Control Board - Bunn FMD-4 Operating & Service Manual

SERVICE (cont.)

CONTROL BOARD

FIG. 11 CONTROL BOARD
Location:
The Control Boards are located behind the lower front
access cover mounted on the component bracket.
Test Procedure:
Liquid Level Control Circuitry(Control Board #1):
1. Disconnect the dispenser from the power source.
2. Disconnect the six pin connector from J3 of the
control board.
3. Check the voltage across pins 5 & 6 of the six pin
connector on the wiring harness with a voltmeter.
Connect the dispenser to the power source. The
indication must be 24 volts ac.
4. Disconnect the dispenser from the power source.
If voltage is present as described, proceed to step 5.
If voltage is not present as described, refer to the wiring
diagram and check the dispenser wiring harness.
5. Reconnect the six pin connector of the wiring har-
ness to J3 of the control board.
6. Disconnect the four pin connector from J4 of control
7. Check the voltage across pins 1 & 4 of the four pin
8. Disconnect the dispenser from the power source.
If voltage is present as described, proceed to step 9.
If voltage is not present as described, refer to the wiring
diagram and check the dispenser wiring harness.
9. Reconnect the four pin connector of the wiring
10. Disconnect the ten pin connector from J2 of control
11. Carefully connect a piece of insulated jumper wire
#2
#1
12. Check the voltage across the terminals of the
P2635
13. Touch the free end of the jumper wire to the dis-
14. Move the jumper wire away from the housing. The
15. Disconnect the dispenser from the power source
If voltage is present as described, proceed to step
16.
If the voltage is not present as described, replace
control board #1.
20
board #1.
connector on the wiring harness with a voltmeter.
Connect the dispenser to the power source. The
indication must be 120 volts ac for two wire 120
volt models, three wire 120/208 volt models, three
wire 120/240 volt models, or 230 volts ac for two
wire 230 volt models.
harness to J4 of control board #1.
board #1.
to pin 10 (top right) of J2 on the control board.
Keep the other end of this wire away from any metal
surfaces of the dispenser.
inlet solenoid valve with a voltmeter. Connect the
dispenser to the power source. The indication
must again be 120 volts ac for two wire 120 volt
models, three wire 120/208 volt models, three wire
120/240 volt models, or 230 volts ac for two wire
230 volt models after a delay of approximately 10
seconds.
penser housing. The indication must be 0.
indication must again be 120 volts ac for two wire
120 volt models, three wire 120/208 volt models,
three wire 120/240 volt models, or 230 volts ac
for two wire 230 volt models after a delay of ap-
proximately 5 seconds.
and remove the jumper wire.
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