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Refrigerant Piping Installation
This product is designed to work with refrigerant R410A. Always follow these instructions to perform installation
procedures.
•
Be sure to use the specified refrigerant during refrigerant circulation and prevent air from contaminating the
refrigerant
•
If the refrigerant leaks during the installation process, make sure to ventilate any enclosed
Selection of Field-Supplied Piping Material
WARNING
•
Always follow local codes when selecting and installing
copper pipe and piping system components. Approved
piping for use with Multi V products will be marked “R410
RATED” along the length of the pipe. Piping wall thickness
must meet local code requirements and be approved for a
maximum operating pressure of 551 psi. When bending
piping, try to keep the number of bends to a minimum, and
use the largest radii possible to reduce the equivalent
length of installed piping; also, bending radii greater than
ten (10) piping diameters can minimize pressure drop. Be
sure no traps or sags are present.
•
LG prefers the use of hard drawn copper in pipe segments
connecting a Dedicated Outdoor Air System (DOAS)
product and an outdoor unit
Selection of Piping Size
Note:
•
Always reference the LATS HVAC software report (latest
version)
•
Larger-capacity outdoor units must be the master in a multi-
frame system
•
Master outdoor unit capacity must be greater than or equal
to the slave1 outdoor unit capacity, and, where applicable,
slave1 outdoor unit capacity must be greater than or equal
to the slave2 outdoor unit capacity.
•
Connection piping from branch to branch cannot exceed
the main pipe diameter (A) used by the outdoor unit.
•
Other Indoor units cannot be connected with DOAS units.
•
Header Branch is not allowed to install in DOAS
Application.
Refrigerant System Engineering and
Allowable Pipe Length
Proper system operation depends on the installer using
utmost care while assembling the piping system.
Note:
•
LG Electronics U.S.A.,Inc. is not responsible for any piping
calculations, refrigerant leaks, degradation of performance,
any other potential problems or damages caused by the
interconnecting piping, their joint connections, isolation
valves, or introduced debris inside the piping system
WARNING
•
Combining Multi V DOAS units and Multi V indoor units on
the same system is prohibited.
One of the most critical elements of a Multi V system is
the refrigerant piping. The table.20 lists pipe length limits
that must be followed in the design of a Multi V
refrigerant pipe system
Table 20: Multi V 5 Refrigerant Piping System Limitations.
Pipe Length
(ELF = Equivalent Length of pipe
in Feet)
Longest total equivalent piping length
3,280 feet
Longest distance from outdoor unit to DOAS unit
656 feet (Actual) 738 feet (Equivalent)
Distance between fittings and DOAS unit
≥ 20 inches
Distance between fittings and Y-branches
≥ 20 inches
Distance between two Y-branches
≥ 20 inches
Minimum distance between DOAS unit to any Y-branch
3 feet from DOAS unit to Y-branch
Maximum distance between first Y-branch to farthest DOAS unit
131 feet
(295 feet for conditional applications)
Elevation
(All Elevation Limitations are
Measured in Actual Feet)
If outdoor unit is above or below DOAS unit
164 feet
Between DOAS Units
98 feet
Table 20:
Equivalent Piping Length for Y-branches, Headers, and Other Piping Components.
Components
Size (inches)
Long Radius Elbow(ft.)
1/4
3/8
1/2
5/8
3/4
7/8
1
1-1/8
1-1/4
1-3/8
1-1/2
1-5/8
1-3/4
2-1/8
Y-branch (ft.)
1
0.5
0.6
0.7
0.8
1.2
1.3
1.5
1.6
1.8
2.0
2.1
2.3
2.5
2.8
1
Kit contains two Y-branches: one for liquid and one for vapor.
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