Water Level Switch - LG WM0742H Series Training Manual

TRAINING MANUAL WM0742HGA
DISASSEMBLY and REPAIR, continued

WATER LEVEL SWITCH

The water level detector switch monitors the water level and feeds this information to
the main board. The sensor reads air pressure in an air chamber on the tub. The air
pressure changes in relation to the depth of the water, moving a diaphragm in the switch.
As the water level fluctuates, it raises or lowers the iron center in the coil, which, in turn,
changes the electric resonance of the oscillator circuit of which it is a part. As water level
decreases, frequency increases.
(e.g. A low water level may read 25.5 kHz, while a high water level may read 21.4 kHz.
These readings are approximate; washers in the field may vary slightly from these
figures.)
To read the frequency while the WM0742 is running, simultaneously press and hold the
SOIL LEVEL and CUSTOM buttons. The number on the display should be divided by 10
to obtain the frequency reading in kHz. A display of 254 would indicate a frequency of
25.4 kHz. The MICOM interprets the frequency reading as one of eight levels, with one
being the lowest water level and any level greater than eight indicating an overflow
situation.
WM0742HGA Page 39 TRAINING MANUAL