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11.4 Refrigerating compressor
The employed refrigerating compressors are constructed by leading manufacturers. The hermetically sealed
construction is absolutely gastight. The integrated safeguard protects the compressor against overheating and excess
current. The protection is automatically reset as soon as the nominal conditions are reached again.
11.5 Condenser
The condenser is the component in which the gas coming from the compressor is cooled down, condensed and
liquefied. Under no circumstances must the temperature of the ambient air exceed the nominal values. It is also
important that the condenser unit is kept free from dust and other impurities.
11.6 Filter dryer
Despite controlled vacuuming, traces of moisture can accumulate in the refrigeration cycle. The filter dryer serves to
absorb this moisture and to bond it.
11.7 Capillary tube
The capillary tube is a copper tube with a reduced diameter which is located between the condenser and the
evaporator, serving as a restrictor to reduce the pressure of the refrigerant. The pressure reduction serves to reach an
optimum temperature inside of the evaporator. The lower the outlet pressure at the capillary tube, the lower the
evaporation temperature.
The length and the inner diameter of the capillary tube are exactly dimensioned to ensure the performance of the
dryer. Settings or maintenance works are not required.
11.8 Aluminium heat exchanger
The heat exchanger module consists of an air/air heat exchanger, an air/refrigerant heat exchanger, and of a high-
performance separator. The compressed air flows top-down through the heat exchanger. The large cross-sections of
the flow passages cause low flow rates and low compressed-air losses. In the air/air heat exchanger, the heat
exchange is effected in a reverse current. This guarantees maximum heat transfer. The heat transfer in the
air/refrigerant heat exchanger also takes place in a reverse current. This allows full evaporation of the refrigerant. The
high-performance separator ensures almost complete separation of the condensate. Maintenance of the high-
performance separator is not required.
11.9 Hot-gas bypass valve
At partial load, the valve directly returns a part of the hot gas to the suction line of the refrigerating compressor. The
evaporation temperature and the evaporation pressure remain constant.
ADJUSTMENT
The hot gas by-pass valve is adjusted during the manufacturing testing phase.
As a rule no adjustment is required; anyway if it is necessary the operation
must be carried out by an experienced refrigerating engineer.
WARNING
the use of ¼" Schrader service valves must be justified by a real malfunction
of the refrigerating system. Each time a pressure gauge is connected, a part
of refrigerant is exhausted.
Without compressed air flow through the dryer, rotate the adjusting screw
(position A on the drawing) until the following value is reached:
Hot gas setting :
R134.a pressure 29.0 psig (+ 1.45 / -0 psi) [2.0 barg (+0.1 / -0 bar)]
R407C pressure 65.3 psig (+1.45 / -0 psi) [4.5 barg (+0.1 / -0 bar)]
DRYPOINT® RAC 10-480 NA
Technical description
A
4 mm
5/32 in.
-
+
23
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