Air cooled liquid chiller
Outdoor installation type air cooled water chiller with axial fans. The
unit is supplied with anti-freeze oil, refrigerant charge, testing and
working proofs. Just the electrical and hydraulic connections are
necessary on site.
Unit charged with R407C refrigerant fluid.
STANDARD UNIT COMPOSITION
Base and frame in thick hot-galvanised shaped sheet steel. All parts
(including the electrical panel) epoxy-painted.
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 therefore the gas discharges continuously
without the typical throbbing of reciprocating compressors.
Leading-edge numerical control machines were used to make the
rotors and machine the bearing seats. The slide valve can limit the
cooling capacity of each compressor by 50% and 75%. 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 refrigerant 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 the vibrations typical
of reciprocating compressors do not occur. The absence 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 standardly fitted.
Refrigerant-air heat exchanger
Alluminium fins and copper tubes type heat exchanger. The alluminium
fins are correctly spaced to garantee 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
Each refrigerant circuit comprises the following components:
- compressor delivery check 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 (if required by regulations).
- high and low pressure switches,
- high and low pressure gauges.
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 with double door and seals for outdoor installation,
- electronic controller.
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.
Model with total 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.
AVAILABLE VERSIONS
B (base)
Standard unit.
HT (High Temperature)
Version suitable for operation with high condenser input air
temperatures. This version features an oversized condensing section
in order to ensure that heat is correctly exchanged even in
particularly tough environmental conditions. As a result, when
working at normal air temperatures, an increase in cooling capacity
and a decrease in power input is obtained, thereby improving the
cooling efficiency ratio (E.E.R.). In this version, the electrical panel is
fitted with a dedicated cooling fan.
LN (Low Noise)
Low noise version. This configuration features special soundproofing
for the compressor chamber and reduced fan speed. Fan speed is
automatically increased if environmental conditions are particularly
tough.
SL (Super Low Noise)
Super low noise version. This configuration features special
soundproofing for the compressor chamber, reduced fan speed, an
oversized condensing section, spring supports for the compressors,
vibration proof joints on the compressor intake and delivery lines, and
a muffler on the compressor delivery line. Fan speed is automatically
increased if environmental conditions are particularly tough.
Accessories
DVV for B/LN/HT version
High ambient press. control on capacity
Extra price on top of DP or DVV for -20℃
Compressor suction valve
Shut off valves com. suct & dusch. compres.
Electronic soft start
Flanges on evaporator or unit
Flow switch (supplied loose)
Oversized electric heater on evap.
Increased evaporator insulation.
Cu/Cu - condensing coil
Epoxy coated cond. coil fins
Fin Guard Silver coil treatment
Cond. coil protection grille
Anti-intrusion grilles
Spring isolators
Electronic Expansion Valves
Power factor correction
Automatic circuit breaker compr.
Automatic circuit breaker fans
Numbered wires
Loc/O/Rem
Compr. operatation signal free voltage contacts
Upgrade controller CVM300 to CVM3000
CVM-Interface (with CVM300 or CVM3000)
CVM-Interface extension board small
CVM-Interface extension board big
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