Hitachi CA47TLA-D2PE3 Manual page 29

(3) Refrigerant Pipe Connection
*The oil in this compressor is synthetic oil, and it has a higher moisture-absorbent than
conventional oil. Do not leave the compressor with the suction and discharge pipes open to
the air for a long period of time. As a guide, it should be limited to within 3 to 5 minutes.
*To avoid the oxidation of pipes, brazing should be carried out while nitrogen flows into the
brazing junction.
Be careful not to contaminate it with waste such as flux.
*The power supply terminal box and the coated surface should be protected from heat damage
by the burner. In addition, do not overheat so as not to increase the temperature of the parts
in the compressor.
(4) Impurities and Water-drop Management during the Refrigerant Cycle
*Cleaning agents used for cleaning a heat exchanger, etc. should be completely eliminated
because they will damage the bearings for the compressor. Foreign particles on the internal
surface of the heat exchanger and pipes shall be 0.05g/m
not be included.
These figures represent the mass of foreign particles collected with the filter after alkaline
cleaning is performed on the internal surface of the heat exchanger pipes.
*Carry out vacuum drawing fully so that the water-drops in the refrigerant cycle are 100ppm or
less. A dryer shall be set during the refrigerant cycle if necessary.
*The cycle structure or the dryer structure shall be used so as not to scatter crushed powder of
the desiccant of the dryer over the refrigerant cycle.
(5) Degree of Vacuum Before Charging Refrigerants
*The degree of vacuum in the refrigerant cycle should be 666Pa_abs or less in order to avoid
the entry of air.
(6) Charging Refrigerants
*First, refrigerants should be charged from the outlet of the condenser of the refrigerant cycle
in the state of not operating the compressor.
compressor.
*Operate the compressor for more than 5 minutes within 15 minutes after charging the
refrigerants.
*Refrigerants should be charged in a liquid state.
*Refrigerants must not be leaked.
(7) Refrigerant Charged Capacity
The weight ratio of the oil charged capacity (a) to the refrigerant charged capacity (b) should
be (a) / (b) = 0.4 or higher.
with a lack of refrigeration capabilities and a tendency to increase the discharge gas
temperature. In the case of excessive charged capacity, there will be problems with reliability,
such as the liquid return of refrigerants and lower lubricant performance of refrigerant oil.
Accordingly, it is recommended that the refrigerant charged capacity be minimized.
*Example of calculation of the recommended refrigerant charged capacity
Calculation conditions
・Specified refrigerant oil: FVC68D
・Density of specified refrigerant oil = 0.937 g/cm
Oil charged
capacity
φ 160 series
1.4 liter (1,400cm
1.5 liter (1,500cm
φ 190 series
2.0 liter (2,000cm
Do not charge them directly in the
If the refrigerant charged capacity is small, there will be problems
3
(when at 15℃)
Refrigerant charged
capacity≦
3
) 1,400×0.937/0.4= 3,280g
3
) 1,500×0.937/0.4= 3,510g
3
) 2,000×0.937/0.4= 4,690g
10
2
or less, and metal powder shall
Remarks
CA47TLA model only