Lennox Dave Signature XP21 Installation Instructions Manual page 13

STEP 3 -- REFRIGERANT PIPING -- Flushing Existing Line Set & Indoor Coil
lush the existing line set per the following instruc­
F
tions. For more information, refer to the Installation
and Service Procedures
LennoxPros.com. 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 LennoxPros.com (Corp.
9351-L9), or contact the Technical Support Department
Product Application group for assistance.
NOTE - For new or replacement line set installation refer to
Service and Application Note - Corp 9112-L4 (C-91-4).
TABLE 1
REFRIGERANT LINE SET — INCHES (MM)
Liquid Vapor
Model
Line Line
-024, -036
3/8" (10) 7/8" (22)
and -048
1-1/8"
-060 3/8" (10)
(29)
NOTE — Some applications may require 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 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.
manual available on
L15
Line Sets
Feet (Meters)
L15 line set sizes are depen­
dent on unit match up. See
XP21Engineering Handbook to
determine correct line set sizes.
Field Fabricated
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
refrigeration 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.
Some scroll compressors have an internal vacuum
protection devices that will unload scrolls when
suction pressure goes below 20 psig. A hissing
sound will be heard when the compressor is run­
ning unloaded. The protection device will reset
when pressure in system rises above 40 psig. This
is normal operation. DO NOT replace compressor.
Page 13
WARNING
WARNING
WARNING
WARNING
IMPORTANT !
XP21 SERIES