Ball Sensor (Unbalance Switch) - LG WM3677HW Training Manual

COMBO

BALL SENSOR (Unbalance Switch)

DIODE (light emitting)
light
BALL
HOLE
TR (light sensing)
WM3677 COMBO
CASE
Page 53 of 68
The BALL SENSOR is so named
because it contains a small ball
covering an even smaller hole. The ball
rests so it blocks the light from the LED
above from shining through the hole to
the phototransistor below. If the tub
moves enough to strike the, the ball is
moved temporarily from its resting
place, allowing the light to trigger the
phototransistor. This, in turn, causes
the drum rotation to stop and then
attempt to rebalance the load.
The sensor assembly is bolted to the
back of the washer near the bottom.
The tub (surrounding the drum) is
suspended on springs and dampers to
allow some motion while the drum
rotates. However, if the load is out of
balance and the tub moves too far out
of place, a tab on the tub will strike the
ball sensor.
The black hose connects the air
chamber to the water level switch. If
this hose fails or is broken off its
connector, the COMBO will continue to
fill because the sensor does not detect
an increase in water level.
TRAINING MANUAL