LG MULTI F LMU243HV - Page 36

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MULTI F / MULTI F MAX Outdoor Unit Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
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MULTI
F
MAX
MULTI
F
Using Refrigerant Components
Field-supplied elbows are allowed as long as they are designed for
use with R410A refrigerant. The designer, however, must be cau-
tious with the quantity and size of fittings used, and must account
for the additional pressure losses in equivalent pipe length calcula-
tion for each branch. The equivalent pipe length of each elbow must
be added to each pipe segment.
Table 12: Equivalent Piping Length for Elbows, Y-branches, and Branch
Distribution Units.
5()5,*(5$176$)(7<67$1'$5'6
DEVICE CONNECTION LIMITATIONS
Component
Size (Inches)
1/4 3/8 1/2 5/8 3/4
Elbow (ft.) 0.5 0.6 0.7 0.8 1.2
Y-Branch Kit
(ft., Multi F MAX systems only)
1
1.6
Branch Distribution Unit
(ft., Multi F MAX systems only)
8.2
1
.LWFRQWDLQVWZR<EUDQFKHVRQHIRUOLTXLGDQGRQHIRUYDSRU
Example: LMU541HV outdoor unit with seven (7)
indoor units, and two (2) branch distribution units
connected.
ODU: Outdoor Unit.
IDU: Indoor Unit.
BD: Branch Distribution Unit(s).
A: Main Pipe.
B: Branch Pipe (Branch Distribution Unit[s] to Indoor Unit[s]).
B
A
h2 ≤ 49.2 feet
A
h3 ≤ 32.8 feet
h4 ≤ 49.2 feet
h1 ≤ 98.4 feet
BDU Y-Branch
BDU
IDU
A
ODU
IDU
IDU
IDU
IDU
IDU
IDU
B
B
B
B
B
B
Pipe Length
(ELF = Equivalent
Length of pipe in
Feet)
7RWDOSLSLQJOHQJWKȉ$ȉ% IHHW
Main pipe (Outdoor Unit to
Branch Distribution Units:
A)
Minimum for Each
(A) Piping Segment
16.4 feet
0D[LPXPȉ$ IHHW
7RWDOEUDQFKSLSLQJOHQJWKȉ% IHHW
Branch pipe (Branch
Distribution Units to Indoor
Units: B)
Minimum 16.4 feet
Maximum IHHW
Elevation Differential
(All Elevation
Limitations are
Measured in Actual
Feet)
If outdoor unit is above or below indoor unit (h1) IHHW
Between the farthest two indoor units (h2) IHHW
Between branch distribution unit and farthest
connected indoor unit(s) (h3)
IHHW
Between branch distribution units (h4) IHHW
Max. Combination of
IDUs
LMU481HV = 65,000 LMU541HV = 73,000 LMU601HV = 81,000
Piping Main Pipe A (inch) Branch Pipe B
Liquid Ø3/8
Depends on the size
of the indoor unit piping
Gas Ø3/4
Multi F MAX System Example with Two Branch Distribution Units
Multi F MAX Outdoor Unit Piping Length and Elevation Limitations
Table 13: Multi F MAX Refrigerant Piping System Limitations.
h1
C
Branch Pipe
Main Pipe
BD Unit
BD Unit
A
B
h2
Figure 27: Multi F MAX Refrigerant Piping
System Limitations.
Table 14: Multi F MAX Piping Sizes.