Service manual

11
COMPONENT INFORMATION
Spray arm diverter
Certain machines are tted with a spray arm
diverter. The spray arm diverter comprises a
synchronous motor that drives a disc valve
via a gearbox. The disc distributes dierent
amounts of water from the circulation pump
to the lower and upper spray arms at dierent
pressures. The motor/gearbox also drives a
cam with four dierent step times. A switch
detects the cam (step time) and provides
the control unit with feedback on its current
position when setting the desired spray arm
status.
Note that the spray arms never rotate at the
same time. The spray arms can report the
following status:
• Upper spray arm half or full pressure
• Lower spray arm half or full pressure
Depending on the program, dishwashing
stage and options, the spray arms are set to
various intervals and pressures.
Machines that lack a spray arm diverter utilise
a water distributor instead, which routes the
water to both spray arms. The spray arms
always rotate at the same time.
Heater
The heater is of the ow-through type and is
tted between the bottom drain and the suc-
tion side of the circulation pump. It comprises
a pipe with a heating coil. One side of the
heating coil is tted with an overheating cut-
out with a trigger temperature of 98°C and an
automatic reset. The other side is tted with a
safety fuse that blows at 229°C.
Drain pump
The drain pump comprises a 30 W synchro-
nous motor and a pump component. The
direction of rotation is random, making the
pump partially self-cleaning.
Fan
The fan extracts the damp air from the ma-
chine during the drying phase of the program.
The fan system has a fan motor that drives
a double-sided fan wheel. Dry air is sucked
in from the opening on one side of the fan
wheel. The hot and damp air from the clean-
ing compartment is drawn through the other
side of the fan wheel, when a Vax motor
opens a damper. This is done with a slight
delay. Dry and damp air are mixed in a con-
duit that ends at the top of the door, where
the air is expelled through a nozzle.
Detergent and rinse aid dispenser
The detergent and rinse aid dispenser is
tted with an electromagnet which upon rst
activation dispenses detergent and upon
second activation dispenses rinse aid. The
system is reset when the dishwasher door is
opened.
The dispenser contains a chamber of adjust-
able volume to set the desired rinse aid dose.
The rinse aid level can be checked using the
optical indicator on the top of the dispenser.
Some models have a sensor, a reed switch,
tted to the dispenser. This measures the
rinse aid level, which is then indicated on the
panel.
Mainpowerswitch
The main power switch has 2 pins and breaks
the phase and the earth. However, power to
the lters, overow cut-out, drain pump and
inlet valve is not cut when the main power
switch is turned o.
On the DW-70.4 the main power switch is elec-
tronic and is integrated with the control unit.
It puts the machine into standby mode when
deactivated.
EMC protection
EMC protection ensures that the machine
does not interfere with nearby electrical
equipment. It also protects the machine from
external interference.