Recovering Refrigerant From Existing System - Lennox Merit 13HPX Series Installation Instructions Manual

Recovering Refrigerant from Existing System

1
DISCONNECT POWER
Disconnect all power to the existing outdoor unit at the disconnect
switch and/or main fuse box/breaker panel.
3
RECOVERING REFRIGERANT
Remove existing refrigerant using one of the following procedures:
METHOD 1:
Use 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 to flush the system.
Recover all refrigerant from the existing system using a recovery machine and
clean recovery cylinder. Check gauges after shutdown to confirm that the entire
system is completely void of refrigerant.
METHOD 2:
Use Method 2 if the existing outdoor unit is equipped with manual shut−off valves,
and you plan to use new refrigerant to flush the system.
Perform the following task:
A Start the existing system in the cooling mode and close the liquid line valve.
B Use the compressor to pump as much of the existing HCFC−22 refrigerant into
the outdoor unit until the outdoor system is full. Turn the outdoor unit main power
OFF and use a recovery machine to remove the remaining refrigerant from the
system.
NOTE It may be necessary to bypass the low pressure switches (if equipped) to
ensure complete refrigerant evacuation.
C When the low side system pressures reach 0 psig, close the vapor line valve.
D Check gauges after shutdown to confirm that the valves are not allowing
refrigerant to flow back into the low side of the system.
The Environmental Protection Agency (EPA) prohibits the intentional venting of HFC refrigerants during maintenance,
service, repair and disposal of appliance. Approved methods of recovery, recycling or reclaiming must be followed.
Refrigerant can be harmful if it is inhaled. Refrigerant must be used and recovered responsibly.
Failure to follow this warning may result in personal injury or death.
Downloaded from ManualsNet.com
MAIN FUSE BOX/
BREAKER PANEL
SERVICE
DISCONNECT
SWITCH
Figure 3. Refrigerant Recovery
search engine
2
CONNECT MANIFOLD GAUGE SET
Connect a manifold gauge set, clean recovery cylinder and a
recovery machine to the service ports of the existing unit..
NOTE
the correct manifold gauge set connections for recovery
refrigerant. The illustration below is a typical connection.
RECOVERY MACHINE
NOTE
below could prevent full system charge recovery into
the outdoor unit:
S
S
S
Once the compressor can not pump down to a lower
pressure due to any of the above mentioned system
conditions, shut off the vapor 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.
IMPORTANT
WARNING
Page 5
Use the recovery machine instructions to make
MANIFOLD GAUGES
LOW
OUTDOOR UNIT
CLEAN RECOVERY
CYLINDER
METHOD 2 LIMITATIONS
When using Method 2, the listed devices
Outdoor unit's high or low−pressure switches (if
applicable) when tripped can
compressor OFF.
Compressor can stop pumping due to tripped
internal pressure relief valve.
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.)
HIGH
cycle the
13HPX SERIES