10
1-5. Tubing Length
Select the installation location so that the length and size of refrigerant tubing are within the allowable range shown in the figure below.
1.
Main tubing length (
maximum tubing size of gas tube and liquid tube
) LM = LA + LB …
2.
Main distribution tubes LC – LH are selected according to the capacity after the distribution joint.
3. The outdoor connection main tubing (L
O, LP portion) is determined by the total capacity of the outdoor units that are connected
to the tube ends.
4.
Sizes of indoor unit connection tubing
1 –
64 are determined by the connection tubing sizes on the indoor units.
Table 2 Ranges that Apply to Refrigerant Tubing Lengths and to Differences in Installation Heights
Unit: m
Item
Mark
Contents
Length
Allowable tubing
length
L1
Max. tubing length
Actual length
200*
2
Equivalent length
210*
2
∆
L (L2 – L4)
Difference between max. length and min. length from the 1st distribution
joint
50*
5
LM
Max. length of main tubing (maximum tubing size of gas tube and liquid tube)
*
Even after 1st distribution joint, LM is allowed if at maximum
tubing length.
-
*
3
1, 2~ 64
Max. length of each distribution tube
50*
7
L1 + 1 + 2 + ~ + 63 + A
+ B + C + LF + LG + LH
Total max. tubing length including length of each distribution tube (only
liquid tubing)
1000
A, B + LO, C + LO + LP,
D + LO + LP
Maximum tubing length from outdoor’s 1st distribution joint to each
outdoor unit
10
Allowable elevation
difference
H1
When outdoor unit is installed higher than indoor unit
50
When outdoor unit is installed lower than indoor unit
40
H2
Max. difference between indoor units
15*
6
H3
Max. difference between outdoor units
4
Allowable length of
joint tubing
L3
T-joint tubing (field-supply); Max. tubing length between the first T-joint
and solidly welded-shut end point
2
L*, * = Length H* = Height
NOTE
1: The outdoor connection main tubing (L
O, LP portion) is determined by the total capacity of the outdoor units that are connected to
the tube ends.
2: If the longest tubing length (L1) exceeds 90 m (equivalent length), increase the sizes of the main tubes (LM) by 1 rank for gas tubes
and liquid tubes. Use a field supply reducer. Select the tube size from the table of main tubing sizes (Table 3) and from the table of
refrigerant tubing sizes (Table 8).
3: If the longest main tubing length (LM) exceeds 50 m, increase the main tubing size at the portion before 50 m by 1 rank for the gas
tubes. Use a field supply reducer. Determine the length less than the limitation of allowable maximum tubing length.
For the portion that exceeds 50 m, set based on the main tubing size (LA) listed in Table 3.
4: If the size of the existing tubing is already larger than the standard tubing size, it is not necessary to further increase the size.
* If the existing tubing is used, and the amount of on-site refrigerant charge exceeds the value listed below, then 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 or 4 outdoor units: 105
kg
LO
LP
LA
LF
LM
LB
LC
L2
L4
LG
3
L
LD
LH
H2
H3
H1
L1
2
3
1
5
62
63
64
4
A
B
C
D
Explanation of symbols
Balance tube
(ø 6.35mm)
Max. 40cm
Max. 40cm
For
extension
For
extension
R410A distribution joint
CZ-P680PJ2 (for outdoor unit)
CZ-P1350PJ2 (for outdoor unit)
CZ-P160BK2 (for indoor unit)
CZ-P680BK2 (for indoor unit)
CZ-P1350BK2 (for indoor unit)
1st distribution joint for outdoor unit
Distribution joint
(CZ: optional parts)
Ball valve (field supply)
T-joint (field supply)
Solidly welded shut
(pinch weld)
Use special R410A distribution joints (CZ: optional parts) for outdoor unit connections and tubing branches.
NOTE
1st distribution joint
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2022/8/4 14:28:27
