Page 76
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, re-
sulting 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 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
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 Itelco-
Clima’s Service Centers.
Compressors use polyester oil, for both the
versions manufactured for R134a and
R407C. During maintenance 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 replace-
ment 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
aluminium fins. In the presence of leaks caused by
any damage or shock, the coils shall be repaired or
replaced by one of Itelco-Clima’s authorised Service
Centers. To ensure the effective and correct opera-
tion 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. Fur-
thermore, the maximum pressure alarm may be acti-
vated 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.
Manuale CLS-CLH2 7.2.2005 10:23 Pagina 76
