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9.3 Refrigerant charge
Do not inject refrigerant liquid into the LP
side of the circuit. Be very careful, and
charge the circuit properly. If the charge is
insufficient, the efficiency of the unit will be
lower than expected. (In the worst of cases
the LP transducer may stop the unit.)
In the presence of an excess charge, the con-
densing pressure will rise (in the worst of cas-
es, the HP pressure switch may be activated,
resulting in the stop of the equipment), and
the consumption will increase as well.
It is strictly forbidden to use the compressor
as a vacuum pump to drain the plant.
Fill the refrigeration circuit after it has been drained
for maintenance purposes (leaks, replacement of the
compressor etc.). The amount of the charge is indi-
cated on the plate affixed to the unit.
Before refilling, it is important to drain and de-hydrate
the circuit, thus obtaining a minimum abs. pressure
value of 50 Pa.
Inject the refrigerant fluid before removing the vacu-
um, then fill the circuit up to 90% of the total gas re-
quirement (in liquid form). The appliance must be filled
through the filling valve on the liquid line, on the outlet
side of the condenser.
It is recommended to connect the refrigerant cylinder
to the filling valve on the liquid line, and to arrange it
in such a way as to inject only liquid refrigerant.
Then start the compressor and let the gas flow from
the cylinder, up until the liquid flow, which can be ob-
served through the sight glass, is limpid.
9.4 Compressor
Compressors are delivered with the necessary charge
of lubricating oil. During normal operation, this
charge is sufficient for the whole life of the unit, pro-
viding that the efficiency of the refrigeration circuit is
satisfactory and if it has not been overhauled.
If the compressor needs to be replaced (following a
mechanical failure or if burnt), contact one of author-
ised Service Centers.
Compressors use polyester oil. During main-
tenance operations on the compressor, or
if you have to open the refrigerant circuit
in any point, remember that this type of oil
is highly hygroscopic, and accordingly it
is important that it is not left exposed to the
weather for prolonged periods, as this would
require the replacement of the oil.
In a few cases, the polyester oil may be pre-
sent also in R22 units (a refrigerant that can
be used also in extra UE countries).
9.5 Condenser
The condenser’s coils consist of copper pipes and alu-
minium fins. In the presence of leaks caused by any
damage or shock, the coils shall be repaired or re-
placed by one of authorised Service Centers. To en-
sure the effective and correct operation of the con-
denser coils, it is important to keep the condenser’s
surface perfectly clean, and to check that there is no
foreign matter, such as leafs, wires, insects, waste etc.
If the coil becomes dirty, there is an increase in the ab-
sorption of electric energy. Furthermore, the maximum
pressure alarm may be activated and may halt the
unit.
Be careful not to damage the aluminium fins
during cleaning.
The condenser must be cleaned with a LP compressed
air jet, parallel to the aluminium fins, in the direction
opposite to the air circulation.
To clean the coil you can use also a vacuum cleaner,
or a jet of water and soap.
9.6 Fans
The fans of the condenser, of axial type, are complete
with impeller with aerodynamic profile blades and a
cylindrical nozzle. The motor’s bearings are lubricated
forever.
Before starting the appliance, after any maintenance
operations involving the disconnection of 3-phase
connections, check that the direction of rotation of the
fans is the one indicated by the arrow (upward air cur-
rent). If the direction of rotation is wrong, invert two of
the three supply phases to the motor.
Maintenance
WARNING
WARNING
WARNING
WARNING
