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WARNING
I
USING AN ELECTRONIC
LEAK DETECTOR OR
HALIDE
1, Connect a cylinder of HCFC-22 to the center port of
the manifold gauge set.
2, With both manifold valves closed, open the valve on
the HCFC-22 cylinder (vapor only).
3, Open the high pressure side of the manifold to allow
the HCFC-22 into the line set and indoor unit. Weigh
in a trace amount of HCFC-22, [A trace amount is a
maximum of 2 ounces (57 g) or 3 pounds (31 kPa)
pressure,] Close the valve on the HCFC-22 cylinder
and the valve on the high pressure side of the manifold
gauge set, Disconnect the HCFC-22 cylinder,
4, Connect a cylinder of dry nitrogen with a pressure
regulating valve to the center port of the manifold
gauge set,
5, Connect the manifold gauge set high pressure hose to
the vapor valve service
port, (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.)
6, Adjust the dry nitrogen pressure to 150 psig (1034
kPa). Open the valve on the high side of the manifold
gauge set which will pressurize line set and indoor unit.
7, After a few minutes, open a refrigerant port to ensure
the refrigerant you added is adequate to be detected.
(Amounts of refrigerant will vary with line lengths.)
Check all joints for leaks, Purge dry nitrogen and
HCFC-22 mixture, Correct any leaks and recheck,
Evacuating the system of non-condensables
is critical for
proper operation
of the unit. Non-condensables
are
defined
as
any gas
that
will
not condense
under
temperatures and pressures present during operation of
an air conditioning system. Non-condensables
and water
vapor combine with refrigerant to produce substances that
corrode copper piping and compressor parts.
A IMPORTANT
,
4.
5.
,
Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set,
Open both manifold valves; start the vacuum pump,
Evacuate the line set and indoor unit to an absolute
pressure
of
23,000
microns
(29,01
inches
of
mercury). During the early stages of evacuation, it is
desirable to close the manifold gauge valve at least
once to determine if there is a rapid rise in absolute
pressure,
A rapid rise
in pressure
indicates
a
relatively large leak, If this occurs, repeat the leak
testing procedure,
NOTE - The term absolute
pressure means the total
actual pressure
within a given volume or system,
above
the absolute
zero
of pressure.
Absolute
pressure
in a vacuum
is equal
to atmospheric
pressure minus vacuum pressure,
When the absolute pressure reaches 23,000 microns
(29.01 inches of mercury), close the manifold gauge
valves, turn off the vacuum pump and disconnect the
manifold gauge center port hose from vacuum pump.
Attach the manifold center port hose to a dry nitrogen
cylinder with pressure regulator set to 150 psig (1034
kPa) and purge the hose. Open the manifold gauge
valves to break the vacuum in the line set and indoor
unit, Close the manifold gauge valves.
Xk WARNING
7. Shut off the dry nitrogen cylinder and remove the
manifold gauge hose from the cylinder. Open the
manifold gauge valves to release the dry nitrogen from
the line set and indoor unit,
8. Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line set
and indoor unit until the absolute pressure does not
rise above 500 microns (29.9 inches of mercury) within
a 20-minute period after shutting off the vacuum pump
and closing the manifold gauge valves.
9. When the absolute pressure requirement above has
been met, disconnect the manifold hose from the
vacuum pump and connect it to an upright cylinder of
HCFC-22 refrigerant, Open the manifold gauge valves
to break the vacuum from 1 to 2 psig positive pressure
in the line set and indoor unit. Close manifold gauge
valves and shut off the HCFC-22 cylinder and remove
the manifold gauge set,
1. Connect manifold gauge set to the service valve ports
as follows:
•
low pressure gauge to vapor line service valve
•
high pressure gauge to liquid line service valve
2. Connect micron gauge.
505076M
0_07
Page 12
IMPORTANT
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