Working Principle; Hydraulic System (Water Softener Group) - Blomberg DW 14110 NBL00 Service Manual

8. Working Principle

8.1.

Hydraulic System (Water Softener Group)

The Standard wash cycle starts with drain cycle (1). Than the water inlet valve (2) is activated
by the electronic control board.
Intake water quantity is measured via flowmeter (3)
Intake water passas through water pocket(4) and the air break(5). The regeneration water
volume (17) is automatically filled during the water inlet. The inlet water is directed to the water
softener unit(16). The water pass thorugh the resin chamber and it is softened by the resin
(Ca+ and Mg+ ions romoved from water) . The softened water is collected in the sump (6).
After water inlet is completed, circulation pump (8) is activated and it pumps the water to spray
arms (10-11-12), so that washing operation starts. If ther is only a diverter (9) on the pumping
line, all water is sparyed from the spray arms at the same time. But if the diverter is motorized
(9), than it is possible to pump water to lower(10 and upper (11-12) spray arms seperatelly.
The motorized diveter valve(9) is controlled with electronic control unit according to
proggrammed wash cycle.
The heater (7) located on the suction side of the pumping line, is activated where heating
operation needed to clean the dishes. The temperature of the washing water is controlled with
a NTC which is located inside the sump (6).
After finishing the reqired circulation, wash water is drained with drain pump (1). In a wash
cycle there is at least one step circulation with hot water and detergent. After washing with hot
water and detergent, there exists rinsing step(s). There is at least one hot rince cycle.
The dishwasher is equiped with overflow saftey system. When there is an uncontrolled water
inlet in to the dishwasher, the excess water flows outside the wash chamber via overflow
security pipes (13). The water collected inside the bottom tray (15). If the float mechanism(14)
swins and moves up, it activates the drain pump(1) and stops water inlet valve(2) to prevent
acces water flow outside the dishwasher.
The dishwashers equiped with a softening unit(16), because for a succesfull cleaning and
rinsing operation, good water quality is needed. In some regions, water may have high
hardness values. (Hard water is water that has high mineral content (in contrast with soft
water). Hard water has high concentrations of Ca
harmful to one's health but can pose serious problems in our heating system and also causes
visual defects on glaswares. In domestic settings, the hardness of water is often indicated by
the non-formation of suds when soap is agitated in the water sample.)
The softening unit need to be regenerated after some period of usage. This depends on the
hardness level of water and adjusted regeneration setting on dishwasher.
The regeneration cycle takes place during drying step. Fort he regeneration operation, the
regeneration valve on the water softener(16) is activated for about 2 minutes, so taht the
regeneration water (17) is directed to salt chamber, than to the resin chamber. The resin kept
at rest within salty water solution. After some period of rest, the water inlet valve(2) is activated,
than the fresh water flows through the resin, so that the resin is cleaned from salty water.
BUILT- UNDER DISHWASHER
2+ 2+
and Mg ions. Hard water is generally not
49 2011