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Insulation is necessary to prevent condensation from
forming and dropping from the suction line. Armflex (or
satisfactory equivalent) with 3/8" min. wall thickness is
recommended. In severe conditions (hot, high humidity
areas) 1/2" insulation may be required. Insulation must be
installed in a manner which protects tubing from damage
and contamination.
Where possible, drain as much residual compressor oil
from existing systems, lines, and traps; pay close attention
to low areas where oil may collect. NOTE: If changing
refrigerant types, ensure the indoor coil and metering
device is compatible with the type of refrigerant being used;
otherwise, the indoor coil must be replaced. To facilitate oil
return to the compressor, a horizontal suction line should
be pitched (1/2" per 10' toward the condensing unit.
Filter Drier and Sight Glass
A liquid line filter drier is factory installed. Field-install the
supplied sight glass/moisture indicator on the liquid line as
close as practical to the service valve.
Burying Refrigerant Lines
If burying refrigerant lines can not be avoided, use the
following checklist.
1. Insulate liquid and suction lines separately.
2. Enclose all underground portions of the refrigerant
lines in waterproof material (conduit or pipe) sealing
the ends where tubing enters/exits the enclosure.
3. If the lines must pass under or through a concrete
slab, ensure lines are adequately protected and
sealed.
Refrigerant Line Connections
IMPORTANT: To avoid overheating the service valve, TXV
valve, or filter drier while brazing, wrap the component
with a wet rag, or use a thermal heat trap compound as
recommended by the compound manufacturer. Use a
brazing alloy of 2% minimum silver content. Do not use
flux.
1. The ends of the refrigerant lines must be cut square,
deburred, cleaned, and be round and free from nicks
or dents. Any other condition increases the chance of
a refrigerant leak.
2. This unit is factory shipped with a holding charge.
"Sweep" the refrigerant line with nitrogen or inert gas
during brazing to prevent the formation of copper-
oxide inside the refrigerant lines.
3. After brazing, quench the joints with water or a wet
cloth to prevent overheating of the service valve.
4. Ensure the filter drier paint finish is intact after
brazing. If the paint of the steel filter drier has
been burned or chipped, repaint or treat with a rust
preventative. This is especially important on suction
line filter driers which are continually wet when the
unit is operating.
NOTE: Be careful not to kink or dent refrigerant
lines. Kinked or dented lines will cause poor
performance or compressor damage.
Do NOT make final refrigerant line connection until plugs
are removed from refrigerant tubing.
Leak Testing (Nitrogen or Nitrogen-Traced)
To avoid the risk of fire or explosion, never use oxygen,
high pressure air or flammable gases for leak testing of a
refrigeration system.
To avoid possible explosion, th line from the nitrogen
cylinder must include a pressure regulator and a pressure
relief valve. The pressure relief valve must be set to open
at no more than 150 PSIG.
Pressure test the system using dry nitrogen and soapy
water to locate leaks. If you wish to use a leak detector,
charge the system to 10 psi using the appropriate
refrigerant then use nitrogen to finish charging the system
to working pressure then apply the detector to suspect
areas. If leaks are found, repair them. After repair, repeat
the pressure test. If no leaks exist, proceed to system
evacuation.
System Evacuation
Condensing unit liquid and suction valves are closed to
contain the charge within the unit. The unit is shipped with
the valve stems closed and caps installed. Do not open
valves until the system is evacuated.
REFRIGERANT UNDER PRESSURE!
Failure to follow proper procedures may cause property
damage, personal injury or death.
1. Connect the vacuum pump with 250 micron capability
to the service valves.
2. Evacuate the system to 250 microns or less using
suction and liquid service valves. Using both valves is
necessary as some compressors create a mechanical
seal separating the sides of the system.
3. Close pump valve and hold vacuum for 10 minutes.
Typically pressure will rise during this period.
4
WARNING
WARNING
WARNING
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