Bunn Dual Service Manual page 31

SERVICE (cont.)
RELAY (Brewers W/Recovery Booster)
NOTE - Electro/mechanically controlled brewers have
two relays and the electronically controlled have
one.
FIG. 34 RELAY
Location:
Electro/mechanically Controlled Brewers
The relays are located inside the hood, the right
relay just to the right of the contactor in front of the
tank and left relay is just left of the component bracket
in front of the tank.
Electronically Controlled Brewers
The relay is located inside the hood just to the
right of the contactor in front of the tank.
Test Procedures:
Electro/mechanically Controlled Brewers.
1. Disconnect the brewer from the power source.
2. Locate the black wire on the left center relay ter-
minal and the blue wire on the right center relay
terminal.
3. With a voltmeter, check the voltage across the
black and blue wire. Connect the brewer to the
power source . The indication must be:
ga l
1 1⁄2
l
1 ga
l
ga
1⁄2
Y
AD
RE
O R
LE CT
SE
M ER
/ W AR
O N
T
AR
ST
ga l
1 1⁄2
l
1 ga
l
1⁄2 ga
T
AR
ST
M ER
AR
/ W
O N
O R
LE CT
SE
A DY
RE
AT ER
T W
HO
IO N
UT
CA
!
P796
a.) 120 volts ac for three 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.
4. Disconnect 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
Diagrams and check brewer wiring harness.
5. Remove the white/green wire from the "A" termi-
nal and white/violet wire from the "B" terminal on
the right relay, the white/brown wire from the "A"
terminal and white/red wire from "B" terminal on
the left relay.
6. Check for continuity across the "A" and "B" terminals
of each relay.
If continuity is present as described, reconnect the
white/green wire and white/violet wire to the right
relay or the white/brown wire and the white/red wire
to the left relay and proceed to #7.
If continuity is not present as described, replace the
relay(s).
7. Remove the two blue wires from terminal 5 and
the red wire from terminal 7 on the right relay, the
black wires from terminal 5 and the red wire from
terminal 7 on the left relay.
8. Check for continuity across terminals 5 and 7
of each relay by manually closing relay contact.
Continuity must not be present when contact is
released.
If continuity is present as described, reconnect blue
wires to terminal 5 on the right relay, the black wires to
terminal 5 on the left relay and the red wire to left and
right terminal 7, the relays are operating properly.
If continuity is not present as described, replace the
relay(s).
Electronically Controlled Brewers
1. Disconnect brewer from the power source.
2. Locate the gray wire on terminal 7 and the white/
green wire on terminal B of the relay.
3. Check the voltage across the gray and white/green
Page 31
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