Lennox Merit Series 13HPX Units Installation Instructions Manual page 3

STEP 2 -- REFRIGERANT PIPING -- Flush­
ing Existing Line Set and Indoor Coil
Flush the existing line set per the
instructions. For more information, refer to the
Installation and Service Procedures manual available
on DaveNet. CAUTION - DO NOT attempt to flush and
re-use existing line sets or indoor coil when the system
contains contaminants (i.e., compressor burn out).
NOTE - When installing refrigerant lines longer than 50 feet,
refer to the Refrigerant Piping Design and Fabrication
Guidelines manual available on DaveNet (Corp. 9351-L9),
or contact the Technical Support Department Product
Application group for assistance.
REFRIGERANT LINE SET — INCHES (MM)
Field
Connections
Model
Liquid Vapor
Line Line
-018
-024
3/8 in. 3/4 in.
(10 (19
-030
mm) mm)
-036
-042 3/8 in. 7/8 in.
(10 (22
-048
mm) mm)
3/8 in. 1-1/8
-060 (10 in. (29
mm) mm)
NOTE — Some applications may required a field provided 7/8" to 1-1/8"
adapter
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 installation. Take
care to empty all existing traps. Polyol ester (POE)
oils are used in Lennox units charged with HFC-410A
refrigerant. Residual mineral oil can act as an insula­
tor, preventing proper heat transfer. It can also clog
the expansion device and reduce system perfor­
mance 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.
following
TABLE 2
Recommended Line Set
Liquid Vapor
L15 Line Sets
Line Line
3/8 in. 3/4 in. L15-41 — 15 ft. -
(10 (19 50 ft. (4.6 m - 15
mm) mm) m)
3/8 in. 7/8 in. L15-65 — 15 ft. -
(10 (22 50 ft. (4.6 m - 15
mm) mm) m)
3/8 in. 1-1/8
(10 in. (29 Field Fabricated
mm) mm)
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).
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.
Fire, Explosion and Personal Safety Haz­
ard. Failure to follow this warning could re­
sult in damage, personal injury or death.
Never use oxygen to pressurize or purge re­
frigeration lines. Oxygen, when exposed to
a spark or open flame, can cause fire and/or
an explosion, that could result in property
damage, personal injury or death.
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 !
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.
Protector will reset when low pressure in system is
raised above 40 psig. DO NOT REPLACE COMPRES­
SOR.
Page 3
WARNING
WARNING
WARNING
WARNING
13HPX SERIES