Bunn G9 HD Operating & Service Manual page 13

SERVICE (cont.)
Timer
Single set timer shown
Multi set timer (Urn/Carafe) similar
Location:
The timer is located on the timer bracket in the
grinder base. The bracket can be removed by loosen-
ing the two 8-32 screws beneath the timer dial(s).
Test Procedure:
1. Disconnect the grinder from the power supply.
2. Check the voltage across terminals TL1 & TL2
with a voltmeter when the "Off/On/Start switch
is placed in the "START" (right) position and
released. Connect grinder to the power supply.
The indication must be:
(a) 120 volts ac for two wire 120 volt mod-
els.
(b) 240 volts ac for two wire 240 volt models.
3. Disconnect the grinder from the power supply.
If voltage is present as described, proceed to
step 4.
If voltage is not present as described, refer to
the Wiring Diagram and check the grinder wiring har-
ness.
4. Remove the white/orange and white/yellow wires
from terminals TL3 & TL5.
5. Check for continuity across the white/orange and
white/yellow wires when the Off/On/Start switch
is placed in the "START" (right) position.
If continuity is present as described, reconnect
the white/orange wire to terminal TL3 and the white/
yellow wire to terminal TL5, and proceed to step 6.
If continuity is not present as described, refer
to the Wiring Diagram and check the grinder wiring
harness.
6. Check the voltage across terminals TL1 and TL4
with a voltmeter when the Off/On/Start switch
is placed in the "START" (right) position and
released. Connect grinder to the power supply.
The indication must be:
(a) 120 volts ac for two wire 120 volt mod-
els.
(b) 240 volts ac for two wire 240 volt models.
7. Disconnect the grinder from the power supply.
If voltage is present as described, the timer is
operating properly. Refer to the Adjustments section
to vary the amount dispensed.
If voltage is not present as described, replace
the timer.
P1312
Removal and Replacement:
1. Remove all wires from the timer terminals.
2. Remove the four 6-32 screws and nuts holding
the circuit board to the timer bracket.
3. Remove the two 6-32 screws and nuts holding
the dial plate to the timer bracket.
4. Install the new dial plate and circuit board to the
timer bracket.
5. Refer to the illustration below when reconnecting
the wires.
6. Refer to the Adjustments section to vary the
amount dispensed.
2
3
4
5
Single set timer shown
Multi set timer (Urn/Carafe) connections are the same
Page 13
WHI/RED to Relay N.O.
WHI/RED to
Off/On/Start Switch
WHI to Cordset (120 v)
RED/BLK to Cordset (240 v)
WHI/ORA to
Off/On/Start Switch
WHI/GRN to Relay Coil
WHI/YEL to
Off/On/Start Switch
P1313
10171 121597