New or Replacement Line Set
REFRIGERANT LINE SET
This section provides information on installation or replacement of existing line set. If new or replacement line set is not being installed then proceed to Brazing Connections on page 13.
IMPORTANT
Lennox highly recommends changing line set when converting the existing system from HCFC−22 to HFC−410A. If that is not possible and the line set is the proper size as reference in Table 2, use the procedure outlined under Flushing the System on page 13.
If refrigerant lines are routed through a wall, then seal and isolate the opening so vibration is not transmitted to the building. Pay close attention to line set isolation during installation of any HVAC system. When properly isolated from building structures (walls, ceilings. floors), the refrigerant lines will not create unnecessary vibration and subsequent sounds. See figure 8 for recommended installation practices. Also, consider the following when placing and installing a high−efficiency outdoor unit.
IMPORTANT
Refrigerant lines must not contact structure.
Liquid lines that meter the refrigerant, such as RFC1 liquid lines, must not be used in this application. Existing line set of proper size as listed in table 2 may be reused. If system was previously charged with HCFC−22 refrigerant, then existing line set must be flushed (see Flushing the System on page 16).
Field refrigerant piping consists of liquid and vapor lines from the outdoor unit to the indoor unit coil (braze connections). Use Lennox L15 (sweat, non−flare) series line set, or field−fabricated refrigerant line sizes as listed in table 2.
Table 2. Refrigerant Line Set
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| Liquid | Vapor | L15 |
Model |
| Line Sets | ||
| Line | Line | ||
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| Feet (Meters) | ||
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−024 and |
| 3/8" (10) | 3/4" (19) | L15 line set sizes are depen- |
−030 |
| |||
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| dent on unit match up. See | |
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| XP17 Engineering Handbook to |
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−036, −042 |
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| determine correct line set sizes. |
| 3/8" (10) | 7/8" (22) |
| |
and −048 |
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−060 |
| 3/8" (10) | 1−1/8" | Field Fabricated |
| (29) | |||
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| |
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NOTE |
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1−1/8" adapter |
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NOTE When installing refrigerant lines longer than 50 feet, see the Lennox Refrigerant Piping Design and Fabrication Guidelines, or contact Lennox Technical Support Product Applications for assistance. :
To obtain the correct information from Lennox, be sure to communicate the following information:
SModel (XP17) and size of unit (e.g. −036).
SLine set diameters for the unit being installed as listed in table 2 and total length of installation.
SNumber of elbows vertical rise or drop in the piping.
The compressor is charged with sufficient Polyol ester oil for line set lengths up to 50 feet. Recommend adding oil to system based on the amount of refrigerant charge in the system. No need to add oil in system with 20 pounds of refrigerant or less. For systems over 20 pounds − add one ounce of every five pounds of refrigerant.
Recommended topping−off POE oils are Mobil EAL ARCTIC 22 CC or ICI EMKARATEt RL32CF.
WARNING
Polyol Ester (POE) oils used with HFC−410A refrigerant absorb moisture very quickly. It is very important that the refrigerant system be kept closed as much as possible. DO NOT remove line set caps or service valve stub caps until you are ready to make connections.
IMPORTANT
Mineral oils are not compatible with HFC−410A. If oil must be added, it must be a Polyol ester oil.
Page 11
XP17 SERIES
