Operating Principle - Electrolux EWX11831 Service Manual

13.8.2 Operating principle

1. Plunger
2. Oscillating Coil
3. PCB
4. Spring
5. Piston
The weight sensor incorporated into the shock absorber is made up of an oscillator (which generates a frequency)
consisting of the circuit board (3) and coil (2).
If there is no laundry in the drum when the appliance is turned on, the position of the piston
compared to the plunger is considered as the zero value (Fig. A).
When laundry is placed in the drum, this causes the washing unit to be lowered, with the
consequent compression of the shock absorber (Fig. B); the movement of the piston inside
the plunger changes the inductance of the coil, and consequently changes the frequency,
which is processed by the circuit board and communicated to the display board and the
LCD displays the weight of the laundry in kg.
If there is laundry in the drum when the appliance is turned on, the position of the piston
is different from when the drum is empty, moving the zero value and offsetting the final
measurement.
Efficacy check
To check the efficacy of the weight sensor:
Check that the inside of the drum is empty.
-
- Plug the appliance into the socket, press button P1 to turn it on and select the desired programme.
Open the appliance door if shut.
-
- Place an item of known weight inside the drum (no more than the maximum weight for which the appliance
is sold) and check that the value represented on the LCD display corresponds.
(with an accuracy of ± 1 kg and ± 1.5 kg for heavy loads).
Diagnostics
During diagnostic mode, position 7 (see paragraph entitled "Diagnostics system" on page 34).
The appliance fills water until the first level to perform the heating function. Next, another litre of water is filled
through the solenoid valve (measuring it with the flowmeter) if the weight sensor is efficient, the variation is
recognised, otherwise the alarm EC3 is displayed on the LCD.
Technical Support - DMM
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Fig. A
Fig. B
599 77 23-65 Rev. 03