MCAC-VTSM-2014-04
R410A DC Inverter VRF V4 Plus Individual Series 50Hz
Installation
71
7.2 Refrigerant piping length permitted value
Piping length
Permitted
value
Piping
Pi
p
in
g
l
e
n
g
th
Actual total piping length
1000m
L1+(L2+L3+L4+L5+L6+L7+L8)×2
+a+b+c+d+e+f+g+h+i
Maximum
single
piping length
Actual length
165m
L1+L5+ L8+L9+j
Equivalent length
190m
Maximum piping length from the first
branch joint to the farthest indoor unit
40/90m
L5+L8+L9+j
L
e
v
e
l
d
if
fe
re
n
c
e
Level
difference
between indoor unit
and outdoor unit
Outdoor unit up
50m
/
Outdoor unit down
90m
/
Level difference between indoor units
30m
/
Note:
1. The equivalent length of each branch pipe is 0.5m.
2. The indoor units should be installed as possible as equal in the both sides of the U-shape branch joint.
3. When the outdoor unit is on the top position and the difference of level is over 20m, it is recommended that set a oil return bend
every 10m in the gas pipe of the main pipe, the specification of the oil return bend.
4. When the outdoor unit is lower than indoor units and the level difference is more than 40m, the liquid pipe of the main pipe need
to increase one size.
5. The allowable piping length from the first branch joint which connect to the indoor unit should be equal to or shorter than 40m,
but when the following conditions are all met, the allowable length can be extended to 90m.
It needs to increase all the pipe diameters of the main distribution pipes which between the first and the last branch joint
assembly. (Please change the pipe diameter at field) If the pipe diameter of the main slave pipe is the same as the main pipe,
then it is no need to be increased.
When: L5+L8+L9+j
≤
90m L2,L3,L4,L5,L6,L7,L8,L9 need to increase the pipe diameter of the distribution pipe.