Bunn Ultra-1 Service & Repair Manual page 54

Liquid Autofill System
Location:
Under each hopper motor cover there are two constant
flow (CF) valves, one for water and one for syrup.
Located on top of the cover is a needle valve for adjust-
ing water flow.
Test Procedure:
The water screw adjustment valve is used to set the
product mix ratio, but only as long as the incoming
water pressure is between 30-80 psi. Rotate the ad-
justment screw with a standard screwdriver. Turning
the screw clockwise will decrease the water flow and
counter-clockwise will increase water flow.
NOTE: If water source is not within the specification of
water pressure requirement(s), a water booster pump
will need to be installed and adjusted to maintain the
30 to 80 psi requirement.
CO2 Tank with Pressure Regulator is an alternate source
used in conjunction with syrup CO2 pumps to move
bag-in-box syrup product. Several factors are involved
when setting the actual pressure because of product
viscosities, length and positioning of lines (vertical or
horizontal). Optimal psi range is 40-80. A typical set
point is 65 psi.
Check for voltage at the Water valve solenoid between
the WHT and WHT/YEL wires. The reading should be 120
vac for 120V machines, or 230 vac for 230V machines.
Check for voltage at the Syrup valve solenoid between
the WHT and WHT/YEL wires. The reading should be 120
vac for 120V machines, or 230 vac for 230V machines.
If voltage is not present as indicated, replace solenoid
valve(s).
SERVICE (continued)
Removal and Replacement:
1. Shut off and disconnect the product and water
supply lines to the solenoid valves.
2. Disconnect the product and water supply lines to
the hopper from the solenoid valves.
3. Remove the auger motor cover.
4. Remove WHI and WHT/YEL wires from solenoid
valve.
5. Remove YEL (CommonTerminal) and WHT/YEL
(N/O Terminal) wires from the pressure switch.
6. Replace the faulty solenoid valve with new valve.
7. Reconnect WHI and WHT/YEL wires to solenoid
valve.
8. Reconnect YEL and WHT/YEL wires to the pressure
switch.
9. Reinstall auger motor cover.
10. Reconnect the supply lines from the solenoid valves
to the hopper.
11. Reconnect the water and syrup supply lines to the
solenoid valves.
12. Turn on the water and syrup supply.
13. Inspect for leaks.
WHT/YEL
FIG. 69 SOLENOID WIRING CONNECTIONS
54
WHT/YEL (N/O Terminal)
YEL
(Common Terminal)
WHT/YEL
WHT