Merloni Elettrodomestici
55 CM WIDE BUILT-IN FRIDGE-FREEZERS
Technical Manual
I
04-10-22/01
16-33
Language
Issue/Edition
Page
6
ANALYSIS OF PROBES
INFORMATION:
How It Works
: these are temperature sensors which associate measurements in de-
grees centigrade with resistive values that are easily read and managed by the micro-
processor on the board.
In particular, as the temperature increases, electrical resistance decreases, and as the
temperature decreases, resistance increases.
The control system utilizes four probes, which have the following functions:
FREEZER AMBIENT PROBE
This probe is located in the freezer compartment; its task is to measure the temperature
and communicate it to the microprocessor, which uses this data to manage the alarms
and the fast freezing function.
FRIDGE AMBIENT PROBE
This probe is located on the right hand wall inside the fridge compartment, inside a small
plastic cage. Its task is to measure the internal fridge temperature and communicate it to
the microprocessor, which uses this data to regulate the refrigerator's thermostat.
This is therefore the most important probe in terms of refrigerator operation, since it
determines the thermal cycles (activating and deactivating the compressor and solenoid
valve).
REFRIGERATOR EVAPORATOR PROBE
This probe is located on the fridge evaporator in the same area as the thermostat bulb
in the electromechanical version. Its task is to measure the temperature at the end of
the defrosting cycle (approx. +5 °C) and communicate it to the microprocessor every
time a defrost cycle is carried out.
FREEZER EVAPORATOR PROBE (No-Frost only)
This probe is located in contact with the freezer evaporator. Its task is to measure the
temperature (+8 °C) during freezer defrosting and deactivate the two resistors, thus
ending the defrost cycle.
If the FZ AMBIENT probe breaks: the appliance continues working since it has an al-
ternative timed mode, but obviously the temperature alarms will no longer be signalled!
If the FR AMBIENT probe breaks (only on models with display on the door): the ap-
pliance continues working since the smart microprocessor handles alternation between
fridge and freezer.
The Autotest procedure can in any case be used to pinpoint which probe is not working!
