Indoor Unit Y-Branches; Outdoor Unit Y-Branches; Y-Branch Insulation And Pipe Detail; Lg Engineered Y-Branch Kits - LG Multi IV Engineering Manual

No Substitutions
V IV piping system are 45° and 90° elbows.
Y-Branch Kits
LG Y-branch and kits are highly engineered devices designed to evenly divide the flow of refrigerant, and are used to join one pipe segment
to two or more segments. There are two types of Y-branches used in LG VRF systems: Y-branches that combine two or three outdoor units
to make up one large-capacity outdoor unit (also known as multi-frame connectors), or Y-branches used with the indoor units in the refriger-
ant piping system at each transition. Field-supplied "T" fittings or "Y" branches will not be accepted. Do not install Y-branches backwards;
segment entered into LATS piping design software.
LG Y-Branch Kits Consist of:
• Y-branches:
• For heat pump systems - one liquid line and one vapor line (two [2] total)
• For heat recovery systems - one liquid line, one low-pressure vapor line, and one
high-pressure vapor line (three [3] total)
• Reducer fittings as applicable.
• Molded clam-shell type peel and stick insulation covers.

Indoor Unit Y-Branches

Indoor unit Y-branches may be installed in horizontal or vertical configurations. When
installed vertically, position the Y-branch so the straight-through leg is within ±3° of plumb.
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 within ±5° rotation.
Indoor unit Y-branches must always be installed with the single port end towards the outdoor
unit, the two-port end towards the indoor units (or heat recovery units for heat recovery sys-
tems only). If indoor unit Y-branches are used to combine heat recovery ports to accommo-
date an indoor unit with a capacity of six (6) tons or larger, then the single port end must be
installed with the single port end towards the indoor unit and the two-port end towards
the heat recovery unit. The first indoor unit Y-branch kit must be located at least three
(3) feet from the outdoor unit. Provide a minimum of twenty (20) inches between a Y-
branch and any other fittings or indoor unit piped in series.
There is no limitation on the number of indoor unit Y-branches that can be installed, but
there is a limitation on the number of indoor units connected to a single outdoor 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.

Outdoor Unit Y-Branches

Outdoor unit Y-branches can only be installed in a horizontal or vertical UP configuration.
The vertical DOWN configuration is not permitted. When installed vertically, position the
Y-branch at a level lower than the outdoor units it serves, so the straight-through leg is within
±3° of plumb. 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 within ±5° rotation.
Outdoor unit Y-branches must always be
installed with the two-port ends connected
to the piping coming from the outdoor units,
and the single port end towards the indoor
unit refrigerant piping system supporting the
indoor units. Outdoor unit Y-branches are usu-
ally installed close to the outdoor unit, leaving
enough space for servicing and maintenance.
REFRIGERANT PIPING DESIGN
Figure 23: Y-branch Insulation and Pipe Detail.
©
Figure 20: Y-branch Vertical Installation Alignment
For Indoor and Outdoor Unit For Indoor Unit Y-Branches
Y-Branches. ONLY.
Figure 21:
Branch Leg
Straight-through Leg
Y-branch Inlet
Figure 22: Diagram of an Incorrect
Outdoor Unit Y-branch Installation.
±5°
Horizontal Plane
±5°
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