Page 15
Ball Valve (Valve Open)
Schrader valve
service port
service port
cap
stem cap
stem
Use Adjustable Wrench
To open: rotate Stem Clockwise 90°.
To close: rotate Stem Counter-clockwise 90°.
ball
(shown open)
to outdoor coil
to indoor coil
FIGURE 19
IV − CHARGING
A − Leak Testing
After the line set has been connected to the indoor and out-
door units, check the line set connections and indoor unit
for leaks.
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.
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 or Halide
1 − Connect a cylinder of HFC−410A to the center port of
the manifold gauge set.
2 − With both manifold valves closed, open the valve on the
HFC−410A cylinder (vapor only).
3 − Open the high pressure side of the manifold to allow the
HFC−410A into the line set and indoor unit. Weigh in a
trace amount of HFC−410A.
[A trace amount is a maxi-
mum of 2 ounces (57 g) or 3 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.
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 the 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 nitrogen and
HFC−410A mixture. Correct any leaks and recheck.
B − Evacuating the System
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.
NOTE − This evacuation process is adequate for a new
installation with clean and dry lines. If excessive mois-
ture is present, the evacuation process may be re-
quired more than once.
IMPORTANT
Use a thermocouple or thermistor electronic vacuum
gauge that is calibrated in microns. Use an instrument
capable of reading 50 microns to at least 10,000 mi-
crons.
1 − Connect manifold gauge set to the service valve ports :
low pressure gauge to
vapor
line service valve
high pressure gauge to
liquid
line service valve
2 − Connect micron gauge.
3 − Connect the vacuum pump (with vacuum gauge) to the
center port of the manifold gauge set.
