Lennox XP14 Elite Series Installation Instructions Manual page 12

5. Remove the pressure tap valve cores from the XP14
unit's service valves. Connect an HCFC-22 cylinder
with clean refrigerant to the vapor service valve,
Connect the HCFC-22 gauge set to the liquid line valve
and connect a recovery machine with an empty
recovery tank to the gauge set.
6. Set the recovery machine for liquid recovery and start
the recovery machine. Open the gauge set valves to
allow the recovery machine to pull a vacuum on the
existing system line set and indoor coil.
7. Invert the cylinder of clean HCFC-22 and open its
valve to allow liquid refrigerant to flow into the system
through the vapor line valve. Allow the refrigerant to
pass from the cylinder and through the line set and the
indoor coil before it enters the recovery machine,
8. After all of the liquid refrigerant has been recovered,
switch the recovery machine to vapor recovery so that
all of the HCFC-22 vapor is recovered. Allow the
recovery machine to pull a vacuum on the system,
NOTE - A single system flush should remove all of the
mineral oil from the existing refrigerant lines and
indoor coil, A second flushing may be done (using
clean refrigerant) if insufficient amounts of mineral oil
were removed during the first flush. After each
system flush, allow the recovery machine to pull a
vacuum on the system at the end of the
procedure.
9. Close the valve on the inverted HCFC-22 drum and
the gauge set valves. Pump the remaining refrigerant
out of the recovery machine and turn the machine off.
10. Use dry nitrogen to break the vacuum on the
refrigerant lines and indoor coil before removing the
recovery machine, gauges and HCFC-22 refrigerant
drum. Reinstall pressure tap valve cores into XP14
unit's service valves.
11. Install check expansion valve (approved for use with
HFC-410A refrigerant) in the liquid line at the indoor
coil.
XP 14 units may be used in check thermal expansion valve
(CTXV) systems only. See indoor coil installation
instructions and the Lennox engineering handbook for
approved HFC-410A valve match-ups and application
information,
NOTE - HFC-410A systems will not operate properly with
an HCFC-22 valve,
Check thermal expansion valves equipped with fittings are
available from Lennox, Refer to the Engineering
Handbook for applicable expansion valves for use with
specific match-ups, See table 4 for applicable indoor check
expansion valve kits.
Table 4. Indoor Check Expansion Valve Kits
MODEL Kit Number
XP14-018, -024, -030 49L24
XP14-036, -042 49L25
X P 14-048, -060 91 M02
PATcHTWo(UncaSedpECEpLATE Coil Shown) _ - _
(uncased coil ORIFICE I EXPANSION VALVE
only) HOUSING
I (see no_e)
TUBES X
ACCESS FITTIN/
(no valve core) SENSING BULB
1 pi'EsNu ISal N°( n re qu' red )
On smaller lines, 1/2" & smaller bo,bmaybe •
mounted on top
_ _g
Do not mount bulb
on bo{tom of line
5/8" & larger
suction line
NOTE - If necessary, remove
HCFC-22 flow control device
(fixed orifice/check expansion
valve) from existing line set before
installing HFC-410A approved ex-
pansion valve and o-ring.
Figure 19. Metering Device Installation
IMPORTANT
If you install a check thermal expansion valve with an
indoor coil that includes a fixed orifice, remove the orifice
before the check expansion valve is installed. See figure
19 for installation of the check expansion valve.
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