Lennox Dave Signature SL28XCV Installation Instructions Manual page 7

REFRIGERANT PIPING – Removing Existing Indoor Metering Device
1A
TYPICAL EXISTING FIXED ORIFICE
REMOVAL PROCEDURE
(UNCASED COIL SHOWN)
DISTRIBUTOR TUBES
LIQUID LINE ORIFICE HOUSING
DISTRIBUTOR
ASSEMBLY
REMOVE AND DISCARD
WHITE TEFLON
(IF PRESENT)
A - On fully cased coils, remove the coil access and plumbing panels.
B -
sembly.
C - Using two wrenches, disconnect liquid line from liquid line
ing. T
cess.
D - Remove and discard fixed orifice, valve stem assembly (if present)
®
and Teflon washer as illustrated above.
E - Use a field-provided fitting to temporarily reconnect the liquid line to the
indoor unit's liquid line orifice housing.
2
CONNECT GAUGES AND EQUIPMENT FOR
FLUSHING PROCEDURE
CYLINDER CONTAINING
CLEAN HCFC-22 TO BE
USED FOR FLUSHING
(Positioned to deliver liquid
A
refrigerant)
1
VAPOR LINE
SERVICE VALVE
EXISTING
INDOOR
UNIT
LIQUID LINE SERVICE
VALVE
RECOVERY
CYLINDER
D
A - HCFC-22 cylinder with clean refrigerant (positioned to deliver liquid
refrigerant) to the vapor 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 connected to the gauge set.
D - Connect recovery tank to recovery machine per machine instructions.
®
TEFLON RING
FIXED ORIFICE
BRASS NUT
®
SEAL
LIQUID LINE ASSEMBLY
(INCLUDES STRAINER)
GAUGE
MANIFOLD
LOW
NEW
OUTDOOR
UNIT
OPENED
B
TANK
RETURN
C
INLET
DISCHARGE
RECOVERY MACHINE
1B
TYPICAL EXISTING EXPANSION VALVE REMOVAL
OR
PROCEDURE (UNCASED COIL SHOWN)
TWO-PIECE PATCH PLATE
(UNCASED COIL ONLY)
DISTRIBUTOR
TUBES
DISTRIBUTOR
ASSEMBLY
MALE EQUALIZER
LINE FITTING
A - On fully cased coils, remove the coil access and plumbing panels.
B - Remove any shipping clamps from the liquid line and distributor
assembly.
C - Disconnect the equalizer line from the check expansion valve
equalizer line fitting on the vapor line.
D - Remove the vapor line sensing bulb.
E - Disconnect the liquid line from the check expansion valve at the
liquid line assembly.
F - Disconnect the check expansion valve from the liquid line orifice
housing. Take care not to twist or damage distributor tubes during
this process.
G - Remove and discard check expansion valve and the two Teflon
rings.
HIGH
H - Use a field-provided fitting to temporarily reconnect the liquid line to
the indoor unit's liquid line orifice housing.
3
FLUSHING LINE SET
CLOSED
The line set and indoor unit coil must be flushed with at least the same
amount of clean refrigerant that previously charged the system. Check
the charge in the flushing cylinder before proceeding.
A - 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
B
unit coil.
B - Position the cylinder of clean HCFC-22 for delivery of liquid
refrigerant 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 unit
coil before it enters the recovery machine.
C - 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 the system
down to 0.
D - 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.
FIGURE 2
Page 7
STUB END
LIQUID LINE
CHECK
ORIFICE
EXPANSION
HOUSING
VALVE
®
TEFLON
RING
EQUALIZER
LINE
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
VAPOR
LINE
SENSING BULB
®
TEFLON
RING
SENSING
LINE
LIQUID
LINE
®