LG Multi IV User Manual

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MULTI V IV Outdoor Unit Engineering Manual
REFRIGERANT PIPING DESIGN
Piping Design Guideline Summary
ODU
Capacity
(ton)
Pipe diameter when pipe
length is <295 feet
(Standard)
Pipe diameter when pipe
OHQJWKLVIHHW
2'8ļ,'8
Pipe diameter when height
GLIIHUHQWLDO2'8ļ,'8
is >164 feet
Liquid pipe
(inches OD)
Vapor pipe
(inches OD)
Liquid pipe
(inches OD)
Vapor pipe
(inches OD)
Liquid pipe
(inches OD
Vapor pipe
(inches OD)
6 3/8Ø 3/4Ø 1/2Ø 7/8Ø 1/2Ø No Increase
8 3/8Ø 7/8Ø 1/2Ø 1-1/8Ø 1/2Ø No Increase
10-12 1/2Ø 1-1/8Ø 5/8Ø No Increase 5/8Ø No Increase
12-14* 5/8Ø 1-1/8Ø 3/4Ø 1-1/4Ø 3/4Ø No Increase
14-18 5/8Ø 1-1/8Ø 3/4Ø 1-1/4Ø 3/4Ø No Increase
20 5/8Ø 1-3/8Ø 3/4Ø No Increase 3/4Ø No Increase
22-28 3/4Ø 1-3/8Ø 7/8Ø 1-1/2Ø 7/8Ø No Increase
30-42 3/4Ø 1-5/8Ø 7/8Ø No Increase 7/8Ø No Increase
1
For the first branch pipe, use the branch pipe that matches main
pipe A diameter.
Downstream Total
Capacity of IDUs
(Btu/h)
1
Liquid pipe
(inches OD)
Vapor pipe
(inches OD)
 1/4Ø 1/2Ø
 3/8Ø 5/8Ø
 3/8Ø 3/4Ø
 3/8Ø 7/8Ø
 1/2Ø 1-1/8Ø
 5/8Ø 1-1/8Ø
 5/8Ø 1-3/8Ø
 3/4Ø 1-3/8Ø
 3/4Ø 1-5/8Ø
Master ODU
Slave ODU
131 feet
B
C
B
C
C
C
33 feet
A
IDU
IDU
Header
IDU
IDU IDU
Brazed Cap
C
height1
Y-branch
(first)
Y-branch
(second)
To indoor units
To
outdoor unit
Y-branch
Combination Y-branch Pipe and Header Pipe Sizing When Installing a Dual-
Frame System
Example: Five (5) indoor units connected
ODU: Outdoor Units.
IDU: Indoor Units.
A: Main Pipe from Outdoor Unit to First Y-branch.
B: Y-branch to Y-branch / Header.
C: Y-branch / Header to Indoor Unit.
Table 34: Main Pipe (A) Diameter from Outdoor Unit to First Y-branch / Header Branch. Table 35: Refrigerant Pipe Diameter (B) from
Y-branch to Y-branch / Header.
See pages 122-123 for refrigerant pipe diameter and pipe
length tables.
Indoor Unit Capacity
1
Liquid pipe (inches OD) Vapor pipe (inches OD)
 1/4Ø 1/2Ø
 3/8Ø 5/8Ø
 3/8Ø 3/4Ø
Table 36: Indoor Unit Connecting Pipe from Branch (C).
1
9,600-24,200 Btu/h 4-way 3 feet x 3 feet Cassette and 15,400-24,200 Btu/h High Static Ducted indoor units have 3/8Ø (liquid) and 5/8Ø
(vapor).
• Larger-capacity outdoor units must be the master in a multi-
frame system.
• Single-compressor outdoor units (72,000 Btu/h capacity)
cannot be the master outdoor units in a multi-frame system.
• Master outdoor unit capacity must be greater than or equal
to the slave outdoor unit capacity.
• Y-branches and other header branches cannot be installed
downstream of the initial header branch.
The following is an example of manual pipe size calculations. Designers are highly encouraged to use LATS instead of manual calculations.
*ARUN145BTE4 / ARUN145DTE4 and ARUN169BTE4 / ARUN169DTE4 only.

LG Multi IV Specifications

General

Brand	LG
Model	Multi IV
Category	Heat Pump
Language	English