Bunn STA Coffeemaker User Manual


 
Page 17
SERVICE (cont.)
ON/OFF SWITCH (Models ST, STA, STF & STFA)
Location:
The ON/OFF switch is located second from right
on the switch panel.
Test Procedure:
1. Disconnect the brewer from the power source.
2. Viewing the switch from the back remove the
white or red wire from the upper terminal and the
black wire from the center terminal.
3. Check the voltage across the white or red wire
and the black wire with a voltmeter. Connect the
brewer to the power source. The indication must
be:
a) 120 volts ac for two wire 120 volt models and
three wire 120/240 volt models.
b) 200 to 240 volts ac for two wire 200 or 240 volt
models.
c) 100 volts ac for two wire 100 volt models.
4. Disconnect the brewer from the power source.
If voltage is present as described, reconnect the white
or red wire and proceed to #5.
If voltage is not present as described, refer to the
Wiring Diagrams
and check the brewer wiring har-
ness.
5. With the black wire removed, remove from the
lower terminal the white/red wire for the lower
warmer switch, the brown/black wire for the top
front warmer switch or the blue/black wire for the
top rear switch.
6. Check for continuity across the center and lower
terminal with the switch in the "ON" position.
Continuity must not be present when the switch
is in the "OFF" position.
If continuity is present as described, reconnect the
black wire to the center terminal and the white/red to
the lower terminal.
If continuity is not present as described, replace the
switch.
Removal and Replacement:
1. Remove the wires from the switch terminals.
2. Compress the clips inside the switch panel and
gently push the switch through the opening.
3. Push the new switch into the opening and spread
the clips to hold switch in the switch panel .
4. Refer to FIG. 7 when reconnecting the wires.
P1590
P1589
FIG. 6 ON/OFF SWITCH
FIG. 7 ON/OFF SWITCH TERMINALS
BLK to Terminal
Block (Black
Insert)
WHI/VIO to
Lower Warmer
BRN/BLK to Top
Front Warmer
BLU/BLK to Top
Rear Warmer
WHI to Terminal Block
(White Insert on 120/
208V or 120/240V
Models)
RED to Terminal Blck
(Red Insert on 200V
or 240V Models)
29251 052500