emmeti EC Serie Manual De Instalacion Y Uso página 45

II.9.2 ORDINARY MAINTENANCE
II.9.2.1 Inspection - Cleaning of finned coils
The following operations should be carried out while the unit is switched
off and taking care not to damage the fins during cleaning:
• remove any foreign bodies from the condensing coils which may
block the passage of air, such as: leaves, paper, debris, and so on;
• clean off the dust with a jet of compressed air;
• wash and brush, gently, with water and gentle brushing;
• dry with a jet of compressed air.
• Keep condensation drain pipes free from any obstructions for EH.
II.9.2.2 Inspection of the whole unit
Clean the unit thoroughly and check the status of the machine. Any
points where corrosion is starting need to be touched up with protective
paint.
II.9.2.3 Inspection of the electric circuit
• Check earthing system: with the unit switched off and
disconnected from the power supply check the status of the earthing
system.
• Check and inspect electrical connections: with the unit switched
off and disconnected from the power supply check the status and seal
of the wiring to the terminals.
• Check power consumption: using a clip-on meter assess the
power consumption value and compare the reading with the values
shown in the table on Technical data.
II.9.2.4 Inspection of the refrigerant circuit
• Check refrigerant charge: With the unit switched off, fit one
pressure gauge on the pressure connection on the outlet side and
another one on the pressure connection on the inlet side. Start up the
unit and check both pressure readings once they have stabilised.
• Check there are no refrigerant leaks: With the unit switched off,
check the refrigerant circuit using a suitable leak detector taking extra
care in the connection points and close to the charge connections.
• Compressor inspection: every 3000 working hours of the
compressor, the electronic board shows an alarm while the unit
continues to operate. This is a warning that the compressor requires
inspection. With the unit switched off check the status of the
connections, the electrical wiring and the rubber anti-vibration
mountings. With the unit switched on check that there are no abnormal
vibrations or noise levels in the compressors that require special
maintenance.
II.9.2.5 Inspection of the refrigerant circuit
• Check the water differential pressure switch: with the unit running
normally, slowly close the isolating valve on the unit water inlet pipe.
When this check is performed, if the isolating valve is completely closed
without the differential pressure switch cutting in, switch off the unit
immediately by pressing the ON/OFF key on the control panel and
replace the component.
• Bleeding air from the chilled water system: by using the bleed
valves situated both inside and outside the unit bleed the air trapped
inside the water circuit. Always check pressure of the water system and
pressurize with top-up water if necessary.
• Draining the water system: with the unit switched off the system
can be completely drained through the appropriate supply and drain
pipe situated on the lowest part of the unit. Make sure that the plate
exchanger is completely drained by using all the valves situated on the
water pipes inside the unit.
• Compressor inspection: every 5000 working hours of the pump,
the electronic board shows an alarm while the unit continues to operate.
This is a warning that the pump requires inspection. The inspection
consists of the external cleaning of the pump and a check of its overall
conditions.
• Cleaning the water filter: clean the filter from time to time.
SECTION II: INSTALLATION AND MAINTENANCE
II.9.3 SPECIAL MAINTENANCE
II.9.3.1 Instructions on the repair and replacement of
components
Follow the instructions below to replace a component of the unit's
refrigerant circuit:
• Always refer to the wiring diagrams enclosed with the appliance
when replacing electrically powered components. Always take care to
clearly label each wire before disconnecting, in order to avoid making
mistakes later when re-connecting.
• When the machine is started up again, always go through the
recommended start-up procedure.
II.9.3.2 Instructions on how to drain the refrigerant
circuit
In order to drain the refrigerant circuit completely by means of
homologated devices drain the refrigerant from both the high and low-
pressure sides and in the liquid line. Use the charge connections in
every section of the refrigerant circuit. In order to drain the refrigerant
fluid completely all the circuit lines must be drained. The fluid should not
be discharged into the atmosphere, as it causes pollution. It must be
stored in suitable cylinders and delivered to a company authorised for
the collection.
II.9.3.3 Eliminating circuit humidity
If during the operation of the machine there is evidence of humidity in
the refrigerant circuit, it is essential to drain the circuit completely of
refrigerant and eliminate the cause of the problem. To eliminate all the
humidity the operator must dry out the circuit by evacuating it to 70 Pa,
and then proceed to recharge it with the gas charge indicated in the
plate located on the unit.
II.9.3.4 Replacing the filter drier
To replace the filter drier, drain and eliminate humidity from the
refrigerant circuit by also draining the fluid dissolved in oil.
Once the filter has been replaced, evacuate the circuit again to
eliminate any traces of non-condensable gases which may have
entered the system during replacement. It is advisable to check that
there are no gas leaks before restarting the machine for normal
working.
II.9.3.5 Top-up / replacement of refrigerant charge
The units are factory-tested with the gas charge necessary for correct
operation. The amount of gas inside each circuit is shown on the serial
no. plate.
In cases where the R410A charge needs to be restored, drain and
evacuate the circuit by eliminating any traces of non-condensable
gases with humidity. After any maintenance operations on the
refrigerant circuit and before restoring the gas charge, wash the system
thoroughly.
Then restore the exact amount of new refrigerant shown on the serial
no. plate. The refrigerant piped from a cylinder in the liquid phase, so as
not to alter its composition (R32/R125).
Once this operation has been completed repeat the start-up procedure
of the unit and monitor its working conditions for at least 24 hours.
In case of particular conditions - for example in the event of a drop in
the level of refrigerant - when it is advisable to opt for a topping-up of
the fluid, a slight degradation of the unit performance will have to be
taken into account. In all cases the topping-up must be carried out in
the low pressure section of the machine before the evaporator, using
the appropriate pressure sockets. Make sure that the refrigerant is
introduced only in the liquid phase.
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