Starting And Stopping The Machine - Startup After Prolonged Shutdown; Compressor Operation; Working Of St2: Safety Antifreeze Temperature Sensor; Vte/Vti Operation: Thermostatic Valve - RHOSS TCCE 135 Gebrauchsanweisung

II.4.4 STARTING AND STOPPING THE MACHINE –
STARTUP AFTER PROLONGED SHUTDOWN
IMPORTANT!
Machine commissioning or first startup must be
carried out by skilled personnel from authorised
RHOSS service centres, trained to work on this type
of product.
○ Disconnect at the main isolator switch before carrying out any
maintenance operation, even if it is only an inspection.
○ Before starting the unit, make the following checks:
The electricity power supply must comply with the specifications
indicated on the data plate and/or the wiring diagram (three phase
power supply L1-L2-L3 + NEUTRAL) and it must fall within the following
limits:
• Variation of the power supply frequency: ±2 Hz.
• Variation of the supply voltage: ±10% the nominal voltage.
• Imbalance between the supply phases: < 2%.
Electrical connections must be carried out in compliance with the local
installation standards in force in the place where the unit is installed,
and with the instructions in the wiring diagram provided with the unit.
The installer is responsible for using power supply cables of appropriate
size.
IMPORTANT: before connecting the main L1-L2-L3+N power
supply cables to the terminals on the main isolator switch, make
sure they are in the correct sequence.
• Open the electric panel and make sure the power supply terminals
and contactors are tight (they may have come loose during transport,
which could lead to malfunctions);
• check that the compressor crankcase oil level is at least half-way up
the sight-glass;
• make sure the flow and return pipes on the water system are
connected according to the arrows next to the water exchanger inlet
and outlet;
• make sure the condensing coil is well ventilated and clean.
○ On all units, the microprocessor control board activates starting only
when 3 minutes have passed from the last time the machine stopped.
○ At this point the unit can be started by pressing the main ON/OFF
key on the user interface panel of the microprocessor board, located in
the electrical box. Any malfunctions are immediately displayed on the
control panel by way of alarm signals.
II.4.4.1 End-of-Day Shutdown
The unit can be shut down at the end of the day by pressing the
ON/OFF key situated on the user interface panel, or by the use of a
remote ON/OFF control, which may be fitted following the instructions in
the wiring diagram.
In this way power is maintained to the compressor crankcase electric
heaters.
II.4.5

COMPRESSOR OPERATION

With the unit 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.
If the thermal protection is triggered, normal working is automatically
resumed once the temperature of the windings drops below the pre-set
safety value (this can take anything from a few minutes to several
hours). This protetion 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.
SECTION II: INSTALLATION AND MAINTENANCE
II.4.6 WORKING OF ST2: SAFETY ANTIFREEZE
TEMPERATURE SENSOR
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 trigger 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
socket on the evaporator outlet; take care not to damage the sensor
while removing it from its socket. The sensor must be replaced with the
utmost care: introduce some conduction paste into the socket, insert the
sensor and re-seal the external part with silicone to prevent it from
unscrewing.
II.4.7 VTE/VTI OPERATION: THERMOSTATIC
VALVE
VTI: Winter thermostatic valve.
VTE: Summer thermostatic expansion valve
The thermostatic 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, adjust the valve as
follows:
Fig. 19
Remove the screwcap on the side of the valve and then act on the
adjustment screw. 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 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.
44
Fig. 18