AERMEC NRL 280-75, Техническое руководство

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10 Aermec 13_01. 5641300_00
NRL 0280-0750 60Hz
EN
5. DESCRIPTION OF COMPONENTS
5.1. CHILLER CIRCUIT
SCROLL COMPRESSORS
High efficiency scroll-type hermetic compressors,
assembled on elastic antivibration supports,
driven by a 2-pole electric motor with internal
thermal protection. of the electric heater casing
included as standard. The heater is automatically
powered when the unit stops, provided that the
unit is kept under tension.
WATER SIDE HEAT EXCHANGER
Of the plate-type (AISI 316), externally insula-
ted with closed cell material to reduce thermal
dispersion. Fitted, as standard, with antifreeze
heater.
5.1.1. WATER FEATURES
PH 6-8
Electric
conductivity less than 200 mV/cm
(77°F / 25°C)
Chloride ions less than 50 ppm
Sulphuric acid ions less than 50 ppm
Total iron less than 0.3 ppm
Alkalinity M less than 50 ppm
Total hardness less than 50 ppm
Sulphur ions none
ammonia ions none
Silicone ions less than 30 ppm
SOURCE SIDE HEAT EXCHANGER
Made with copper pipes and aluminium louvered
fins blocked by mechanical expansion of the
pipes. Provided with protective grid.
DESUPERHEATER / TOTAL RECOVERY
Unit with (AISI 316) heat plate, insulated exter-
nally with closed cell material to reduce heat loss.
CYCLE INVERSION VALVE
ONLY HEAT PUMP VERSION
4way cycle inversion valve. Inverts the flow of
refrigerant gas.
LIQUID STORAGE TANK
ONLY HEAT PUMP VERSION/TOTAL RECO
VERY
Compensates the difference in volume between
louveres coil and plate exchanger, withholding
excess liquid.
DEHYDRATOR FILTER
Hermetic-mechanical with cartridges made of ce-
ramic and hygroscopic material, able to withhold
impurities and any traces of humidity present in
the cooling circuit.
ONE WAY VALVES
Allows the passage of the refrigerant in just one
direction.
MECHANICAL THERMOSTATIC VALVE
The mechanical valve, with external equaliser
positioned at the evaporator inlet, modulates the
flow of gas to the evaporator, according to the
heat load, in order to ensure a correct heating
level of the intake gas.
SOLENOID VALVE
The valve closes when the compressor turns off,
preventing the flow of refrigerant gas towards the
evaporator.
INDICATOR FOR LIQUID PASSAGE WITH HU
MIDITY PRESENCE SIGNAL
Used to check the refrigerant gas load and the
eventual presence of humidity in the cooling
circuit.
LIQUID AND PRESSING LINE TAPS
ONLY COOLING VERSION
Allows interruption of the refrigerant in the case
of extraordinary maintenance
.
LIQUID SEPARATOR
ONLY HEAT PUMP VERSION
Located on the suction point of the compressor,
to protect against any flowback of liquid refrige-
rant, flooded start-ups, operation in the presence
of liquid.
BY PASS SOLENOIDE VALVE
ONLY HEATING RECOVERY VERSION
By-passes the thermostatic valve during the
defrosting cycle.
5.2. FRAME AND FANS
SUPPORT FRAME
Load-bearing structure Made of hot-galvanised
steel sheet of a suitable thickness, varnished with
polyester
powders able to resist atmospheric agents over
time.
VENTILATION UNIT
Axial fan, balanced statically and dynamically.
The electric fans are protected electrically by
magnet-circuit breakers and mechanically by
anti-intrusion metal grids, according to the IEC EN
60335-2-40 Standard.
5.3. HYDRAULIC CIRCUIT STANDARD COM
PONENTS
WATER FILTER
Equipped with steel filtering mesh; prevents the
heat exchangers from clogging.
FLOW SWITCH
It checks that there is circulation of water.If
this is not the case, it blocks the unit
SAFETY VALVE
Equipped with a piped discharger and intervenes
by discharges the over pressure in case of anoma-
lous pressures.
WATER TEMPERATURE PROBE (IN-OUT)
AIR VENT
Of the automatic type, assembled on the upper
part of the hydraulic system; it releases any air
bubbles that may be present in the system.
DRAIN TAP
5.4. HYDRAULIC COMPONENTS FOR CONFI
GURABLE VERSIONS
CIRCULATION PUMP
HIGH/LOW PUMP
Depending on the characteristics of the pump
chosen, it offers a useful head to overcome the
pressure drops in the system.
EXPANSION TANK
STANDARD SUPPLY TO PUMP AND STORAGE
TANK VERSION
With nitrogen pre-load membrane.
SAFETY VALVE
Equipped with a piped discharger and intervenes
by discharges the over pressure in case of anoma-
lous pressures.
STORAGE TANK
In order to reduce the thermal dispersion and
eliminate the phenomenon of the formation of
condensation, it is insulated with polyurethane
material of a suitable thickness. It is required to
reduce the number of peaks of the compressor
and to even the temperature of water to
be sent
to the utilities.
STORAGE TANK DRAIN TAP
5.5. SAFETY AND CONTROL COMPONENTS
HIGH PRESSURE SWITCH MANUAL RESET
With fixed calibration, placed on high pressure
side of cooling circuit, inhibits functioning of
compressor if
abnormal work pressure occurs.
HIGH PRESSURE TRANSDUCER
Placed on high pressure side of cooling circuit,
signals the work pressure to control board, gene-
rating a pre-warning in case abnormal pressure
occurs.
LOW PRESSURE TRANSDUCER
Allows displaying, on the microprocessor board
display, the value of the compressor's suction
pressure (one per circuit) on the low-pressure
side of the cooling circuit
SAFETY VALVE
Equipped with a piped discharger and intervenes
by discharges the over pressure in case of anoma-
lous pressures.
- Set at 45 bar on the branch HP
- Set at 30 bar on the branch LP
LOW PRESSURE SWITCH
5.6. ELECTRICAL PANEL CONTROL AND
POWER
Electric board in compliance with standards EN
60204-1/IEC 204-1, complete with:
- door lock main isolating switch,
- fuses and contactors for compressors and fans,