GE Profile PDW8200 Series Technical Service Manual page 26

Turbidity Sensor
The turbidity sensor measures the amount of
suspended particles in the wash water in the
sump. As the sump water lays between the 1/4- to
3/8-in. gap between the LED transmitter and the
receptor during the first fill, the base-line reading is
taken. Successive turbidity measurements are
supplied to the control module and used to deter-
mine whether any pre-wash or rinse cycles can be
skipped. Decisions are based on a comparison of
clean water measurements at the beginning of the
first fill, measurements taken at selected fills, and
water temperature. By measuring the turbidity
level, the control module can conserve energy on
lightly soiled loads by skipping unnecessary
cycles.
Note: If the turbidity sensor circuit fails open or
shorted, the sensing LED on the control panel will
not light and the unit will operate for the maximum
amount of time, using the maximum number of
wash and rinse fills for the selected cycle.
The turbidity sensor also contains the thermistor
for automatic temperature control.
Turbidity Sensor Test
The Factory test mode is the most accurate way
to test the turbidity sensor circuit. The turbidity
sensor circuit contains the control module, wiring,
and turbidity sensor (see Factory Test Mode).
To Replace the Turbity Sensor:
To remove the turbidity sensor from the side of the
sump, loosen the screw and slide the retaining
clamp back. Remove turbidity sensor from the
sump and unplug connector from the turbidity
sensor.
Note: When installing the turbidity sensor, align
the key on the sensor with the keyway on the
sump.
Bottom View
TURBIDITY SENSOR
GY
NX
SX
OX
Refer to Wiring Diagram for voltages and pin-outs.
Retaining Clamp and Screw
– 24 –
Turbidity Sensor
Heating Element Nuts
NTC
1
2
3
4
Keyway and Key