GE PDW8900 Series Technical Service Manual page 15

Detergent Level Sensor
The SmartDispenseTM detergent level sensor consists
of a single level detection continuity sensor and
includes the following components:
a grommet seol -
a low
detergent
LED
indicator light
a wire harness.
When the detergent in the reservoir drops below
the continuity sensor, a signal is sent to the control
board and the low detergent LED indicator light is
turned on. The light indicates 3 to 7 wash cycles left
before the detergent reservoir is completely empty.
STATUS
Lightwill
SmarfDispense
turn on
A
0
LOWDETERGENT
DRYING
when time
m
refill
SENSING SANITIZED
WASHING CLEAN
Note: The Low Detergent LED may look like it is
illuminated when in fact it is not. An indicator that is
illuminated will be a
brisht
red.
Note: If the SmartDispenseTM system is not being
used, the low detergent light can be turned off (or
on1 by pressing the Added Heat pad 5 times within
3 seconds. There will be
3
audible beeps when the
light goes off.
The sensor is similar to the type used in several
automotive applications such as the windshield
w i ~ e r fluid reservoir.
The routing of the DC wiring from the tank is very
important. The 3 tape points on the tank keep the
DC wiring perpendicular to the AC harness wiring
running down across the front of the tank. (See tank
photo.)
r -
- -
le Point
Note: The dispenser tank, sensor with wire harness.
and gasket are only available as a complete
The control takes a reading of the detergent level at
assembly [part
#
WD35X10058). ~h~~ are shipped
power up (when power is restored from an outage)
with a new dispenser tank retaining collor.
and each time the door is closed and latched.
The control outputs a pulsing 5 VDC analog signal
to the
sensor
and
monitors the return voltage. Detergent Level Sensor Strip Circuit
Changes in the quantity of detergent in the tank
DETERGENT
change the amount of current drawn by the sensor.
SENSOR
, -
BRNNELLOW
J4-1
RED
J4-3