Operation; Normal Operation; Defrosting - Electrolux Eurocombi Service Manual

4. Operation

4.1. Normal operation

The external (in air) NTC sensor in the freezer compartment controls the compressor's operating cycles
according to the cut-in and cut-out temperatures for the selected operating mode (warm, normal or cold). As
explained previously, the fans switch off two minutes after the compressor has stopped; they remain
switched off for 30 minutes, and are then switched on again.
The refrigerator compartment is controlled independently by the flap-operated thermostat, which opens to
allow cold air to flow in from the freezer compartment.

4.2. Defrosting

The first operating cycle after the appliance is switched on has a fixed duration of 6 hours. After this cycle,
the defrosting cycle starts*: the compressor and the fans are switched off and the heating elements switch
on. When the NTC sensor on the evaporator detects a temperature of +15°C, the heating elements are
switched off and the defrosting cycle is complete.
In any case, the maximum duration of the defrosting cycle is 30 minutes, after which the appliance returns to
normal operation, even if the +15°C temperature has not been reached.
If due to a malfunction the temperature of the evaporator battery should rise to an excessive level, two heat
cut-outs connected in series intervene at +55°C to open the circuit of the heating elements (i.e. switch them
off).
The standard time for the defrosting cycle is 22 minutes. If the time required for the cycle is longer, this
means that a large quantity of ice has accumulated on the evaporator, and the subsequent operating cycle
will have a duration of less than 6 hours. If the time required for the cycle is shorter than 20 minutes, this
means that only a small quantity of ice has accumulated on the evaporator, and the subsequent operating
cycle will have a duration of more than 6 hours. In either case, the duration of the operating cycle is subject
to a lower limit of 4 hours and an upper limit of 25 hours.
In this way, the appliance adapts the duration of the normal operating cycle to the duration of the previous
defrosting cycle: this is the concept of adaptivity which distinguishes the Eurocombi range of fridge-freezers.
compressor
fans
heaters
N1,N2= normal operating cycle (if N1 is the first: N1=6 hours)
D1,D2= defrosting cycle
A=drain delay = 5 minutes
The compressor does not switch on immediately at the end of the defrosting cycle. Instead, there is a 5-
minute "drain delay" designed to prevent the formation of ice in the drainage duct.
The fans switch on two minutes after the compressor so that warm air is not circulated inside the appliance.
* The electronic control system does not interrupt the operating cycle of the compressor.
Eurocombi 19/32