Refrigerant Metering Device - Lennox XP14 Elite Series Installation Instructions Manual

INVERTED HCFC−22
CYLINDER CONTAINS
CLEAN HCFC−22 TO BE
USED FOR FLUSHING.
A
SUCTION LINE
SERVICE VALVE
EXISTING
INDOOR
B
UNIT
LIQUID LINE SERVICE VALVE
RECOVERY
CYLINDER
D
A Inverted HCFC−22 cylinder with clean refrigerant to the
suction service valve.
B HCFC−22 gauge set (low side) to the liquid line valve.
C HCFC−22 gauge set center port to inlet on the recovery
machine. with an empty recovery tank to the gauge set.
D Connect recovery tank to recovery machines per machine
instructions.
NOTE − The inverted HCFC−22 cylinder must contain at least the same
amount of refrigerant as was recovered from the existing system.
Figure 18. Flushing Connections
4. Remove the existing HCFC−22 refrigerant flow control
orifice or check expansion valve before continuing with
flushing procedures. HCFC−22 flow control devices
(fixed orifice/check expansion valve) are not approved
for use with HFC−410A refrigerant and may prevent
proper flushing. Use a field−provided fitting to
reconnect the lines.
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
GAUGE
MANIFOLD
LOW
NEW
OUTDOOR
UNIT
OPENED CLOSED
TANK
RETURN
C
INLET
DISCHARGE
RECOVERY MACHINE
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.
HIGH
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.

Refrigerant Metering Device

XP14 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.
(Uncased Coil Shown)
TWO PIECE
PATCH PLATE
(uncased coil
only)
DISTRIBUTOR
TUBES
ACCESS FITTING
(no valve core)
On smaller lines,
bulb may be
mounted on top
12
9
Suction
Line
Do not mount bulb
on bottom of line
Figure 19. Metering Device Installation
Page 11
ORIFICE
EXPANSION VALVE
HOUSING
(see note)
O−RING
EQUALIZER
LINE
Remove and discard
SEAL ASSEMBLY
(if applicable)
SUCTION
LINE
SENSING BULB
(insulation required)
1/2" & smaller
suction line
3
NOTE − If necessary, remove
HCFC−22 flow control device
Bulb (fixed orifice/check expansion
valve) from existing line set before
installing HFC−410A approved ex-
5/8" & larger
pansion valve and o−ring.
suction line
O−RING
SENSING
LINE
STRAINER
LIQUID
LINE
XP14 SERIES