Beko B7S-B7SLED, Service Handbook

Page: 47 / 100

B7S B7SLED WASHING MACHINE SERVICE HAND BOOK
47
Picture 8.5 NTC
Table 8.1 NTC values
8.10. Water Level Sensor
An analog water level sensor which is fed by 5 V voltage is used. This sensor ensures that
the water level is determined instantly with the frequency values which it generates against
the pressure created. There are frequency values corresponding to the all pressure values.
An infinite number of levels can be determined in the analog water level sensor. Water levels
change according to the wash criteria of the designed program depending on the selected
program, temperature and auxiliary function.
Analog water level sensors are pressure
– displacement inverter components in general.
Analog water level sensors generate frequency modulation as output.
There are basically 2 capacitors, 1 coil and an inverter circuit on itself or the control system
to which it is connected.
Pressure increase pushes a ferrite part inside the sensor into the coil. Therefore L
(inductance) value of coil winding changes and the output value of the sensor
– inverter
system changes. Therefore pressure value can be measured in an analog manner.
The amount of water to be taken in for the programs is controlled by the water meters.
Water level sensor serves the basic functions of deciding to take in water again, control the
heater safety level, door opening level or foam level.
Also, if there are any error in the water meters or its connections, water is taken in with the
water level sensor.
Resistance (25

C) : 4773 ohm (

4.2%, Siemens)-
4837 ohm (

3.2%, elth)
Operating Temperature : -10

C...+100

C
Thermal time constant : 16

2 s
Resistance values which are read from the NTC ends by means
of multimeter are compared to the below table. These
approximate values should be read.