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Ball Valve (Valve Open)
Schrader valve
service port
service port
cap
stem cap
stem
Use Adjustable Wrench
To open: rotate Stem Counter-clockwise 90°.
To close: rotate Stem Clockwise 90°.
ball
(shown open)
to outdoor coil
to indoor coil
Figure 12
Leak Testing
After the line set has been connected to the indoor and
outdoor units, check the line set connections and indoor
unit for leaks.
WARNING
Refrigerant can be harmful if it is inhaled. Refriger-
ant must be used and recovered responsibly.
Failure to follow this warning may result in personal
injury or death.
WARNING
Danger of explosion: Can cause
equipment damage, injury or death.
Never use oxygen to pressurize a re-
frigeration or air conditioning system.
Oxygen will explode on contact with
oil and could cause personal injury.
WARNING
Danger of explosion: Can cause equipment damage,
injury or death. 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).
Using an Electronic Leak Detector
1 − Connect a cylinder of R410A to the center port of the
manifold gauge set.
2 − With both manifold valves closed, connect the cylinder
of R410A refrigerant. Open the valve on the R410A cyl-
inder (vapor only).
3 − Open the high pressure side of the manifold to allow
R410A into the line set and indoor unit. Weigh in a trace
amount of R410A.
[A trace amount is a maximum of 2
ounces (57 g) refrigerant or 3 pounds (31 kPa) pres-
sure].
Close the valve on the R410A cylinder and the
valve on the high pressure side of the manifold gauge
set. Disconnect R410A cylinder.
4 − Connect a cylinder of nitrogen with a pressure regulat-
ing 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 pres-
sure hose is connected to the liquid line port; however,
connecting it to the vapor port better protects the man-
ifold gauge set from high pressure damage.)
6 − Adjust nitrogen pressure to 150 psig (1034 kPa). Open
the valve on the high side of the manifold gauge set in or-
der to pressurize the line set and the 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 nitrogen and R410A
mixture. Correct any leaks and recheck.
IMPORTANT
Leak detector must be capable of sensing HFC re-
frigerant.
Evacuation
Evacuating the system of noncondensables is critical for
proper operation of the unit. Noncondensables are defined
as any gas that will not condense under temperatures and
pressures present during operation of an air conditioning
system. Noncondensables and water vapor combine with
refrigerant to produce substances that corrode copper pip-
ing and compressor parts.
IMPORTANT
Use a thermocouple or thermistor electronic vacuum
gauge that is calibrated in microns. Use an instrument
that reads from 50 microns to at least 10,000 microns.
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.
