9
description of components
Compressor
COOLING CIRCUIT
Scroll hermetic compressors with 2-pole electric motors. All the compres
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sors are equipped with guard resistance, inner electronic thermal protec
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tion device with centralised manual reset.
System side heat exchanger
Braze welded AISI 316 steel plate heat exchanger. The heat exchanger is
insulated externally with closed cell neoprene anti-condensation material.
When the unit is not running, it is protected against formation of ice by an
electric resistance.
Source side heat exchanger
Microchannels heat exchanger that guarantees higher thermal exchange
yield. Circuit that optimises the liquid distribution in the coil, which is arran
-
ged with V beam geometry with open angle. The configurator has always
the standard copper/aluminium coils available.
Recovery side heat exchanger (optional)
Braze welded AISI 316 steel plate heat exchanger. The heat exchanger is
insulated externally with closed cell neoprene anti-condensation material.
When the unit is not running, it is protected against formation of ice by an
electric resistance.
Dehydrator filter
Hermetic-mechanical with cartridges made of ceramic and hygroscopic
material, able to withhold impurities and any traces of humidity present in
the cooling circuit.
Mechanical thermostatic valve
With external equaliser positioned at evaporator outlet, it modulates the
flow of gas to the evaporator, according to the heat load, in order to ensure
correct heating level of the intake gas.
Electronic thermostatic valve
Compared to the classic thermostatic valve, the electronic thermostatic val
-
ve stands out for its best overheating regulation. This way, the evaporator is
fully exploited increasing the machine yield.
Its use in applications intended for comfort provides important benefits,
especially in the presence of variable loads, as it allows you to maintain
maximum efficiency with any outdoor air temperature.
In industrial applications, where temperature changes are often required in
relation to various environmental conditions, the electronic valve is ideal to
prevent the system from continuous calibration, thus adapting the system
to different load conditions, making it independent.
Solenoid valves (3)
The valves close when the compressor switches off, blocking the flow of
refrigerant gas to the evaporator, recovery and the coil.
Liquid indicator
It is used to verify that the expansion system is powered correctly and the
presence of humidity in the cooling circuit.
STANDARD HYDRAULIC CIRCUIT
Water filter
Equipped with steel filtering mesh, it prevents the heat-exchanger from
clogging system side due to any impurity inside the circuit.
Differential pressure switch
Positioned before and between the input and output of the heat exchanger,
its task is to ensure water circulation. If triggered, it locks the unit.
Throttle valve
Useful for cutting out the hydraulic system in case of maintenance, for
example, to clean the filter.
In the event of variable flow rate, the motorised hydronic valves can
intercept one or more modules to reduce the flow rate in low heat load
conditions.
COMPONENTS OF THE STRUCTURE AND FANS
Structure
Supporting structure made of hot-dipped galvanised steel sheets, painted
with polyester powders, built to guarantee easy accessibility for service and
maintenance.
Standard fan unit
Equipped with accident-prevention net, it consists of axial fans and 6-pole
motor with external rotor and protection rating IP54. Moreover, the motor
is equipped with inner thermal protection with automatic reset.
Inverter fans (option)
Continuous modulation of revolution speed according to the condensation
pressure, highly efficient motor for low energy consumption.
CONTROL AND SAFETY COMPONENTS
Manually reset high pressure switch
With fixed calibration, placed on the high pressure side of the cooling cir
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cuit, it inhibits the operation of the compressor if abnormal work pressure
occurs
Low pressure transducer
Placed on low pressure side of cooling circuit, it signals the work pressure
to the control board, generating a pre-warning in case abnormal pressure
occurs.
High pressure transducer
Placed on the high pressure side of the cooling circuit, signals the work
pressure to control board, generating a pre-warning in case abnormal
pressure occurs
Control and electric power board
complete with:
- - spring type control circuit terminal board,
- Circuit breakers and contactors for compressors and fans,
- terminals for REMOTE PANEL
- - evaporator pump and recovery pump control consent relay (only for
versions without pump units),
- - all numbered cables.
- DOOR-LOCK ISOLATING SWITCH
- pump evaporator and pump recovery unit control consent relay (only for
versions without pump units).
- Act on the opening lever of the control
3 Only with mechanical thermostatic valve
Summary of Contents for NRV 0550
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