507607-03
Issue 1827
Page 10 of 23
Leak Testing
After the line set has been connected to the indoor and
outdoor units, the line set connections and indoor unit must
be checked for leaks.
Figure 12. Service Valve (valve shown closed)
Figure 13. Ball Type Service Valve (valve shown open)
Refrigerant can be harmful if inhaled. Refrigerant must
always be used and recovered responsibly. Incorrect or
irresponsible use of refrigerant can result in personal
injury or death.
WARNING
Never use oxygen to pressurize refrigeration or air
conditioning systems. Oxygen will explode on contact
with oil and could cause personal injury or death.
WARNING
Using an Electronic Leak Detector
1. Connect the high pressure hose of the manifold gauge
set to the suction valve service port. (Normally the
high pressure hose is connected to the liquid line port;
however, connecting it to the suction ports helps to
protect the manifold gauge set from damage caused
by high pressure.)
2. With both manifold valves closed, connect the cylinder
of R410A refrigerant. Open the valve on the R410A
cylinder (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 oz. of refrigerant or 3 lbs. 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
regulating valve to the center port of the manifold
gauge set. When using high pressure gas such as
nitrogen for this purpose, be sure to use a regulator
that can control the pressure down to 1 or 2 psig.
5. Adjust nitrogen pressure to 150 psig. Open the valve
on the high side of the manifold gauge set to pressurize
the line set and the indoor coil.
6. After a short period of time, open a refrigerant port to
make sure that an adequate amount of refrigerant has
been added for detection (refrigerant requirements
will vary with length). Check all joints for leaks. Purge
nitrogen and R410A mixture. Correct any leaks and
rechecks.
Evacuation
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.
