Lennox Merit ML14XC1-018-230A Installation Instructions Manual page 3

IMPORTANT !
If this unit is being matched with an approved line
set or indoor unit coil that was previously charged
with mineral oil, or if it is being matched with a coil
which was manufactured before January of 1999,
the coil and line set must be flushed prior to installa­
tion. Take care to empty all existing traps. Polyol es­
ter (POE) oils are used in Lennox units charged with
HFC-410A refrigerant. Residual mineral oil can act
as an insulator, preventing proper heat transfer. It
can also clog the expansion device and reduce sys­
tem performance and capacity.
Failure to properly flush the system per this instruc­
tion and the detailed Installation and Service Proce­
dures manual will void the warranty.
WARNING
Fire, Explosion and Personal Safety
Hazard. Failure to follow this warning
could result in damage, personal injury or
death.
Never use oxygen to pressurize or purge
refrigeration lines. Oxygen, when ex­
posed to a spark or open flame, can
cause fire and/or an explosion, that could
result in property damage, personal inju­
ry or death.
WARNING
When using a high pressure gas such as
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).
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.
Model Number
ML14XC1-018-230
ML14XC1-024-230
ML14XC1-030-230
ML14XC1-036-230
ML14XC1-041-230
ML14XC1-042-230
ML14XC1-047-230
ML14XC1-048-230
ML14XC1-059-230
ML14XC1-060-230
* Some applications may require a field-provided 1-1/8" to 7/8" adapter.
TABLE 2. REFRIGERANT LINE SET — INCHES (MM)
Valve Size Connections
Liquid Line Suction Line
3/8" (10 mm) 3/4" (19 mm)
3/8" (10 mm) 7/8" (22 mm)
3/8" (10 mm) 1-1/8" (29 mm) *
Some scroll compressors have an internal vacuum
protector that will unload scrolls when suction pres­
sure goes below 20 psig. A hissing sound will be
heard when the compressor is running unloaded.
The protector will reset when low pressure rises
above 40 psig. DO NOT REPLACE COMPRESSOR.
LIQUID LINE FILTER DRIER INSTALLATION
The provided filter drier must be field installed in the liquid
line between the outdoor unit's liquid line service valve and
the indoor coil's metering device (fixed orifice or TXV) as
illustrated in figure 5. This filter drier must be installed to
ensure a clean, moisture-free system. Failure to install the
filter drier will void the warranty. A replacement filter drier is
available from Lennox. See Brazing Connections page 6
for special procedures on brazing filter drier connections to
the liquid line.
Typical Liquid Line Filter Drier Installation
LIQUID LINE
SERVICE VALVE
OUTDOOR
UNIT
Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.
Failure to follow this warning may result in personal injury
or death.
NOTE - When installing refrigerant lines longer than 50
feet, refer to the Refrigerant Piping Design and Fabrication
Guidelines manual available on LennoxPros.com (Corp.
9351-L9), or contact the Technical Support Department
Product Application group for assistance.
L15 Line Set Model
L15-41-20
L15-41-30
L15-41-40
L15-41-50
L15-65-30
L15-65-40
L15-65-50
Field-fabricated
Page 3
IMPORTANT !
BRAZE CONNECTION POINTS
LINE
LIQUID LINE
FILTER DRIER
FIGURE 5
WARNING
Recommended Line Sets
Line Set Length
20 feet (6.1 m)
30 feet (9.1 m)
40 feet (12.2 m)
50 feet (15.2 m)
30 feet (9.1 m)
40 feet (12.2 m)
50 feet (15.2 m)
N/A
LIQUID
LINE
Catalog Number
89J56
89J57
89J58
89J59
89J60
89J61
89J62
N/A
ML14XC1 SERIES