Straight Equivalent Length Of Joints; System Limitations; 1-8. Additional Refrigerant Charge - Panasonic U-8ME1E8 Installation Instructions Manual

1-7. Straight Equivalent Length of Joints

Design the tubing system by referring to the following table for the straight equivalent length of joints.
Table 1-7 Straight Equivalent Length of Joints
Gas tubing size (mm)
90° elbow
45° elbow
U-shape tube bent (R60-100 mm)
Trap bend
Y-branch distribution joint
Ball valve for service
Table 1-8 Refrigerant tubing (Existing tubing can be used.)
Tubing size (mm)
Material O
ø6.35 t0.8
ø9.52 t0.8
ø12.7 t0.8
ø15.88 t1.0
ø19.05 t1.2

1-8. Additional Refrigerant Charge

Additional refrigerant charge amount is calculated below.
Required amount of additional refrigerant charge = [ (Amount of additional refrigerant charge per meter of each size of liquid tube x
its tube length) + (...) + (...)] + [(Necessary amount of additional refrigerant charge per outdoor unit) + (...) + (...)]
*Always charge accurately using a scale for weighing.
* If the existing tubing is used and the amount of on-site refrigerant charge exceeds the value listed below, change the size of the tubing
to reduce the amount of refrigerant.
Total amount of refrigerant for the system with 1 outdoor unit: 50 kg
Total amount of refrigerant for the system with 2 outdoor units: 80 kg
Total amount of refrigerant for the system with 3 outdoor units: 100 kg
Table 1-9-1 Amount of Additional Refrigerant Charge Per Meter, According to Liquid Tubing Size
Liquid tubing size
Amount of additional
refrigerant charge/m (g/m)
Table 1-9-2 Necessary Amount of Additional Refrigerant Charge Per Outdoor Unit
U-8ME1E8(E) U-10ME1E8(E)
2.5 kg 3.5 kg
Table 1-10 Refrigerant Charge Amount at Shipment (for Outdoor Unit)
U-8ME1E8(E) U-10ME1E8(E)
9.9 kg 9.9 kg

1-9. System Limitations

Table 1-11 System Limitations
Max. No. allowable connected outdoor units
Max. capacity allowable connected outdoor units
Max. connectable indoor units
Max. allowable indoor/outdoor capacity ratio
*1: In the case of 22 hp (type 61.5 kW) or smaller units, the number is limited by the total capacity of the connected indoor units.
*2: Up to 3 units can be connected if the system has been extended.
*3: It is strongly recommended that you choose the unit so the load can become between 50 and 130%.
12.7
0.30
0.23
0.90
2.30
Material 1/2H • H
ø22.22
ø25.4
ø28.58
ø31.75
ø38.1 over t1.35
ø41.28 over t1.45
6.35 9.52 12.7 15.88
26 56 128 185
U-12ME1E8(E) U-14ME1E8(E)
3.5 kg
U-12ME1E8(E) U-14ME1E8(E)
9.9 kg
168 kW (60 hp)
50 – 200 % *
15.88 19.05 22.22
0.35 0.42 0.48
0.26 0.32 0.36
1.05 1.26 1.44
2.80 3.20 3.80
Equivalent length conversion not needed.
Equivalent length conversion not needed.
* When bending the tubes, use a bending
radius that is at least 4 times the outer
diameter of the tubes.
t1.0
In addition, take sufficient care to avoid
t1.0
crushing or damaging the tubes when
t1.0
bending them.
t1.1
19.05 22.22 25.4
259 366 490
U-16ME1E8(E)
6.4 kg 6.4 kg
U-16ME1E8(E)
9.9 kg 9.9 kg
2
3 *
1
64 *
3
11
25.4 28.58 31.8 38.1
0.52 0.57 0.70 0.79
0.39 0.43 0.53 0.59
1.56 1.71 2.10 2.37
4.30 4.70 5.00 5.80
U-18ME1E8(E) U-20ME1E8(E)
7.6 kg
U-18ME1E8(E) U-20ME1E8(E)
9.9 kg
7.6 kg
9.9 kg