Maintenance - AERMEC VENICE Manual Del Usuario

temperature read by a thermometer
in contact positioned on the exit pipe
of the condenser with the temperature
shown on the high pressure manometer
(saturation temperature correponding
tot he condensation pressure).
The difference between these two
temperatures gives the undercooling
value. The optimal values are between
4 and 5°C.
The manometer is not supplied
with these units. Installation is
recommended on
pressure point.
6.2.4 Pressing temperature
If the undercooling and overheating
values are regular, the temperature
measured in the pressing pipe at the
exit from the compressor must be
30/40°C above the condensation
temperature.
NOTE
All routine and extraordinary maintenance
operations must be carried out exclusively
by qualified staff.
The unit's electric power supply must
be removed before any operation or
cleaning.
All appliances are subject to inevitable
deterioration through time.
Maintenance allows to:
- Keep the unit efficient
- Reduce the speed of deterioration
- Collect information and data and
understand the state of efficiency of the
unit in order to prevent possible faults.
Regular checks are therefore fundamental
• WEEKLY
• MONTHLY
• YEARLY
• PARTICULAR CASES
Prepare a book for the machine (not supplied
and under the user's responsibility), that
allows to trace the interventions carried
out on the unit. In this way it will be easier
to suitably organise the interventions, also
making troubleshooting and prevention of
machine faults easier.
State the following in the book: date,
type of intervention performed (routine

maintenance,

inspection
28
6.3
If the plant should stop during the
winter period, the water present
in the heat exchanger can freeze,
causing irreparable damage to the
heat exchanger itself, the complete
discharging of the cooling circuits
and, sometimes, damage to the
compressors.
The following solutions are possible in
the relative order to prevent this problem.
Circuit without glycol:
- Complete discharge of the water
from the heat exchanger at the end
of the season and filling at the start
of the following season, by means of
a draining valve, whose installation is
the responsibility of the installer.
- Use
resistances (not supplied).
In this case the resistances must
always be live for the entire period
7
description of the intervention, measures
activated...
61
Functioning test at full pressure
• Check the values listed below
- E n t r y / e x i t p r e s s u r e o f t h e
compressor
- Check, using t he appr opriat e
instruments, the evaporation/
condensation pressure, checking
overheating and undercooling.
- The temperature difference between
entry and exit from the water side
evaporator.
6.2
• Cooling circuit
Functioning test at full pressure, as well as
weekly checks also control:
1. The compressor exit temperature
2. The level of compressor oil
3. The real undercooling of the liquid
4. Check the state of the dehydrator
filter, positioned at the condenser
exit, by means of exit and entry
temperature controls of the same.
If this is higher than 3 °C the filter
is dirty and must be replaced
or repair), 5. In the heat pump units, check
PLANT LOADING/
UNLOADING
heat exchanger heating
MAINTENANCE
WEEKLY checks
MONTHLY checks
when freezing is possible (machine in
stand-by).
Circuit with glycol
- Functioning with glycoled water, with
a percentage of glycol chosen on
the basis of the envisioned minimum
winter temperature. In this case
the different performances and
absorptions, dimensioning of the
pumps and performance of the
terminals of the chiller must be taken
into consideration.
the good de-frosting of the air
batteries.
• Electric checks
- Check that all of the electric connections
are correctly fixed and all clamps are
suitably tightened.
- Check the state of the contactors, the
fuses...
• Hydraulic checks
- Check that the hydraulic circuit is water-
proof.
- Clean the water filter
- Check the flow meter
6.3 YEARLY checks
• Cooling circuit
- Check that the cooling circuit is
waterproof and that its pipes have not
undergone damage.
- Carry out the acidity test of the oil in the
cooling circuit.
- Check functioning of the high and
low pressure pressure switches.
They must be replaced in the case of
malfunctioning.
- Check the state of scaling of the
dehydrator filter. If positive, replace it.