Lennox DAVE SIGNATURE CBX32MV Manual page 32

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. Re­
sidual mineral oil can act as an insulator, preventing
proper heat transfer. It can also clog the expansion de­
vice and reduce system performance and capacity.
Failure to properly flush the system per the XP25 Install­
ation and Service Procedures will void the warranty.
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.
WARNING
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.
WARNING
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.
WARNING
When using a high pressure gas
such as nitrogen to pressurize a
refrigeration
system, use a regulator that can
control the pressure down to 1 or 2
psig (6.9 to 13.8 kPa).
or air conditioning
Page 4
IMPORTANT !
Some scroll compressors have an internal vacuum pro­
tector that will unload scrolls when suction pressure 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 COMPRESSOR.
IMPORTANT !
If unit is equipped with a crankcase heater, and outdoor
ambient temperature is below 60°F, unit should be ener­
gized 24 hours before start­up to prevent compressor
damage as a result of slugging.
The XP25 is a variable capacity cooling and heat pump
system utilizing variable speed compressor technology.
With the variable speed compressor and variable pumping
capacity, additional consideration must be given to
refrigerant piping sizing and application. The guidelines
below are to be used exclusively for the XP25 systems.
HEAT PUMP SYSTEM (HFC­410A)
S
Total equivalent length equals 180 feet (piping and all
fittings included).
NOTE — Length is general guide. Lengths may be more or
less, depending on remaining system design factors.
S
Maximum linear (actual) length = 150 feet.
S
Maximum linear liquid lift = 60 feet.
NOTE —­ Maximum lifts are dependent on total length,
number of elbows, etc. that contribute to total pressure
drop.
S
Maximum length vapor riser equals 60 feet.
S
Up to 50 Linear Feet: Use rated line sizes listed in
table 1.
S
Between 51 ­ 150 Linear Feet: Crankcase heater and
non­bleed port TXV factory installed. No additional
components required. Vertical vapor riser must be
sized to the vapor riser listed in the table 2 on systems
with line sets longer than 51 feet. Use tables 2 and 3
to determine the correct liquid and vapor line sizes.
S
Over 150 Linear Feet: not recommended.
S
Additional oil is not required for systems with line
lengths up to 150 feet except for the XP25-048 and
XP25-060, which will required 2 ounces of oil for every
10 feet beyond 100 feet. Recommended POE oils are
Mobil EAL ARCTIC 22 CC or ICI EMKARATE
RL32CF.
SUCTION TRAPS
For systems with the outdoor unit 5 ­ 60 feet above the
indoor unit, one trap must be installed at the bottom of the
suction riser.
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