High efficiency series
This new series of units combines elevated efficiency rates (EER) with
the use of R134a refrigerant.
The excellent level of performance was achieved thanks to the
accurate sizing of all internal components in order to fully exploit the
characteristics of the ecological refrigerant used. Special attention was
paid to all the heat exchange surfaces, fans and compressors.
The newly designed condenser coils with special construction features
have larger surfaces, as do the new asymmetrical evaporators with
improved and more efficient refrigerant distribution both in the liquid
and steam phases.
The fans with elevated unit efficiency are suitably adjusted to optimise
air flow to the condensing section and guarantee maximum
silent-running in all operating conditions.
The new screw compressors are specially designed for R134a
refrigerant. The continual adjustment feature constantly modulates the
capacity of each compressor between 100% and 50% of its potential.
This adjustment mode also allows the exact power required by the
system to be instantaneously delivered and precisely adapted to load
variations. This in turn reduces the number of start-ups and
consequently improves reliability. The accompanying unit adjustment
feature, based on evaporator outlet water temperature control with
Quick Mind adjustment logic, guarantees extremely small variations
compared with the set point (+/- 0.5 ℃, probe precision limit) as well as
considerably reducing the time required for the system to become fully
operative.
The advantages of the continual adjustment of individual compressors
are enhanced with the use of electronic thermostat valves (optional for
the entire range).
Their precision and rapidity of response optimise load variations and
allow stable conditions to be achieved in a very short time, even when
operating in the part load mode.
The accurate sizing of the system combined with this series of units
offers considerable energy saving and consequently significant
reductions in running costs.
Air-cooled water chillers
Air-cooled water chiller with axial fans for outdoor installation. The unit
is supplied with anti-freeze oil and refrigerant and has been factory
tested. On-site installation therefore just involves making connections
to the mains power and water supplies.
Unit charged with R134a refrigerant.
STANDARD UNIT COMPOSITION
Base and frame in thick hot-galvanised shaped sheet steel. All parts
polyesters-painted.
compressors
Hermetic scroll compressors. All the compressors are fitted with an oil
sump heater, electronic overheating protection with centralised manual
reset (thermal contact on size 0302) and a two-pole electric motor.
Screw compressors
Semi-hermetic screw-compressors with 2 five and six-lobe rotors. The
five-lobe rotor is directly splined onto the 2-pole motor (2,950 rpm)
without the use of overgears. Compression occurs five times every
motor turn and the gas therefore discharges continuously without the
typical throbbing common to reciprocating compressors. Leading-edge
numerical control machines were used to make the rotors and machine
the bearing seats. Compressor cooling power is continuously
modulated from 100 to 50%. In addition to the standard no-load starting
feature, the motors are fitted with electric starting devices which limit
the power absorbed during the compressor starting phase. A check
valve on the coolant delivery line prevents the rotor from reversing after
stopping. Special maintenance-free bearings allow very long work
cycles. Lubrication is forced, without the use of an oil pump. The high
efficiency built-in oil separator ensures the constant presence of oil in
the compressor. The rotors are dynamically balanced to ensure that the
vibrations common to reciprocating compressors do not occur. The lack
of vibrations and the absence of delicate intake and delivery valves, in
addition to very fine manufacturing tolerances, sophisticated quality
controls during the production process and a limited number of moving
parts, guarantee quiet and highly reliable operation. Each compressor
is fitted with manual-reset motor thermal protection, delivery gas
temperature control, an oil level float, an oil level sight-glass and an
electric resistance for heating the oil when the compressor is stopped.
Water-refrigerant heat exchanger
Direct expansion heat exchanger type with asymmetric refrigerant
paths to maintain the correct refrigerant velocity inside the tubes during
both liquid and gaseous phases. The steel shell is insulated with a
closed-cell anti-condensation lining. The copper pipes are internally
grooved so as to improve the heat exchange. The pipes are
mechanically expanded onto the tube plate ends. An antifreeze electric
heater prevents the formation of ice inside the casing of the exchanger
when the unit is not operating but connected to the electrical supply.
Differential pressure switch for controlling the water flow is fitted
standard.
Refrigerant-air heat exchanger
Aluminium fins and copper tubes type heat exchanger. The aluminium
fins are correctly spaced to guarantee the best heat exchange
efficiency. The lower part of the exchanger functions as a sub-cooling
circuit thus increasing the cooling capacity.
Fans
Axial electric fans, protected to IP 54, with external rotor and profiled
die-cast aluminium blades. Housed in aerodynamic hoods complete
with safety grille. 6-pole electric motor with built-in thermal protection.
Pressure switch condensing control by sequentially excluding certain
fans.
Refrigerant circuit
Main components of the refrigerant circuit:
- compressor discharge check valve,
- compressor discharge shut-off valve,
- liquid line shut-off valve,
- liquid line solenoid valve,
- dryer filter with replaceable cartridge,
- refrigerant line sight glass with humidity indicator,
- externally equalised thermostatic valve,
- high pressure safety valve,
- low pressure safety valve,
- high and low pressure transducers
- high pressure switches,
- differential pressure switch for water
Electric power and control panel
Electric power and control panel, built to EN 60204-1/EC 204-1 standards, complete with:
- control circuit transformer,
- general door lock isolator,
- power circuit with bar distribution system,
- fuses and contactors for compressors and fans,
- terminals for cumulative alarm block (BCA),
- remote ON/OFF terminals,
- spring-type control circuit terminal board,
- electric panel for outdoor installation,
- electronic controller.
- phase sequence relay
Basic model
Unit without heat recovery.
Model with partial heat recovery (D)
Air cooled chiller with partial heat recovery. Compared with the basic
configuration, this version features an additional refrigerant/water heat
exchanger on the gas delivery line. This heat exchanger, fitted in series
before the traditional cooling circuit condenser, is large enough to
recover heat for the production of medium-to-high temperature water
for domestic hot water and the like. The heating capacity of the heat
recovery circuit is approximately equal to the power input of the
compressor. Each exchanger is fitted standard with an antifreeze
heater.
Model with heat recovery (R)
Air cooled chiller with total heat recovery. Compared with the basic
configuration, this version features an additional refrigerant/water heat
exchanger on the gas delivery line. This heat exchanger, fitted in
parallel with the traditional cooling circuit condenser, is large enough to
recover heat for the production of domestic hot water and the like. The
heating capacity of the heat recovery circuit is approximately equal to
the cooling power plus the power input of the compressors. Each
exchanger is fitted standard with an antifreeze heater.
AVAILABLE VERSIONS
B (base)
Standard unit. Unit with Low Temperature Pressure Device for condensation control
LN (Low Noise)
Low noise version. This configuration features special soundproofing
for the compressor chamber and reduced fan speed. Unit with Low
Temperature Variable Speed Device for condensation control
SL (Super Low Noise)
Super low noise version. This configuration features special
soundproofing for the compressor chamber, reduced fan speed, an
oversized condensing section. Unit with Low Temperature Variable
Speed Device for condensation control
Accessories
Increased noise insulation (std on LN/SL units)
Rubber isolators
Spring isolators
High temperature pressure control
Extra charge for AE up to -18℃ (in addition to DP or DVV)
Compressor suction valve
Oversized electric heater on evaporator
Increased evaporator insulation.
Cu/Cu condensing coils
Condensing coils with epoxy-coated fins
Condensing coils with Fin Guard Silver treatment
Coil protection with peraluman grille
Anti-intrusion grilles
Flanges on evaporator
Evaporator water flow switch (supplied separately)
Power factor correction
Automatic circuit breakers
Free voltage contacts for compr. operation signalling
Remote keyboard
Pump relay
Numbered wires
Sequencer (supplied separately)
Electronic expansion valves
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