Wascomat W620 Classic, Service Manual

Page: 98 / 132

40
40. Heating
4
Service
Manual
2
3
5205
Programme
unit Al
Card
A21
Heating
elements
Temperature
sensor
Voltage supply
K21
5202
Heating
elements
Voltage supply
K21 K22
Programme
unit A1
Card
A21
Temperature
sensor
Programme
unit A1
Card
A21
5208
Rear control unit
Steam
valve
Y51
Temperature sensor
Fig.
2
Fig.
3
Function
Electric heating
The three heating elements in the machine are
connected to separate phases and are switched
on and off using one or two heating contactors,
K.21 and K22 (two contactors are used for higher
heating power). The heating contactors are
controlled by the programme unit and thermostat
B1.
The programme unit receives information on the
water temperature in the machine from the
thermostat situated in the outer drum. The
programme unit controls the heating contactors
to achieve the set water temperature for the
current washing programme.
When there is no water in the drum, the
programme unit prevents switch-on of the
heating elements. If an error would nevertheless
cause the elements to switch on, a slow-blow
fuse triggers to switch them off again.Then the
heating element has to be changed.
Steam heating
The steam valve is controlled by the programme
unit A1. The control signal goes via the
communication card A21.