13
4.1 COOLING
CIRCUIT
Compressor
High-efficiency, scroll-type compressors fitted
on shock absorbers operated by a two-pole
electric motor with internal thermal protec-
tion;
Supplied with an antifreeze electric heater,
automatically powered when the unit pau-
ses, so that the unit is kept powered up.
Air side heat exchanger (coil)
Made with copper pipes and aluminium fins
locked into place by means of mechanical
expansion of the pipes. With a protection
grille.
Water side heat exchanger (plate type)
of the plate type, it is insulated externally
with closed cell material to reduce thermal
dispersions.
Filter drier
Of the mechanical type made of ceramics
and hygroscopic material able to trap impuri-
ties and any traces of humidity in the cooling
circuit.
Thermostatic valve
The mechanical type valve with outside equa-
liser on the evaporator outlet modulates the
gas flow to the evaporator dependent on the
thermal load in such a way as to ensure the
proper intake gas degree of overheating.
HOT GAS INJECTION solenoid valve (only for
heat pumps.)
The valve placed between the compressor de-
livery and thermostatic valve outlet controls:
- Defrosting cycle without cycle reversing
- Safety capacity control if pressure increa-
ses
- Safety capacity control if delivery tempera-
ture increases
- Safety capacity control if low pressure de-
creases
- Low pressure decrease
Cycle reversing valve
only heat pump
Inverts the flow of the refrigerant when the-
re is a change of summer / winter operation
and during the defrosting cycles if necessary.
One way valve
This allows the refrigerant to flow in just one
direction.
Separator
It compensates the difference of volume
between the finned coil and the plate heat
exchanger, keeping the excessive liquid during
winter operation.
4.2
FRAME AND FANS
Fan unit
Screw type, statically and dynamically balan-
ced. The electric fans are protected elec-
trically with thermomagnetic switches and
mechanically with anti-intrusion metal grilles
in accordance with the CEI EN 60335-2-40
standard.
Load-bearing structure
Made of hot galvanised steel sheet of ade-
quate thickness, it is painted with polyester
powders able to resist the atmospheric
agents over time.
4.3 HYDRAULIC
COMPONENTS
Circulating pump (circulator)
Versions P and versions A
.
Differential pressure switch
Placed between the evaporator inlet and out-
let. It checks that there is water circulation.
If there is not, it blocks the unit.
Water filter
It allows to block and remove any impurities
in the water circuits. Inside, it has a filtering
mesh with holes no bigger than one millime-
tre.
It is essential for avoiding serious damage to
the plate heat exchanger.
Accumulation tank
(only in versions HA - HK)
Serves to lower the number of compressor
peaks and standardise the temperature of
the water to send to the users.
HA - HK - HP drain valve
(only in versions with hydronic unit or with
pump)
Manual valve that discharges any present air
pockets. It is intercepted by a stopcock so
that it can be substituted if necessary.
HA - HK - HP expansion tank
(only in versions with accumulation or with
pump)
Membrane tank with preloaded nitrogen.
Hydraulic circuit safety valve
HA - HK - HP
(only in versions with hydronic unit or with
pump)
Calibrated to 6 bar and with discharge that
can be conducted, it releases overpressure
in case of abnormal pressure.
Softstart
Electronic device that reduces the starting
current (standard in single phase versions).
4.4
SAFETY AND CONTROL
COMPONENTS
High pressure switch
With fixed calibration, placed on the high
pressure side of the refrigeration circuit,
it shuts down compressor operation in the
case of abnormal operating pressure.
Low pressure transducer.
standard on heat pumps
Placed on the low pressure side of the refri-
geration circuit, it communicates to the con-
trol card the operating pressure, sending a
pre-alarm in case of abnormal pressure.
High pressure transducer
standard on heat pumps
Placed on the high pressure side of the refri-
geration circuit, it communicates to the con-
trol card the operating pressure, sending a
pre-alarm in case of abnormal pressure.
DCPX
standard in versions (HP)
The standard units are not suitable for
being installed in a salty environment. The
minimum and maximum limits for water flow
speed to the heat exchanger are indicated by
the curves shown in the diagrams related to
pressure drop. For information about opera-
ting limits, consult the diagrams below, which
are valid if
∆
t = 5 °C.
WARNING:
- To use the machine beyond the limits indi-
cated in the diagram, contact AERMEC engi-
neering department.
- If the machine is placed in a windy area,
install an adequate wind break to avoid the
DCPX device to operate in an unstable con-
dition.
4.5 ELECTRICAL
COMPONENTS
Electrical panel
Contains the power section and the mana-
gement of the controls and safety devices.
This conforms with standard CEI 60204-1,
and electromagnetic compatibility directives
EMC 89/336/EEC and 92/31/EEC.
Door lock knife switch
THE electrical panel can only be accessed
by cutting off power using the opening lever
on the panel itself. This lever can be locked
in place using one or more padlocks, during
maintenance in order to prevent the machi-
ne from being powered up accidentally.
Control keypad
Provides full control functions.
For a detailed description of the keypad refer
to the user manual.
- thermomagnetic compressor protec-
tion;
- thermomagnetic fan protection;
- secondary thermomagnetic switch pro-
4 STANDARD EQUIPMENT
