CLIMAVENETA ACCURATE Operating instructions

GB
USER AND MAINTENANCE MANUAL
precision air-conditioners
ACCURATE
Direct expansion
Direct expansion
AXO air outlet from the top
AXU air outlet from the bottom
Water-cooled
AWO air outlet from the top
AWU air outlet from the bottom
frame 1: 07-10
frame 2: 15-18
frame 3: 20-26-29
frame 4: 39-30-40-50
frame 5: 55-60-70

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ACCURATE AX* - AW*
INDEX
General characteristics 2
Unit configuration 2
Air flows 5
Rating plate 6
General technical data 6
Commissioning and testing 8
Operation and control 9
Instruments and alarms 10
Calibrating the control and safety devices 11
Calibrating the pressure control valve 11
Calibrating the air flow sensor 12
Calibrating the dirty filter sensor 12
Temperature and humidity probe 13
Servomotor and hot water valve 13
Electrical specifications 14
Maintenance 15
Electric heaters 17
Tightening the drive belts 17
Humidifier 18
Terminal and board configuration 19
Troubleshooting 19
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AIU
In some parts of this manual, the following symbols are
used:
WARNING = for actions that require special
care and suitable preparation
PROHIBITED = for actions that absolutely
MUST NOT be performed
A
I
U
The following symbols are used in this publication and inside the unit:
User
Installer
Assistance
Important
Prohibition
Specialist personnel
(electrician)
Person with in-depth knowledge
and experience such as to be
able to recognise risks and avoid
dangers that may derive from
electricity (IEV 826-09-01).

ACCURATE AX* - AW*
2English 01/07
DOCUMENTS
DOCUMENTS ENCLOSED WITH THE UNIT
Each unit is delivered complete with the following documents:
• Air-conditioner installation manual;
• Air-conditioner user and maintenance manual;
• Instruction manual for the microprocessor controller;
• Wiring diagram;
• List of spare parts;
• CE declaration with list of European directives and standards
that the unit is compliant with;
• Warranty conditions.
AIU
DIRECT EXPANSION UNIT CONFIGURATION AIU
12345678910111213141516171819202122
AXO2 9ME
RANGE A ACCURATE air-conditioner Climaveneta Version
L Air-cooled “LT” (low temperature)
VERSION W Water-cooled
X Air-cooled
COMPRESSORS AND CIRCUITS B N° 2 Compressors N° 2 Circuits
M N° 1 Compressor N° 1 Circuit
C Centrifugal direct traction (standard from 07 to 18 kw)
E EC Inverter fans high efficiency
P Centrifugal direct traction high ESP, 3 speeds (from 07 to 18 kw)
FANS T Centrifugal V-belts ESP 20 Pa (from 21 to 88 kw)
U CentrifugalV-belts ESP 50 Pa (from 21 to 88 kw)
X CentrifugalV-belts ESP 100 Pa (from 21 to 88 kw)
Y Centrifugal V-belts ESP 150 Pa (from 21 to 88 kw)
Z Centrifugal V-belts ESP 200 Pa (from 21 to 88 kw)
VOLTAGE M 230 V 1Ph+N 50Hz
T 400 V 3Ph+N 50Hz
B Over (intake from the bottom)
AIR FLOW O Over (intake from the front)
R Over (intake from the rear)
U Under (intake from the top)
07 Frame 1 (7 kw)
10 Frame 1 (10 kw)
15 Frame 2 (15 kw)
18 Frame 2 (18 kw)
20 Frame 3 (20 kw)
26 Frame 3 (26 kw)
FRAME/POTENZA 29 Frame 3 (29 kw)
30 Frame 4 (30 kw)
39 Frame 4 (39 kw)
40 Frame 4 (40 kw)
50 Frame 4 (50 kw)
55 Frame 5 (55 kw)
60 Frame 5 (60 kw)
70 Frame 5 (70 kw)
Digit 1
Digit 2
Digit 3
Digit 4-5
Digit 6
Digit 7
Digit 8
FLUID + 0 R407 C
CONDENSER 1 R407 C + pressostatic valve x condenser control
CONTROL 3 R22
4 R22 + pressostatic valve x condenser control
Digit 9
type
digit
exe
0 Semi-graphic user terminal on the unit
CONTROL 1 Without user terminal
2 Semi-graphic user terminal + wall mounting kit
Digit 10

ACCURATE AX* - AW* 3
English 01/07
THERMOSTATIC VALVE 0 Mechanical thermostatic valve
1 Electronic thermostatic valve
0 No post-heating
1 STD heaters with 3 steps
HEATING 3 Hot water post-heating coil
4 Hot water post-heating coil + STD heaters with 3 steps
6 Hot gas post-heating coil
7Hot gas post-heating coil + STD heaters with 3 steps
0 No humidity and condensate management
1 Probe for humidity reading only
2 Humidifier
HUMIDITY CONTROL 4 Dehumidification with partial coil operation
6 Humidifier + Dehumidification / part coil
8 Humidifier + Dehumidification / part coil + condensate drain pump
9 PPump for draining the condensate and/or the steam cylinder
0 No board
A Clock board
B RS485 board
C RS232 board (GSM modem)
D Ethernet board
ELECTRONIC BOARDS E LON board
F Trend board
G Clock board + RS485 board
H Clock board + RS232 board
L Clock board + Ethernet board
M Clock board + LON board
N Clock board + Trend board
0 No sensor
1 Dirty filter sensor
2 Fire sensor
3 Smoke sensor
SENSORS 4 Fire + smoke sensor
5 Fire + smoke + flooding sensor
6 Flood sensor
7 Dirty filter + fire + smoke sensor
8 Dirty filter + flood sensor
9 Dirty filter + fire + smoke + flood sensor
0 Class 0 panels (A1-DIN 4102)
1 Class 1 panels STD insulation
HEAT AND SOUND 2 Class 1 panels soundproof insulation
INSULATION 3 Class 0 panels (A1-DIN 4102) + soundproofing hoods on the compressors
4 Class 1 panels STD insulation + soundproofing hoods for compressors
5 Class 1 soundproofed panels + soundproofing hoods for compressors
0 No damper
1 Pressure-relief damper (Over units only)
DAMPERS 2 Motor-driven damper
3 Motor-driven damper with spring return, in view
4 Motor-driven damper + side panel
5 Motor-driven damper + rwith spring return + side panel
2 Air filter with EU2 efficiency
4 Air filter with EU4 efficiency
AIR FILTER 5 Air filter with EU5 efficiency
6 Air filter with EU2 efficiency + air change filter
7 Air filter with EU4 efficiency + air change filter
8 Air filter with EU5 efficiency + air change filter
PACKAGING 0 Thermoplastic perimeter protection + cardboard lid
1 Wooden crate
EXTRAS 0 No extras requested
S No Digit for request
Digit 11
Digit 12
Digit 13
Digit 14
Digit 15
Digit 16
Digit 17
Digit 18
Digit 19
Digit 20

4English 01/07 ACCURATE AX* - AW*
AW*AX*
AIR-COOLED DIRECT EXPANSION UNIT - VERSION
AX*
Refrigerant circuit
All models have a single refrigerant circuit, and in some cases two
circuits.
See the DIGIT on the previous page.
The compressor pumps the hot refrigerant gas into the outdoor
condenser.
The liquid refrigerant then flows to a liquid receiver installed in
the indoor unit, to ensure a constant flow of refrigerant to the
thermostatic valve and subsequently the evaporator.
Here the liquid refrigerant absorbs the heat from the environ-
ment and changes state, becoming a gas, then returning to the
compressor: the cycle is then repeated.
To ensure the correct discharge pressure of the refrigerant, the
outdoor condenser is fitted as standard with fan speed control.
Valves for isolating the refrigerant circuit are supplied as standard
to assist the routine maintenance operations.
The Scroll compressor is fitted with a non-return valve to pre-
vent the migration of liquid from the outdoor condenser in the
summer, and unwanted flows of refrigerant during start-up.
A second non-return valve, to be fitted by the installer, is recom-
mended during operation in winter, to prevent the migration of
the refrigerant charge from the liquid receiver to the outdoor
condenser, with consequent low pressure alarms.
Air-cooled condenser, outdoor installation
The indoor unit can be connected to different types of outdoor
condensers, standard or low noise versions, with special treat-
ments on the coils.
For the corresponding information refer to the manual on out-
door air-cooled condensers.
Note 1: the outdoor units and condensers are supplied separately
Note 2: the indoor unit is delivered charged with nitrogen at near
atmospheric pressure. The outdoor condenser, on the other hand,
is supplied pressurised with dry air (around 3 bar.)
Note 3: the customer is considered responsible for making the
correct connections between the indoor and outdoor unit, as
clearly indicated in the Installation manual, and for ensuring the gas
and oil charges, where necessary.
WATER-COOLED DIRECT EXPANSION UNIT - VER-
SION AW*
Refrigerant circuit
All models have a single refrigerant circuit, and in some cases two
circuits.
See the DIGIT on the previous page.
The compressor pumps the hot refrigerant gas into the indoor
condenser made from braze welded steel plates.
The liquid refrigerant then flows to a liquid receiver installed in
the indoor unit, to ensure a constant flow of refrigerant to the
thermostatic valve and subsequently the evaporator.
Here the liquid refrigerant absorbs the heat from the environ-
ment and changes state, becoming a gas, then returning to the
compressor: the cycle is then repeated.
To ensure the correct discharge pressure of the refrigerant, the
outdoor condenser is fitted as standard with fan speed control.
Valves for isolating the refrigerant circuit are supplied as standard
to assist the routine maintenance operations.
The Scroll compressor is fitted with a non-return valve to pre-
vent the migration of liquid from the outdoor condenser in the
summer, and unwanted flows of refrigerant during start-up.
A second non-return valve, to be fitted by the installer, is recom-
mended during operation in winter, to prevent the migration of
the refrigerant charge from the liquid receiver to the outdoor
condenser, with consequent low pressure alarms.
Water condenser
The units are fitted with an internal braze welded steel plate heat
exchanger.
During installation, a pressure control valve should be fitted
(available in the price list) to manage the condensing pressure.
(See the User and Maintenance Manual)
This circuit works with primary water or with a closed circuit
connected to an external Dry Cooler or an evaporative tower.
For “closed” circuits, the water should be mixed with antifreeze
to prevent frost during the winter, with consequent damage to
the systems: see the installation manual to calculate the required
percentage of antifreeze fluid.
The Dry Coolers are supplied as an accessory (see the price list),
while the antifreeze fluid and fluid circulating pump are generally
supplied by other companies.
For “open” circuits, mechanical filters are required to protect
against impurities and prevent the braze welded plate heat
exchanger from blocking.
To reduce energy consumption (pump), a valve should be fitted to
close the circuit when the indoor unit is off.
Note 1: the water-cooled indoor units (AW*) come with the
refrigerant circuit completely charged and tested in the factory
before being delivered.

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ACCURATE AX* - AW*
AIR FLOWS AI
The ACCURATE air-conditioners are available in different con-
figurations, based on the air intake and outlet positions; the main
distinction is between OVER and UNDER units.
The versions defined as OVER with air outlet from the top gene-
rally have the air intake at the front, rear and/or from the bottom,
as required by the customer, and the air outlet from the top of
the unit, in ducts, false-ceilings, or from outlet plenums at the
front.
fig. 1 fig. 2
fig. 3 fig. 4
1OVER units with intake from the front and outlet plenum 2OVER units with intake from the front and outlet from the
top
3OVER units with intake from under the floor and outlet from
the top
4OVER units with intake from the rear and outlet from the top
5UNDER units with intake from the top and front outlet
plenum.
6UNDER units with intake from the top and outlet under the
floor
The versions defined as UNDER with air outlet from under the
floor have the air intake through the top of the unit directly from
the environment, or via ducts and/or intake plenums.
fig. 5
fig. 6
AXO - AWO
AXU - AWU

6English 01/07 ACCURATE AX* - AW*
The air-conditioner rating plate is positioned on a panel inside
the unit, and provides the following information:
- Model and serial number of the unit;
- Power supply (voltage, phases and frequency);
- Power input of the unit and the individual components;
- Current input of the unit and the individual components: OA
(Operating current), FLA (Full load current) and LRA (Locked
rotor current);
- Settings of the pressure switches in the refrigerant circuit (HP
and LP);
- Type of refrigerant (R407C/R22);
- Charge or pre-charge in each refrigerant circuit (AW* ver-
sions only)
RATING PLATE AIU
MODEL SERIAL NUMBER
CODE
COOLING CAPACITY kW
POTENZA TERMICA kW
PRESSIONE MASSIM bar
ALIMENTAZIONE ELETTRICA DI POTENZ V - ~ - Hz
ALIMENTAZIONE ELETTRICA AUSILIARI V - ~ - Hz
POTENZA ELETTRICA MAX. ASSORBIT kW
CORRENTE MAX. ASSORBIT A
CORRENTE DI SPUNT A
GRADO DI PROTEZIONE IP X 4
SCHEMA ELETTRIC N°
PESO IN FUNZIONAMENT kg
ANNO DI FABBRICAZIONE
GENERAL TECHNICAL DATA AIU
Total cooling capacity (1) kW 7,2 10 15 18 20,8 26,6 29,5
Sensible cooling capacity (1) kW 7,2 9,1 14,6 17,5 20,8 25,6 27
SHR (1) 1 0,91 0,97 0,97 1 0,96 0,91
Total cooling capacity (2) kW 6,8 9,1 13,5 16,2 18,9 24,2 26,6
Sensible cooling capacity(2) kW 6,8 8,7 13,3 16 18,9 23,7 25,2
SHR (2) 1 0,95 0,98 0,99 1 0,98 0,95
No. of compressors
n°1111111
Total power input kW 1,72 2,52 3,83 4,4 5,05 6,75 7,65
N° circuits n° 1111111
Air flow-rate mc/h 2400 2400 4900 4800 6500 8000 8000
No. of fans
n°1122111
Total power input kW 0,49 0,49 0,9 0,9 1,8 2,2 2,2
ESP (3) Pa 20 20 20 20 20 20 20
Noise level (5) 49 51 55 55 55 56 56
Standard power supply V/ph/Hz 400/3+N/50
Width mm 600 1000
Depth mm 500 790
Height mm 1980
ARC outdoor condenser 014m 014m 021m 025m 030m 040m 040m
Total cooling capacity (1) kW 39,4 30,2 40,5 50,4 55,8 61,6 70,6
Sensible cooling capacity (1) kW 39,4 30,2 40,5 48,4 55,8 61,6 65
SHR (1) 1 1 1 0,97 1 1 0,92
Total cooling capacity (2) kW 35,8 27,5 36,8 45,4 50,8 56 63,6
Sensible cooling capacity (2) kW 35,8 27,5 36,8 45 50,8 56 60,4
SHR (2) 1 1 1 0,99 1 1 0,95
No. of compressors n°1222222
Total power input kW 9,75 7,66 10,1 13,5 13,1 15,6 19,6
N° circuits n° 1222222
Air flow-rate mc/h 13500 10500 13500 13500 19000 19000 19000
No. of fans n°2222333
Total power input
kW43,244666
ESP (3) Pa 20 20 20 20 20 20 20
Noise level (5) 57 54 56 56 57 57 57
Standard power supply V/ph/Hz 400/3+N/50
Width mm 1550 2100
Depth mm 790
Height mm 1980
ARC outdoor condenser 052m 042b 051b 077b 077b 088b 93b
ACCURATE AX air cooled 07 10 15 18 20 26 29
ACCURATE AX air cooled 39 30 40 50 55 60 70
1 - 24°C-50%, 35°C ext
2 - 20°C-50%, 35°C ext
3 - Standard centrifugal fans
5 - measured at 1,5 m haight and 2 m front in free field

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ACCURATE AX* - AW*
Total cooling capacity (1) kW 7,5 10 15 18,9 20,8 27,4 30,8
Sensible cooling capacity (1) kW 7,5 9,1 14,6 17,2 20,8 26 27,6
SHR (1) 1 0,91 0,97 0,9 1 0,95 0,9
Total cooling capacity (2) kW 6,8 9,1 13,5 17 18,9 24,7 27,4
Sensible cooling capacity (2) kW 6,8 8,7 13,5 16,5 18,9 24,2 26,1
SHR (2) 1 0,95 1 0,97 1 0,98 0,95
No. of compressors n°1111111
Compressor power input kW 1,68 2,52 3,83 4,15 5,05 6,2 7,2
N° circuits n° 1111111
Air flow-rate mc/h 2400 2400 4900 4800 6500 8000 8000
No. of fans n°1122111
Fans power input
kW 0,49 0,49 0,9 0,9 1,8 2,2 2,2
ESP(3) Pa 20 20 20 20 20 20 20
Noise level (5) 49 51 55 55 55 56 56
Water flow-rate (1) l/h 1570 2150 3250 3975 4455 5780 6540
Pressure drop Dp (1) kPa 12 19,5 11 10,8 13 14 17,9
Water content l 0,66 0,66 1,16 1,53 1,53 1,77 2,2
Standard power supply V/ph/Hz 400/3+N/50
Width mm 600 1000
Depth mm 500 790
Height mm 1980
ADC outdoor condenser 013 013 025 025 030 038 051
Total cooling capacity (1) kW 39,4 30,2 42 50,4 58 61,6 70,6
Sensible cooling capacity (1) kW 39,4 30,2 42 48,4 58 61,6 68,4
SHR (1) 1 1 1 0,97 1 1 0,97
Total cooling capacity (2) kW 35,8 27,5 38,3 45,4 52,8 56 63,6
Sensible cooling capacity (2) kW 35,8 27,5 38,3 45 52,8 56 63
SHR (2) 1 1 1 0,99 1 1 0,93
No. of compressors n°1222222
Compressor power input kW 9,75 7,66 9,4 13,1 12,6 15,6 19,6
N° circuits n° 1222222
Air flow-rate mc/h 13500 10500 13500 13500 19000 19000 19000
No. of fans n°2222333
Fans power input kW43,244666
ESP (3) Pa 20 20 20 20 20 20 20
Noise level (5) 57 54 56 56 57 57 57
Water flow-rate (1) l/h 8465 2x3260 2x4420 2x5460 2x6070 2x6640 2x7760
Pressure drop Dp (1) kPa 24,1 10,5 13 15,9 15,5 18,3 21,8
Water content l 02,8 2x1,16 2x1,53 2x1,77 2x2,2 2x2,2 2,5,6
Standard power supply V/ph/Hz 400/3+N/50
Width mm 1550 2100
Depth mm 790
Height mm 1980
ADC outdoor condenser 062 078 078 078 078 092 102
ACCURATE AW water cooled 07 10 15 18 20 26 29
ACCURATE AW water cooled 39 30 40 50 55 60 70
1 - 24°C-50%, water IN / OUT 30°-35°c
2 - 20°C-50%, water IN / OUT 30°-35°c
3 - standar centrifugal fans
5 - measured at 1,5 m haight and 2 m front in free field

8English 01/07 ACCURATE AX* - AW*
COMMISSIONING PROCEDURE
Arm the cutout in the auxiliary circuits;
Arm all the cutouts on the electrical panel;
Power up the air-conditioner electrical panel and close the main
disconnecting switch on the unit (position 'I');
Check that the control board is powered; Check that both the
LEDs relating to the phase sequence relay (RSF) are on; the yellow
LED indicates power, the green LED indicates that the sequence of
phases is correct.
If the green LED is off, disconnect power supply from the units, rever-
se two phases of the power cable and restart the commissioning pro-
cedure.
(In the units with sump heaters)
After having powered up the air-conditioner, wait at least 12 hours
before starting so as to suitably heat the oil in the compressors.
During extended shutdown there may be spontaneous migration of
refrigerant to the compressor sump, which at the start may cause the
oil to foam and consequent damage due to insufficient lubrication.
As a result, do not disconnect power during weekly pauses;
Open the on-off valves in the refrigerant circuits and check that the
air-cooled remote condensers are connected (air-cooled models);
Check that the external radiators are connected and make sure there
is water flow for cooling (water-cooled models);
Check that the sections of corrugated pipe with the function of drain
trap (both inside and outside of the air-conditioner) have been filled
with water during installation.
AT LEAST 12 HOURS AFTER POWER UP:
Start the air-conditioner using the buttons on the user terminal;
If an alarm is activated refer to the controller instruction manual.
COMMISSIONING AND TESTING AIU
EMPTYING THE REFRIGERANT CIRCUIT AND
CHARGING WITH REFRIGERANT
The water-cooled units (AWO, AWU) are already charged with
refrigerant, either R407C or R22 (check the rating plate on the
unit and the compressors to see which type of refrigerant is
used).
The air-cooled units (AXO, AXU) are pre-charged with nitrogen
to prevent moisture from entering the circuit; in this case, the
refrigerant charge must be completed by the installer, following
the instructions shown in this paragraph.
R22 R407C
Open any valves in the unit or in the system to ensure that all the components are involved in the emptying operation;
Connect a high efficiency vacuum pump to the Schrader fittings or to the 1/4” SAE fittings on the compressor suction and discharge side;
Connect a cylinder of refrigerant to the charge fittings.
Empty the lines, ensuring an absolute pressure of less than 100
Pa (0.7 mm Hg) for an extended period, so as to remove the air
and any traces of moisture.
Empty the lines, ensuring an absolute pressure of less than 10 Pa
(0.07 mm Hg) for an extended period, so as to remove the air
and any traces of moisture.
The circuit should be emptied slowly and maintained for an extended period, rather than performed too quickly.
Wait 100 seconds and check that the absolute pressure does not rise above 200 Pa.
Break the vacuum by pre-charging from the cylinder of R22
refrigerant.
Break the vacuum by pre-charging from the cylinder of R407C
refrigerant in the liquid phase.
After having started the compressor, complete the charge slowly, until the pressure stabilises in the lines and the gas bubbles disappear
from the flow indicator;
Refrigerant Type of oil
R22 (Mineral oil) Suniso 3 GS White oil
R407C (POE) Mobil EAL Arctic 22 CC ICIEMKARATE RL 32S CF
The charge must be checked at the environmental design conditions
and with a discharge pressure of around 18 bar (equal to a saturated
temperature of 48°C); for units with on-off condenser control, par-
tially close the intake to stop the condenser fan from repeatedly
starting-stopping.
Make sure that the subcooling of the liquid at the thermostatic valve
intake is between 3 and 5°C less than the condensing temperature
read on the pressure gauge and that the superheating of the vapour
at the evaporator outlet is around 5 °C.
The charge must be checked at the environmental design conditions
and with a discharge pressure of around 18 bar (equal to a dew
point of 48°C and boiling point of 43°C); for units with on-off con-
denser control, partially close the intake to stop the condenser fan
from repeatedly starting-stopping.
Make sure that the subcooling of the liquid at the thermostatic valve
intake is between 3 and 5°C less than the condensing temperature
read on the pressure gauge and that the superheating of the vapour
at the evaporator outlet is around 5 °C.

9
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ACCURATE AX* - AW*
CALIBRATING THE THERMOSTATIC VALVE
(air-cooled models)
The thermostatic valve is calibrated using the adjustment screw
shown in the figure; in the water-cooled models, the correct cali-
bration is already performed in the factory.
• Check that the subcooling of the liquid at the condenser
outlet is around 3-5°C;
• Check that the thermostatic valve superheating value is cor-
rect (around 5 °C);
• Check that the valve sensor bulb is correctly positioned, secu-
red and insulated.
If the superheating is above the value indicated previously, open
the valve further; if it is lower, close the valve further.
NOTE: the thermostatic valve must only be calibrated by
specialist personnel.
OPERATION AND CONTROL AIU
WATER-COOLED UNITS
Water in an open circuit
If the temperature of the cooling water is not controlled and may
fall below 25°C, a pressure control valve is required (available as
an accessory) for each condenser; in this case, the supply pressu-
re must not be less than 200 kPa (2 bar).
IMPORTANT: do not use water cooled using an evaporative
tower, as the condensers will rapidly become fouled by lime scale.
Water in a closed circuit
The condensers on the units are supplied with water pumped in
a closed circuit and cooled by external radiators; check that the
cross-section of the pipes and that the characteristics of the cir-
culating pump are suitable: an insufficient water flow-rate affects
the performance of the air-conditioner.
The temperature of the cooling water must be controlled so as
to not fall below 25°C, preferably according to the diagram
shown in the figure.
IMPORTANT: the cooling water must contain a percen-
tage of ethylene glycol (passivated and consequently non-
corrosive) according to the minimum expected outside
temperature.
In the Energy Saving models, the use of glycol is always
required.
-4°C -10°C -17°C -25°C -37°C
10% 20% 30% 40% 50%
Freezing point (°C)
Percentage of ethylene glycol by weight
B
C
A
25 °C
adjustment screw

10 English 01/07 ACCURATE AX* - AW*
The pressure test points for the air flow (F3) and dirty filter (F4)
differential pressure switches are connected in parallel; (on OVER
units)
- the positive pressure test point is located on the right-hand
side of the base of the unit;
- the negative pressure test point is located in a position for
measuring the pressure upstream of the fan; (on UNDER units)
- the positive pressure test point is located behind the electrical
panel, upstream of the air filter;
- the negative pressure test point is located in a position for
measuring the pressure upstream of the fan;
Pressure
test pointPressure
test point
Pressure
test point
Pressure
test point
RIGHT-HAND SIDE
RIGHT-HAND SIDE
FRONT OF
THE UNIT
FRONT OF
THE UNIT
Q.E.
Q.E.
INSTRUMENTS AND ALARMS AIU
The air-conditioner is fitted with the following instruments:
- High pressure switch/switches F1 with manual reset (one
on each refrigerant circuit);
- Low pressure switch/switches F2 with automatic reset
(one on each refrigerant circuit);
- Air flow sensor F3 and dirty filter sensor F4 (differential
pressure switches);
- Temperature sensor BT2 (versions C and T) or room temper-
ature and humidity sensor BH1 (on the units with humidity
control);
Some versions, in addition, have the following sensors:
- Safety thermostat TH1 (in the versions with electric
heaters), with the reset button accessible on the right-hand
side of the electrical panel.
In addition, the following optional devices may be available:
- Flood sensor made up of:
a) FSD device to be inserted in the special socket on the elec-
trical panel;
b) FLOE sensor (or sensors, connected in parallel) to be posi-
tioned at the points monitored;
-Fire and smoke sensors SFFS and SFFF;
-Hot water temperature sensor, for reading and enabling
post-heating with hot water;
-Outlet air limit temperature sensor (BT1), installed as
described in the "Installation manual".
1
2
3
4
5
6
7
8
9
10
11
12
13
1 main board
2 disconnecting switch
3 electric heaters
4 radial fan and inverter
5 compressor
6 dewatering filter
7 liquid valve
8 flow indicator
9 thermostatic valve
10 humidifier
11 dehumidification valve
12 hot water coil valve
13 temperature-humidity probe

11
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ACCURATE AX* - AW*
CALIBRATING THE PRESSURE CONTROL VALVE AIU
(option available for water-cooled models)
The pressure control valve, by managing the flow of water, pre-
vents the condensing pressure from lowering excessively and, at
the same time, saves water consumption.
If necessary, calibrate the pressure control valve using the adjust-
ment knob (the pressure is increased when turning clockwise)
until the condensing pressure stabilises at the recommended
value of 17 bar (equivalent to a saturated temperature of around
45°C when using R22), measured using a pressure gauge connect-
ed to the pressure test point on the outlet valve.
1
2
3
4
5
CALIBRATING THE CONTROL AND SAFETY DEVICES AIU
After starting the air-conditioner, make the following adjustments
- Room temperature (cooling and heating set point).
- Relative humidity (set point for humidification and dehumidifi-
cation);
- Dirty filter differential pressure switch: see the paragraph on
"CALIBRATING THE DIRTY FILTER SENSOR".
The calibration values of the control and safety devices must not
be altered.
Symbol Description
F1 High pressure switch
F2 Low pressure switch
TH1 Safety thermostat (versions T and H)
Symbol Activation Differential Reset
F1 28 bar (opening) - Manual reset
F2 1,5 bar (opening) 1.5 bar 2.5 bar (automatic)
TH1 320 °C (opening) - Manual reset

12 English 01/07 ACCURATE AX* - AW*
CALIBRATING THE AIR FLOW SENSOR AIU
The differential pressure switch F3 must be activated if the fan is
not working (when there is one fan) or one of the fans is not
working.
The factory calibration of the differential pressure switch to con-
trol the air flow (F3) is 0.5 mbar (=50Pa).
As the difference in pressure between the fan intake and outlet
depends on the air flow-rate, the instrument may need to be
recalibrated after installation, checking that the contact closes
when the fan is operating normally.
To calibrate the pressure switch:
• simulate a fault in the fan system (stop the fan - if there is just
one - or one of the fans on the unit) and check that the pres-
sure switch is activated;
• if the device is not activated, progressively increase the calibra-
tion value of the pressure switch.
To calibrate the pressure switch, remove the plastic cover (A) by
unscrewing the two screws (B).
Use the adjustment screw (E) to calibrate the differential pres-
sure switch on a scale from 0.5 to 4.0 mbar (50 to 400Pa).
If having to replace the pressure switch, unscrew the two fasten-
ing screws (D), remove the rubber hoses connected to the pres-
sure test points (+) and (-) and remove the electrical cables con-
nected to terminals 1, 2 and 3.
To install the new pressure switch, perform the same operations
in the reverse order, inserting the cables from point (C).
+- A
mbar
B
B
1
3
2
mbar
D
C
D
E
CALIBRATING THE DIRTY FILTER SENSOR AIU
The factory calibration of pressure switch F4 is 3 mbar (=300Pa).
Pressure switch F4 must be calibrated according to the pressure
drop, which depends not only on the filter being dirty, but also on
the air flow-rate.
The calibration must be performed with a clean filter, as follows:
- switch the unit on
- progressively cover the surface of the air filter and make sure
that the pressure switch is activated when around 50-60%
covered;
- if the device is not activated, progressively reduce the calibra-
tion of the pressure switch;
- if the device is activated too early, increase the calibration.
Pressure test points

13
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ACCURATE AX* - AW*
WARNING: Disconnect power before working on the
servomotor
On the units with ACCURATE controllers the position of the
servomotor is proportional to the control voltage, between 0
and 10 Vdc.The servomotor stops:
- automatically at the end of its travel;
- in the position of equilibrium, corresponding to the control
voltage;
- in the current position, when cutting off power.
OPERATION OF THE MVX57 - 0-10V SERVOMOTORS
The opening of the valve can be controlled by checking the posi-
tion using the indicator located on the top of the servomotor
EMERGENCY MANUAL OPERATION
The valve can be operated manually, in the event of faults to the
servomotor or the control system, using the manual control
knob located near the servomotor.
TEMPERATURE AND HUMIDITY PROBE AIU
The figure shows the optional temperature and humidity probe.
If having to replace the probe, release the white plastic cover by
pressing point (A) with a screwdriver or a pointed object; lift the
cover (B) to access the fastening screws (C) and the terminals
(D).
For the probe electrical connection use a shielded cable; the con-
nections to the terminals on the board are shown on the wiring
diagram.
126 mm
80
A
B
H
TU
O
M
T
TUO
+
C
D
Shielded cable
inlet
Fastening
holes
SERVOMOTOR AND HOT WATER VALVE AIU
2
IN OUT

14 English 01/07 ACCURATE AX* - AW*
Vers. B R H T
Main Switch
mod. V/ph/Hz kW FLA kW FLA kW FLA kW FLA Amp Power.
TOTAL UNIT POWER INPUT
POWER INPUT OF THE INDIVIDUAL COMPONENTS
values for individual fan
07 400/3N/50 2,47 7,95 6,47 25,45 4,72 17,75 6,47 25,45 80 6
10 400/3N/50 3,22 9,85 7,22 27,35 5,47 19,65 7 27,35 80 6
15 400/3N/50 5,02 18,1 13,02 53,1 8,77 23,6 12,58 53,1 80 10
18 400/3N/50 5,66 17,8 13,66 52,8 9,41 23,3 13,22 52,8 80 10
20 400/3N/50 7,65 22,3 16,65 35,3 11,4 27,8 16,65 35,3 80 6
26 400/3N/50 8,35 24,3 17,35 37,3 12,1 29,8 17,35 37,3 80 6
29 400/3N/50 10,55 29,3 19,55 42,3 14,3 34,8 19,55 42,3 80 10
39 400/3N/50 18,3 50,4 33,3 72,4 22,05 55,9 33,3 72,4 80 16
30 400/3N/50 16,04 48,2 31,04 70,2 19,79 53,7 31,04 70,2 80 16
40 400/3N/50 18,5 53,4 33,5 75,4 22,25 58,9 33,5 75,4 80 16
50 400/3N/50 22,3 63,4 37,3 85,4 26,05 68,9 37,3 85,4 100 25
55 400/3N/50 20,8 60 38,8 86 26,8 68,7 38,8 86 100 25
60 400/3N/50 22,8 64 40,8 90 28,8 72,7 40,8 90 100 25
70 400/3N/50 27,1 74 45,1 100 33,1 82,7 45,1 100 100 25
B = cooling only
R = cooling only + heaters
H = cooling only plus humidifier / dehumidification
T = complete version (cooling only + heaters + humidifier/dehumid.)
Centrifugal fans Radial fans
Mod V/ph/Hz n° kW OA FLA LRA n° Volt kW OA FLA LRA
07 - 10 230/1/50 2 4 17,5 -
15 - 18 230/1/50 2 8 35 -
20 - 26 - 29 400/3N/50 3 9 13 -
39 - 30 - 40 - 50 400/3N/50 5 15 22 -
55 - 60 - 70 400/3N/50 6 18 26 -
Electric heaters
Modelli V/ph/Hz n° kW OA FLA
ELECTRICAL SPECIFICATIONS AIU
07 230/1/50 1 0,5 - 2,85 - 1 230/1/50 0,44 - 2,6 -
10 230/1/50 1 0,5 - 2,85 - 1 230/1/50 0,44 - 2,6 -
15 230/1/50 2 0,5 - 2,85 - 2 230/1/50 0,44 - 2,6 -
18 230/1/50 2 0,5 - 2,85 - 2 230/1/50 0,44 - 2,6 -
20 400/3N/50 1 2,4 - 7,3 - 1 400/3N/50 2,2 - 4,9 -
26 400/3N/50 1 2,4 - 7,3 - 1 400/3N/50 2,2 - 4,9 -
29 400/3N/50 1 2,4 - 7,3 - 1 400/3N/50 2,2 - 4,9 -
39 400/3N/50 1 4 - 11,7 - 2 400/3N/50 1,9 - 4,9 -
30 400/3N/50 1 4 - 11,7 - 2 400/3N/50 1,9 - 4,9 -
40 400/3N/50 1 4 - 11,7 - 2 400/3N/50 1,9 - 4,9 -
50 400/3N/50 1 4 - 11,7 - 2 400/3N/50 1,9 - 4,9 -
55 400/3N/50 1 6,5 - 20 - 3 400/3N/50 1,9 - 4,9 -
60 400/3N/50 1 6,5 - 20 - 3 400/3N/50 1,9 - 4,9 -
70 400/3N/50 1 6,5 - 20 - 3 400/3N/50 1,9 - 4,9 -

15
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ACCURATE AX* - AW*
MAINTENANCE AIU
07 - 10 230/1/50 1 3 2,25 9,8 -
15 - 18 400/3N/50 1 5 3,75 5,5 -
20 - 26 - 29 400/3N/50 1 5 3,75 5,5 -
39 - 30 - 40 - 50 400/3N/50 1 5 3,75 5,5 -
55 - 60 - 70 400/3N/50 1 8 6 8,7 -
Modulating humidifier
models V/ph/Hz n° kg/h kW OA FLA
07 400/3N/50 1 1,84 3,5 5,1 32
10 400/3N/50 1 2,72 5 7 46
15 400/3N/50 1 4,02 7,8 12,4 65,5
18 400/3N/50 1 4,66 8,3 12,1 74
20 400/3N/50 1 5,25 10 15 101
26 400/3N/50 1 5,95 12,2 17 123
29 400/3N/50 1 8,15 15,3 22 127
39 400/3N/50 1 10,3 17,8 27 167
30 400/3N/50 2 4,02 7,8 12,4 65,5
40 400/3N/50 2 5,25 10 15 101
50 400/3N/50 2 7,15 14,5 20 123
55 400/3N/50 2 7,15 14,5 20 123
60 400/3N/50 2 8,15 15,3 22 127
70 400/3N/50 2 10,3 17,8 27 167
Compressors
models V/ph/Hz n° kW OA FLA LRA
This section, aimed above all for the end user, is extremely impor-
tant for the correct operation of the appliance.
Just a few operations completed scrupulously and regularly will
avoid serious damage to the components and expensive repairs
by specialist personnel.
The maintenance instructions are simple and do not require spe-
cific technical knowledge of air-conditioning.
The purpose of this chapter is to assist and guide the user and
avoid having to unnecessarily call out specialist personnel.
The maintenance operations can be summarised as follows:
- Clean the air filter.
- Check and clean the condenser coils
- Check the water-cooled condensers for fouling.
- Check and clean the drains.
- Check the drive belts.
- Check the humidification system.
- General examination of the overall operation of the appliance.
- Visual check of the condition of the pressurised containers.
Cleaning the air filter
Authorised personnel: maintenance mechanic
Checks:
The gradual fouling of the filters reduces the flow-rate of the
conditioned air, with a consequent reduction in cooling capacity.
In the direct expansion units, a reduction in the air flow-rate may
cause the activation of the low pressure switch and/or cause seri-
ous damage to the compressor.
This can be avoided by the periodical cleaning of the filters.
The frequency at which the filters must be checked exclusively
depends on the amount of dust in the environment.
In any case, the following are recommended:
- Every week check that the filters are clean
- Every two weeks clean the filters with a vacuum cleaner
- Every month wash the filters with soapy water
- Every 6 months replace the filters.
It is clear that the recommended times are purely indicative, and
in some cases it may be necessary to increase the frequency of
the checks and maintenance operations.
These operations must be carried out with the unit off and after
having made sure that the appliance is disconnected from the
power supply.
values for individual compressor

16 English 01/07 ACCURATE AX* - AW*
Checking and cleaning the condenser coils
Authorised personnel: maintenance mechanic
Checks:
In the hotter period, when the unit operates at maximum capaci-
ty, the condensing coils must be able to offer the maximum heat
exchange.
Normally installed outside or communicating with the outside,
these may pick up dirt such as paper, dry leaves and dust, thus
reducing the heat exchange.
Make sure that this situation does not arise.
Failure to perform maintenance will cause the activation of the
high pressure switch and the unit to shutdown.
Frequently check the condition of the heat exchanger during the
poplar pollination period or the autumn (falling leaves).
Remove any objects accumulated on the coil and wash with a jet
of water.
These operations must be carried out with the unit off and after
having made sure that the appliance is disconnected from the
power supply.
Checking the water-cooled condensers for fouling
Authorised personnel: maintenance mechanic
Checks:
To check the water-cooled condensers for fouling, simply check
the water inlet and outlet temperature and compare it against
the condensing temperature.
Normally, for good heat exchange, the difference between the
water outlet temperature and the condensing temperature must
be 5.8°C.
Increases in these values, over time, indicate a reduction in effi-
ciency and consequently the fouling of the condenser.
The condenser is cleaned by chemical washing and must be per-
formed by specialist personnel.
This operation must be carried out with the unit off and after
having made sure that the appliance is disconnected from the
power supply).
Checking and cleaning the drains
Authorised personnel: maintenance mechanic
Checks:
All the water drains (humidifier and condensate) must ensure
perfect drainage, to avoid flooding in the room.
When the humidifiers drain the water, they discharge a quantity
of lime scale that depends on the hardness of the supply water.
This lime scale may accumulate in the bottom of the drain hose
and block the flow of water.
If cleaning is required, add ordinary descaler to the section of cir-
cuit involved.
This operation must be carried out with the unit off and after
having made sure that the appliance is disconnected from the
power supply.
Checking the drive belt
Authorised personnel: maintenance mechanic
Checks:
On the units with fans coupled to the electric motor by pulleys
and drive belts, after a certain number of operating hours the belt
may become loose, sliding on the pulleys and causing excessive
wear.
This situation, if it persists, causes overheating and consequently
the breakage of the belt.
Loosening can be resolved using the special belt tightener fitted
on the appliance (this operation must be carried out with the
unit off and after having made sure that the appliance is discon-
nected from the power supply).
Check the tension of the drive belts once a month.
Avoid excessively tightening the belts, as this may cause damage
to the bearings.
General examination of operation
Authorised personnel: system supervisor
Checks:
This is a general examination aimed at comparing the operation
of the appliance with the last check performed.
Consequently, any differences in the operating characteristics
over time can be highlighted.
A detailed and periodical visual check of the appliance and gener-
al cleaning are always important to ensure correct operation.
The above-mentioned operations can in general be performed
once a month.
Naturally, in special situations and specific installations the fre-
quency may change.
A well maintained system is unlikely to cause disruptions and
stoppages to the production cycles.
Visual check of the condition of the pressurised contain-
ers
Authorised personnel: system supervisor
Checks:
Check the condition of the pressurised containers at least once a
year (if these are fitted).
It is very important to check that rust does not form on the sur-
face, that there is no corrosion and that there are no visible
deformations.
If not controlled and stopped, surface oxidation and corrosion
will over time cause a decrease in the thickness of the container
and a consequent reduction in its mechanical strength.
Protect with paint and/or corrosion proofing products.
In the event of visible deformations, stop the unit and contact the
nearest service centre.

17
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ACCURATE AX* - AW*
TIGHTENING THE DRIVE BELTS AIU
ELECTRIC HEATERS AIU
In the versions from frame 3 upwards, the fans in the standard
version are centrifugal with forward blades and belt drive.
A required periodical maintenance operation (at least once a
year) involves having specialist personnel check the correct ten-
sion of the belt.
To check the tension, proceed as follows: apply a perpendicular
force of around 20 N (2 kg) to the centre of the belt (between
the 2 pulleys).
The belt must have a deformation of around 6-8 mm.
If this is not the case, adjust the tension using the worm screw
located on the slide that supports the electric motor.
Overly tight belts will cause unbalanced transmission.
Too loose belts, on the other hand, will cause the motor to over-
heat and excessive power consumption.
DRIVE PULLEYS
Below is a description of how to assemble and dismantle the pul-
leys if these require replacement or repair.
Dismantling
Take out the 2 safety screws and remove the pulley from the
elastic ring
See Fig.A
Assembly
Slide the elastic ring onto the motor pin. Insert the pulley on top,
then tighten the fastening screws
See Fig. B
ELECTRIC HEATERS
The overall power of the electric heaters is divided into a num-
ber of elements, each with a power of 2/3/4 kW.
The colour of the wires on each element has the following mean-
ing:
• BLACK wire = low power element (0.7/1/1.3 kW);
• WHITE wire = high power element (1.3/2/2.7 kW);
• RED wire = common.
The wires for each element are connected to contactors M5 and
KM6 on the electrical panel so as to balance the load between
the phases and create three stages of power (see the wiring dia-
grams on the unit).
If having to replace the electric heaters, disconnect power to the
air-conditioner and wait until the heating elements have cooled
down.
After having replaced the heaters, make sure the earth is con-
nected.
6-8mm
20N
AB

18 English 01/07 ACCURATE AX* - AW*
HUMIDIFIER AIU
SYSTEM COMPONENTS
Upon request, the air-conditioning unit can be fitted with an
immersed electrode humidifier (versions D and H).
1 Humidifier interface board:A3; (inside the electrical panel).
2 Current transformer TA1 (inside the electrical panel) for
measuring the current input of the steam cylinder.
3 Water fill tank.
4 High water level electrodes in the steam cylinder.
5 Overflow pipe (BEHIND THE CYLINDER).
6 Boiler cylinder (or steam cylinder).
7 Water fill solenoid valve:YV1.
8 Cylinder drain solenoid valve:YV2.
9 Microprocessor control board:A1.
10 Temperature and humidity probe: BH1.
3
4
6
7
8
9. B1
2. TA1
4
6.
8.YV2
7. YV1
5
3
1. A3
10. BH1
KM4
HUMIDIFIER OPERATING PRINCIPLE
In the immersed electrode humidifier, the current that runs
between the electrodes, through the water contained in the boil-
er cylinder, generates the heat required to boil the water.
By controlling the level of the water and the concentration of
salts inside the steam cylinder (6) using the fill (7) and drain (8)
solenoid valves, the amount of current delivered can be regulated,
and measured using a current transformer (2).
When steam production is required, the humidifier contactor CU
closes (see the wiring diagram) so as to supply power to the
immersed electrodes.
When the current falls below the set value due to the lowering
of the water level, the fill valve (7) is opened.
The drain valve (8) is activated cyclically, depending on the char-
acteristics of the supply water, so as to maintain the optimum salt
concentration inside the cylinder (6).
The only periodical maintenance operations required are the
inspection and cleaning of the parts in the steam production unit.
The operations indicated below should be performed annually,
preferably before shutting down the unit in summer.
STEAM CYLINDER
The steam cylinder requires periodical cleaning to remove the
scale deposits that form on the surface of the electrodes and the
flakes that deposit on the filter at the base of the cylinder.
To remove the cylinder, proceed as follows:
• completely drain the water from the boiler; to do this, see the
paragraph “MANUAL CONTROL” in the EVOLUZIONE con-
troller instruction manual;
• disconnect the power supply by opening the main switch on
the electrical panel;
• remove, from the top of the cylinder, the hose that carries the
steam to the distributor;
• disconnect the power connections by unscrewing the knobs
on the cable ends and remove the plugs from the level elec-
trodes;
• release the strap that secures the cylinder to the unit;
• slide the cylinder out upwards.
The steam cylinder can be reused a number of times after clean-
ing the electrodes: if, however, the wear on the grills of electrodes
is such that these cannot be regenerated, they must be replaced.
The only spare part is the complete cylinder body (with filter
included).