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CU MANUAL
IOM-14
11 of 46
Feb 06 R4
Condensate Line (Systems with Receivers Only)
The condensate line connects the condenser to the liquid receiver. This is perhaps one of the most critical
and misunderstood lines in a system. Condensate lines contain liquid and gas together, and are sized and
installed to provide sewer flow to the receiver.
Size condensate lines for a maximum liquid velocity of 100 FPM (0.4 m/s). This is often the same size as the
discharge line. The condensate must “free drain” to the receiver with no intervening traps. Recommended
slope is 1:50.
REFRIGERATION SPECIALTIES (BY OTHERS)
NOTE:
Refrigerant specialties are selected, supplied and installed by the installing contractor.
Most of these devices have specified directions of flow and may be permanently damaged if
not installed correctly. Always follow the installation instructions provided with the
components.
Service Valves (Recommended)
Service valves should be installed to allow servicing of the equipment. A suction and liquid line service
valve at the condensing unit is considered a minimum requirement.
Sight Glass/Moisture Indicator (Required)
Sight glasses are installed in the liquid line to give a visual indication of the
refrigerant charge. The moisture indicator gives an indication of the moisture
content of the refrigerant.
Liquid Line Filter-Drier (Required)
The filter-drier is installed in the liquid line to filter particulate and foreign matter
from the refrigerant. Filter-driers also absorb small amounts of moisture and acid.
Suction Line Filter (Optional)
A suction line filter is designed to catch any debris from the installation before it enters the compressor.
Suction filters are recommended on all systems with long refrigerant piping runs.
Liquid Line Solenoid Valve (Required)
The liquid line solenoid valve is installed to control liquid refrigerant in the off
cycle. The solenoid valve must be installed close to the TX valve at the evaporator
coil. Several different control methods are used to control liquid line solenoid
valves. See wiring diagram and unit function for details.
