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English 05/09
ACCURATE AX - AW - AD - AT - AF
FREECOOLING UNIT – VERSION AF
All models have a single refrigerant circuit, and in some cases two
circuits. See the DIGIT on the previous page.
Each refrigerant circuit includes the compressor and a pressure-
balanced thermostatic valve (or electronic valve) to ensure stable
superheat temperatures. A liquid indicator is fitted before the
thermostatic valve to display the gas charge.
A dewatering filter is installed on the liquid line to keep the cir-
cuit clean and free of dirt.
The refrigerant circuit is also fitted with high and low pressure
switches. The low pressure switch has automatic reset, while for
safety reasons the high pressure switch has manual reset. Remem-
ber that circulation pump is NOT selected, nor provided from
Climaveneta. The AF units are provided, as standard, with radial
fans EC.
Condenser
Each unit is fitted with one (for single circuit units) or two (two
circuit units) condensers made from braze welded stainless steel
heat exchangers. Each condenser is fitted with an HP8 automatic
valve to control the condensing phase. In addition, the condensers
are oversized in order to limit pressure drop (and minimise the
power input of the circulating pumps).
The units generally work via closed circuits with dry coolers
cooled by the outside air. To prevent the formation of frost, the
fluid used inside the closed circuit should always contain a per-
centage of glycol, as indicated in this manual, based on the average
minimum temperature reached in the place of installation in the
coldest periods.
The cooling fluid must be circulated by pumps (not supplied as
standard). Suitably-sized dry coolers are available as options.
Water circuit
The unit is fitted with a 3-way modulating valve to control the
flow of cooling fluid to the indoor exchanger on the freecooling
units. The opening and closing signal is generated and completely
managed by the electronic controller on the air-conditioner, so as
to maintain the desired conditions and ensure maximum energy
saving.
DUAL FLUID UNITS – VERSION AD (air-cooled)
& AT (water-cooled)
All models have a single refrigerant circuit, and in some cases two
circuits.
See the DIGIT on the previous page. Each refrigerant circuit
includes the compressor and a pressure-balanced thermostatic
valve (or electronic valve) to ensure stable superheat tempera-
tures. A liquid indicator is fitted before the thermostatic valve to
display the gas charge. A dewatering filter is installed on the liquid
line to keep the circuit clean and free of dirt.
The refrigerant circuit is also fitted with high and low pressure
switches. The low pressure switch has automatic reset, while for
safety reasons the high pressure switch has manual reset. The AD
and AT units are provided, as standard, with radial fans EC.
Version AD (air-cooled)
A non-return valve should be installed on the liquid line between
the indoor unit and the outdoor unit by the installer.
The units are supplied separately from the outdoor condenser
and are pre-charged with nitrogen. The customer is responsible
for the connection between the two indoor and outdoor units
and for the emptying and charging operations. For these opera-
tions, follow the instructions provided in the installation manual.
Outdoor air-cooled condenser
The air-cooled condenser should be selected from the models
available in the vast range provided by the manufacturer
Water circuit
The unit is fitted with a 3-way modulating valve to control the
flow of cooling fluid to the indoor exchanger so as to maintain
the desired conditions.
In the DUAL FLUID units, the two circuits, direct expansion DX
and chilled water CW, never work at the same time.The direct
expansion circuit DX is used as backup to the chilled water cir-
cuit CW. Activation set points for the two circuits are available
and are described in the User Terminal manual.
AF - water cooled
AD - air cooled
