Removing Existing Outdoor Unit - Lennox AC13 -018 Installation Instructions Manual

OPEN TO LINE SET WHEN VALVE IS CLOSED,
TO BOTH LINE SET AND UNIT WHEN VALVE IS
OPEN.
TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90°.
TO CLOSE ROTATE STEM
CLOCKWISE 90°.
SERVICE PORT
SERVICE PORT
CORE
SERVICE PORT CAP
TO OUTDOOR UNIT
Figure 5. Ball−Type Service Valve
Recovering Refrigerant from Existing
HCFC−22 System
Remove existing HCFC−22 refrigerant using one of the
following methods:
METHOD 1:
Use this method if the existing outdoor unit is not equipped
with manual shut−off valves, and plan on using existing
HCFC−22 refrigerant to flush the system.
NOTE − Use recovery machine instructions for specific
setup requirements.
Perform the following task:
1. Disconnect all power to the existing outdoor unit.
2. Connect to the existing unit a gauge set, clean
recovery cylinder and a recovery machine. Use the
instructions provided with the recover machine on how
to setup the connections.
3. Remove all HCFC−22 refrigerant from the existing
system. Check gauges after shutdown to confirm that
the entire system is completely void of refrigerant.
RECOVERY MACHINE
CLEAN RECOVERY
CYLINDER
Figure 6. Typical Refrigerant Recovery (Method 1)
TO INDOOR UNIT
BALL (SHOWN
CLOSED)
VALVE
STEM
STEM CAP
MANIFOLD GAUGES
OUTDOOR UNIT
Page 5
METHOD 2:
Use this method if the existing outdoor unit is equipped
with manual shut−off valves, and plan on using new
HCFC−22 refrigerant to flush the system.
IMPORTANT: Some system configurations may contain
higher than normal refrigerant charge due to either large
internal coil volumes, and/or long line sets. The following
conditions may cause the compressor to stop functioning:
The following devices could prevent full system charge
recovery into the outdoor unit:
S
Outdoor unit's high or low−pressure switches (if
applicable) when tripped can cycled the compressor
OFF.
S
Compressor can stop pumping due to tripped internal
pressure relief valve.
S
Compressor has internal vacuum protection that is
designed to unload the scrolls (compressor stops
pumping) when the pressure ratio meets a certain
value or when the suction pressure is as high as 20
psig. (Compressor suction pressures should never be
allowed to go into a vacuum. Prolonged operation at
low suction pressures will result in overheating of the
scrolls and permanent damage to the scroll tips, drive
bearings and internal seals).
Once the compressor can not pump down to a lower
pressure due to one of the above system conditions, shut
off the suction valve. Turn OFF the main power to unit and
use a recovery machine to recover any refrigerant left in
the indoor coil and line set.
Perform the following task:
1. Start the existing HCFC−22 system in the cooling
mode and close the liquid line valve.
2. Pump as much of the existing HCFC−22 refrigerant
with the compressor back into the outdoor unit until
you have reached the limitations of the outdoor
system. Turn the outdoor unit main power OFF and
use a recovery machine to remove the remaining
refrigerant in the system.
NOTE − It may be necessary to bypass the low pressure
switches if equipped to ensure complete refrigerant
evacuation.
3. When the low side system pressures reach 0 psig,
close the suction line valve.
4. Check gauges after shutdown to confirm that the
valves are not allowing refrigerant to flow back into the
low side of the system.

Removing Existing Outdoor Unit

Perform the following task at the existing outdoor unit:
S
Disconnect line set at the service valves.
S
Disconnect electrical service at the disconnect switch.
S
Remove old outdoor unit.
AC13 SERIES