54
MUL
TI V 5 Outdoor Unit Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
INSTALLING FOR HEAT PUMP
OPERATION
No Substitutions on Piping Components
Only LG supplied Y-branch and Header fittings can be used to join one pipe segment to two or more segments.
Third-party
or field-fabricated components such as tee’s, Y-fittings, couplings, headers, or other branch fittings are not permitted. The
only field-provided fittings allowed in a Multi V piping system are 45° and 90° long radius elbows and full port ball valves (if
applicable).
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 refrigerant
piping system at each transition.
Field-supplied “T” fittings or “Y” branches will not be accepted.
Do not install Y-branches backwards;
refrigerant flow cannot make U-turns through Y-branches. The equivalent pipe length of each Y-branch (1.6′) must be added to each pipe
segment entered into LATS piping design software.
LG Y-Branch Kits for Heat Pump Operation Consist of:
Indoor Unit Y-Branches
Indoor unit Y-branches may be installed in horizontal or vertical configurations. When installed vertically, the straight-through leg should be
within ±3° of plumb. When installed horizontally, the straight-through leg should be level, and the branch leg should be within ±5° of horizon-
tal rotation.
Indoor unit Y-branches must always be installed with the single port end towards the outdoor unit, and the two-port end towards the indoor
units. The first indoor unit Y-branch kit must be located no closer than 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 units.
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.
Indoor Unit Y-Branch Horizontal Configuration.
Indoor Unit Y-branch Vertical Installation Alignment
Specifications.
+5°
Horizontal
Plane
-5°
Branch Leg
Straight-through Leg
ELEVATION VIEW
Y-branch Inlet
-3° of Plumb +3° of Plumb
-3° of Plumb +3° of Plumb
Vertical DOWN Configuration for Indoor
Unit Y-Branches.
Vertical UP Configuration for Indoor Unit
Y-Branches.
Indoor Unit Y-Branch Kits
Y-Branch Insulation and Piping Detail.
LG-Supplied
Insulation Jacket
Field-Supplied
Insulation
Field-Supplied
Insulation
Field-Supplied Copper Piping
LG Supplied
Y-Branch
PLAN VIEW
Install Correctly
• Y-branches can be installed upstream between the Header and the outdoor unit, but a Y-branch cannot be installed between a header and
an indoor unit.
• To avoid the potential of uneven refrigerant distribution through a header fitting, minimize the difference in equivalent pipe length between the
header fitting and each connected indoor unit.
• One liquid line and one vapor line (two [2] total).
• Reducer fittings as applicable.
• Molded clam-shell type peel and stick insulation covers.
ELEVATION VIEW