Water Fill System - Functional Description; Anti-Overflow Safety Level - Electrolux Diva Service Manual

6.3 WATER FILL SYSTEM - FUNCTIONAL DESCRIPTION

In all versions of the dishwasher (electromechanical and electronic), the water fill system is constantly
controlled by the level pressure switch, which acts as a pressure sensor.
6.3.1 DEFINITION OF WATER LEVEL
The pressure switch is connected hydraulically to the sump, inside which an air trap (pressure
chamber) is connected via a small tube in order to determine the level of water in the appliance.
In the water level circuit, the air pressure is proportional to the quantity of water present in the sump.
When this pressure exceeds the pre-determined threshold, the pressure switch (which acts as a
pressure sensor) switches the electrical contact to "full".
In order to maintain this condition, the stability of the water level is ensured during operation (washing),
which maintains the pressure switch closed on "full".
It is therefore possible to ascertain with certainty that the status of the pressure switch - i.e. its position
of "empty" or "full" - ensures that the cycle is performed correctly.

6.4 ANTI-OVERFLOW SAFETY LEVEL

In all dishwashers (electromechanical and electronic), the anti-overflow safety system is constantly
monitored by the safety pressure switch (which acts as a pressure sensor) in order to prevent water
from overflowing due to an excessively high level.
- The safety pressure switch is connected pneumatically via a small tube to the sump, which contains
a second pressure chamber (air trap), located adjacent to that of the level pressure switch. In the
safety circuit, too, the air pressure is proportional to the quantity of water present in the sump.
- Therefore, in case of a malfunction in the hydraulic circuit, and if the water level exceeds the pre-
determined safety threshold, the pressure switch intervenes by switching the electrical contact to
"full".
6.4.1 INTERVENTION OF THE ANTI-OVERFLOW DEVICE
The safety pressure switch commutates to "full", which immediately activates the drain pump, which is
connected electrically downstream of the circuit; the pump remains in operation until the safety
thermostat returns to "empty".
Versions with electromechanical control
The washing cycle continues in any case.
- If the malfunction is caused by a temporary fault (leakage
from the solenoid valve, excessive foam etc.) which
ceases to exist during the cycle, the user is unlikely to be
aware that the fault has occurred.
- If the fault persists, water will remain in the tub at the end
of the cycle, and the drain pump will switch on and off
alternately, since it is controlled by the pressure switch
(which cycles between "full" and "empty").
The connections for the anti-overflow system are shown in the
diagram opposite.
N.B. - If the appliance is switched off using the ON/OFF
switch at the end of the cycle, the drain pump
switches off.
- In order to ensure that the anti-overflow safety device remains in operation even when the
dishwasher is not in use, (1) the machine must remain connected to the power supply and
(2) the ON/OFF switch must be set to ON.
Versions with electronic control
Important: - If at the end of the cycle the door is opened or the appliance is switched off, the drain
pump will be disactivated.
- To ensure that the anti-overflow device remains in operation, the appliance must remain
connected to the power supply with the ON/OFF switch in the ON position and the door
closed.
N.B.:- For further details, refer to the Service Notes describing the functions of each specific model.
SOI/TD - PR 26/32 599 38 72-30