Lennox HP40, Installation Instructions Manual

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Page 5
Plumbing
Field refrigerant piping consists of liquid and vapor lines
from the heat pump (sweat connections) to the indoor
evaporator coil. Use Lennox L15 (sweat connection) se-
ries line sets as shown in table 1 or use field-fabricated re-
frigerant lines. Refer to Refrigerant Piping Guide (Corp.
9351−L9) for proper size, type, and application of field−
fabricated lines.
If refrigerant tubes are routed through a wall, seal and iso-
late the opening so vibration is not transmitted to the
building.
NOTE − Line length should be no greater than 15.2 m. Se-
lect line set diameters from table 1 to ensure that the oil
returns to the compressor.
TABLE 1
REFRIGERANT LINE SET KITS
HP40 UNIT
LIQUID
LINE
SUCTION
LINE
L15 LINE
SETS
HP40−024 8 mm* 16 mm
L15 − 21
4.6 m − 15 m
HP40−036 10 mm 19 mm
L15 − 41
4.6 m − 15 m
HP40−048 10 mm 22 mm
L15 − 65
4.6 m − 15 m
HP40−060 10 mm 29 mm
FIELD
FABRICATED
*Use the coupling reducer that is supplied in the bag assembly.
Sweat Connection Procedure
1 − The ends of refrigerant lines must be cut square, free
from nicks or dents and deburred. The pipe must re-
main round. Do not pinch the end of the line.
2 − Wrap a wet cloth around the liquid line valve body and
copper tube stub to protect them from heat damage
during brazing. Wrap another wet cloth underneath
the liquid valve to protect the base paint.
3 − Quench the joints with a wet cloth to prevent possible
heat damage to the valve core and opening port.
Refrigerant Metering Device
HP40 units are applicable to thermal expansion valve
systems only. An expansion valve appropriate for use
with R407C refrigerant is shipped with the outdoor unit.
IMPORTANT
Failure to remove an existing refrigerant flow con-
trol orifice when installing an expansion valve on
the indoor coil will result in improper operation and
damage to the system.
Flushing Existing Line Set and Indoor Coil
IMPORTANT
If this unit is being matched with an approved line
set or indoor coil which was previously charged
with R22 refrigerant, 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 R407C refrigerant. Polyol ester oils
are not compatible with mineral oils. Residual
mineral oil can act as an insulator, preventing
proper heat transfer. It can also clog the thermal
expansion valve, reducing system performance
and capacity.
Failure to properly flush the system per the in-
structions below will void the warranty.
CAUTION
This procedure should not be performed on sys-
tems which contain contaminants (Example:
compressor burn out).
Required Equipment
You will need the following equipment in order to flush the
existing line set and indoor coil: two clean R22 recovery
bottles, an oilless recovery machine with a pump down
feature, and two sets of gauges (one or use with R22 and
one for use with the R407C).
Flushing Procedure
1 − Remove existing R22 refrigerant using the appropri-
ate procedure below.
If the existing outdoor unit is not equipped with shut−
off valves, or if the unit is not operational AND you
plan to use the existing R22 refrigerant to flush the
system −−
Disconnect all power to the existing out-
door unit. Connect the existing unit, a clean recovery
cylinder and the recovery machine according to the
instructions provided with the recovery machine. Re-
move all R22 refrigerant from the existing system.
Refer to gauges after shutdown to confirm that the
entire system is completely void of refrigerant. Dis-
connect the liquid and vapor lines from the existing
outdoor unit.
If the existing outdoor unit is equipped with manual
shut−off valves AND you plan to use NEW R22 refrig-
erant to flush the system
−− Start the existing R22 sys-
tem in the cooling mode and close the liquid line
valve. Pump all of the existing R22 refrigerant back
into the outdoor unit. (It may be necessary to bypass