GE PROFILE PDE9900 Technical Service Manual page 17

Positive Displacement Pump
The SmartDispense TM positive displacement pump
consists of a continuous fl exible tube running from
the detergent reservoir to the inner door detergent
outlet. The tube runs around the inside edge of the
pump housing. A 3-roller impeller fi ts tightly into
the center of the pump housing with each of the
3 rollers squeezing the sidewall of the tube. As the
impeller is driven counterclockwise by the motor, it
squeezes out a predetermined amount of detergent
for each 1/3 revolution of the impeller.
From
Detergent
Reservoir
Pump
Housing
Impeller
The dispenser pump operates on 120 VDC. During
each pre-wash cycle, the pump is energized for 5
seconds, dispensing 4ml of detergent.
The electronic control uses two inputs to determine
the total amount of detergent dispensed during the
main wash cycle:
• Soil Level determined by the turbidity sensor
• Water Hardness as calibrated for the location
A water hardness selection mode permits the
calibration of the water hardness for the location
at installation. (See
Water Hardness Test and
.)
Calibration
To determine the amount of detergent to dispense
during the main wash, the control uses the following
formula:
4ml x Number of Pre-washes
+ 25ml + Additional Quantity for Hardness
The additional quantity is a predefi ned quantity
of detergent based on the water hardness level
programmed into the control.
To Detergent
Outlet
– 17 –
Approximate Detergent Use
Smart Dispense Dosage Amount
Dosage (ml)
1
1 33
2 35.4
3 37.8
4 40.2
5 42.6
Smart Dispense Bottle Duration
Bottle Duration (wks)
1
1 10.3
2 9.6
3 9.0
4 8.4
5 8.0
To remove the pump
1. Remove the door panel. (See
2. Remove 2 Phillips head screws from the lower
right side of the door edge to release the pump
bracket.
3. Remove the grommet from the inner door panel
and unplug the tube from the reservoir outlet.
4. Disconnect the wires and remove the pump.
Positive Displacement Pump Strip Circuit
BULK DETERGENT
ORANGE
J2-1
Soil Level
2 3 4
41 49 57
43.4 51.4 59.4
45.8 53.8 61.8
48.2 56.2 64.2
50.6 58.6 66.6
Soil Level
2 3 4
8.3 6.9 5.9
7.8 6.6 5.7
7.4 6.3 5.5
7.0 6.0 5.3
6.7 5.8 5.1
.)
Door Panel
PUMP
WHITE
M
875 Ω