Bunn FMD DBC-3 Operating & Service Manual page 20

SERVICE (cont.)
AUXILIARY CONTROL BOARD (cont.)
5. On the dispenser whipper panel, ensure that the
tank heater switch is in the "ON" (lower) position.
6. Disconnect the black wire coming from the control
thermostat from the limit thermostat.
7. Remove the control thermostat bulb from the tank.
8. Remove the six pin connector from J2 of the
auxiliary control board.
9. With a voltmeter, and using pin 5 as a reference,
check for voltage, in turn, at pin 3 and pin 6 of the
six pin connector of the wiring harness. Connect
the dispenser to the power source. The indication
must be :
a) 120 volts ac for two wire 120 volt models
b) 120 volts ac for three wire 120/208 or 120/240
volt models
c) 240 volts ac for two wire 240 volt models.
d) 230 volts ac for two wire 230 volt models.
10. Disconnect the dispenser from the power source.
If voltage is present as described, proceed to step 11.
If voltage is not present as described, refer to the
wiring diagram and check the dispenser wiring har-
ness.
11. Reconnect the black wire coming from the control
thermostat to the limit thermostat.
12. Re-install the control thermostat bulb.
13. Noting the starting position of the control thermo-
stat knob, adjust the control thermostat knob
counter-clockwise until a click is heard.
14. With a voltmeter, check for voltage between pins
3 and 6 of the six pin connector of the wiring
harness. Connect the dispenser to the power
source. The indication must be:
a) 120 volts ac for two wire 120 volt models
b) 208 volts ac for three wire 120/208 or 240 volts
ac for three wire 120/240 volt models
c) 240 volts ac for two wire 240 volt models.
d) 230 volts ac for two wire 230 volt models.
15. Disconnect the dispenser from the power source.
Return the control thermostat knob to the starting
position.
If voltage is present as described, replace the auxiliary
control board. If voltage is not present as described,
refer to the wiring diagram and check the dispenser
wiring harness.
Removal and Replacement:
1. Loosen the two #8-32 screws securing the com-
ponent mounting bracket to the dispenser hous-
ing.
2. Slide the component mounting bracket forward
until the screw heads align with the large diam-
eters of the keyhole openings.
3. Lift the component mounting bracket, and pull it
through the lower access panel opening.
4. Disconnect the two plugs on the main wiring
harness from the connectors on the auxiliary con-
trol board.
5. Remove the two #6-32 keps nuts securing the
auxiliary control board to the component mount-
ing bracket.
6. Remove the auxiliary control board.
7. Remove the two snap-in stand-offs from the aux-
iliary control board and install them in the new
auxiliary control board. Discard the old auxiliary
control board.
8. Install the new auxiliary control board using the
two #6-32 keps nuts.
9. Reconnect the two plugs on the main wiring har-
ness to the connectors on the auxiliary control
board.
10. Replace the component mounting bracket and
tighten the two #8-32 screws.
J 1
FIG. 6 AUXILIARY CONTROL
BOARD TERMINALS
20
J 2
P1996.80
29215 052104