LG LC248HV - Refrigerant Piping Design

APPLICATION | 71
Application Guidelines
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REFRIGERANT PIPING DESIGN
Device Connection Limitations
A single-zone system consists of one outdoor unit and one indoor unit. One of the most critical elements of a single-zone system is the
refrigerant piping. If the connection piping is not within allowable limits, there will be reliability, performance, noise, and vibration issues. The
table below lists pipe length limits that must be followed in the design of a Single Zone Four-Way Ceiling-Cassette refrigerant pipe system.
See paragraph below for calculating additional refrigerant charge necessary for longer piping lengths. Refer to the figures for maximum
length and elevation of piping.
Table 47: Single-Zone Four-Way Ceiling Cassette
Refrigerant Piping System Limitations.
System Model Name
LC098HV4, LC128HV4 LC188HV4, LC248HV LC368HV, LC428HV
Pipe Sizes
Vapor
3/8 5/8 5/8
Liquid
1/4 3/8 3/8
Pipe Length
(ELF = Equivalent
Length of Pipe)
Standard length (no add’l refrigerant)
24.6 feet 24.6 feet 24.6 feet
Longest total equivalent piping length
66 feet 164 feet 246 feet
Shortest total equivalent piping length
6.6 6.6 6.6
Distance between fittings and indoor or
outdoor units
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Elevation
(All Elevation Limitations are
Measured in Actual Feet)
If outdoor unit is above indoor unit
49 feet 98.4 feet 98.4 feet
If outdoor unit is below indoor unit
49 feet 98.4 feet 98.4 feet
Additional Refrigerant Needed (oz/ft)
0.22 0.43 0.43
Outdoor unit
Indoor unit
A
B
Outdoor unit
Indoor unit
A
B
98
98
164
Max Length = A
Max Elevation = B
164
Unit = Feet
Figure 59: Typical LC098HV4 and LC128HV4 System Layout. Figure 60: Typical LC188HV4 and LC248HV System Layout.
Outdoor unit
Indoor unit
A
B
Outdoor unit
Indoor unit
A
B
49
49
66
Max Length = A
Max Elevation = B
66
Unit = Feet
Outdoor unit
Indoor unit
A
B
Outdoor unit
Indoor unit
A
B
98
98
246
Max Length = A
Max Elevation = B
246
Unit = Feet
Figure 61: Typical LC348HV4 and LC428HV System Layout.
Additional Refrigerant Charge
Each outdoor unit is factory charged (nameplate charge) for the
evaporator as well as a standard 24.6 foot line. Any time a line
set is used longer then the standard 24.6 foot line set length, the
refrigerant charge has to be adjusted.
The charge must be adjusted on 0.22 oz. or 0.43 oz. of R410A per
foot based on how many feet of piping are added. The factory charge
accommodates pipe lengths up to the standard length without
requiring refrigerant removal.
Example:
A 50 ft line set is used -- 9 additional feet x 0.22 oz per ft = Add 1.98 oz.
of R410A.
If the unit charge is unknown, reclaim, evacuate and weigh in the correct
charge using the unit nameplate (capacity) charge adjusting for line sets
longer than 24.6 ft. This will prevent any interruptions to the functioning
of the unit and possible damage.