Engineering Manual
Table Of Contents
- Convergence of Technology, Innovation, Flexibility, & Style
- Unit Nomenclature
- Outdoor Unit Overview
- Indoor Unit Overview
- Controls and Options Overview
- Art Cool Mirror Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Art Cool Gallery Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Standard Wall-Mounted Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Duct (Low Static) Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- External Static Pressure
- Acoustic Data
- Refrigerant Flow Diagrams
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Duct (High Static) Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- External Static Pressure / Acoustic Data
- Refrigerant Flow Diagrams
- Wiring Diagrams
- Factory Supplied Parts and Materials / Installation
- Installation and Best Layout Practices
- Four-Way Ceiling Cassette Indoor Units
- General Data / Specifications
- Dimensions
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Vertical-Horizontal Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- External Static Pressure
- Acoustic Data
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Equipment Selection Procedure
- Building Ventilation Design Guide
- Placement Considerations
- Refrigerant Piping Design
- Design Guideline Summary
- Creating a Balanced System / Manual Layout Procedure
- LG Engineered Multi F MAX Y-Branch Kit
- Refrigerant Charge
- Installation & Layout Best Practices
- Refrigerant Piping System Layout
- Piping Insulation
- Condensate Drain Piping
- Y-Branch Kit
- Wiring Connections
- Power Wiring (208-230V) and Communications Cable Details
- Indoor Unit Group Control
- Acronyms
Table 119:Outdoor Unit Piping Connections.
Figure 281:Multi F Refrigerant Pipe Connec-
tions (LMU36CHV shown as example).
Avoid Pipe Damage
• When routing eld-provided piping, avoid damaging the outdoor unit from excessive vibration.
• Correctly route the piping so it does not make contact with mounting bolts. Allow room for eld installation.
• Properly insulate the liquid and gas lines separately up to the point of connection at the unit frame.
• See table below for Multi F outdoor unit connection types.
Main gas
valve
Main liquid
valve
Gas Piping Connections
Liquid
Piping
Connections
A-UNIT
B-UNIT
C-UNIT
D-UNIT
Connection sockets (included as a factory-supplied accessory with the indoor
units) may need to be used when piping the indoor units to the outdoor unit.
Indoor Unit
Capacity
Vapor (in., OD) Liquid (in., OD)
A B A B
18,000 Btu/h Ø3/8 → Ø1/2, Ø1/2 → Ø5/8 Ø1/4 → Ø3/8
24,000 Btu/h Ø3/8 → Ø1/2 N/A
A
B
Flare
to
Indoor
Unit
Flare
to
Outdoor
Unit
Indoor Unit Capacity
Vapor Line Connection
(in., OD)
Liquid Line Connection
(in., OD)
7,000 Btu/h
Ø3/8
Ø1/4
9,000 Btu/h
12,000 Btu/h
15,000 Btu/h
18,000 Btu/h
Ø1/2
24,000 Btu/h
1. Align the center of the piping sections and tighten the flare nut by
hand.
2. Tighten the flare nut with a torque wrench, using the arrows on
the wrench as a guide, until a click is heard.
INSTALLATION & LAYOUT BEST PRACTICES
Refrigerant Piping System Layout
Multi F Outdoor Unit to Indoor Unit Piping Connections
Outdoor Unit Piping Connections LMU18CHV LMU24CHV LMU36CHV
Liquid Line Connection (in., OD) x Qty. 1/4 x 2 1/4 x 3 1/4 x 4
Vapor Line Connection (in., OD) x Qty. 3/8 x 2 3/8 x 3 3/8 x 4
Table 120:Indoor Unit Pipe Sizes.
Table 121:Connection Socket Dimensions.
Figure 282:Connection Socket Diagram.
Using the Connection Socket
Connection Socket
(Factory-supplied with
the indoor unit)
Figure 283:Performing Connections.
Indoor Unit Capacity
Vapor Line Connection
(in., OD)
Liquid Line Connection
(in., OD)
7,000 Btu/h
Ø3/8 Ø1/4
9,000 Btu/h
12,000 Btu/h
15,000 Btu/h
18,000 Btu/h Ø5/8 Ø3/8
24,000 Btu/h Ø1/2 Ø1/4
Table 122:Indoor Unit Piping Connections.
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
204 | DESIGN & PRACTICES
Multi F and Multi F MAX Indoor Unit Engineering Manual
MULTI
F
MAX
MULTI
F