Bunn FMDA DBC-3 User Guide
24
CONTROL THERMOSTAT
FIG.11 CONTROL THERMOSTAT
Location
The control thermostat (mechanical or elec-
tronic) is located inside the dispenser on the upper
left side of the housing.
left side of the housing.
Test Procedure
Mechanical Thermostat
1. Disconnect the dispenser from the power source.
2. Disconnect the black wire of the control thermo-
1. Disconnect the dispenser from the power source.
2. Disconnect the black wire of the control thermo-
stat from the black lead from the limit thermostat.
3. Remove bulb from the tank.
4. With a voltmeter check the voltage across black
4. With a voltmeter check the voltage across black
wire on the control thermostat and the white or
red wire on the tank heater with the tank heater
switch in the “ON” lower position. 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 volt mod-
els.
c) 240 volts ac for two wire 240 volt models and
three wire 120/240 volt models.
d) 230 volts ac for two wire 230 volt models.
red wire on the tank heater with the tank heater
switch in the “ON” lower position. 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 volt mod-
els.
c) 240 volts ac for two wire 240 volt models and
three wire 120/240 volt models.
d) 230 volts ac for two wire 230 volt models.
5. Disconnect the dispenser from the power source.
If voltage is present as described the control thermo-
stat is operating properly. Reinstall bulb into the tank.
If voltage is not present as described, replace the
thermostat.
stat is operating properly. Reinstall bulb into the tank.
If voltage is not present as described, replace the
thermostat.
P1682.40
J3
J2
J1
J4
J1
FIG. 10 CONTROL BOARD CONNECTORS
P1680
If the voltage is present as described, the whipper
motor and dispense solenoid control circuitry is oper-
ating properly.
If the voltage is not present as described, replace the
control circuit board.
motor and dispense solenoid control circuitry is oper-
ating properly.
If the voltage is not present as described, replace the
control circuit board.
Removal and Replacement:
1. Disconnect the three plugs on the main wiring
1. Disconnect the three plugs on the main wiring
harness from the connectors on the control board.
2. Remove the four #6-32 keps nuts securing the
control board to the component bracket.
3. Remove control board and discard.
4. Install new control board on the component bracket
4. Install new control board on the component bracket
using four #6-32 keps nuts.
5. Reconnect the three plugs on the main harness to
the connectors on the control board.
SERVICE (cont.)
J3
J2
CONTROL BOARD (cont.)
9. Disconnect the dispenser from the power source.
10. With a voltmeter check the voltage across the
10. With a voltmeter check the voltage across the
terminals of the appropriate dispense solenoid.
Connect the dispenser to the power source. Press
the appropriate dispense switch. 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.
Connect the dispenser to the power source. Press
the appropriate dispense switch. 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.
29215 052104