tcaes 230÷4160 thae - Rhoss

SECTION II: INSTALLATION AND MAINTENANCE
Fig. 11
1. TCAE-TCAES-THAE-THAES
2. Auxiliary cock
3. Gate valve
4. Wash pump
5. Filter
6. Acid tank
II.4.3 SEASONAL BREAKS
DANGER!
When the appliance is not used for long periods of
time, disconnect the unit by opening the general
isolator with door interlock on the power circuit.
To avoid the migration of coolant into the compressor while the
appliance is not in use, stock the coolant charge in the condensing coils
by carrying out a pump-out procedure.
II.5
SPECIAL MAINTENANCE
IMPORTANT!
Maintenance work must be carried out by skilled
technicians from service centres authorised by
RHOSS, qualified to work on this type of product.
DANGER!
Do not introduce pointed objects through the air
delivery intake grilles.
DANGER!
Always act on the disconnecting switch to
disconnect the unit from the mains power supply
before carrying out any maintenance work, even if
you only intend to make an inspection.
DANGER!
In the case of cooling or fan circuit component
breakage or a drop in the coolant gas charge, the
upper part of the compressor casing and the
discharge line may reach temperatures as high as
180°C for brief periods of time.
II.5.1 REPAIRS AND COMPONENT
REPLACEMENT
• If any of the cooling circuit components need replacing, it is
necessary to bear in mind the indications in the following Paragraphs.
• 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 to avoid making mistakes
later when re-wiring.
• When the machine is started up again, always repeat the start-up
procedure outlined in Paragraph II.2.3.7.
• After carrying out any maintenance work, keep an eye on the liquidmoisture
sight-glass (LUE). After the appliance has been running for at
least 12 hours the cooling circuit must be completely “dry” and the LUE
must be green, otherwise replace the filter.
II.5.1.1 Topping up or replacing the coolant
○ The units are factory tested with a suitable coolant charge. When
the charged is replaced or topped up, the ambient and working
conditions of the appliance must be taken into account.
○ While the unit is running the coolant may be topped up on the low
pressure branch, upstream of the evaporator, using the pressure
connections provided. Any topping up of coolant must be carried out
while the coolant is in a liquid state to avoid changing its composition.
○ While topping up, watch the liquid indicator to make sure the liquid
is completely clear without any bubbles whatsoever.
○ Only restore the gas charge following maintenance operations on
the cooling circuit after the circuit has been washed-out very carefully
and after the following operations have been carried out:
• install an antacid filter on the compressor inlet and then run the unit
for at least 24 hours;
• check the degree of acidity, if necessary change the gas and oil and
then run the unit for at least 24 hours;
• remove the antacid filter cartridge.
II.5.1.2 Compressor operation
While the unit is switched off, the oil level in the compressors must
reach half way up the sight glass on the casing. The oil may be topped
up after pumping-out the compressors, using the pressure connection
on the compressor inlet.
Whenever the overload protection is triggered, normal running
conditions are automatically restored when the temperature of the
windings falls below the set safety value (this could take from a few
minutes to some hours). The power circuit overload protection is
managed by the microprocessor controller. Once the overload
protection has been triggered and reset, it is necessary to reset the
alarm on the control board. We recommend installing a remote
controlled lamp/LED signal for each compressor to warn that the
overload protections have been triggered.
II.5.1.3 ST2 antifreeze safety temperature sensor
operation
After the sensor has been activated, the alarm on the control board
must be reset. The unit restarts automatically only when the water
temperature exceeds the intervention differential.
Check the efficiency of the antifreeze protection with the help of a
precision thermometer immersed with the sensor in a container full of
cold water at a temperature below the antifreeze alarm temperature
setting. This may be done after the sensor has been removed from the
pocket on the evaporator outlet; take care not to damage the sensor
while removing it from its pocket. The sensor must be replaced with the
utmost care: introduce some conduction paste into the pocket, insert
the sensor and re-seal the external part with silicone to prevent it from
slipping out.
II.5.1.4 VTE/VTI thermostat operation
The thermal expansion valve is calibrated to maintain the gas
superheated by at least 6°C, to avoid any liquid being sucked into the
compressor.
If the superheating setting needs to be changed, act on the valve as
follows:
1. Bulb with MOP charge
2. Equalisation capillary connection
3. Valve body
4. Superheating adjustment screw
Fig. 12
Remove the screwcap on the side of the valve and then act on the
adjustment screw. By increasing or decreasing the amount of coolant,
the superheating temperature value is either decreased or increased.
The temperature and pressure inside the evaporator remains more or
less the same, regardless of changes to the heat load. After any
adjustments to the valve it is advisable to allow a few minutes to elapse
to give the system the chance to re-stabilise.
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