Transformer - Bunn U3 Operating & Service Manual

SERVICE (cont.)
TRANSFORMER (380V THREE WIRE MODELS ONLY)
FIG. 34 TRANSFORMER
Location:
The transformer is located on the top rear of the
timer mounting bracket.
Test Procedures:
1. Disconnect the brewer from the power source.
2. Disconnect black wire and the red wire from the
terminal block at the transformer.
3. With a voltmeter, check the voltage across the
black wire and the red wire. Connect the brewer
to the power source. The indication must be 380
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 wiring
diagram and check the brewer wiring harness.
5. Reconnect the black wire and the red to the trans-
former.
6. Disconnect the black wire and the white wire from
the transformer terminals.
7. With a voltmeter, check the voltage across the
transformer terminals. Connect the brewer to the
power source. The indication must be 120 volts
ac.
If voltage is present as described, the transformer is
operating properly
If voiltage is not present as described, replace the

transformer.

Removal and Replacement:
1. Disconnect all the wires from the transformer.
2. Remove the two #8-32 screws securing the trans-
form to the transformer mounting bracket.
3. Remove the transformer and discard.
4. Position new transformer on transformer mounting
bracket and secure with two #8-32 screws.
5. Refer to Fig. 35 and reconnect the wires.
P1752.55
RED from
Terminal Block
BLK from
Terminal Block
FIG. 35 TRANSFORMER TERMINALS
Page 35
WHI from Main
Harness
BLK from
Main Harness
P1753
10060 031599