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Maintenance
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 pressure switch may be activated,
resulting in the halting of the unit.
In the presence of an excess charge, the
condensing pressure will rise (in the worst
of cases, the HP pressure switch may be ac-
tivated, resulting in the stop of the equip-
ment), 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-hy-
drate the circuit, thus obtaining a minimum abs. pres-
sure value of 50 Pa.
Inject the refrigerant fluid before removing the vac-
uum, then fill the circuit up to 90% of the total gas
requirement (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
observed 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,
providing that the efficiency of the refrigeration cir-
cuit 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
authorised
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
present 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
aluminium fins. In the presence of leaks caused by
any damage or shock, the coils shall be repaired or
replaced by one of authorised Ser
vice Centers.
To ensure the effective and correct
operation
of
the condenser 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 absorption 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 com-
pressed 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 com-
plete 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 current). If the direction of rotation is wrong, in-
vert two of the three supply phases to the motor.
WARNING
WARNING
WARNING
WARNING
VLS-GB.indd 77
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