Bunn STFA Coffeemaker User Manual


 
Page 22
SERVICE (cont.)
BREW TIMER (Early Models ST, STA, STF & STFA)
Location:
The timer dial is located inside the front inspection
panel on the top of component mounting bracket. The
timer board is located inside the rear inspection panel
on the component mounting bracket.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Rotate the dial fully counterclockwise.
3. With a voltmeter, check the voltage across termi-
nals TL1 and TL2 when the "ON/OFF" switch is in
the "ON" position. Connect the brewer to the power
source. The indication must be:
a.) 120 volts ac for two wire 120 volt models,
three wire 120/208 volt models and three wire
120/240 volt models.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models.
4. Disconnect the brewer from the power source.
P1594
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. Disconnect the white/orange wire from terminal
TL3 and the white/yellow wire from terminal TL5.
Check for continuity across the two wires when the
start switch is pressed to the "START" position.
If continuity is present as described, reconnect the
wires and proceed to #6.
If continuity is not present as described, refer to the
Wiring Diagrams
and check the brewer wiring har-
ness.
6. With a voltmeter, check the voltage across termi-
nals TL1 and TL4 when the "ON/OFF" switch is in
the "ON" position. Connect the brewer to the power
source. The indication must be zero.
If voltage indications are other than described, discon-
nect the brewer from the power source and replace the
timer.
If voltage is correct, proceed to #7.
7. With a voltmeter, check the voltage across termi-
nals TL1 and TL4 when the "ON/OFF" switch is in
the "ON" position. Connect the brewer to the power
source and press the start switch. The indication
must be:
a.) 120 volts ac for two wire 120 volt models,
three wire 120/208 volt models and three wire
120/240 volt models.
b.) 200 to 240 volts ac for two wire 200 or 240 volt
models.
If voltage indications are other than described, discon-
nect the brewer from the power source and replace the
timer.
If voltage is correct, readjust the timer as required.
FIG. 14 BREW TIMER
29251 082100
OLD STYLE