ARA Range
Nominal Cooling Capacities
ARAC – Air cooled water chillers
ARAH – Air / water cooled heat pumps
ARAF – Air cooled water chillers with free-cooling
AQUAFLAIRARA is the new range of UNIFLAIR chillers and heat pumps created
according to new and unique criteria regarding flexibility.
Featuring six air cooled models (0574A – 0644A – 0744A – 0964A – 1084A – 1204A)
equipped with axial fans, with nominal cooling capacities ranging from 118 to 260 kW and
available in three series:
- Chillers
- Heat pumps
- Free-cooling
Standard operation with R407c refrigerant and, on request, R22 or R134a.
Layout – Macro Components
Simple maintenance and installation of components
Easily accessible
electrical panel
Simple replacement of
components (access
from 3 sides)
Protected user
Anti-vibration supports to avoid
vibrations inside the unit
Layout – Macro Components
Condensing section
Shell & tube evaporator
Water tank
Electrical panel
Circulation pump
receiver (24 l - 10
bar max)
Temperature sensor
H2O inlet
Second temperature
sensor H2O outlet
Pump shut-off
Temperature sensor
H2O outlet
Check valve
in tandem
Main characteristics of the hydraulic section:
• The check valve is downstream from the
pumps: this allows easy replacement in the event
of pump installation.
• 1 or 2 circulation pumps (1+1 in stand by) with
automatic control: exchange if one of the two is
• 2 possible configurations: standard & high
pressure (150 and 300 kPa)
• Water tank (500 litres and 650 litres) and
expansion receiver with safety valve
•Anti-freeze heaters
• Algorithm regulation of the inlet water temperature
Cooling system
Twin system
All of the units are equipped with 4 identically sized compressors placed in parallel in pairs on two
refrigerant circuits. For this reason the circuits and the compressors are independent from each other.
Components – the compressor
All of the models are equipped with four rotary SCROLL compressors,
connected in tandem.
All of the models have two independent refrigerant circuits, guaranteeing at
least 50% of the cooling capacity in the event of problems with one of the two
circuits as well as elevated energy performance at partial loads.
• Electronic protection device on each compressor
• Internal check valve on the compressor discharge
• Rubber anti-vibration supports
• Compressor discharge tap
• A cover and other solutions which make the unit Low Noise
• R134a on request
Components – refrigerant circuit
• Composed of two independent refrigerant circuits
• Expansion valve with internal equalisation
• Accessible dehydration filters
• Valve on the liquid line and liquid sight glass with
humidity sensor
• High and low pressure gauges (onboard)
• High and low pressure transducers
Components – fans
• The units are equipped with axial fans which have a diameter of 800 mm.
• There are between 2 and 8 installed on each unit.
• They are directly coupled to the electric rotary motor which regulates the speed by means of
modulating the power supply.
• If it has been requested, modulating control of the condensing temperature is available with cut off
regulation of the fan speed.
This control is standard in low noise and low water temperature versions and when the unit features total
or partial heat recovery.
Components – condensing coil
All of the units are designed to work with maximum external temperatures of up to 45°C.
• Each unit features two coils which are placed vertically
• Copper piping and collection trays and aluminium fins (pitch 1.8 mm)
• Cataphoresis treatment (significant resistance to corrosion
thanks to epoxy resin covering)
• Metallic protection filters for the coils
• Cu – Cu protection
Components – evaporating coil
Removable Shell & Tube chilled water exchanger:
• Two gas circuits and a single hydraulic circuit which is able
to operate with low head losses
• The exchanger is completely insulated with closed cell
expanded polyurethane to prevent the formation of
condensation and to limit thermal dispersion
• Equipped with anti-freeze sensors
• Anti–freeze heaters around the evaporator
• Hydraulic connection Kit (standard on units with pumps,
water tank and ARAF)
Components – anti-vibration supports
Composed of four springs, these supports provide large deflection under load with a small
footprint, and are therefore particularly effective at insulating at low frequencies.
Moreover, it is suitable to be used in environments which
are particularly difficult and / or aggressive, since it is
highly resistant to oil, corrosion and high temperatures.
• the springs are made from elastomer with metallic
• the base is made from metal covered in elastomer
(Lexan with stud bolts).
Hydronic section
The maximum working pressures are:
• Basic version (without hydraulic fittings onboard the unit): 10barg
• Basic version equipped with hydraulic connections onboard the unit: 6barg
• All of the other versions: 5barg
Pump group: 1 or 1+1, with standard or elevated head (optional);
Water tank (with primary / secondary predisposition) (optional);
Hydraulic tubes Kit: hydronic polyurathane fittings onboard the unit
(optional for ARAC and ARAH without pump group, standard with pump group or water tank and
in the ARAF range).
Expansion tray and safety valve
Water tank
Double pump shut-off valve
Bleeding valves on the connections
Anti-freeze heaters on the: evaporator, pumps, water tank, tube fittings.
Diagram of the hydraulic circuit
Water tank
Pump shut off tap
Expansion collection tank
Check valve
Discharge water temperature sensor
Safety valve
Differential pressure switch
Second discharge water temperature sensor
Inlet water temeprature sensor
Pumps: both standard and high head versions can be selected, featuring two pole motors, with
2900 rotations per minute.
The materials used allow pump operation with pump temperatures between -10°C and 85°C.
The control
The AQUAFLAIRARA range is based on advanced technology which has lead to the use, even in the
standard version, of a new advanced control. The control is based on a UPC1m card and a mP20II user
interface which is equipped with a large size display. Moreover, the units are equipped with a LAN card
and, thanks to a RS485 serial adaptor (optional), are able to be connected to various supervision
The control is principally composed of:
· microcompressor control board, to which the sensors are connected;
· user interface.
All of the control algorithms can be found in the microprocessor control and it is also where all of the
operating parameters are memorised, displayed and set via the user terminal.
The control
The main functions which are offered by the system are:
· discharge water temperature control based on a settable setpoint;
· possibility of setting a double set-point (in cooling mode);
· possibility of calculating the setpoint depending on the compensation of the external temperature;
· complete alarm detection system with visual and acoustic signals, indicating the interventions needed to
be carried out;
· historical alarm events;
· Alarm signal contacts divided by type;
· possibility of programming automatic start-up when the power supply returns;
· remote start-up/shut-down of the unit;
· control of all of the compressors operating times, pump-down management and compressor rotation in
order to guarantee efficiency and reliability;
· 3 types of condensation regolation: modulating, step and ultra low noise step;
· suction pump management;
· anti-freeze heater management;
· unit management in heat pump mode;
· defrost management;
· password on 2 programming levels (setting, hardware and software configuration);
· possibility of communicating with a supervision system by means of a communciation protocol: Netvisor,
Modbus, Bacnet, Lon, Metasys, SNMP (TCP/IP) and Trend;
The control
· clock/date management (optional clock card);
· operating hours counter for the main components;
· display of the operating status of all of the unit components and display of the values read by the
sensors connected to the control board;
· management of the local network with the possibility of placing a unit in stand-by and
setting the operation of this unit in set back mode, regulation based on the average temperature and
the implementation of step regulation;
· override function with which the operation of the main components can be manually controlled
· improved control algorithm which continuously measures the external temperature in order to
operate more effectively in free-cooling mode.
Programme identification
Language change
It is possible to see the programme version installed in the pCO1 at any time
by using the
key. This is very important if other units need to be connected to the same
LAN network. In fact, it is necessary for all the units to have the same software installed.
Moreover, it is possible to change the language used by pressing the
buttons at the same
However, the language cannot be changed on the menus concerning hardware and software
configuration of the unit, that is, the service menu.
Switch between units in LAN
Display of unit status
To pass from one chiller to another by means of the same user terminal when the units are
connected on the same LAN network, these buttons
must be pressed at the same
The operating parameters of the unit (temperature, humidity….) can be seen by pressing
Return to the status mask by pressing the
To carry out a reset of the factory set set-point and other values (except the hardware
configurations), press the
buttons at the same time for at least 5 seconds.
If the microprocessor board has a clock card installed, the date and time will be shown on the
status mask.
There is also the possibility of setting:
• The start-up and shut-down of the unit according to a time programme.
• Historical alarm event memory
Access to the parameters:
Consultation & Programming
READ ONLY: allows the parameters to be consulted without the possibility of modifying them.
READING & PROGRAMMING: allows the data and parameters which are memorised in the
microprocessor board to be modified.
Press the
button until an acoustic signal is heard
Immediately press the
Insert the password required
Allows the hour-counter to be reset and the hour thresholds to be
modified for each component
Allows the second level alarms to be configured
Allows the real configuration of the unit, delay setting, manual start-up of
the units and their components
Contains all the functions linked to the clock card
Allows the set points to be modified
Allows the remote control, the LAn and the serial settings to be configured
Hardware configuration
The regulation programme of the unit needs to be “configured”,
that is, adapted to the unit in which it is installed; it is necessary to define all
of the elements featured on the unit and which the microprocessor must control.
In general, this intervention is required only when the control is installed onboard the unit and this is
therefore carried out in the factory during final testing; it may, however, be necessary to reconfigure the
unit should further modifications be made to the unit.
The passwords are contained inside an envelope along with the documentation which is sent on delivery
of the unit.
For simple settings the password is 0000, while for hardware configurations it is 0121.
Hardware configuration
Mask 60 allows:
• Configure the type of unit depending on if the unit is:
- a standard chiller
- low temperature chiller
- chiller with condensing heat recovery
- heat pump
- heat pump with condensing heat recovery
- chiller with free-cooling
• Selection the number of pumps and modulating regulation of the fan
Mask 61 allows the type of refrigerant gas to be set.
Hardware configuration
Allows the minimum and maximum limits of the set point
to be set.
Mask 64 allows the parameters and and condensing temperature
intervals to be set by using a remote control switch with a star
connection (lowest speed) and a triangle connection (maximum
 T.Cond.Preset.: when one of the two circuits moves from
operation with one compressor running to operation with two
compressors running, automatic change from star to triangle only
occurs if the condensing temp. (during star operation) is higher at
that value.
 T.Cond.y Set.P.: if the condensing temperature exceeds this
value when two compressors are operating on one circuit, it
switches to triangle operation;
 T.Cond.D Set.P.: if, in triangle operation, the condensing
temperature falls below this value, it returns to star operation.
Hardware configuration
The T.ev.Preset , T.ev.Y SetP and T.ev.D SetP parameters which
appear on the following masks have the same means as the previous
ones, the only difference being that they refer to the evaporating
Star / Triangle regulation and viceversa
Hardware configuration
Mask 66 allows the frequency of the electric network to be set for fan
Mask 67 and the ones following it allow the parameters concerning
modulating regulation of the fans to be set depending on the
condensing pressure: by setting the low noise mode the fan speed
regulation is based on three steps rather than two.
Hardware configuration
Standard modulating regulation
Modulating Regulation in low noise mode
Hardware configuration
In units with free-cooling, the mask which is shown here
appears which allows the start-up delta T to be set. When the
external air temperature is lower than the inlet water
temperature by the value indicated, the unit enters into freecooling mode: the water circulation pump through the freecooling coil activates and changes the profile of the compressor
insertion steps to increase the efficiency of the air-water
It is also possible to activate free-cooling in the stand – by units.
Hardware configuration
Intelligent Free Cooling activated also in the stand – by units
Hardware configuration
Screen 74 gives the option of activating or not the water circulation
pump through the free-cooling coil in anti-freeze function. If it is
activated in the stand-by unit, the FC pump is switched on as soon
as the external temperature falls below 4.5°C; it switches off when it
rises above 5.5°C.
N.B.: Only a correct glycol mixture ensures that the coil does not
freeze if the external temperature falls below zero: the function
indicated does not guarantee the integrity of the coil aboveall at
extremely low temperatures
Hardware configuration
This function can be useful if there is “fouling” of the data (setpoint, configuration, etc.) since it enables the memory to be
cleaned (including the data concerning the HARDWARE
configuration of the unit); all of the set points will automatically be
reset to the values set in the factory (see the "DEFAULT
VALUES” section).
After this operation has been carried out it is necessary to
reconfigure the control and change the set-points if they are
required to be different from the default values.
AL. PAGE CLEAR-UP. The cleaning of the historical alarm
events cancels all of the alarm events held in the memory.
HARDWARE SET-UP. This enables automatic recognition of the
devices connected to the control. This operation is useful when
options need to be added to the board, a sensor needs to be
replaced or when the display shows "NC" instead of a
temperature sensor reading.
Remote control of the unit
Start-up and shut-down of the unit can be carried out alternatively
by means of:
1. A remote contact (or “remote control");
2. A “Supervision system" connected to the microprocessor with a
serial cable.
The control of the resources with which the unit is equipped is,
however, carried out by the microprocessor.
ON/OFF BY REMOTE CONTACT: start-up of the unit is carried out
by the closure of a remote N.O. contact when power is connected
to the main board (see electrical diagram). In units with a standard
regulation programme the digital input 1 is dedicated to the sartup/shut-down of the unit.
SUPERVISION SYSTEM: a supervision system exchanges data
via a serial cable with the main board of the unit and is controlled
remotely; for this reason an optional Serial Card is available which
opto-couples the interface to a RS485 network to transmit data.
Remote control of the unit
Mask 141 allows the following to be set
1. The serial address of the unit connected to the serial supervision
2. The speed of the data transmission : 1200, 2400, 4800, 9600 and
19200 per RS485.
3. The type of protocol (standard or Modbus).
Moreover, on the fourth line the number of units connected in the LAN local
network is set (if the unit is predisposed for LAN connection)
Units in a local LAN network
• presence of such management (Yes/No); when automatic rotation is activated,
on a unit with an address lower than the network it is necessary to press the
ON button.
• the duration of the automatic cycle between one inversion and the next; if it is
zero ("0") the control will carry out a test, placing the units in rotation at intervals
of 2 minutes.
• the number of units in stand-by
Automatic rotation can happen:
• on a timed basis (according to the time of the above mentioned cycle);
• following a second level alarm, that is following an alarm for which AR or BR
has been set in the alarm address mask.
Mask 143, which is only displayed if the local network is configured, allows the
temperature regulation to be managed in three different ways:
• Independent mode: the unit control only manages water temperature
• Interconnected mode: the unit control carried out water temperature regulation
by calculating the average temperature of the units which are operating.
• Cascade mode: The control carries out an off-set on the regulation set point
depending on the units connected in the network enabling the units therefore to
be switched on in succession. Each unit maintains its own regulation schedule.
Units in a local LAN network
Mask 144, which is only displayed if the local network is configured, allows the
unit operation to be managed according to the average temperature reading
taken from the ambient of with a "local" value taken from a single sensor
present inside the unit:
-Mode: Local - Unit control is based on the temperature and humidity readings
read by the sensors present on the unit.
-Mode: Average – Unit control is based on the average temperature and
humidity reading read by the sensors present on the units connected in the local
If the difference between the average value and the reading taken by a single
sensor is higher than the “AVERAGE/LOC. DIFF.“ value (which by default is
2°C), the control automatically changes from “AVERAGE” mode to “LOCAL”
Operating parameters – the setpoint
Mask 120 does not allow settings. The discharge water temperature
setpoint used as a reference point for regulation is shown.
A message is shown in the third and fourth line indicating the origin of the
setpoint value if it is different that that which is set as standard:
-Compensation T.ext.: indicates that the setpoint shown in the second line
is calculated according to the external temperature (according to the
parameters set in the masks shown on the following pages);
-Optional SetPoint: indicates that a second setpoint is activated due to the
commutation of the contact for digital input 10;
-Supervision SetP.: indicates that the setpoint on the set-back cycle is
- Remote Offset Activated: indicates that the setpoint is calculated based
on the offset read by the analogical input 3 (an option which is possible
only if there isn’t an evaporator pressure sensor present).
Operating parameters – the setpoint
This allows the main cooling setpoint to be set and an eventual “second
setpoint” activated via commutation of a contact connected to digital input
This allows summer compensation of the ccoling setpoint to be set
according to the external temperature based on a ramp in which the
coordinates of the two angular P1 and P2 points are indicated.
Operating parameters – set back cycle
The set back cycle consists of the automatic start-up of a unit which
is switched off – but connected to the power supply – based on a
settable setpoint.
Basically, the intervention of the set back cycle has the task of
controlling the ambient conditions – even in a large area – and
even when the system is switched off; its intervention is therefore
not conditioned by the signals issed by a remote controlled system,
over which it has priority.
The intervention of the set back cycle is not considered an alarm
Reading of the alarms
By pressing the
button the alarm buzzer will switch off and the alarm description will be shown on
the display.
If the cause of the alarm has been eliminated, the last alarm message can be reset
By pressing the
button for a few seconds; the red light on the button will turn off immediately.
If the cause of the alarm has not been eliminated, the acoustic signal made by the buzzer will be activated
once more.
In order to be able to reconstruct the historical alarm sequence, the microprocessor keeps the last 100
alarm events in its memory.
All of the memorized alarm events can be read in series by pressing the button on the STATUS mask.
For alarms which are still active, general guidelines are
shown underneath the description to resolve the
Reading of the alarms
For a more in-depth description of each alarm please refer to the Control Manual.
Thermal pre-alarm of the compressor 1 This automatically re-arms when the contact
closes. If it is triggered three times in a row within a period of three hours, the alarm
is activated (N.B.: it is necessary to reset).
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