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507994-01 11/19
IMPORTANT
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.
IMPORTANT
If this unit is being matched with an approved line set or
indoor unit coil which was previously charged with
mineral oil, or if it is being matched with a coil which was
manufactured before January of 1999, the coil and line
set must be flushed prior to installation. Take care to
empty all existing traps. Polyol ester (POE) oils are used
in Lennox units charged with HFC-410A refrigerant.
Residual mineral oil can act as an insulator, preventing
proper heat transfer. It can also clog the expansion
device, and reduce the system performance and
capacity.
Failure to properly flush the system per the instructions
below will void the warranty.
Leak Test Line Set and Indoor Coil
IMPORTANT
Leak detector must be capable of sensing HFC
refrigerant.
After completing the leak testing the line set and indoor coil
as outlined in figure 12, proceed to
Evacuating Line Set
and Indoor Coil
WARNING
When using a high pressure gas such as
dry nitrogen to pressurize a refrigeration
or air conditioning system, use a
regulator that can control the pressure
down to 1 or 2 psig (6.9 to 13.8 kPa).
WARNING
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.
TO VAPOR
SERVICE VALVE
HFC-410A
MANIFOLD GAUGE SET
OUTDOOR UNIT
HIGH
LOW
NITROGEN
A
With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set. Open the valve
on the HFC-410A cylinder (vapor only).
B
Open the high pressure side of the manifold to allow HFC-410A into the line set and indoor unit. Weigh in a trace amount of HFC-410A.
[A
trace amount is a maximum of two ounces (57 g) refrigerant or three pounds (31 kPa) pressure].
Close the valve on the HFC-410A cylinder
and the valve on the high pressure side of the manifold gauge set. Disconnect the HFC-410A cylinder.
C
Connect a cylinder of dry nitrogen with a pressure regulating valve to the center port of the manifold gauge set.
D
Adjust dry nitrogen pressure to 150 psig (1034 kPa). Open the valve on the high side of the manifold gauge set in order to pressurize the
line set and the indoor unit.
E
After a few minutes, open one of the service valve ports and verify that the refrigerant added to the system earlier is measurable with a leak
detector
.
F
After leak testing disconnect gauges from service ports.
After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit for leaks. Use the
following procedure to test for leaks:
A
Connect an HFC-410A manifold gauge set high pressure
hose to the vapor valve service port.
NOTE
— Normally, the high pressure hose is connected to
the liquid line port. However, connecting it to the vapor port
better protects the manifold gauge set from high pressure
damage.
B
With both manifold valves closed, connect the cylinder of
HFC-410A refrigerant to the center port of the manifold gauge
set.
NOTE — Later in the procedure,
the HFC-410A container will be
replaced by the nitrogen
container.
1
CONNECT GAUGE SET
2
TEST FOR LEAKS
A
B
Figure 12. Leak Test
