Multi F Outdoor Unit Engineering Manual

• Design pressure is 551 psig.
• All dimensions in inches. Tolerance ±1/4 inch.
• Images are not to scale.
REFRIGERANT PIPING DESIGN
LG Engineered Multi F MAX Y-Branch Kit
The LG supplied Y-Branch Kit PMBL5620 MUST be used when two
branch distribution units are connected on one Multi F MAX system.
Field-supplied fittings are not permitted. Each Y-Branch kit comes
with two (2) Y-branches (one for the liquid line and one for the vapor
line) and insulation covers.
Y-branches may be installed in horizontal or vertical configurations.
When installed vertically, position the Y-branch so the straight-
through leg is ±3° of plumb (Figure 50). When installed horizontally,
position the Y-branch so the take-off leg is level and shares the
same horizontal plane as the straight-through leg ±10° rotation as
shown in Figure 50.
Y-branches must be properly installed following instructions in
the applicable LG manual. Y-branches should always be installed
with the single port facing the outdoor unit and the two-port end
facing the branch distribution units (see Figure 48). Do not install
Y-branches backwards as refrigerant flow cannot make U-turns. The
Y-branch kit must be located at least three (3) feet from the outdoor
unit. Provide a minimum of 20 inches between a Y-branch and the
branch distribution unit.
It is recommended that when a Y-branch is located in a pipe chase
or other concealed space, access doors should be provided for
inspection access.
TheequivalentpipelengthofeachY-branch(1.6′)mustbeaddedto
the main pipe segment entered into LATS piping design software.
Figure 48: Y-Branch Connections.
Figure 49: Y-Branch Dimensions Diagram.
Figure 50: HorizontalCongurationEndView.
Multi F MAX Y-Branch Kit PMBL5620
Table 169: Y-Branch Connection Diameters.
Model
Y-Branch
Type
PortIdentier(inch) Dimensions
1 2 3 X Y
PMBL5620
Liquid 3/8 3/8 3/8 13.80 3.24
Vapor 3/4 3/4 3/4 12.48 3.02
To Branch Distribution Unit Ø3/4
Ø3/4
To Outdoor Unit
Ø3/4
Ø3/8
Ø3/8
To Outdoor Unit
To Branch Distribution Unit Ø3/8
Y-Branch Kit Insulation
Each Y-branch kit comes with clam-shell type peel-and-stick insula-
tion jackets molded to fit the Y-branch fittings as shown in Figure
51—one for the liquid line, one for the vapor line.
•Check the fit of the Y-branch clam-shell insulation jacket after the
Y-branch is installed.
•Mark the pipe where the insulation jacket ends.
• Remove the jacket.
• Install field-provided insulation on the pipes first.
• Peel the adhesive glue protector slip and install the clam-shell
jacket over the fitting
Figure 51: Y-branchInstallationAlignmentSpecication.
Viewed from A in direction of arrow
Horizontal
plane
Within 10°
A
Vertical Up
Configuration
Within ± 3°Within ± 3°
Vertical Down
Configuration
Liquid and Gas
Pipe Joints
Y-Branch Kit Insulation
Insulation for
Field-Installed Piping
Field-Supplied Insulation Tape
A
B
X
Y
1
2
3
A = To Outdoor Unit
B = To Branch
Distribution Unit
Figure 52: Y-branch Insulation Detail.
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
DESIGN & PRACTICES | 201
Refrigerant Piping Design and Best Practices
MULTI
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MULTI
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