Timer (Early Models) - Bunn GMB-PS Operating & Service Manual

SERVICE (cont.)

TIMER (early models)

FIG. 14 TIMER
Location:
The timer is located inside the right front of the
hood.
Test Procedure.
1. Disconnect the brewer from the power source.
2. Rotate the brew timer dial fully counterclockwise.
3. With a voltmeter, check the voltage across termi-
nals TL1 & TL2 (white or red and white/red wires)
when the "ON/OFF" switch is in the "ON" upper
position. Connect the brewer to the power source.
The indication must be:
a) 120 volts ac for two wire 120 volt models and
three wire 120/208 or 120/240 volt models.
b) 200 to 240 volts ac on two wire 200 volt or 240
volt models.
4. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #5.
If voltage is not present as described, refer to the
Wiring Diagrams and check the brewer wiring har-
ness.
5. With a voltmeter, check the voltage across the
terminals TL1 & TL3 (white/red and white/green
wires) when the "ON/OFF" switch is in the "ON"
upper position and start switch pressed. Connect
the brewer to the power source. The indication
must be:
a) 120 volts ac for two wire 120 volt models and
three wire 120/208 or 120/240 volt models.
b) 200 to 240 volts ac for two wire 200 volt or 240
volt models.
6. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #7
If voltage is not present as described, refer to Wiring
Diagrams and check the brewer wiring harness.
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EARLY MODELS
T
A R
S T
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P1170
Page 20
7. Disconnect white/red and white/green wires to the
solenoid.
8. With a voltmeter, check the voltage across the
white/red and white/green wires when the "ON/
OFF" switch is in the "ON" upper position and the
"START" switch is pressed to the "START" lower
position and released. Connect the brewer to the
power source. The indication must be:
a) 120 volts ac for approximately 20 seconds for
two wire 120 volt models and three wire 120/208
or 120/240 volt models.
b) 200 to 240 volts ac for approximately 20-30
seconds for two wire 200 volt or 240 volt models.
If voltage is present as described, the brew timer is
operating properly. Reset the timer dial as required, to
obtain the desired brew volume.
If voltage is not present as described, replace the
timer.
Removal and Replacement:
1. Disconnect all the wires from the timer board
terminals.
2. Remove the circuit board and dial plate from the
brackets.
3. Install new timer circuit board as described in Late
Model Timer section on the following pages.
4. Refer to Fig. 17 when reconnecting the wires.
5. Install the timer setting decal, provided with the
replacement kit, underneath the top cover of the
brewer.
6. Readjust the timer as required.
FIG. 15 TIMER TERMINALS
P1177
27479 121500