Maintenance; Standard Maintenance - Riello NXHP Series Installation, Operation And Maintenance Instructions

5 - MAINTENANCE

5.1 - Standard maintenance

To ensure optimal efficiency and reliability of the units, we
recommend establishing a maintenance contract with your local
Service organisation. This contract will include regular inspections
by Service specialists so that any malfunction is detected and
corrected quickly, ensuring that no serious damage can occur.
A Service maintenance contract is the best way to ensure the
maximum operating life for your equipment and, through the
expertise of technicians, provides the ideal way to manage your
system cost effectively. Air conditioning equipment must be
maintained by professional technicians, whilst routine checks can
be carried out locally by specialised technicians.
All refrigerant charging, removal and draining operations
must be carried out by a qualified technician and with the
correct material for the unit. Any inappropriate handling can
lead to uncontrolled fluid or pressure leaks.
CAUTION:
Before doing any work on the machine ensure that the power
is switched off. If a refrigerant circuit is opened, it must be
evacuated, recharged and tested for leaks (electronic leak
detector). Before any operation on a refrigerant circuit, it is
necessary to remove the complete refrigerant charge from
the unit with a refrigerant charge recovery group.
Ensure that the outlet of the vacuum pump is not close to any
potential ignition source and that ventilation is available.
It is also mandatory to flush the circuit twice with dry nitrogen
to evacuate all the remaining refrigerant.
Before starting the maintenance operation, make sure to have
a proper lightening of the entire unit. It is also mandatory to
conduct a leak detection before opening any panel and a leak
detection after opening the panels.
Make sure that the fan grid protection and top panels are
properly installed and attached before powering up the unit.
Simple preventive maintenance will allow you to get the best
performance from your HVAC unit:
■ Improved cooling and heating performance
■ Reduced power consumption
■ Prevention of accidental component failure
■ Prevention of major time-consuming and costly interventions
■ protection of the environment
There are five maintenance levels for HVAC units.
NOTE:
Any deviation or non-observation of these maintenance
criteria will render the guarantee conditions for the HVAC unit
nul and void, and the manufacturer, will no longer be
responsible.
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5.1.1 - Level 1 maintenance
See note in §5.1.3 Level 3.
Simple procedures can be carried out by the user on a weekly
basis:
■ Visual inspection for oil traces (sign of a refrigerant leak),
■ Air heat exchanger cleaning - see §5.3Air heat exchanger,
■ Check for removed protection devices, and badly closed panels,
■ Check the unit alarm report when the unit does not work (refer
to WUI end user manual),
■ General visual inspection for any signs of deterioration (cable
wear, rust, plugged water drain...),
Check that the water temperature difference between the heat
exchanger inlet and outlet is correct.
5.1.2 - Level 2 maintenance
This level requires specific know-how in the electrical, hydraulic
and mechanical fields.
The frequency of this maintenance level can be monthly or annually
depending on the verification type.
In these conditions, the following maintenance operations are
recommended.
Carry out all level 1 operations, then:
Electrical checks
■ At least once a year verify that the power circuit electrical
connection are well attached with the spring connector.
■ Check and verify that the control/command electrical connection
are well attached with the spring connector.
■ Remove the dust and clean the interior of the control boxes, if
required.
■ Check the status of the contactors, disconnect switches and
capacitors.
■ Check the presence and the condition of the electrical protection
devices.
■ Check the correct operation of all electric heaters.
■ Check that no water has penetrated into the control box.
■ Mechanical checks
■ Check the tightening of the fan tower, fan, compressor and
control box fixing bolts.
■ Check continuity of earth bonding
■ Check that cabling is not subject to wear
Water circuit checks
■ Always take care when working on the water circuit to ensure
that the condenser close by is not damaged.
■ Check the water connections.
■ Check the expansion tank for signs of excessive corrosion or
gas pressure loss and replace it, if necessary.
■ Purge the water circuit (see §2.5 Water flow rate control).
■ Clean the water filter (see §2.5 Water flow rate control).
■ Examine the water pump bearing after 17500 hours of operation
with water and the water pump mechanical seal after 15000
hours. Check the operation of the low water flow rate safety
device.
■ Check the status of the thermal piping insulation.
■ Check the concentration of the anti-freeze protection solution
(ethylene glycol or propylene glycol).