Bunn U3A SERVICE cont, Transformer Terminals, TRANSFORMER 380V THREE WIRE MODELS ONLY

SERVICE (cont.)

TRANSFORMER (380V THREE WIRE MODELS ONLY)

P1752.55

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.

RED from	WHI from Main
Terminal Block
	Harness
BLK from	BLK from
Terminal Block	Main Harness
FIG. 35 TRANSFORMER TERMINALS		P1753

Page 35 10060 031599