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The data inside this manual are not binding and they can be modified by the manufacturer without notice.
All rights reserved.
NPC 280 - 400
C
HAPTER
4
D
ESCRIPTION
4 . 1
C o m p o n e n t s
The data relating to the materials refer to standard machines. In case of particular units special materials are used, so it is necessary to refer to the
data on the offer.
The machines essentially consist of the following components:
•
Refrigerant compressor
•
Condenser
•
Evaporator
•
Tank
•
Pump
•
Frame/outer panelling
•
Electronic controller
4 . 2
C o o l i n g c i r c u i t
Models TAEevo have two refrigerant circuits with two compressors connected in parallel (tandem).
Each circuit consists of the following components:
•
refrigerant fluid used R407C;
•
Scroll hermetic compressor;
•
pressure switches for high and low refrigerant pressure;
•
high pressure transducer for fan electronical regulation and for unloading (NOT present with 460/3/60 supply, centrifugal fans);
•
liquid solenoid valve (with prismatic tank and plate-type evaporator);
•
thermostatic throttle valve with external equalization;
•
dryer filter;
•
liquid flow sight glass;
•
refrigerant manometers;
•
check valve;
•
Schrader service valves;
Consult the enclosed drawings for additional information.
4 . 3
C o m p r e s s o r s
All the machines are equipped with SCROLL compressors, which are distinguished for their high energy efficiency, low vibrations and
consequent silence in normal operation.
They are cooled by the aspirated gas, protected against overheating of the windings by an internal module that monitors their temperature and,
upstream, by magnetothermic circuit breakers. These components are housed in a closed, but easily accessible, compartment.
4 . 4
C o n d e n s e r
Condensation occurs through fin-pack coils consisting of copper tubes and collectors, aluminium fins and shoulders in galvanised sheet.
4 . 5
E v a p o r a t o r
The evaporator is a finned pack type; the water flows in contact with the finned surface and at a speed that guarantees low pressure drops, while
the refrigerant fluid flows inside the tubes.
In the TAEevo models, the exchanger is protected against the formation of ice, caused by low evaporation temperatures, through an anti-freeze
function in the electronic controller. A probe monitors the temperature of the evaporator outlet water. If it is necessary to achieve a negative
ambient/water temperatures, a mixture of water and glycol must be used.
To drain the circuit, see Chapter 9.4 “Emptying the process water circuit” .
4 . 6
T a n k
The storage tank is cylindrical.
The tank can be protected against freezing by means of an electric heater managed by the electronic controller. A level sensor in the tank serves
to signal low water level conditions. The standard supply includes anti-condensation cladding, a drain valve and an air bleed valve. An internal
bypass between the water delivery and return connections, makes it possible to read the anti-freeze probe if the unit's process water inlet and
outlet connections are inadvertently closed. In this case the unit stops due to tripping of the antifreeze alarm and the shut-off valves must be
reopened.
The bypass serves exclusively to allow an antifreeze alarm to trip (if present) and to allow the pump to run with a reduced water flow rate
without damage. It is advisable to avoid repeated antifreeze alarm trip cycles in the foregoing conditions.
4 . 7
P u m p
Centrifugal pumps are installed and it is possible to choose between 2 different types, which provide two different pressures based on
requirements (a 3 or 5-barg pump). It is also possible to have units without pump.
The unit can be equipped with a tandem pump, managed by the controller.
The pump seals are made of ceramics/treated carbon/EPDM.
ATTENTION
Bleed the circuit by unscrewing the bleed cap on the pump whenever the water circuit is filled .See 5.4 “Collegamenti idraulici” .
Содержание NPC 280
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