ø9.52) 0.602
Required amount of charge = (Amount of refrigerant
charge per ft. of each size of liquid tube
×
its tube
length) + (...) + (...)
*Always charge accurately using a scale for weighing.
Table 1-6 Required Copper Tubing Dimensions
Unit: in. (mm)
Gas tubing size (in. (mm))
90
°
elbow
45
°
elbow
U-shape tube bend (R2-3/8" – 4" (60 – 100))
Trap bend
1/2" (12.7)
1
0.8
3
7.5
5/8" (15.88)
1.1
0.9
3.4
9.2
3/4" (19.05)
1.4
1
4.1
10.5
Y-branch distribution joint Equivalent length conversion not needed.
Ball valve for service Equivalent length conversion not needed.
1-6. Straight Equivalent Length of Joints
Design the tubing system by referring to the following table for the straight equivalent length of joints.
Table 1-5 Straight Equivalent Length of Joints
Unit: ft.
Material O
Copper tube
Outer diameter 1/4 (6.35) 3/8 (9.52) 1/2 (12.7) 5/8 (15.88) 3/4 (19.05)
Wall thickness 1/32 (0.8) 1/32 (0.8) 1/32 (0.8) 5/128 (1.0) over 5/128 (1.0)
Table 1-4 Indoor Unit Tubing Connection (
1
,
2
...
n–1
)
Gas tubing
Liquid tubing
Indoor unit type 7 9 12 15 18 19 24 36 48 54
o1/2" (o12.7)
o1/4" (o6.35)
o5/8" (o15.88)
o3/8" (o9.52)
Unit: in. (mm)
24,200 (2.5 hp)
ø5/8" (ø15.88) ø1/2" (ø12.7) ø3/4" (ø19.05)
ø3/8" (ø9.52) ø3/8" (ø9.52)
24,200 (2.5 hp)
–
38,200 (4 hp) 47,800 (5 hp) 52,900 (6 hp) Below BTU/h
Over BTU/h
Tubing size
Total capacity
after distribution
Gas tubing
Liquid tubing
hp = horsepower
Unit: in. (mm)
1-5. Tubing Size
Table 1-2 Main Tubing Size (LA)
ø3/4" (ø19.05)
6
Unit: in. (mm)
52,900 (15.5)
ø3/8" (ø9.52)
ø5/8" (ø15.88)
4
38,200 (11.2) BTU/h (kW)
System horsepower
Gas tubing
Liquid tubing
Table 1-3 Main Tubing Size After Distribution (LB, LC...)
Note: In case the total capacity of connected indoor units exceeds the total capacity of the outdoor units, select the main
tubing size for the total capacity of the outdoor units.
Note: If the system consists of only one indoor unit with an outdoor 6HP (Type 52), the main tube of the unit (LA) should be ø19.05.
Convert ø19.05 to ø15.88 using a reducer (field supply) close to the indoor unit and then make the connection.