Bunn G3 Coffee Grinder User Manual


 
19
SERVICE (Cont.)
DC MOTOR AND GRIND CHAMBER - G1MD ONLY
FIG. 6 DC MOTOR AND GRIND CHAMBER
P1706
Location:
The motor is located inside the upper part of the grinder
housing.
Test Procedures:
1. Remove the rear panel. Press the red “Reset”
button visible on the rear of the motor. Listen care-
fully for a “click”. This resets the motor protection
circuit and may indicate that something other than
coffee was inserted into the hopper for grinding.
If the grinder remains unable to start, proceed to #2.
If the grinder stops operating shortly after starting, refer
to removal and replacement instructions and inspect
for foreign materials.
2. Disconnect the grinder from the power source and
place a coffee bag behind the dispense chute.
3. Remove the black wire from the rectifier (+) ter-
minal and the red wire from the (-) terminal.
4. Check the voltage across the (+) and (-) terminals
with a voltmeter. Connect the grinder to the power
source. When the Off/On/Start switch is momen-
tarily placed in the “START” (lower) position and
then left in the “ON” (center) position and a bag
is in place behind the coffee dispense chute. The
indication must be approximately 108 volts dc.
5. Disconnect the grinder from the power source.
If voltage is present as described replace the motor.
If voltage is not present as described, reconnect the
white or red and white/blue wires to the motor, refer
to the Wiring Diagrams and check the grinder wiring
harness.
Removal and Replacement - Motor (Refer to Fig. 8)
1. Disconnect all wires from the motor.
2. Remove the two .250”-20 screws (1) securing
grind selector dial plate and grind selector knob
(2) to the grind chamber. Remove dial plate and
selector knob as an assembly.
3. Slide burr (7), auger rotor/spring assembly (3) and
burr rotor disc (4) off the grinder motor shaft as
an assembly.
4. Remove the two .250”-20 screws (8) securing the
stationary burr (9) to the grind chamber.
5. Remove bushing (10) and washer (11) from the
grinder motor shaft.
6. Remove the two #8 thread forming screws (12)
securing the fill plate (13) to grinder housing and
remove plate (13).
7. Remove the four #10-24 screws (14) securing the
chute assembly (15) to the grind chamber and
remove chute assembly (15).
8. Disconnect all the wires from the rectifier (23).
9. Remove the four .312”-18 screws (20), rubber
washers (22) and flat washers (21) securing
the motor and bracket to the grinder housing
bracket.
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