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506238−01 06/09
Recovering Refrigerant from Existing
System
Connect gauge set as illustrated in Figure 2 for removing
refrigerant.
MANIFOLD GAUGES
RECOVERY
MACHINE
CLEAN
RECOVERY
CYLINDER
OUTDOOR
UNIT
HIGH
LOW
CONNECT TO THE EXISTING UNIT A GAUGE SET, CLEAN RECOVERY
CYLINDER AND A RECOVERY MACHINE. USE THE INSTRUCTIONS
PROVIDED WITH THE RECOVERY MACHINE ON HOW TO SETUP THE
CONNECTIONS.
Figure 2. Setup Gauge Set
REMOVING REFRIGERANT
Remove existing HCFC−22 refrigerant using one of the
following procedures:
METHOD 1:
If the existing outdoor unit is not equipped with shut−off
valves, or if the unit is not operational and you plan to use
the existing HCFC−22 to flush the system.
Remove all HCFC−22 refrigerant from the existing system.
Check gauges after shutdown to confirm that the entire
system is completely void of refrigerant.
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 set. 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.
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
as illustrated in Figure 3.
S
Remove old outdoor unit.
SERVICE
DISCONNECT
SWITCH
MAIN FUSE
BOX/BREAKER
PANEL
Disconnect all power to the existing outdoor unit at the disconnect
switch or main fuse box/breaker panel.
Figure 3. Disconnect Power