Page 18
Vapor Line (Ball Type) Service Valve
(Valve Open)
Schrader
valve
stem cap
Use Adjustable Wrench
To open: rotate stem counter-clockwise 90°.
To close: rotate stem clockwise 90°.
ball
(shown open)
service port
cap
service
port
field side
unit side
stem
FIGURE 24
IV−CHARGING
Units are factory charged with the amount of R410A refrig-
erant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15 ft.
(4.6m) line set. For varying lengths of line set, refer to table
9 for refrigerant charge adjustment.
TABLE 9
Liquid Line Set
Diameter
Ozs. per 5 ft. (grams per 1.5m) adjust
from 15 ft. (4.6m) line set*
3/8 in.
(10mm)
3 ounces per 5 feet
(85g per 1.5m)
*If line length is greater than 15 ft. (4.6m), add this amount.
If line length is less than 15 ft. (4.6), subtract this amount.
A−Leak Testing
After the line set has been connected to the indoor and out-
door units, the line set connections and indoor unit must be
checked for leaks.
WARNING
Refrigerant can be harmful if inhaled. Refrigerant
must be used and recovered responsibly. Failure
to follow this warning can lead to injury or death.
WARNING
Danger of explosion!
When using a high pressure gas such
as dry nitrogen to pressurize a refrig-
erant or air conditioning system, use
a regulator that can control the pres-
sure down to 1 or 2 psig (6.9 to 13.8
kPa).
WARNING
Fire, Explosion and Personal Safety
Hazard.
Failure to follow this warning could
result in damage, personal injury or
death.
Never use oxygen to pressurize or
purge refrigeration lines. Oxygen,
when exposed to a spark or open
flame, can cause damage by fire
and / or an explosion, that can re-
sult in personal injury or death.
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, open the valve on
the R410A cylinder (vapor only).
3 − Open the high pressure side of the manifold to allow
the 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) or 3 pounds (31 kPa) pressure.]
Close the valve on the R410A cylinder and the valve
on the high pressure side of the manifold gauge set.
Disconnect the 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 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 R410A
mixture. Correct any leaks and recheck.
IMPORTANT
Leak detector must be capable of sensing HFC re-
frigerant.
B−Evacuating
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.
