E/0204/39/51
12. After having connected the refrigerant lines, connect a suitable vacuum pump (complete with
vacuum meter) to both the refrigerant taps of the motor-condensing unit. Evacuate the air inside
the lines.
13. Then, open the refrigerant taps of both units following this order:
• IN tap of motor-condensing unit
• OUT tap of motor-condensing unit
• Then the two taps of evaporating (order for evaporating unit is not relevant).
14. If distance* covered by refrigerant lines is more than 5 m, refrigerant must be added. This
operation must be done after having completed the installation and the start-up of the unit.
While compressor is running, connect the charge cylinder to the low pressure (suction) gas
side of compressor and fill with the right quantity as per table 2.
NOTE: make sure, while the system is in standard operation, that the superheating complies with
following values in table 3.
TABLE 3: R407c-Superheating table.
Internal temperature °C 25 28
Internal relative humidity % RH 40 40
Compressor superheating °C 8 12
NOTE: values applying with condensation T = 50°C
OIL CHARGE
The compressor is supplied with an initial oil charge. The standard oil charge for the use of the
refrigerants R407c and R134a is a polyolester (POE) lubricant Copeland 3MA (32 cSt). In the field,
the oil level could be topped up with ICI Emkarate RL 32 F or Mobil EAL Arctic 22 CC, if 3MA is not
available.
In R22 applications "White Oil" is used. White Oil is compatible with Suniso 3GS, Texaco WF 32
and Fuchs KM. These oils may be used if an addition is required in the field.
CAUTION:
• High hygroscopicity: both types of oil (in particular POE) rapidly absorb humidity present in
the air when they are exposed to the atmosphere. If the oil absorbs humidity, the ester molecules
can break down, forming acidity.
Therefore, we recommend exposing the oil for as short a time as possible (a few minutes).
• High solvent power: this oil shows excellent solubility towards the deposits of the system.
This interaction of lubricant and coolant with the residue present in the circuit may cause the
formation of agglomerates of insoluble particles which can obstruct small holes and valves.
Therefore, we recommend you to ensure a high cleanliness of the plant.
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