6
GENERAL SPECIFICATIONS
Description of the components
1. Fans.
These are the helical type with scythe-shaped blades to increase the efficiency and reduce the noise level. The fans are
directly coupled to the single-phase motor by means of an external rotor. Thermal protection against operating faults is installed insi-
de the winding. As standard they are equipped with continuous adjustment of axial fans rotating speed in order to allow the units to
operate both with low outdoor temperature in cooling mode and with high outdoor temperature in heating mode.
2. Electric control and monitoring panel.
It is housed in a cabinet made of adequately thick painted sheet metal suitable for outdoor installation (protection degree IP 54). The
panel comprises the following main components:
- Main door-locking circuit-breaker.
- Fuse holders with protection fuses for each compressor.
- Fuse holders with protection fuses for the antifreeze heater.
- Fuse holders and protection fuses for the fans (accessories).
- Fan control contactors.
- Insulating and safety transformer to power the auxiliaries, protected with fuses.
- Basic monitoring board with microprocessor
Control system main functions:
temperature control of the water produced by the unit, compressor and pump operating hour counter, timing and cycling of start-ups,
input parameters by keyboard, alarms management, smart defrosting control and operating mode change (only IP unit), dynamic
set-point (climatic control), scheduling and integrative heaters contro. If you installed the hydronic kit these functions are enabled:
antifreeze with pump, start-up cycle after prolonged inactivity (anti-sticking), if the hydronic kit installed has 2 pumps there is a cycling
between each pump to ensure an equivalent lifetime.
Digital input functions
: low pressure, high pressure, high temperature on compressor supply, phase presence and sequence mo-
nitoring device on power supply, differential water pressure control, compressors thermal protection, fans thermal protection, pumps
thermal protection (only if installed MP accessory), remote ON/OFF and remote operating mode change E/I (only IP unit), demand
limit, double Set-point.
Digital output functions:
compressor start-up, pump start-up (only with MP accessory), plate heat exchanger electrical heater,
remote general alarm, 4-way valve (only IP unit), additional heating management, available digital contact on compressors running.
Analogic input functions:
in and out water temperature, coil temperature probe, external air temperature probe.
Analogic output functions:
continuous adjustment of axial fans rotating speed (if installed).
Moreover the controller allows:
- Alarm history (max 50m alarms managed with FIFO logic)
- Time scheduling (daily and weekly)
- Precise control of the water leaving temperature
- ATC (Advanced Temperature Control) prevention of the block of the unit: In case of critical conditions the machine does not stop
but is able to regulate itself and provide the maximum power that can be generated in those conditions with the compressors working
inside the admissible limits.
-Demand Limit by Digital Input and/or by Analog Input (4-20mA)
-Double Set Point by Digital Input
-Connection to BMS (supervision systems) through serial port RS 485 and MODBUS protocol
3. User interfacing terminal with display.
Control panel: composed of the instrument’s front panel, equipped with an LCD display, three indicator LEDs, and one joystick buttons
and three function button, it enables viewing and/or checking the operating mode and parameters, resources and complete alarm
diagnostics.
In particular, it enables:
· Managing alarm situations
· Checking the status of resources.
KEY
1.
Display
2.
Alarms LED
3.
LED for communication between the motherboard governing
the unit and the keypad
4.
Power supply LED
5.
Joystick Menu Button
6.
Function Button
4. Compressors.
They are the SCROLL type with orbiting coil equipped with built-in thermal protection and oil heater. The version
unit AS and AX includes: a soundproofing jacket for the compressors, acoustic cladding for the entire compressor compartment to
reduce the noise level and continuous adjustment of axial fans rotating speed. All units are equipped with five/six compressors con
-
nected in parallel (2 cooling circuits) which can operate at the same time (100% cooling power) or individually (17-33-50-67-83-100%
of the cooling power), thus adapting to the different thermal loads of the system supplied.
5. Frame structure
made of galvanized sheet metal panels coated with polyurethane powder paint to ensure maximun protection
against adverse weather conditions.
6. Evaporator
made of brazed stainless steel plates (AISI 316). It is installed in a shell of heat-insulating material to prevent the
formation of condensation and heat exchanges towards the outside. Standard supply also includes antifreeze heater a differential
pressure switch on the water circuit to avoid the risk of freezing if the water flow is shut off for some reason.
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Summary of Contents for RHA series
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