Contactor Assembly - Bunn Dual Service Manual

SERVICE (cont.)

CONTACTOR ASSEMBLY

FIG. 7 CONTACTOR ASSEMBLY
Location:
The contactor assembly is located inside the hood
just to the rear of the dispense valve (Right side for
DUAL and DUAL SH models).
Test Procedures:
Mechanical Thermostat (Brewers with or without
Recovery Booster)
1. Disconnect the brewer from the power source.
2. Disconnect the white wire of the two pole 120V ter-
minal block, white wire of the three pole 120/208V
or 120/240V or the red wire of the two pole 200V
or 240V terminal block and the black wire of the
contactor coil. Disconnect the black wire of the
control thermostat from the remaining black wire
of the contactor coil.
3. Gently remove the capillary bulb and grommet
from the tank.
4. With a voltmeter, check the voltage across the white
wire from the terminal block on 120, 120/208,
120/240 volt units or the red wire from 200 or
240 volt units and the black wire from the control
thermostat when the thermostat is turned clockwise
to the "FULL ON" position. Connect the brewer to
the power source. The indication must be:
a.) 120 volts ac for two wire 120 volt models, three
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Page 15
wire 120/208 volt models and three wire 120/240
volt models.
b.) 200 to 240 volts ac for two wire 200 or 240
volt models.
5. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #6.
If voltage is not present as described, refer to the Wiring
Diagrams and check the brewer wiring harness.
6. Check for continuity between the two black wires
of the contactor coil.
If continuity is present as described, reconnect one
black wire to red or white wire from the terminal block
and the other black wire to the black wire from the
control thermostat. Reinstall capillary tube into the
tank to a line 7" above the bulb and proceed to #7.
If continuity is not present as described, replace the
contactor.
7. Locate the white wire or red wire on L1 terminal
and black wire on the L2 terminal on the contac-
tor.
8. With a voltmeter, carefully check the voltage across
the white or red and black wires. The indication
must be:
a.) 120 volts ac for two wire 120 volt models, 208
volts ac for three wire 120/208 volt models and
240 volts ac for three wire 120/240 volt models.
b.) 200 to 240 volts ac for two wire 200 or 240
volt models.
9. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #10.
If voltage is not present as described, refer to the Wiring
Diagrams and check brewer wiring harness.
10. Check for continuity across the terminals on the
left side of the contactor by manually closing the
contacts. Continuity must not be present when the
contact is released.
11. Check for continuity across the terminals on the
right side of the contactor by manually closing the
contacts. Continuity must not be present when the
contact is released.
If continuity is present as described, the contactor is
operating properly.
41976 031709