Limit Thermostat - Bunn TU5Q Operating & Service Manual

SERVICE (cont.)

LIMIT THERMOSTAT

FIG. 14 LIMIT THERMOSTAT
Location:
The limit thermostat is located inside the hood on the
tank lid.
Test Procedure:
1. Disconnect the brewer from the power source and
remove the black wire from the limit thermostat.
2. With a voltmeter, check the voltage across the
black wire removed from the limit thermostat and
the white or red wire on the tank heater terminal.
Connect the brewer to the power source. The in-
dication must be:
a) 120 volts ac for 2-wire 120 volt models.
b) 208 volts ac for 3-wire 120/208 volt models.
c) 240 volts ac for 3-wire 120/240 volt models.
3. Disconnect the brewer from the power source.
If voltage is present as described, reconnect the black
wire and proceed to #4.
If voltage is not present as described, refer to the Wir-
ing Diagrams and check the wiring harness.
4. Remove the blue wire from the limit thermostat.
5. With a voltmeter, check the voltage across the ex-
posed terminal of the limit thermostat and the
white or red wire on the tank heater terminal. Con-
nect the brewer to the power source. The indica-
tion must be:
a) 120 volts ac for 2-wire 120 volt models.
b) 208 volts ac for 3-wire 120/208 volt models.
c) 240 volts ac for 3-wire 120/240 volt models.
6. Disconnect the brewer from the power source.
If voltage is present as described, reconnect the blue
wire to the limit thermostat. The limit thermostat is
operating properly.
If voltage is not present as described, replace the limit
thermostat.
Removal and Replacement
1. Remove both wires from the limit thermostat ter-
minals.
2. Carefully slide the limit thermostat out from un-
der the retaining clip.
3. Carefully slide the new limit thermostat into the
retaining clip.
P2143.35 4. Refer to Fig. 15 when reconnecting the wires.
FIG. 15 LIMIT THERMOSTAT TERMINALS
Page 19
BLU to
Control
Thermostat
BLK to Terminal Block
P1800
10777 041500