Level Control System - Electrolux Compact Service Manual

9.

Level control system

There are two basic ways of metering the right amount of water into a dish-washer. The first is to
open the inlet valve for a certain predetermined period of time, while the other is to use some
means for measuring the water level in the machine.
The major disadvantage of the first method is that if the mains water pressure is low (which is very
common in Europe), the time allowed will be too short to fill the machine with a sufficient amount of
water. A time-controlled machine needs a water pressure of at least 1.0 - 1.5 kg/cm2. The Compact
dishwasher is level-controlled and will perform satisfactorily at mains water pressures down to 0,5 kg/
cm².
Operation of the level control system of the
Compact dishwasher
As the machine is being filled with water, the water
level in a level control container located on the
side, outside the chassis will also rise. The
container is connected to a pressure switch by
means of a hose.
As the water level in the contairier rises, the air
pressure in the hose will also increase and will
act on the pressure switch. When the pressure
has risen to a preset value, the pressure switch
will open, which will cause the inlet valve to close.
The programmer motor can now advance to the
next step.
When the drain valve then empties the machine,
it will also empty the level control container, and
the pressure switch will revert to its original
position, in preparation for the next
water fill.
The inlet hole of the level control container is below
the strainer, and the water in the level control
system is therefore always clean and filtered.
If the water level should drop for any reason while
dishwashing is in progress, the pressure switch
will close, which will interrupt the water circulation,
and the water heating possibly restart the
programmer and allow the programmer to
advance in the programme.
It is important for the machine to be perfectly level
when it is in operation, since a 5 mm difference in
level corresponds to about 1 litre of water.
between 20 - 24 mm
Spares Operation - R.Kurzke 02/03
Water level
Level control container
- 16 -
PRESSURE
SWITCH
LEVEL CONTROL
CONTAINER
Air pressure, p
Washing
chamber
Water pressure, p
599 516 219 EN