Metering Devices And Flushing The System - Lennox T?CLASS TPA024S4 Unit Information

Metering Devices and Flushing the System14

FLUSHING
LINE SET AND INDOOR COIL
1
TYPICAL FIXED ORIFICE REMOVAL
DISTRIBUTOR TUBES
LIQUID LINE ORIFICE HOUSING
DISTRIBUTOR
ASSEMBLY
REMOVE AND DISCARD
WHITE TEFLON SEAL (IF
PRESENT)
(Uncased Coil Shown)
A On fully cased coils, remove the coil access and plumbing panels.
B Remove any shipping clamps holding the liquid line and distributor
assembly.
C Using two wrenches, disconnect liquid line from liquid line orifice
housing. Take care not to twist or damage distributor tubes during
this process.
D Remove and discard fixed orifice, valve stem assembly if present
and Teflon washer as illustrated above.
E Use a field−provided fitting to temporary reconnect the liquid line to
the indoor unit's liquid line orifice housing.
F Replace with expansion valve.
2
CONNECT GAUGES AND EQUIPMENT FOR
FLUSHING PROCEDURE
INVERTED HCFC−22
CYLINDER CONTAINS
CLEAN HCFC−22 TO BE
USED FOR FLUSHING.
A
1
VAPOR LINE
SERVICE VALVE
EXISTING
INDOOR
B
UNIT
LIQUID LINE SERVICE
VALVE
RECOVERY
CYLINDER
D
A Inverted HCFC−22 cylinder with clean 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 to the gauge set.
D Connect recovery tank to recovery machines per machine
instructions.
TEFLON RING
FIXED ORIFICE
BRASS NUT
LIQUID LINE ASSEMBLY
(INCLUDES STRAINER)
GAUGE
MANIFOLD
LOW
NEW
OUTDOOR
UNIT
OPENED
CLOSED
TANK
RETURN
C
INLET
DISCHARGE
RECOVERY MACHINE
TYPICAL EXPANSION VALVE REMOVAL AND
REPLACEMENT PROCEDURE
TWO PIECE PATCH PLATE
LIQUID LINE
(UNCASED COIL ONLY)
DISTRIBUTOR
TUBES
OR
DISTRIBUTOR
ASSEMBLY
MALE EQUALIZER
LINE FITTING
SENSING BULB
A On fully cased coils, remove the coil access and plumbing panels.
B Remove any shipping clamps holding the liquid line and distributor as-
sembly.
C Disconnect the equalizer line from the expansion valve equalizer line
fitting on the vapor line.
D Remove the vapor line sensing bulb.
E Disconnect the liquid line from the expansion valve at the liquid line as-
sembly.
F Disconnect the expansion valve from the liquid line orifice housing.
Take care not to twist or damage distributor tubes during this process.
G Remove and discard expansion valve and the two Teflon rings.
H Use a field−provided fitting to temporary reconnect the liquid line to the
indoor unit's liquid line orifice housing.
I Reverse above order to install.
HIGH
CAUTION This procedure should not be performed on systems
which contain contaminants (Example compressor burn out.
3
FLUSHING LINE SET
The line set and indoor unit coil must be flushed with at least the
same amount of clean refrigerant that previously charged the sys-
tem. Check the charge in the flushing cylinder before proceeding.
B
A Set the recovery machine for liquid recovery and start the recov-
ery machine. Open the gauge set valves to allow the recovery
machine to pull a vacuum on the existing system line set and in-
door unit coil.
B 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 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 down to 0
the system.
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.
Page 15
(Uncased Coil Shown)
STUB END
EXPANSION
ORIFICE
VALVE
HOUSING
TEFLON
RING
EQUALIZER
LINE
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
VAPOR
LINE
TEFLON
RING
SENSING
LINE
LIQUID
LINE