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 5 for recommended installation practices. Also, consider the following when placing and installing a high−efficiency outdoor unit.
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 14).
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
| Field | Recommended Line Set | ||||
| Connections | |||||
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Model |
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| L15 | ||
Size | Liquid | Vapor | Liquid | Vapor | ||
Line Sets | ||||||
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| Line | Line | Line | Line | ||
| Feet (Meters) | |||||
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−024 | 3/8 | 3/4 | 3/8 | 3/4 | L15−41 | |
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| (10) | (19) | (10) | (19) | 15 − 50’ (5 − 15) | |
−030 | ||||||
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−036 | 3/8 | 7/8 | 3/8 | 7/8 |
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(10) | (22) | (10) | (22) |
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| L15−65 | |
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−042 | 3/8 | 7/8 | 3/8 | 7/8 | 15 − 50’ (5 − 15) | |
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−048 | (10) | (22) | (10) | (22) |
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−060 | 3/8 | 1−1/8 | 3/8 | 1−1/8 | Field Fabricated | |
(10) | (29) | (10) | (29) | |||
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NOTE
1−1/8" adapter
NOTE When installing refrigerant lines longer than 50 feet, see the Lennox Refrigerant Piping Design and Fabrication Guidelines, CORP. 9351−L9, or contact Lennox Technical Support Product Applications for assistance.
IMPORTANT
Mineral oils are not compatible with HFC−410A. If oil must be added, it must be a Polyol ester oil.
The compressor is charged with sufficient Polyol ester oil for line set lengths up to 50 feet. If line set lengths longer than 50 feet will be required, all one (1) ounce of oil for every additional 10 feet of line set. Do not add any more than seven (7) ounces of oil.
Recommended topping−off POE oils are Mobil EAL ARCTIC 22 CC or ICI EMKARATEt RL32CF.
To obtain the correct information from Lennox, be sure to communicate the following information:
SModel (XC17) 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.
WARNING
Danger of fire. Bleeding the refrigerant charge from only the high side may result in the low side shell and suction tubing being pressurized. Application of a brazing torch while pressurized may result in ignition of the refrigerant and oil mixture − check the high and low pressures before unbrazing.
WARNING
When using a high pressure gas such as dry nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).
CAUTION
Brazing alloys and flux contain materials which are hazardous to your health.
Avoid breathing vapors or fumes from brazing operations. Perform operations only in well ventilated areas.
Wear gloves and protective goggles or face shield to protect against burns.
Wash hands with soap and water after handling brazing alloys and flux.
Page 11
XC17 SERIES