Maintenance
96
EN
• the modification of the parameters set at the factory (ap-
plication changes);
• the removal or disassembly of the HVAC unit;
• any intervention resulting from a scheduled maintenance
intervention that was not performed;
• any interventions covered by warranty;
• one or two leak checks per year, performed by a qualified
person using a certified leak detector.
In order to reduce waste, the refrigerant and the oil must be
compliant with the current regulations, and the relative usa-
ge methods must limit the refrigerant and load losses, and
must be carried out using materials suitable for the products.
Any faults and leaks detected must be immediately repaired.
The oil recovered from the compressor during maintenance
activities contains refrigerant, and must be handled accor-
dingly.
The pressurized refrigerant must never be discharged into the
open air.
If a cooling circuit is opened, plug all the openings if the
operation is expected to last up to one full day; for longer
periods, fill the circuit with nitrogen.
Any deviations or failure to observe these maintenance
criteria will nullify the HVAC unit's warranty conditions,
thus absolving the manufacturer of any responsibility.
5.2 AIR EXCHANGER
It is recommended to regularly inspect the finned coils in or-
der to check their level of cleanliness. This depends on the
environment in which the unit is installed, and the condi-
tions will be worse in industrial and urban environments,
and around deciduous trees.
To clean the finned coil:
• if the air heat exchangers are clogged, use a brush to gen-
tly clean them in vertical direction;
• the fan must be off when working on the air heat exchan-
gers;
• the unit should be shut off for this type of operation if
deemed necessary, taking into account all the appropriate
maintenance considerations;
• clean the air heat exchangers in order to ensure the unit's
optimal operation. This cleaning operation is required on-
ce the air heat exchangers start to get dirty;
• the frequency of the cleaning operations depends on the
season and the unit's location (presence of wind, dust,
plants, etc.).
Clean the finned coil with appropriate products.
Never use pressurized water without a large diffuser at-
tachment. Never use high-pressure detergents for Cu/Cu
and Cu/Al coils.
Concentrated or rotating jets of water are strictly prohi-
bited. Never use liquids with temperatures greater than
45° C to clean the air heat exchangers. 2/3 of corrosion
problems can be prevented with proper and frequent cle-
aning (approximately every three months).
5.3 WATER HEAT EXCHANGER MAINTENANCE
Check that:
• the insulating foam is intact and remains firmly in posi-
tion.
• The BPHEs and the electric pipe heaters are functioning
properly and are correctly positioned in a secure manner.
• The connections on the water side are clean and do not
show any signs of leaks.
5.4 UNIT MAINTENANCE
Prior to performing any intervention upon the unit, make
sure that the circuit has been isolated and that no electri-
cal voltage is present. It should be noted that the circuit's
condensers could take up to 5 minutes to completely di-
scharge after the circuit has been isolated. Work upon the
VFD must only be carried out by qualified personnel.
In the event of an alarm or a persistent problem relating to
the VFD, contact the Technical Service.
VFDs equipped with units do not require an isolation test,
even if they are replaced; in fact, they are systematically in-
spected prior to delivery. Furthermore, the filtering compo-
nents installed in the VFD can distort the measurements and
can also be damaged. If the isolation of the device's compo-
nents (fan and pump motors, cables, etc.) needs to be veri-
fied, the VFD must be disconnected from the power circuit.
5.5 REFRIGERANT VOLUME
The unit must be activated in cooling mode in order to de-
termine whether the unit charge is correct, by checking the
actual subcooling.
A small refrigerant leak with respect to the initial charge will
be evident in cooling mode, and will affect the subcooling
value obtained at the output of the air heat exchanger (ca-
pacitor), but will not be visible in heating mode.
It is therefore not possible to optimise the refrigerant
charge in heating mode following a leak. The unit must be
activated in cooling mode in order to determine whether
an additional charge is required.
