Electrolux EDW 503 User manual

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
SERVICE MANUAL
© AEG Hausgeräte GmbH
Muggenhofer Straße 135
D-90429 Nürnberg
Germany
Fax [phone]
Spares Operation
Publ.-Nr.:
599 528 133
11.06
EN
Edition:
Dishwasher
COMPACT
EDW 503
DISHWASHER
COMPACT
EDW 503

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
Index
1. Programme selection ............................................................................................ 3
2. Technical specifications ......................................................................................... 3
3. Programme chart ................................................................................................... 3
4. Components .......................................................................................................... 5
Capacitor ............................................................................................................... 5
Pressure switch ..................................................................................................... 5
Heater element ....................................................................................................... 5
Circulation pump .................................................................................................... 6
Drain pump ............................................................................................................ 6
NTC temperature sensor ....................................................................................... 6
EDW 503 ............................................................................................................... 6
Detergent dispenser .............................................................................................. 7
Rinse aid dispenser ...............................................................................................7
Inlet valve ............................................................................................................... 7
Anti flood switch ..................................................................................................... 7
Water softening system .........................................................................................8
5. Position of components .................................................................................. 9- 12
6. Water course scheme .........................................................................................13
7. Water inlet ............................................................................................................ 14
8. Rinsing system .................................................................................................... 15
9. Strainer system.................................................................................................... 16
10. Level control system ............................................................................................ 17
11. Drain system ....................................................................................................... 18
12. Regeneration ....................................................................................................... 19
13. Thermostats ........................................................................................................ 20
14. Temperatur and safety systems .......................................................................... 21
15. Wirings and diagrams ...................................................................................22 - 25
16. Service informations ............................................................................................ 26
Spülraum ............................................................................................................. 26
Housing ................................................................................................................ 27
Base plate ............................................................................................................ 28
Components (lower region) ................................................................................. 29
Door components ................................................................................................ 30
Door switch .......................................................................................................... 31
Rinse aid dispenser / detergent dispenser coil .................................................... 32
Pressure switch / Anti-siphon valve / level control container ............................... 33
Heater element ..................................................................................................... 34
Thermostats / switch unit / float switch / inlet valve ............................................. 35
Circulation pump / drain pump ............................................................................. 36
Softener / regeneration valve ............................................................................... 37
Leakage points ..............................................................................................38 - 39
16. Fault tracing ..................................................................................................40 - 42

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
2. Technical specifications
1. Programme selection / cancel button

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3. Programme chart

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
4. Components
Capacitor
The circulation pump is connected to a capacitor.
2,0 μF for UK
2,5 μF for Europe
Pressure Switch
The pressure switch controls the water level.
Without water, contact is closed.
Adjusting:
Turning the marked screw clockwise +level
Turning the marked screw anti clockwise -level
Heating element
Power output 1200 W
Resistance approx 42 Ω

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Circulation Pump
The circulation pump is driven by an asynchronous
motor with an starting winding. The starting winding
ist in circuit with a 2,5 μF (Euro) capacitor. (2 μF UK)
Rating: 60/80 W
Main winding resistance 158 Ohm
Starting winding resistance 158 Ohm
Drain Pump
The drain pump is driven by a synchronous motor.
Power output 21/19 W.
Pump rate 10-12 l/min.
Main winding resistance 200 Ohm
Thermostats (normally open)
45°C closes at 41°C
opens at 33°C
55°C closes at 50°C
opens at 42°C
65°C closes at 61°C
opens at 53°C
Overheating protection (normally closed)
opens at 83°C
closes at 0°C
Electronic EDW 503
On electronic models, a micro processor controls all
components, this is done using triacs. The electronic also
memorizes all programme data.
The heating is switched by a relay on the electronic board.

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
Detergent dispenser
Coil resistance
3000 Ohm
Rinse aid dispenser
Rinse agency capacity 140 ccm
Solenoid coil resistance 1900 Ohm
Inlet valve
Capacity, max, 4 l/min
Resistance 4800 Ohm
Anti flood switch
If the anti flood swich in the base tray is activated, all
components are switched off except the drain pump

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
Water softening system
Operation of the water softening system
When water is admitted, the inlet valve (1) opens and the
hard water flows down into the ion exchanger (5),
through which it flows and is softened before flowing
through the water inlet (6) and then being sprayed into
the Washing chamber.
!n the meantime, the container for the regeneration
water (2) is also filled with water.
lf the rubber plug (3) at the rear of the machine is in place
as shown in the ilustration, the machine can handle
water with a hardness of up to 20'dH. !f the rubber plug
is removed. The regeneration water volume will be
increased, and the machine can then handle water with
a hardness of up to 35°dH.
During the dishwashing programme, the ion exchanger
will gradually be filled with lime and, to be able to soften
the water during the next dishwashing cycle, the ion
exchanger must be restored to its original condition.
This is done by a process known as regeneration, which
takes place according to the actual programmer dia-
gram.
The solenoid valve (7) between the salt container and
the ion exchanger will then open, and regeneration
water will flow into the salt container (4).
A corresponding amount of water saturated with salt is
thus forced into the ion exchanger. The salt solution is
present in the ion exchanger during the last rinse, and
the small plastic balls will be recharged with sodium ions.
According to the actual programmer diagram, the inlet
valve will open and will allow about 2 litres of water to flow
through the ion exchanger to flush away the now dissolved
lime residues. The lime-rich water is then flushed
immediately out to drain, and the machine is reset and
ready for the next water fill.
The whole of this process is integrated into the
programme of a machine with water softening, and thus
takes place fully automatically.
It should also be noted that it is important to use only
coarse salt, since fine-grained salt would. form lumps.
Water which is rich in lime is said to be "hard".
Water hardness is measured in German degrees
of hardness (dH). Water up to 10dH is normally
regarded as soft, and above this value, it is
regarded as hard.
The phosphates in the detergent can handle the
hard-
ness in soft water. But if the water is hard,
precipitations will occur, i.e. lime will be deposited
on the dishes and in the dishwasher.

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Spares Operation - R.Kurzke 11/06 599 528 133 EN
5. Position of components
Outer door
Inner door
Door opener
Door seal
EDW 503
Panel
upper panel

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Thermostats
Rinse-aid dispenser
Housing
Interference filter
Coarse sieve
Fine strainer
Base plate
Basek rails
Door switch
Coil for detergent
dispenser
Heating element

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Pressure switch
Regeneration valve
Circulation pump
Drain pump
Float switch
Inlet valve
anti-siphon valve
Inlet hose
Drain hose
Base plate
Softener
Reed switch
salt indicator
Air chamber
Water collector

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Cup support
Dish rack
Cuttlery basket
Pump housing
Sealing ring
Spray arm
Basket roller

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6. Water Course Scheme

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7. Water Inlet
The water flows into the regeneration dosage chamber via inlet valve, over air break, into
regeneration dosage chambers and into softener
The level control container operates the pressure switch.

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8. Rinsing system
The function of the rinsing system is to wet the
dishes loaded into the machine.
The electric motor of the circulation pump is
delivered with the impeller fitted to it. Half the
pump casing forms part of the plastic chassis,
and the other half is bolted in position inside the
washing chamber.
This arrangement ensures, that the joint between
the two halves of the pump casing is inside the
washing chamber.
An O-ring provides the seal between the motor
assembly and the chassis.
The rating of the electric motor is 60 watts(50 Hz)
or 80 watts(60 Hz) and the pump circulates around
30 litres per minute.
The electric motor needs assistance at the instant
of starting, which is provided by a starting
capacitor.
The motor mounting is very important to the sound
level. Since the movements of the motor are a
minimum at the centre, the motor is secured to a
rubber mounting in the centre, at the rear end of
the motor.
To ensure that no vibrations will be transmitted
from the motor to the base plate, a plastic foam
spacer strip is fitted to the bottom of the chassis.
The pump casing half which is inside the wash-
ing chamber also contains the spray tube bear-
ing with a stainless steel shaft.
The underside of the spray tube is fitted with a
seal ring to minimize leakage.
The shape and orientation of the holes in the spray
tube are such that the dishes furthest away in the
corners of the machine will also be effectively
washed.
The spray tube rotates anti-clockwise at a speed
of 10 - 20 1/min.
If the speed is too high, the dishwashing results
will be poor, and if the speed is too low, the spray
tube may stop al-together.
The pressure in the spray tube is just over 0.2 kg/
cm². The spray tube is retained by a ceramic nut
with a left-hand thread, to en-sure that the rotation
of the spray tube will not cause the nut to unscrew
itself. This means that the nut must be un-screwed
in the „wrong“ direction.
CERAMIC NUT
SPRAY TUBE
SEAL RING
PUMP CASING HALF
MOTOR MOUNTING
O-RING
PLASTIC
TRAY CIRCULATION PUMP

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9. Strainer system
The strainer system is one of the systems which are most important to the performance of the
dishwasher.
The design of this system is largely decisive to whether the dishwasher will be able to perform its
most fundamental task: to wash the dishes clean.
The strainer system must trap particles of food, etc. and ensure that these particles will not be
recircu-lated and deposited back on the dishes.
Another consumer requirement is that the strainer system must be self-cleaning, so that it will not
be necessary to wash the strainers by hand every time or every other time the dish-washer is
used.
The strainer system consists of two parts which
jointly contain three different strainers, each of
which with its own particular task.
The fine strainer consists of a shaped stainless
steel plate which is perforated with 0.5 mm
diameter holes and is retained in a plastic frame.
The dishwashing water passes through this
strainer about 420 times during a normal
dishwashing programme.
The bottom of the chassis is designed in such a
manner that particles will continually be flushed
away to the coarse strainer. All particles larger
than 0.5 mm will be trapped, and the water flowing
through the strainer will thus be virtually clean.
The performance of the strainer is highly
dependent on the suction of the circulation pump
being equally distributed over the entire strainer
area. If the suction is higher at any one point,
particles will be drawn through the fine strainer at
that point, and they would then disintegrate and
would be very dif-ficult to trap.
It is also very important for the plastic frame of the fine strainer to seal well against the chassis, so that
particles will not by-pass the strainer and be deposited back on the dishes.
The fine strainer also includes a small plastic boss. This is designed to prevent the build-up of pressure
and air cushions under the strainer. An air cushion under the fine strainer would otherwise prevent the
water from flowing through the fine strainer, and insufficient water would then be supplied to the cir-
culation pump.
Particles are thus flushed continuously down into the coarse strainer, where they are retained until
the water is pumped out to drain. The coarse strainer is also designed to trap larger particles, such as
pieces of meat, toothpicks, etc.
To retain the good dishwashing properties of the machine, the consumer must empty and rinse the
strainers as soon as they show signs of clogging.
Coarse strainer
Fine strainer

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10. 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.
PRESSURE
SWITCH
LEVEL CONTROL
CONTAINER
Air pressure, p
Water pressure, p
Washing
chamber
Level control container
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.
Water level
between 20 - 24 mm

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11. Drain system
The system consists of inner and outer drain hoses and a drain pump, and its function is to transport
the contaminated water as efficiently as pos-sible from the machine to the waste water system of the
buildin
OUTER DRAIN HOSE
INNER DRAIN HOSE
DRAIN PUMP
DRAIN CASING
The drain pump is connected to the chassis at the coarse
strainer and is sealed with an O-ring. The motor is a per-
manent-magnet motor, with the rotor.mounted inside a
plastic housing and the stator fitted to the outside of the
plastic housing. The design is such that the pump has no
traditional shaft seat which always invol-ves the risk of
leakage.
The pump performs equally well in both directions of rotation, and the direction in which it
rotates is a matter of pure chance. This also means that the pump is vir-tually proof against
jamming. If some object should enter the pump casing and jam the impellar, the motor will
immediately make a new starting attempt in the op-posite direction. Even if the impellar is
seriously jammed (e.g. by a toothpick), the motor will most probably release the impellar
within about a second. The power consumption of the motor is 23 watt, and the pump
capacity is about 10 I/min.
The internal drain hose is connected to the drain pump. To prevent the risk of the machine
being emptied by siphon action, the hose routes the drain water through a loop running up
to the top of the chassis and then through the outlet at the bot-tom of the machine, to the
outer (visible) drain hose. A hole is provided at the highest point of the inner drain hose for
venting the system.
If the drain hose is permanently connected to a water trap, it is very important that the
inside diameter of the drain system should not be less than 13 mm at any point.
Anti siphonic device
If the end of the take-off hose
is below the level of the water
in the wash space, a siphon
effect is possible, that is, the
machine runs empty. This is
avoided by the ventilation
through the anti-siphon valve.

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12. Regeneration
The water chamber for regeneration contains 350 ml water. During regeneration, the regeneration
valve is energized. The 350 ml water runs into the salt container and mixes with the salt to form a
brine solution.
In the top of the salt container there is an opening with a small filter, from here the brine solution
enters the softener where the resins are regenerated.
The softener has 5 settings and can be adjusted to suit the degree of water hardness.

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13. Thermostats
The thermostats are pressed into the
tubular mountings in the plastic chassis.
They measure the temperature on the
outside of the plastic wall, which leads to
a certain difference between the water
temperature and the thermostat
temperature.
However, the specifications of the
thermostats take this into account. (In one
particular case, the same thermostat is
used for two different temperatures.
This is possible because the thickness of
the chassis is different at the two
thermostat mountings.
The thicker the wall, the greater the
temperature difference and the higher the
water temperature.)
Depending on the Programme selected,
the thermostats will be switched in, and
will interrupt the power supply to the heater
element via the programmer when the
water has been heated to the required
temperature.
As in the case of al! other components,
there is a certain amount of tolerance on
the nominal temperature of the
thermostats.
For the breaking temperatures, the
tolerance is ±3°. There is also a "differen-
tial", i.e. a difference between the
temperature at which the thermostat opens
the circuit and the temperature at which it
returns to the original position. This diffe-
rential is 8°C.
The breaking values are adjusted to give
the following water temperatures: 45, 55,
65 and 72'C.
Colours coding of the thermostats
A = brown 83°C (anti boiling protection)
B = black 65°C (two)
C = grey 55°C
D = white 40°C