Bunn U3A - Manual (Page 26)

Page 26
SERVICE (cont.)
THERMAL FUSES
FIG. 26 THERMAL FUSES
P2179.65
Location:
The thermal fuses are mounted between the tank
heater terminals and contactor terminals or terminal
block.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect the thermal fuses from the tank heater
terminal and the contactor terminal or terminal
block.
3. Check for continuity across the terminals on the
ends of each thermal fuse.
If continuity is present as described, the thermal fuse
is operating properly.
If continuity is not present as described, replace the
thermal fuse.
Removal and Replacement:
1. Disconnect the thermal fuse from the tank heater
terminal and the contactor, or terminal block and
discard.
2. Connect the new thermal fuse to the tank heater
terminal and the contactor terminal, or terminal
block.
TIMER (Early Models)
FIG. 27 TIMER
P2178.55
Location:
The timer is located on the front center of the
component bracket.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect the polarized, three pin connector from
the brewer main harness and rotate the brew timer
dial fully counterclockwise.
3. With a voltmeter, check the voltage across sockets
P2 and P3 (black wire and red wire) of the female
connector on the main wiring harness when the
"ON/OFF" switch is in the "ON" (upper) position.
Connect the brewer to the power source. The
indication must be 230 volts ac.
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 diagram and check the brewer wiring harness.
5. With a voltmeter, check the voltage across the
sockets P1 and P2 (blue and black wires) of the
female connector on the main harness when the
"ON/OFF" switch is in the "ON" (upper) position and
the start switch pressed. Connect the brewer to the
power source. The indication must be 230 volts ac.
6. Disconnect the brewer from the power source.
7. Reconnect the three pin connector from the main
wiring harness to the connector on the timer.
OLD STYLE
10060.3 070102