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Installation, operation and maintenance instructions - VMGFE102
16 STANDARD MAINTENANCE
Air conditioning equipment must be maintained by profes-
sional 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 qualifi ed technician and with the
correct material for the unit. Any inappropriate handling can
lead to uncontrolled fl uid or pressure leaks.
WARNING: 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. 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.
Simple preventive maintenance will allow you to get the
best performance from your HVAC unit:
•
improved cooling performance
•
reduced power consumption
•
prevention of accidental component failure
•
prevention of major time-consuming and costly
interventions
•
protection of the environment
There are fi ve maintenance levels for HVAC units, as defi ned
by the AFNOR X60-010 standard.
16.1 - Level 1 maintenance
See note on page 38
.
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 (condenser) cleaning - see chapter
‘Air heat exchanger - level 1’,
•
Check for removed protection devices, and badly closed
doors/covers,
•
Check the unit alarm report when the unit does not work
(see report in the AR05 017-160 control manual),
•
General visual inspection for any signs of deterioration,
•
Verify the charge in the sight-glass,
•
Check that the water temperature diff erence between
the heat exchanger inlet and outlet is correct.
16.2 - Level 2 maintenance
This level requires specifi c know-how in the electrical,
hydronic and mechanical fi elds. It is possible that these skills
are available locally: existence of a maintenance service,
industrial site, specialised subcontractor.
The frequency of this maintenance level can be monthly or
annually depending on the verifi cation type.
In these conditions, the following maintenance operations
are recommended.
Carry out all level 1 operations, then:
Electrical checks
•
At least once a year tighten the power circuit electrical
connections (see table with tightening torques).
•
Check and retighten all control/command connections, if
required (see table with tightening torques).
•
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 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 fi xing bolts.
Water circuit checks
•
Check the water connections.
•
Check the expansion tank for signs of excessive corro-
sion or gas pressure loss and replace it, if necessary.
•
Purge the water circuit (see chapter ‘Water fl ow control
procedure’).
•
Clean the water fi lter (see chapter ‘Water fl ow control
procedure’).
•
Replace the pump fi ttings after 15000 hours of operation
with defrost solution or after 25000 hours of opera-tion
with water.
•
Check the operation of the low water fl ow rate safety
device.
•
Check the status of the thermal piping insulation.
•
Check the concentration of the anti-freeze protection
solution (ethylene glycol or polyethylene glycol).
Refrigerant circuit
•
Fully clean the air heat exchangers with a low-pressure jet
and a bio-degradable cleaner (counter-current cleaning
- see chapter ‘Air heat exchanger - level 2).
•
Check the unit operating parameters and compare them
with previous values.
•
Carry out an oil contamination test. Replace the oil, if
necessary.
•
Check and if necessary re-tighten the Rotalock
connections in the oil balancing line to the specifi ed
torque value.
•
Check the operation of the high-pressure switches.
Replace them if there is a fault.
•
Check the fouling of the fi lter drier. Replace it if
necessary.
•
Keep and maintain a maintenance sheet, attached to
each HVAC unit.
All these operations require strict observation of adequate
safety measures: individual protection garments, compliance
with all industry regulations, compliance with applicable
local regulations and using common sense.
