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M.FDK44.1-00 12/03/2015
3. DESCRIPTION OF THE MACHINE
FUNCTIONING
This dehumidifier is a refrigerating cycle dehumidifier: its functioning is based on a physical principle according to
which the air, coming into contact with a cooled surface, it wets the surface by covering it with humidity in the form of
condensed drops, or ice with low ambient temperature. What really happens is that a refrigerating machine maintains
in a refrigerated state the coil through which is conveyed the incoming air that, in this way, is cooled and dehumidified.
Then the air, passing through a warm heat-exchanger, heats up and returns in the room dehumidified and at a slightly
higher temperature.
With reference to the drawing , the air is drawn in through the back side of the dehumidifier, then it passes through the
filter , through the aluminium refrigerated coil or evaporator , again trough the heat- exchanger or condenser .
Finally, the motor fan expels the air back into the room through the front grilled panel: The condensed water is
collected in the
drip
and discharged
through the outlet
on the bottom
of the dehumidifier
.. The humidistat starts the
functioning of the dehumidifier when the humidity his higher than the preset level. An electronic circuit controls the
defrosting and prevents the compressor repeated starts within too short a time by delaying each new start.
Machines provided with Hot Gas Defrosting System
The models with hot gas defrosting system have one by-pass solenoid valve and a special electronic card.
The functioning of Hot Gas Defrosting is an exclusive Fral system for the dehumidifiers: this system consists of a
thermostat and one electronic control, which use the hot gas by-pass system only when it is necessary and for the
period of time required; this will lengthen the life of the machine by reducing the hot gas functioning phases.
4. CONTROL
Dehumidostat
May be placed on the front or rear side of the machine.
It consists of a number scale ranging from 1 to 5 or from 1 to 7. The minimum value correspond to 80%, the highest
value to 20%; the intermediate value (3-4) indicates that the humidity is at approx. 55%, a suggested good general
value.
In the position “CONT”, the machine will keep running all the time, independelntly from the relative humidity in the
room.
In position “OFF”, the machine is not running and will never start running (one-pole switch)
Hour Counter
Some models are equipped with an Hour Counter which is normally located in the rear side of the machine: this will
show the hours that the machine has been working
.
