Maintenance - RHOSS TCAEBY 269 Mode D'emploi

EN
Calibration of safety and control devices
The units are tested in the factory, where they are also calibrated and
the default parameter settings are put in. These guarantee that the
appliances run correctly in rated working conditions. The devices which
monitor safety of the unit are the following:
High pressure switch (PA)
Water differential pressure switch
High pressure safety valve
Low pressure transducer (triggers low pressure alarm, see Electronic
Control Manual coupled to the unit)
Safety component calibration settings
High pressure switch (PA)
Water differential
High pressure safety valve
!
DANGER!
The safety valve on the high pressure side is calibrated at 43 bar. It can intervene
burst that could cause burns (just like the other valves of the circuit).
Operation of components
Compressor functioning
Scroll compressors are equipped with internal circuit breaker
protection. Once the inner thermal protection has tripped, it is restored
automatically when the windings temperature drops below the pre-set
safety value (this can take from a few minutes to several hours). To
restore normal machine operation, reset the alarm on the control panel.
Refer to the Troubleshooting section to detect the problem and carry
out the necessary maintenance.
Operation of work, antifreeze and pressure probes
Temperature probes are inserted inside a socket in contact with
conductive paste and externally sealed with silicon:
One is placed at the entrance of the heat exchanger and measures
the temperature of the return water from the system;
The other is placed at the exit of the evaporator and acts as an operational
and antifreeze probe in units with no water buffer tank and only as an anti-
freeze probe in units with water buffer tank.
that this is properly inserted in the housing on the electronic board (see
wiring diagram provided).
thermometer immersed with the probe in a container full of water at a
certain temperature, after having removed the probe from the socket
paying attention to not damage it in the process.
The probe must be carefully repositioned by placing some conductive
paste in the socket, inserting the probe and re-sealing the external part
with silicon to avoid unscrewing. If the antifreeze alarm is triggered, this
must be reset through the control panel. The unit starts up again only
when the water temperature exceeds the triggering difference.
Section II :: Installation and maintenance
Reset
Intervention
33 bar
42 bar
manual
105 mbar
80 mbar
automatic
43 bar -
84
Thermostatic valve operation
The thermostatic expansion valve is calibrated to
maintain the gas superheated by at least 5°C, to prevent the compressor
from sucking liquid.
If the superheating setting must be changed, adjust the valve as follows:
rotate anticlockwise to reduce overheating;
rotate clockwise to increase overheating.
Remove the screw cap on the side of the valve and then turn the
adjustment screw using a screwdriver.
By increasing or decreasing the amount of refrigerant, 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 thermal load.
After any adjustments to the valve, we recommend waiting a few
minutes to allow the system to re-stabilise.
Electronic thermostatic valve functioning
The electronic thermostatic expansion valve is calibrated to maintain
the compressor. The operator is not called upon to perform calibration
since the control software of the valve monitors these operations
automatically.
Functioning of PA: high pressure switch
After the pressure switch has been triggered, it must be reset manually by
pressing the black button on the pressure switch itself completely and reset
the alarm from the control panel. Refer to the Troubleshooting section to
detect the problem and carry out the necessary maintenance.

MAINTENANCE

IMPORTANT!
Maintenance is reserved exclusively for skilled personnel from workshops
close attention to the danger signs on the unit. Use the personal protective
equipment foreseen by current laws. Pay the utmost attention to the symbols
located on the unit. Use EXCLUSIVELY original RHOSS S.p.a. spare parts.
DANGER!
Always act on the general automatic switch protecting the system before carrying
out any maintenance work, even if it is purely for inspection purposes. Make sure
that no one supplies power to the machine accidentally; lock the master switch
in zero position.
DANGER!
Pay attention to high temperatures near the compressor heads and the supply
pipes of the refrigeration circuit.