LG Multi V Water V ARWM072CAS5 Engineering Manual Download Page 36

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66 | LIMITS / PLACEMENT

LIMITS / PLACEMENT | 67

Piping Limitations and Placement Considerations

MUL

TI V W

ater IV Source Unit Engineering Manual

WSU

Capacity

(ton)

Pipe diameter when equivalent pipe length

from WSU to farthest IDU is <295 ft.

Pipe diameter when equivalent pipe length

from WSU to farthest IDU is >295 ft.

Liquid Pipe

(inches OD)

Low Pressure Vapor

Pipe (inches OD)

High Pressure Vapor

Pipe (inches OD)

Liquid Pipe

(inches OD)

Low Pressure Vapor

Pipe (inches OD)

High Pressure Vapor

Pipe (inches OD)

3/8

3/4

5/8

1/2

3/4

5/8

3/8

7/8

3/4

1/2

7/8

3/4

1/2

1-1/8

3/4

5/8

1-1/8

3/4

1/2

1-1/8

7/8

5/8

1-1/8

7/8

5/8

1-1/8

3/4

1-1/8

5/8

1-3/8

1-1/8

3/4

1-3/8

1-1/8

3/4

1-3/8

1-1/8

7/8

1-3/8

1-1/8

3/4

1-3/8

1-1/8

7/8

1-3/8

1-1/8

3/4

1-5/8

1-1/8

7/8

1-5/8

1-1/8

3/4

1-5/8

1-1/8

7/8

1-5/8

1-1/8

3/4

1-5/8

1-1/8

7/8

1-5/8

1-1/8

Table 36: Main Pipe (A) Diameter from Water Source Unit to First Y-branch.

PIPING LIMITATIONS

For Systems Designed for Heat Recovery Configuration

Following pages present Multi V Water V piping limitations and are for illustrative purposes only. Designers MUST use LATS when designing LG VRF

systems.

Figure 29: Heat Recovery Triple-Frame Connections.

Triple-Frame Heat Recovery Water Source Unit Connections

• A1, A2, and A3 diameters match the water source unit connection diameters. Main pipe C diameters are sized by LATS.

• For single and dual-frame systems, the pipe size is the same size as the frame connections.

• Always reference the LATS Multi V software report.

• Larger-capacity water source units must be the master in a multi-frame system.

• Master water source unit capacity must be greater than or equal to the slave1 water source unit capacity, and, where applicable, slave1

water source unit capacity must be greater than or equal to the slave2 water source unit capacity.

• Connection piping from branch to branch cannot exceed the main pipe diameter (A) used by the water source unit.

• Install the header branches so that the pipe distances between the between the connected indoor units are minimized. Large differences in

pipe distances can cause indoor unit performances to fluctuate.

•

Y-branches and other header branches cannot be installed downstream of the initial header branch.

PIPING LIMITATIONS

For Systems Designed for Heat Recovery Configuration

Following pages present Multi V Water V piping limitations and are for illustrative purposes only. Designers MUST use LATS when designing LG VRF

systems.

Slave 2

Slave 1

Master

To Heat Recovery Units

ARCNB21 Kit

Three (3) Y-branches

for liquid pipe, high-pressure vapor

pipe, and low-pressure vapor pipe

C – Main Pipe Sized by LATS

Liquid Pipe

Low Pressure Vapor

ARCNB21 and ARCNB31

Multi-Frame WSU

Heat Recovery Systems

Y-Branch Connector Kits

Liquid Pipe

Low Pressure

Vapor Pipe

Represents THREE* pipes

ARCNB31 Kit

Three (3) Y-branches

for liquid pipe, high-pressure vapor

pipe, and low-pressure vapor pipe

*Liquid

Low Pressure Vapor

High Pressure Vapor

Liquid Pipe

Low Pressure Vapor

High Pressure Vapor

Liquid Pipe

Low Pressure Vapor

High Pressure Vapor

High Pressure

Vapor Pipe

LIMITS / PLACEMENT | 73

Piping Limitations and Placement Considerations

Due to our policy of continuous product innovation, some specifications may change without notification.

Downstream IDU total capacity

(Btu/h)

Liquid pipe (inches OD)

Vapor pipe (inches OD)

Low pressure

High pressure

Table 7: Refrigerant Pipe (B) Diameters between Y-branches and Y-branches / Heat Recovery Unit / Headers.

Table 8: Indoor Unit Connecting Pipe from Branch (C).

Indoor Unit Capacity

Liquid pipe (inches OD)

Vapor pipe (inches OD)

≤19,100

1/4Ø

1/2Ø

≤54,600

3/8Ø

5/8Ø

≤76,400

3/8Ø

3/4Ø

≤95,900

3/8Ø

7/8Ø

9,600-24,200 Btu/h 4-way 3 feet x 3 feet Cassette and 15,400-24,200 Btu/h High Static Ducted IDUs have 3/8Ø (liquid) and 5/8Ø (vapor).

PIPING LIMITATIONS

For Systems Designed for Heat Recovery Operation

Following pages present Multi V 5 piping limitations and are for illustrative purposes only. Designers MUST use LATS when designing LG VRF systems.

Conditional Applications

Conditional applications are computed in LATS. See below for an explanation of when pipes are upsized.

If the equivalent length between the first Y-branch to the farthest indoor unit is >131 feet (maximum 295 feet):
• Pipe segment diameters between the first branch and the last branch must be sized up by one. This applies to both liquid and low / high

vapor pipes. If the next size up is not available, or if the pipe segment diameters are the same as main pipe (A) diameters, sizing up is not

possible.

• While calculating total refrigerant piping length, pipe (B) segment lengths between the first Y-branch and second Y-branch, and between the

second Y-branch and the heat recovery unit must be calculated by two.

• Length of pipe (C) from each indoor unit to the closest Y-branch, header, or heat recovery unit ≤49 feet.

• [Length of pipe from outdoor unit to farthest indoor unit (A+B+C)] - [Length of pipe from outdoor unit to closest indoor unit (A+B+C)] ≤131

feet.

≤19,100

1/4Ø

1/2Ø

3/8Ø

≤54,600