4
The heat exchanger consists of a steel shell insulated with
closed-cell foam material, while the tube bundle is made
with copper tubes. The heads can be removed for tube
inspection and cleaning. Victaulic couplings on water side
(complete with nipple for connection). On the hydraulic
connections of the heat exchanger, there are also pipe
taps for the differential pressure switch, and wells for the
temperature probes.
REFRIGERANT CIRCUIT
The refrigerant circuit of the unit comprises:
•
discharge valve for each compressors
•
charging valves
•
liquid sight glass
•
a solid cartridge dehydrator filter, which can be replaced
on the fluid line;
•
a hermetic dehydrator filter on the oil recovery line;
•
an oil warning light;
• electronic expansion valve
•
pressure transducers for reading the high and low pres
-
sure values and relevant evaporating and condensing
temperatures
•
pressure transducers and a temperature probe designed
to sense the subcooling value after the condenser;
•
a high pressure switch;
•
a high and low pressure safety valve;
• an oil separator in the delivery line;
•
an oil level warning light;
• jet pumps for oil recovery from the evaporator.
The pipes of the refrigerant circuit and the heat exchanger
on the user side are insulated with extruded closed-cell
expanded elastomer.
With reference to the Hybrid Falling Film technology, the
refrigerant subcooling value is checked through the meas
-
urement of the temperature and pressure downline of the
condenser, as shown in the picture below:
The electronic expansion valve is designed to offer en
-
hanced stability during operation and to maximise the use
of evaporation under all load conditions. This also acts as
shut-off valve on the liquid line, thereby preventing haz
-
ardous refrigerant migrations during compressor stops.
ELECTRICAL CONTROL PANEL
The electrical control panel is made in a painted galva
-
nised sheet-iron box with forced ventilation and IP21 pro
-
tection rating.
The electrical control panel of the basic unit comprises:
• main disconnect switch
• fuses to protect the compressors and the auxiliary cir-
cuits
• compressor contactors
• phase monitor
•
potential-free general alarm contacts
•
single potential free operating contacts
• microprocessor controller with display accessible from
the outside
•
Capacitive backup battery for electronic expansion valve
•
AC inverter fitted outside the panel
All the electrical cables inside the panel are numbered and
the terminal board dedicated to the customer's connec-
tions is coloured blue so that it can be quickly identified
in the panel.
Standard power supply of the unit is 400V/3~/50Hz
CONTROL BLUETHINK
Programmable microprocessor control, having proprietary
control algorithms.
The control allows the following functions:
•
Inverter management
•
Vi management
•
Electronic valve management
•
water temperature adjustment, with outgoing water
control
•
freeze protection
•
compressor timings
•
recording of the log of all machine inputs, outputs and
states
•
automatic rotation of compressor starting sequence
•
recording of the alarm log
•
management of capacity reduction of the compressors
during starting, switching off and load tracking
•
management of capacity reduction of the compressors
in the event of operation outside the limits
Connection resources
The control includes the following connection resources:
•
RS485 serial port with Modbus protocol
•
Ethernet serial port with Modbus protocol; access to in
-
tegrated web server
•
digital input for remote setting of state (on/off)
•
digital input for setting of summer/winter mode (only
for HPW version)
•
digital input for selection of double set point
By default, the serial connections present as standard are
enabled only for reading from BMS. Enabling of writing
from BMS is to be requested when ordering.
